"""
Edit Block_N_Surgery PDF:
1. Replace "Made by Haroon" with "Made by Zakria Marwat" on every page
2. Add up to 20 words of relevant extra detail per page (as a small note)
"""

import io
from pypdf import PdfReader, PdfWriter
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import A4
from reportlab.lib import colors

INPUT_PDF = "/tmp/workspace/attachments/2098dca5-f665-490c-9bd6-6a49cdacd54e/Block_N_Surgery_260721_185719.pdf"
OUTPUT_PDF = "/tmp/workspace/pdf_edit/Block_N_Surgery_ZakriaMarwat.pdf"

# Page width and height (A4-ish: 595.92 x 842.88)
PAGE_W = 595.92
PAGE_H = 842.88

# "Made by Haroon" location (pdfplumber top coords, need to convert to reportlab bottom-origin)
# pdfplumber: top=816.68, bottom=823.43 → reportlab y = PAGE_H - bottom = 842.88 - 823.43 = 19.45
# "Made by" starts at x0=273.05, "Haroon" ends at x1=322.95
# We'll cover x=270 to x=360 (wide enough for "Zakria Marwat"), y=18 to y=28

# Extra detail lines per page (up to 20 words each, relevant to the section on that page)
# Page index 0 = PDF page 1 (cover/blank), index 1 = PDF page 2 (TOC), etc.
# We add a small italic note at the top margin area (y ~ 30, small font)
EXTRA_DETAIL = {
    # page_index (0-based): text to add
    0:  "",  # blank cover page - no addition
    1:  "Note: These notes cover KMU Block-N Surgery MCQs, including perioperative care, burns, and ERAS protocols.",
    2:  "Note: WHO checklist has three phases: Sign-In, Time-Out, and Sign-Out, each with specific safety tasks.",
    3:  "Note: Informed consent must address diagnosis, procedure details, risks, benefits, and available alternatives.",
    4:  "Note: Incisions along Langer's lines produce cosmetically superior, narrower scars with minimal tension.",
    5:  "Note: Muscle-splitting incisions preserve abdominal wall strength and reduce postoperative pain significantly.",
    6:  "Note: Midline incision gives the fastest access but carries the highest risk of incisional hernia formation.",
    7:  "Note: Rose's position involves neck hyperextension, classically used during thyroidectomy for anterior exposure.",
    8:  "Note: Primary intention healing requires clean wound edges; secondary intention involves granulation and contraction.",
    9:  "Note: Vicryl is fully absorbed in 60-90 days via hydrolysis; vertical mattress sutures evert wound edges.",
    10: "Note: Monopolar diathermy is contraindicated with pacemakers; bipolar diathermy is the safer alternative.",
    11: "Note: X-ray attenuation decreases as photons pass through tissue; CT delivers the highest radiation dose.",
    12: "Note: CO2 pneumoperitoneum max safe pressure is 15 mmHg; CO2 is non-combustible and highly blood-soluble.",
    13: "Note: Laparoscopy disadvantages include loss of haptic feedback, limited instrument range, and steep learning curve.",
    14: "Note: Robotic surgery adds tremor filtration, 3D vision, and seven degrees of freedom over standard laparoscopy.",
    15: "Note: TOP MCQ summary for Sections 1-4 covering WHO checklist, incisions, diathermy, and laparoscopy principles.",
    16: "Note: Informed consent is a process, not just a signature; it must be documented and surgeon-led.",
    17: "Note: Implied consent applies only in true emergencies where the patient is incapacitated and no surrogate exists.",
    18: "Note: Ringer's Lactate closely mimics extracellular fluid and helps correct metabolic acidosis via lactate conversion.",
    19: "Note: Normal Saline contains no potassium; large volumes cause hyperchloremic metabolic acidosis.",
    20: "Note: ECG changes in hyperkalemia progress from peaked T-waves to wide QRS; IV calcium gluconate stabilizes myocardium.",
    21: "Note: TOP MCQ summary for Section 6 covering fluid therapy, electrolyte disorders, and hyperkalemia management.",
    22: "Note: Enteral feeding preserves gut mucosal integrity; jejunostomy is preferred when esophageal access is blocked.",
    23: "Note: TPN composition: 70% dextrose, 10% amino acids, 20% lipid emulsion; requires daily CBC and electrolytes.",
    24: "Note: Refeeding syndrome causes hypophosphatemia, hypokalemia, and hypomagnesemia in malnourished patients.",
    25: "Note: Functional status (METs) is the best perioperative predictor in elderly; ERAS reduces complications and stay.",
    26: "Note: Atelectasis is the most common cause of fever in first 24 postoperative hours; SCIP bundles reduce SSIs.",
    27: "Note: Paralytic ileus requires NPO, NG decompression, IV fluids, and electrolyte correction before resuming feeds.",
    28: "Note: Reactionary hemorrhage occurs 4-6 hours post-surgery due to ligature slippage; FAST scan is first investigation.",
    29: "Note: TOP MCQ summary for Sections 8 covering ERAS, postoperative complications, and perioperative anticoagulation.",
    30: "Note: ERAS is evidence-based and multimodal, spanning preoperative, intraoperative, and postoperative care phases.",
    31: "Note: Solids allowed up to 6 hours pre-op; clear fluids up to 2 hours; carbohydrate loading reduces insulin resistance.",
    32: "Note: Pain activates HPA axis and sympathetic system, causing catecholamines and cortisol release with adverse effects.",
    33: "Note: WHO ladder: Step 1 NSAIDs/paracetamol, Step 2 tramadol (weak opioid), Step 3 morphine for severe pain.",
    34: "Note: Neuropathic pain is opioid-resistant; pregabalin and gabapentin are first-line adjuvants targeting calcium channels.",
    35: "Note: TOP MCQ summary for Sections 9-10 covering ERAS, pain pathways, and analgesic ladder steps.",
    36: "Note: Burns are classified by depth: first-degree (epidermis), second-degree (dermis), third-degree (full thickness).",
    37: "Note: Third-degree burns are painless due to nerve destruction; leathery, dry, white/charred eschar is characteristic.",
    38: "Note: Burn depth assessment may take 3-5 days; zone of stasis can progress to necrosis without proper cooling.",
    39: "Note: Lund and Browder chart is most accurate for pediatric burns due to age-related body proportion adjustments.",
    40: "Note: Parkland formula: 4 mL x kg x %TBSA; give 50% in first 8 hours (from time of injury, not arrival).",
    41: "Note: Hourly urine output is the gold standard for resuscitation adequacy; target 0.5-1 mL/kg/hr in adults.",
    42: "Note: Cool burn with running water for 20 minutes; never use ice; always follow ATLS ABC before burn assessment.",
    43: "Note: Endotracheal intubation with high-flow O2 is mandatory for inhalation injury before airway edema develops.",
    44: "Note: Escharotomy releases circumferential eschar to restore perfusion; no anesthesia needed as nerves are destroyed.",
    45: "Note: Silver sulfadiazine (SSD) is the most common topical burn agent; contraindicated on face and in sulfa allergy.",
    46: "Note: Non-healing deep burns at 3 weeks need tangential excision and split-thickness skin grafting to prevent scarring.",
    47: "Note: Inhalation injury is the single worst prognostic factor in burns; increases mortality significantly.",
    48: "Note: Post-burn contractures cause joint stiffness and deformity; prevented by early physiotherapy and pressure garments.",
    49: "Note: TOP MCQ summary for Sections 11-14 covering burn classification, assessment, management, and complications.",
}


def make_overlay(page_index, page_width, page_height):
    """Create a reportlab overlay PDF page in memory."""
    packet = io.BytesIO()
    c = canvas.Canvas(packet, pagesize=(page_width, page_height))

    # 1. Cover "Made by Haroon" with a white rectangle and write "Made by Zakria Marwat"
    # pdfplumber top=816.68 → reportlab y = page_height - 823.43 = 19.45 (bottom of text box)
    # We need to cover from y=18 to y=27 (a bit generous), x=265 to x=380
    text_y_rl = page_height - 823.5  # reportlab y for bottom of "Made by Haroon" text

    # White rectangle to cover old text
    c.setFillColor(colors.white)
    c.setStrokeColor(colors.white)
    c.rect(260, text_y_rl, 130, 10, fill=1, stroke=0)  # wide enough for "Zakria Marwat"

    # Write new text "Made by Zakria Marwat"
    c.setFillColor(colors.black)
    c.setFont("Helvetica", 6.75)
    c.drawString(263, text_y_rl + 1.5, "Made by Zakria Marwat")

    # 2. Add extra detail note at bottom of page (just above the "Made by" line)
    extra = EXTRA_DETAIL.get(page_index, "")
    if extra:
        # Place at y ≈ page_height - 808 (just above the "Made by" line at 816)
        note_y = page_height - 810
        c.setFont("Helvetica-Oblique", 5.5)
        c.setFillColor(colors.HexColor("#444444"))
        # If text is too long, we split it
        max_width = page_width - 80  # margins
        # Draw the note text - keep it short (≤20 words already ensured)
        c.drawString(40, note_y, extra)

    c.save()
    packet.seek(0)
    return packet


def main():
    import os
    os.makedirs("/tmp/workspace/pdf_edit", exist_ok=True)

    reader = PdfReader(INPUT_PDF)
    writer = PdfWriter()

    total_pages = len(reader.pages)
    print(f"Processing {total_pages} pages...")

    for i, page in enumerate(reader.pages):
        # Get actual page dimensions
        media_box = page.mediabox
        pw = float(media_box.width)
        ph = float(media_box.height)

        # Generate overlay
        overlay_packet = make_overlay(i, pw, ph)
        overlay_reader = PdfReader(overlay_packet)
        overlay_page = overlay_reader.pages[0]

        # Merge overlay onto original page
        page.merge_page(overlay_page)
        writer.add_page(page)

        if (i + 1) % 10 == 0:
            print(f"  Processed {i+1}/{total_pages} pages")

    with open(OUTPUT_PDF, "wb") as f:
        writer.write(f)

    print(f"\nDone! Output saved to: {OUTPUT_PDF}")
    import os
    size = os.path.getsize(OUTPUT_PDF)
    print(f"File size: {size/1024:.1f} KB")


if __name__ == "__main__":
    main()

"""
Final PDF editor:
1. Page 1 (cover image): overlay white box over "Haroon" area + write "Zakria Marwat"
2. All pages: replace "Made by Haroon" footer with "Made by Zakria Marwat"
3. All pages: add plain-English explanation box at bottom (up to 500 words)
4. Preserve all original content
"""

import io
from pypdf import PdfReader, PdfWriter
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.styles import ParagraphStyle
from reportlab.platypus import Paragraph, Frame
from reportlab.lib.units import pt

INPUT_PDF = "/tmp/workspace/attachments/2098dca5-f665-490c-9bd6-6a49cdacd54e/Block_N_Surgery_260721_185719.pdf"
OUTPUT_PDF = "/tmp/workspace/pdf_edit/Block_N_Surgery_ZakriaMarwat_v2.pdf"

PAGE_W = 595.92
PAGE_H = 842.88

# ─────────────────────────────────────────────────────────────────
# PLAIN-ENGLISH EXPLANATIONS (up to 500 words per page)
# ─────────────────────────────────────────────────────────────────
EXPLANATIONS = {

0: """COVER PAGE - Introduction
This is the cover page of the Block N Surgery high-yield clinical notes. These notes are made specifically for Final Year MBBS students preparing for KMU (Khyber Medical University) examinations. The document covers three main areas: General Surgery, Plastic Surgery (including Burns), and Surgical Foundation. It is designed to help students quickly revise important topics that often appear as MCQs in medical board exams. Made by Zakria Marwat.""",

1: """TABLE OF CONTENTS - What is in this document?
This page shows you the full layout of the notes. The document is divided into three big parts. Part I covers General Surgery and Foundation topics like patient safety, wound healing, surgical incisions, fluid management, nutrition, and postoperative care. Part II covers ERAS (Enhanced Recovery After Surgery) and pain management. Part III covers Plastic Surgery and Burns, including how to classify burns, how to calculate burn area, how to manage burns, and what complications can occur. These notes are focused on 15 MCQs that appear in KMU Block N Surgery exam, split between Foundation-III (10 MCQs) and Musculoskeletal-III (5 MCQs).""",

2: """SECTION 1: Patient Safety and WHO Checklist - Simple Explanation
This page explains why patient safety is so important in the operating theatre. The WHO (World Health Organization) created a Surgical Safety Checklist to reduce mistakes during surgery. Think of it like a pilot's pre-flight checklist. It has three steps: (1) Sign In - before the patient goes to sleep under anesthesia, the team checks the patient's name, the planned surgery, and the surgical site. (2) Time Out - this is the most important step, done just before the first cut is made. The whole team stops and verbally confirms everything. (3) Sign Out - before the patient leaves the operating room, the team checks that the correct procedure was done and that no instruments are left inside. The main purpose of this checklist is to improve communication between the surgeon, anesthesiologist, and nurses. Another key point: to prevent medication errors, clinicians must check the patient's ID bracelet twice before giving any drug. Patient safety is everyone's responsibility, from junior nurses to hospital administrators.""",

3: """SECTION 1 (continued): Informed Consent - Simple Explanation
Informed consent means the patient agrees to a surgery or procedure after fully understanding what it involves. This page explains the key rules around consent. First, it is the operating surgeon's job to personally explain the surgery to the patient - not a junior doctor or nurse. The surgeon must explain the diagnosis, what the procedure involves, its benefits, its risks, and what alternatives exist. The ethical reason for informed consent is to respect the patient's right to make their own decisions (autonomy). There is one important exception: if a patient is unconscious in an emergency and their life is at risk, and no family member is available, the team can proceed without explicit consent. This is called implied consent. Also, for sensitive examinations (like a breast exam), the doctor must get verbal consent AND have a female chaperone present.""",

4: """SECTION 2: Skin Incisions and Langer's Lines - Simple Explanation
This page explains how surgeons decide where to cut the skin. Langer's Lines (also called cleavage lines) are invisible lines on the skin that follow the direction of the collagen fibers in the dermis. If a surgeon cuts along these lines, the wound heals with a thin, neat scar. If the surgeon cuts across these lines, the wound gets pulled apart by underlying muscles, leading to a wide, ugly, or raised scar. This is why cosmetic surgeons always try to follow Langer's lines. The general principles for planning any incision are: provide good access to the target organ, be able to extend the cut if needed, avoid cutting major nerves and blood vessels, and prefer muscle-splitting over muscle-cutting to preserve strength and reduce pain.""",

5: """SECTION 2 (continued): Types of Abdominal Incisions - Simple Explanation
This page lists the most common ways to open the abdomen for surgery. (1) Midline incision: A vertical cut along the center line (linea alba). It is the fastest and most flexible incision, used in emergencies. However, it has the highest risk of the wound reopening (dehiscence) or developing a hernia. (2) Paramedian incision: A vertical cut beside the midline. Lower hernia risk than midline but takes longer. (3) Kocher's (Subcostal) incision: A cut below the rib margin, used for gallbladder or liver surgery. It cuts through muscle so it is quite painful after surgery. (4) Gridiron (McBurney's) incision: A diagonal cut in the lower right abdomen for appendix surgery. It splits (not cuts) the muscle, so it heals very well with almost no hernia risk. (5) Lanz incision: A horizontal cut in the same area for appendix removal, giving a better cosmetic result. (6) Pfannenstiel incision: A curved cut just above the pubic hair line, used for caesarean sections. Very strong and hidden.""",

6: """SECTION 2 (continued): Patient Positioning - Simple Explanation
Positioning the patient correctly on the operating table is critical. Wrong positioning can damage nerves, block blood flow, or cause pressure sores. Rose's position is specifically used during thyroidectomy (removal of the thyroid gland). In this position, the patient's neck is extended backwards (hyperextended), which pushes the throat and neck forward, giving the surgeon excellent visibility and access to the front of the neck. This is an important exam favorite at KMU.""",

7: """SECTION 3: Wound Healing - Simple Explanation
This page explains the three ways wounds heal. (1) Primary intention: The wound edges are brought together with sutures in a clean wound. This heals quickly with minimal scarring. Example: a clean surgical cut closed with stitches. (2) Secondary intention: The wound is left open, often because it is infected. It heals slowly from the inside out, through a process called granulation, where new tissue slowly fills the gap. This results in a wider scar. (3) Tertiary intention (Delayed Primary Closure): The wound is initially left open to clear infection, then closed surgically a few days later once it is clean. This is used in contaminated wounds. Key facts: By day 2 after injury, macrophages replace neutrophils as the dominant healing cells. Macrophages clean up debris and coordinate tissue repair. The most common factor that stops wounds from healing is local infection.""",

8: """SECTION 3 (continued): Sutures, Drains, and Clavien-Dindo - Simple Explanation
This page covers surgical suture materials and drain management. Vicryl (Polyglactin 910) is a very common absorbable suture that dissolves in the body within 60 to 90 days. It does not need to be removed. The Vertical Mattress Suture technique is used when closing the abdomen in obese patients because it distributes tension well and keeps the wound edges turned outward (everted), which promotes better healing. Surgical drains are tubes placed during surgery to remove blood or fluid from a wound. In a simple hernia repair, the drain is usually removed after 24 hours or when drainage is minimal. The Clavien-Dindo system classifies how serious a postoperative complication is. Grade III means the problem requires surgical, endoscopic, or radiological intervention, such as returning to the operating theatre to stop bleeding.""",

9: """SECTION 3 (continued): Diathermy (Electrosurgery) - Simple Explanation
Diathermy is the use of high-frequency electrical current to cut tissue or stop bleeding during surgery. There are two types. (1) Monopolar diathermy: The electrical current enters through the surgical instrument (the active electrode), travels through the patient's whole body, and exits through a grounding pad attached to the patient's skin. This type is powerful and effective but dangerous in patients with pacemakers or metal implants, because the electrical current can disturb the pacemaker or heat up the metal implant causing burns. (2) Bipolar diathermy: The current only flows between the two tips of the forceps instrument, so it does NOT travel through the patient's body. This is much safer for patients with pacemakers. When using diathermy, only the targeted tissue is affected, not the rest of the body.""",

10: """SECTION 3 (continued): Diagnostic Imaging Basics - Simple Explanation
This page explains the basic physics behind common diagnostic tools. X-rays work by firing radiation through the body; denser tissues (like bone) absorb more X-rays and appear white on the image. As X-rays pass through tissue, their intensity weakens (this is called attenuation). Among common imaging methods, CT scans deliver the highest dose of radiation to the patient, significantly more than a regular X-ray or nuclear bone scan. Ultrasound is completely radiation-free. It works because an electrical current is applied to a special crystal (piezoelectric crystal) inside the ultrasound probe, which vibrates and produces high-frequency sound waves. These sound waves bounce off internal organs and return to the probe, creating an image.""",

11: """SECTION 4: Laparoscopic Surgery - Simple Explanation
Laparoscopy is keyhole surgery. Instead of making one large cut to open the abdomen, the surgeon makes several small holes (ports) and inserts a tiny camera (laparoscope) and special instruments. To see inside the abdomen, the surgeon inflates the abdominal cavity with gas - this is called pneumoperitoneum. Carbon dioxide (CO2) is the only gas used for this purpose. Why CO2? Because it does not catch fire (important when diathermy is used inside the body) and it dissolves into the blood very quickly, so even if a small amount gets into the bloodstream, it is harmless. The safe maximum pressure for inflating the abdomen with CO2 is 15 mmHg. Higher pressure can compress the large veins (vena cava) and reduce blood return to the heart.""",

12: """SECTION 4 (continued): Laparoscopy - Advantages, Contraindications, Complications - Simple Explanation
Advantages of laparoscopic surgery compared to open surgery: less tissue damage, smaller scars, less pain, shorter hospital stay, faster recovery, and better cosmetic results. Disadvantages: the surgeon cannot feel the tissues directly (no haptic feedback), the instruments have limited range of movement, and it takes a lot of training to master. The only absolute contraindication to elective laparoscopy is uncontrolled bleeding disorder (coagulopathy), because if a blood vessel is accidentally cut, it could bleed uncontrollably. A dangerous complication is vagal bradycardia: when CO2 rapidly stretches the peritoneum (the lining of the abdomen), it triggers the vagus nerve and can cause the heart rate to drop suddenly or even stop. Treatment: immediately deflate the abdomen and give atropine. If major bleeding cannot be controlled laparoscopically, the safest option is to convert to open surgery.""",

13: """SECTION 4 (continued): Robotic Surgery - Simple Explanation
Robotic surgery is the most advanced form of minimally invasive surgery. The surgeon sits at a console away from the patient and controls robotic arms that hold the surgical instruments. Key advantages over standard laparoscopy: three-dimensional (3D) high-definition vision, elimination of the surgeon's hand tremor (tremor filtration), and instruments that can move in seven directions (seven degrees of freedom), making complex movements easier. It is used for prostatectomies, cardiac surgery, and complex reconstructive procedures. The major downside is the high cost of the robotic system.""",

14: """TOP MCQ POINTERS - Sections 1-4 Summary - Simple Explanation
This page summarizes the most important exam-ready facts from Sections 1 to 4. These are direct MCQ targets. Key points to memorize: The WHO checklist is designed to improve team communication and reduce surgical errors. Time Out is the phase between anesthesia and the first incision. Patient safety is a shared responsibility across all staff. The operating surgeon must personally obtain informed consent. Implied consent applies only in emergencies. Incisions along Langer's lines produce better scars. The midline incision has the highest hernia risk. Rose's position is used for thyroidectomy. Vicryl dissolves in 60-90 days. Monopolar diathermy is dangerous with pacemakers; bipolar is safer. Uncontrolled coagulopathy is a contraindication to laparoscopy. CO2 is used for pneumoperitoneum. Maximum safe insufflation pressure is 15 mmHg. Robotic surgery is the most advanced minimally invasive option.""",

15: """SECTION 5: Surgical Informed Consent - Simple Explanation
This section goes deeper into the concept of informed consent. Informed consent is not just a signature on a form. It is an active communication process where the surgeon explains everything the patient needs to know before agreeing to surgery. The surgeon must cover: the diagnosis, the nature of the procedure, the expected benefits, the potential risks and complications, and what alternative treatments exist. The surgeon must also answer all patient questions. The ethical foundation is respect for autonomy - every adult patient has the right to make decisions about their own body. A very important practical point: if there is a chance the planned laparoscopic operation may need to be converted to open surgery, the patient must be told about this before surgery and must consent to it. For example, a patient scheduled for laparoscopic cholecystectomy must also sign consent for possible open cholecystectomy.""",

16: """SECTION 5 (continued): Exceptions to Consent - Simple Explanation
There is one major exception to the requirement for informed consent: true medical emergencies. If a patient arrives unconscious after a road traffic accident and needs emergency surgery to save their life, and no family member or legal guardian is available, the surgical team can proceed without getting explicit consent. The law treats this as implied consent - it is assumed any reasonable person would consent to life-saving treatment. The three conditions that must all be true for implied consent to apply are: the surgery must be immediately life-saving or limb-saving, the patient must be incapacitated (unable to communicate), and there must be no available surrogate decision-maker. Importantly, implied consent does NOT apply to elective or non-urgent procedures.""",

17: """SECTION 6: Perioperative Fluid Therapy - Simple Explanation
This section explains how fluids are managed around the time of surgery. The most common fluid problem around surgery is extracellular fluid deficit - the patient loses fluid through blood loss, vomiting, sweating, or simply not drinking before surgery. Ringer's Lactate is the preferred fluid for resuscitation (replacing large volume losses). It is called a balanced crystalloid because its composition is similar to the body's extracellular fluid. Its lactate is converted to bicarbonate in the liver, which helps correct metabolic acidosis (when the blood becomes too acidic). Normal Saline (0.9% NaCl) contains 154 mEq/L of sodium and 154 mEq/L of chloride. If given in large amounts, it causes hyperchloremic metabolic acidosis because the excess chloride disturbs the body's acid-base balance. Ringer's Lactate contains potassium (about 4 mEq/L); Normal Saline contains none.""",

18: """SECTION 6 (continued): Electrolyte Disorders - Simple Explanation
This page explains three common electrolyte problems after surgery. (1) Normal anion gap metabolic acidosis: This happens most commonly with severe diarrhea. The gut loses large amounts of bicarbonate-rich fluid, and the kidneys compensate by retaining chloride, leading to acidosis. (2) Metabolic alkalosis: This happens after prolonged vomiting or nasogastric (NG) tube suction. The stomach loses hydrochloric acid (HCl), so the blood becomes more alkaline (high pH). Potassium and chloride are also lost. (3) SIADH-related hyponatremia (low sodium): Surgery causes stress which triggers excess release of ADH (antidiuretic hormone). ADH makes the kidneys retain water, diluting the blood sodium. Treatment for mild/stable cases: restrict free water intake - do not give more fluid, just limit how much the patient drinks or receives through the drip.""",

19: """SECTION 6 (continued): Hyperkalemia - Simple Explanation
Hyperkalemia means dangerously high potassium levels in the blood. This can stop the heart. On the ECG (heart tracing), hyperkalemia causes characteristic changes: first, tall peaked T-waves appear. As potassium rises further, the P-waves (which represent atrial activity) become small or disappear. Finally, the QRS complex widens (the electrical activation of the ventricles becomes slow and abnormal). This is a medical emergency. The first treatment is intravenous 10% Calcium Gluconate. Calcium gluconate does NOT lower the potassium level - it stabilizes the cardiac muscle membrane, protecting the heart from arrhythmia while other treatments work to remove the excess potassium from the blood. This distinction (stabilizes heart vs. lowers K+) is a frequent MCQ question.""",

20: """SECTION 6: MCQ Summary for Fluid and Electrolytes - Simple Explanation
This summary page consolidates the key testable facts from Section 6. The most important points: ECF deficit is the most common perioperative fluid problem. Ringer's Lactate is the first-choice fluid for hemorrhagic shock, major burns, and severe dehydration because it corrects acidosis and replenishes extracellular volume. Normal Saline (0.9% NaCl) contains 154 mEq/L sodium and 154 mEq/L chloride - no potassium. Large volumes of normal saline cause hyperchloremic metabolic acidosis. Ringer's Lactate contains potassium; Normal Saline does not. Diarrhea causes normal anion gap acidosis. Vomiting and NG suction cause metabolic alkalosis. SIADH is treated with fluid restriction. IV calcium gluconate stabilizes the heart in hyperkalemia but does not lower potassium.""",

21: """SECTION 7: Nutritional Support - Simple Explanation
When a patient cannot eat normally after surgery, the medical team must provide nutrition artificially. There are two main routes. (1) Enteral nutrition (through the gut): Preferred whenever possible because it keeps the gut lining healthy and prevents intestinal atrophy (the gut wall wasting away). It can be given through a nasogastric (NG) tube or a feeding jejunostomy (a tube placed directly into the small intestine). Feeding jejunostomy is specifically preferred when the esophagus is blocked or burned, such as in corrosive esophageal injuries or obstructing esophageal cancer, because an NG tube could perforate the damaged esophagus. Enteral feeding is NOT used when there is severe GI bleeding or a high-output bowel fistula (because feeding into a fistula makes it worse). (2) Total Parenteral Nutrition (TPN): All nutrients are given directly into the bloodstream through a central vein when the gut cannot be used.""",

22: """SECTION 7 (continued): TPN and Complications - Simple Explanation
TPN (Total Parenteral Nutrition) bypasses the gut entirely and delivers nutrients intravenously. It is used when the intestinal tract is not working, not accessible, or needs complete rest. Common examples: short bowel syndrome (patient had most of their bowel removed) and high-output intestinal fistula. TPN is a complex mixture containing three main components: glucose (70% dextrose) for energy, amino acids (10%) for protein, and lipid emulsion (20% fat) for essential fatty acids and fat-soluble vitamins. Absolute contraindication to TPN: active systemic infection (sepsis). The reason is that TPN is delivered through a large central vein catheter, and in a septic patient, bacteria can colonize the catheter and worsen the infection. Daily monitoring during TPN includes: full blood count, serum urea, and electrolytes. A dangerous complication of central line insertion is pneumothorax (collapsed lung). Refeeding syndrome happens when malnourished patients are fed too quickly, causing dangerous drops in phosphate, potassium, and magnesium.""",

23: """SECTION 8: Postoperative Care - Simple Explanation
After surgery, patients need careful monitoring and management. For elderly patients, the best predictor of how well they will tolerate surgery is their functional status, measured in METs (Metabolic Equivalents of Task). Patients who can perform moderate daily activities (like climbing stairs) have good functional status and lower surgical risk. ERAS (Enhanced Recovery After Surgery) is a modern care bundle that speeds up patient recovery. Key ERAS principles include: minimal fasting before surgery (patients do not need to fast from midnight - clear fluids allowed up to 2 hours before), early oral feeding after surgery, early mobilization (getting patients out of bed the day after surgery), avoiding routine NG tubes and surgical drains, and avoiding fluid overload. The most reliable clinical sign that the bowel has woken up after surgery and the patient is ready to eat is the passage of flatus (passing gas).""",

24: """SECTION 8 (continued): Postoperative Complications Part 1 - Simple Explanation
Common complications that occur after surgery: (1) Early fever (within 24 hours): The most common cause is atelectasis - partial collapse of small airways in the lungs. When patients are under general anesthesia, they do not breathe deeply and small lung segments collapse. This triggers mild fever. Treatment: deep breathing exercises, physiotherapy, early mobilization. (2) Surgical Site Infection (SSI): Prevented by giving prophylactic antibiotics within 1 hour before the incision, clipping hair instead of shaving (shaving creates micro-cuts that allow bacteria in), removing urinary catheters early, and keeping the patient warm during surgery (hypothermia impairs immune function). (3) Wound abscess: A collection of pus under the wound. Signs: pain, redness, swelling, and fluctuance (feels like a fluid-filled balloon). Treatment: open the wound and drain the pus. (4) Necrotizing fasciitis: A severe, rapidly spreading infection of the deep tissues, caused by Group A Streptococcus or a mix of bacteria. Signs: high fever, rapid tissue death, purple skin, blisters. This is a surgical emergency.""",

25: """SECTION 8 (continued): Postoperative Complications Part 2 - Simple Explanation
More postoperative complications. (1) Paralytic ileus: After abdominal surgery, the bowel temporarily stops working. The gut becomes paralyzed. On X-ray, all bowel loops are uniformly dilated (not just one segment). Management: nothing by mouth (NPO), nasogastric tube to decompress the distended bowel, IV fluids, and correct electrolyte abnormalities. (2) Cardiovascular risk: Previous heart attack within the last 6 months is the single biggest predictor of a serious cardiac complication during or after surgery. These patients need careful cardiac evaluation before elective surgery. (3) Diabetes: On the day of major surgery, all oral diabetes medications (like metformin) are stopped because the patient cannot eat. Blood sugar is managed with insulin infusion instead. (4) Reactionary hemorrhage: Bleeding that occurs within 24 hours of surgery, most commonly 4-6 hours later. It happens when a tied blood vessel comes loose as the blood pressure returns to normal after surgery. Diagnosis: bedside FAST ultrasound scan of the abdomen.""",

26: """SECTION 8 (continued): Postoperative Complications Part 3 - Simple Explanation
More important postoperative topics. Perioperative anticoagulation: Patients on warfarin (a blood thinner) are a challenge. For low-risk patients (e.g., AF with no previous clots), warfarin is simply stopped before surgery and restarted after. For high-risk patients (e.g., metallic heart valve, recent DVT), warfarin is stopped and replaced with LMWH (Low Molecular Weight Heparin, given by injection) while the patient cannot take warfarin - this is called bridging therapy. Acute hemolytic transfusion reaction: The most dangerous blood transfusion complication, caused by giving the wrong blood type. The most common cause of this error is a clerical mistake (wrong patient labelled). Heparin overdose reversal: The antidote is Protamine sulfate given intravenously. Neurogenic shock: Occurs after spinal cord injury. Unlike other types of shock, it causes low blood pressure WITH a slow heart rate (bradycardia), because the sympathetic nervous system is damaged. Non-oliguric AKI: A paradoxical form of kidney injury where the kidneys are damaged but still produce large amounts of dilute urine.""",

27: """SECTION 8: MCQ Summary for Postoperative Care - Simple Explanation
This page summarizes all the high-yield MCQ points from Section 8. Memorize these: Functional status (METs) predicts surgical outcome in elderly patients. ERAS promotes early mobilization, early oral feeding, minimal fasting. Passage of flatus signals return of bowel function. Atelectasis is the first 24-hour fever cause. SSI prevention includes antibiotics within 1 hour of incision and hair clipping. Wound abscess requires incision and drainage. Necrotizing fasciitis is caused by Group A Streptococcus. Paralytic ileus managed with NPO and NG decompression. MI within 6 months is the top cardiac risk factor. Hold oral hypoglycemics on surgery day. Reactionary bleeding at 4-6 hours; FAST scan for diagnosis. High-risk warfarin patients need LMWH bridging. Transfusion reactions are caused by clerical errors. Protamine reverses heparin. Neurogenic shock has hypotension with bradycardia.""",

28: """SECTION 9: ERAS Protocol - Simple Explanation
Enhanced Recovery After Surgery (ERAS) is a modern, evidence-based approach to perioperative care that aims to reduce surgical stress and speed recovery. The idea is to minimize how much surgery disrupts the body's normal physiology. Preoperative phase: Patients do not need to fast from midnight. Solid food can be eaten up to 6 hours before surgery. Clear fluids (like water or carbohydrate drinks) can be taken up to 2 hours before surgery. Carbohydrate-rich drinks (like Preload or similar products) are given before surgery to reduce postoperative insulin resistance and prevent the patient from being hungry and thirsty. Local guidelines at some hospitals restrict clear fluid fasting to a maximum of 4 hours. Before surgery, any reversible health problems (anaemia, uncontrolled diabetes) should be corrected to optimize the patient.""",

29: """SECTION 9 (continued): ERAS Intraoperative and Postoperative Phases - Simple Explanation
Intraoperative ERAS principles: Use minimally invasive (laparoscopic or robotic) surgery whenever possible. Manage fluids precisely using goal-directed fluid therapy - give exactly the right amount, neither too much nor too little. Use multimodal analgesia that avoids heavy opioid use - combine regional nerve blocks with paracetamol, NSAIDs, and local anesthetics. Postoperative ERAS principles: Get the patient out of bed and walking as early as possible (early mobilization). Start oral feeding as soon as the patient is awake and tolerating it. Avoid routine use of NG tubes (they do not help recovery and just cause discomfort), urinary catheters (remove early), and surgical drains (avoid unless absolutely necessary). These measures collectively reduce complications, shorten hospital stay, and improve patient experience. Multiple studies have confirmed ERAS reduces surgical morbidity significantly.""",

30: """SECTION 10: Postoperative Pain - Simple Explanation
Uncontrolled postoperative pain is not just uncomfortable - it actually harms the body in several ways. Pain activates the stress response system, specifically the HPA (hypothalamic-pituitary-adrenal) axis and the sympathetic nervous system. This causes the body to release large amounts of adrenaline, noradrenaline (catecholamines), and cortisol. The effects on different body systems are: Heart: blood pressure rises, heart rate increases, and the heart needs more oxygen (risk of heart attack). Lungs: pain makes patients breathe shallowly (they are afraid to take a deep breath because it hurts). This leads to retained secretions, collapsed lung segments (atelectasis), and risk of pneumonia. Gut: elevated cortisol slows the bowel down, prolonging postoperative ileus. Metabolism: elevated cortisol raises blood sugar (hyperglycemia), breaks down fat (lipolysis), and puts the body into a catabolic (wasting) state. This is why good pain management is essential after surgery - it is not just about comfort but about preventing serious complications.""",

31: """SECTION 10 (continued): WHO Analgesic Ladder and Pain Management - Simple Explanation
The WHO Analgesic Ladder is a step-by-step guide to prescribing pain relief based on how severe the pain is. Step 1 (Mild pain): Start with non-opioid drugs like paracetamol (acetaminophen) and NSAIDs (e.g., ibuprofen, diclofenac). These work by reducing inflammation and blocking pain signals. Step 2 (Moderate pain): Add a weak opioid like tramadol. Tramadol works in two ways: it weakly activates opioid receptors (reducing pain perception) AND it blocks the reuptake of serotonin and norepinephrine in the spinal cord (like an antidepressant effect on pain). Step 3 (Severe pain): Use a strong opioid like morphine. Morphine is the gold standard for severe acute pain, such as pain from cancer spreading to the bones (metastatic bone pain). Modern pain management uses multimodal analgesia - combining drugs from different levels of the ladder to get better pain control while using smaller doses of each drug, reducing side effects.""",

32: """SECTION 10 (continued): Neuropathic Pain and Special Pain Scenarios - Simple Explanation
Neuropathic pain is different from ordinary pain. It is caused by damage to the nerves themselves rather than to tissues. Patients describe it as burning, shooting, electric shock-like, or tingling sensations. Common causes in surgical patients: tumor invading a nerve, phantom limb pain after amputation, diabetic nerve damage. Neuropathic pain is resistant to normal painkillers like paracetamol, NSAIDs, and even strong opioids. The first-line drugs for neuropathic pain are pregabalin and gabapentin. These drugs work on calcium channels in nerve cells (they are called alpha-2-delta ligands) and reduce abnormal nerve firing. They are added on top of standard pain medications. Another important topic: methotrexate (a chemotherapy drug) can cause painful mouth ulcers (mucositis/stomatitis) by blocking folate metabolism. If blood tests are otherwise normal, the treatment is to increase folic acid supplementation, and methotrexate can be continued.""",

33: """SECTION 10: MCQ Summary for ERAS and Pain Management - Simple Explanation
This summary covers the most testable facts from Sections 9 and 10. Important points: ERAS stands for Enhanced Recovery After Surgery and its primary goal is to reduce the surgical stress response and speed up recovery. The cornerstones of ERAS are early mobilization and early oral feeding. Preoperative carbohydrate loading reduces insulin resistance and patient thirst. ERAS fasting allows clear fluids up to 2 hours before surgery. Acute postoperative pain activates the HPA axis, increasing catecholamines and cortisol. WHO Step 3 pain (severe cancer pain) is managed with morphine. Tramadol is a weak opioid that also inhibits serotonin/norepinephrine reuptake. Neuropathic pain does not respond to standard opioids. Pregabalin and gabapentin are first-line for neuropathic pain. Methotrexate-induced mouth sores are managed with folic acid supplementation.""",

34: """SECTION 11: Classification of Burns - Simple Explanation
Burns are classified by how deep into the skin they penetrate. The skin has two main layers: the epidermis (outer layer) and the dermis (inner layer, which contains nerves, blood vessels, and hair follicles). First-Degree Burns (Superficial): Only the outer epidermis is damaged. The skin looks red and feels painful and hot. There are NO blisters. Example: mild sunburn. Second-Degree Burns (Partial-Thickness): The burn goes through the epidermis into the dermis. Superficial partial-thickness: epidermis plus the superficial part of the dermis (papillary dermis). Blisters form, the wound is moist and weeping, and it is VERY PAINFUL because the nerve endings in the dermis are still intact. Deep partial-thickness: reaches the deeper dermis (reticular dermis). Less painful. High risk of hypertrophic scarring. Third-Degree Burns (Full-Thickness): The entire skin (epidermis + dermis) is destroyed, sometimes reaching muscle or bone. The wound looks dry, leathery, white or charred. It is completely PAINLESS because all the nerve endings have been destroyed.""",

35: """SECTION 11 (continued): Burn Depth and Zone of Stasis - Simple Explanation
This page continues the classification of burns and introduces an important concept about how burns change over time. After a burn injury, the wound is not static. It is divided into zones. The zone of coagulation is the central area where tissue is irreversibly dead. Surrounding this is the zone of stasis, where tissue is damaged and has poor blood flow but is not yet dead. If this zone is not treated properly (inadequate fluids, infection, low blood pressure), it will progress to full-thickness necrosis and the burn gets deeper. This is why early and aggressive burn resuscitation is so important. Because of this evolving nature, the true depth of a burn often cannot be determined immediately after injury. An accurate assessment usually requires 3 to 5 days of observation. Deep partial-thickness burns that heal very slowly (taking more than 3 weeks) tend to develop hypertrophic (raised, thick) scarring.""",

36: """SECTION 12: Assessment of Burns - TBSA Calculation - Simple Explanation
To treat a burn patient correctly, you must first calculate how much body surface area has been burned. This is called TBSA (Total Body Surface Area). The method used depends on the patient's age. For children: the Lund and Browder Chart is the most accurate method. Children have different body proportions from adults - for example, a child's head is proportionally much larger and each leg is proportionally smaller. The Lund and Browder chart has age-adjusted percentages that account for this. For adults: the Wallace Rule of Nines divides the body into areas, each worth 9% or a multiple of 9%. Head and neck = 9%. Each arm = 9%. Front of trunk = 18%. Back of trunk = 18%. Each leg = 18%. Perineum (genitals) = 1%. Total = 100%. Only second-degree and third-degree burns are counted in the TBSA calculation - first-degree burns (like sunburn) are NOT included when calculating fluid resuscitation needs.""",

37: """SECTION 12 (continued): Fluid Resuscitation with Parkland Formula - Simple Explanation
Once the TBSA is calculated, the Parkland Formula is used to calculate how much IV fluid to give in the first 24 hours after a burn. The formula is: Total fluid = 4 mL x body weight in kg x %TBSA burned. Only second- and third-degree burns are included in the TBSA for this calculation. The preferred fluid is Ringer's Lactate. The timing is critical: HALF of the total calculated fluid is given in the first 8 hours, and the remaining HALF over the next 16 hours. Importantly, the 8-hour countdown starts from the TIME OF THE BURN INJURY, not from when the patient arrives at hospital. Example: A 30 kg child with 30% burns: 4 x 30 x 30 = 3,600 mL. Give 1,800 mL in first 8 hours and 1,800 mL over the next 16 hours. Example: An 80 kg adult with 50% burns: 4 x 80 x 50 = 16,000 mL. First 8 hours = 8,000 mL = 1,000 mL/hour.""",

38: """SECTION 12 (continued): Monitoring Burn Resuscitation - Simple Explanation
During burn resuscitation, the most reliable way to check if the patient is receiving enough fluid is to measure the hourly urine output. This is the gold standard. Urine output reflects kidney perfusion, which reflects overall blood flow. Target urine outputs: Adults: 0.5 to 1 mL per kg per hour. Children: 1 to 2 mL per kg per hour (children need relatively more fluid). High-voltage electrical burn patients: 1 to 1.5 mL/kg/hour, because their muscles are releasing myoglobin (a muscle protein) that can damage the kidneys, and higher urine output helps flush it out. If the patient is producing too little urine (oliguria) during resuscitation, it almost always means they are not getting enough fluid. The correct response is to increase the Ringer's Lactate infusion rate. Do NOT give diuretics (like furosemide) to treat oliguria in this setting - diuretics would mask the problem without solving it.""",

39: """SECTION 13: Initial Management of Burns - Simple Explanation
Immediate first aid for burns is simple but critical. The very first thing to do is cool the burn with cool (not cold or iced) running tap water for at least 20 minutes. This limits how deep the burn goes, reduces swelling (edema), and relieves pain. Never use ice or ice-cold water (causes frostbite and worsens the injury), and never apply butter, toothpaste, or any greasy substance (these trap heat and cause infection). Remove any clothing or jewelry near the burn before swelling starts, but do not pull away clothing that is stuck to the wound - leave it for the medical team. Give tetanus toxoid to all patients with partial- or full-thickness burns who are not up to date with their tetanus vaccination. In the hospital, the management follows the ATLS protocol (Advanced Trauma Life Support): Airway first, then Breathing, then Circulation. Always assess and secure the airway BEFORE evaluating how large or deep the burns are.""",

40: """SECTION 13 (continued): Inhalation Injury and Escharotomy - Simple Explanation
Inhalation injury: If a patient was trapped in an enclosed fire (like a house fire or car fire), they may have inhaled hot gases or smoke. Warning signs of inhalation injury: hoarseness of voice, stridor (high-pitched breathing noise), wheezing, or difficulty breathing. These symptoms mean the airway is swelling and could close completely very soon. The immediate action is endotracheal intubation (putting a breathing tube down the throat) and giving high-flow oxygen BEFORE the airway swells shut. Escharotomy: Circumferential (all around) third-degree burns of a limb create a rigid, inelastic shell of dead skin (eschar). As the tissues swell underneath, this eschar acts like a tight tourniquet, cutting off blood flow to the limb. Treatment: surgically cut through the eschar (escharotomy) along the sides of the limb to release the pressure. No anesthesia is needed because third-degree burns have destroyed all nerve endings - the eschar itself is completely insensate. Similarly, circumferential chest burns restrict breathing and need escharotomy to allow chest expansion.""",

41: """SECTION 13 (continued): Topical Burn Agents - Simple Explanation
Dead burn tissue (eschar) has no blood supply, so systemic antibiotics (given by mouth or IV) cannot reach it. Topical agents applied directly to the wound are therefore used to control infection. Silver Sulfadiazine (SSD, brand name Flamazine 1%): The most widely used topical burn cream. Applied as a white cream to partial and full-thickness burns. Important side effects: it can temporarily reduce white blood cell count (leukopenia/neutropenia) - monitor with blood count. It is contraindicated on the face (can cause permanent black skin staining), and in patients with sulfa drug allergy, in pregnancy near term, and in G6PD deficiency. Mafenide Acetate: Used for deep wounds, cartilage burns (like ears), and thick eschar because it penetrates tissue better than SSD. Disadvantage: it is painful on application. It also inhibits an enzyme called carbonic anhydrase, which can cause metabolic acidosis (blood becomes too acidic) and the patient breathes faster to compensate.""",

42: """SECTION 13 (continued): Surgical and Rehabilitative Management of Burns - Simple Explanation
Burns that do not heal on their own within 3 weeks need surgical treatment. The procedure is: (1) Tangential excision: The surgeon uses a special blade to shave off thin layers of dead tissue until healthy, bleeding tissue is reached. This removes all the dead, infected material. (2) Split-thickness skin grafting: Healthy skin is harvested from another part of the patient's body (the donor site) using a dermatome (a special blade). This thin sheet of healthy skin is then placed over the excised wound and held in place. Over days, it attaches and becomes permanent skin. Benefits of surgical treatment: prevents infection, minimizes hypertrophic (raised) scarring, prevents contractures (tightening of scar tissue across joints), and speeds up wound closure. Rehabilitation: Physiotherapy is started early after burns. Patients must exercise affected joints to prevent contracture. Pressure garments are worn for months to prevent hypertrophic scarring.""",

43: """SECTION 14: Early Complications of Burns - Simple Explanation
Burns can cause serious complications very quickly. (1) Inhalation injury: Breathing in hot gases, steam, or chemical smoke causes direct damage to the airways and lungs. It is the single most important factor that increases the death rate in burn patients. It can cause respiratory failure. Any patient with possible inhalation injury needs immediate hospital admission and airway assessment. (2) Burn shock: Major burns (usually over 20% TBSA) cause a massive systemic inflammatory response. The body releases inflammatory chemicals that make blood vessels leaky. Plasma (the fluid component of blood) leaks out of the blood vessels into the surrounding tissues. This creates massive fluid loss from the circulation, leading to hypovolemia (low blood volume) and burn shock. (3) Rhabdomyolysis and AKI from electrical burns: High-voltage electrical burns (above 1,000 Volts) cause severe muscle damage throughout the body. Damaged muscles release myoglobin into the bloodstream. Myoglobin blocks kidney tubules and causes acute kidney injury (AKI).""",

44: """SECTION 14 (continued): Late Complications of Burns - Simple Explanation
Late complications develop weeks to months after the initial burn injury. (1) Hypertrophic scarring: After the burn heals, the scar tissue may grow excessively, becoming thick, raised, red, and itchy. This is called a hypertrophic scar. It is most likely after deep partial-thickness burns and burns that take longer than 3-4 weeks to heal. Prevention: pressure garments worn continuously for up to 18 months, silicone sheets, and physiotherapy. (2) Post-burn contractures: Scar tissue naturally contracts (shrinks) as it matures. When burns cross over a joint (like the elbow, knee, neck, or fingers), the contracting scar pulls the joint into a fixed, bent position. This is called a contracture. It leads to reduced joint movement and permanent deformity. Prevention: positioning, splinting (keeping joints extended with splints during the night), and active physiotherapy. Treatment: surgical release of the contracture and skin grafting.""",

45: """SECTION 14: MCQ Summary for Burns - Simple Explanation
This is the final MCQ summary page covering all burn-related topics. Key facts to memorize: Lund and Browder chart is used for children (most accurate). Wallace Rule of Nines is used for adults. Hourly urine output is the gold standard for monitoring burn resuscitation. Ringer's Lactate is the fluid of choice for burns. Always follow ATLS ABC before assessing burn size. Third-degree burns are painless, dry, leathery, and charred. Second-degree burns have painful blisters. Inhalation injury = immediate intubation + high-flow O2. Burn depth assessment takes 3-5 days. Inhalation injury is the worst prognostic factor for mortality. If urine output drops during resuscitation, increase crystalloid - do not give diuretics. High-voltage injury is over 1,000 Volts and causes myoglobinuria and AKI. Burns not healed in 3 weeks need tangential excision + skin grafting. Deep burns cause contractures and hypertrophic scarring.""",

46: """FINAL SUMMARY PAGE - Simple Explanation
This is the last page of the document, completing the MCQ summary for the entire Burns section. Key points from the final list: The Parkland formula calculates fluid needs as 4 mL x kg x %TBSA, with half given in the first 8 hours. The time starts from injury, not arrival. Silver sulfadiazine (SSD) is the most common topical burn agent - contraindicated on the face and in sulfa allergy. Fasciotomy is needed when deep tissue pressure exceeds 30 mmHg despite escharotomy, or in high-voltage electrical injuries with deep muscle damage. The Escharotomy is done without anesthesia because third-degree burns destroy sensory nerve endings. Physiotherapy and pressure garments are essential to prevent post-burn contractures and joint stiffness. Split-thickness skin grafting is the definitive treatment for non-healing deep burns. These notes comprehensively cover all KMU Block-N Surgery exam topics and are made by Zakria Marwat.""",

47: """SECTION 14 (continued): Complications MCQ Summary - Simple Explanation
This page continues the MCQ summary for early and late burn complications. Inhalation injury from enclosed-space fires requires immediate intubation - do not wait for symptoms to worsen. Burn shock is a form of distributive/hypovolemic shock caused by plasma leakage due to increased capillary permeability. The massive fluid shift happens within the first 24-48 hours and is why the Parkland formula front-loads fluid resuscitation. Electrical burns above 1,000 Volts cause rhabdomyolysis (muscle breakdown), releasing myoglobin that blocks kidneys and causes AKI. The urine may appear dark red or brown (myoglobinuria). Treatment: aggressive IV fluids to force high urine output (1-1.5 mL/kg/hr) to flush myoglobin from the kidneys. Hypertrophic scarring is distinguished from a keloid scar - hypertrophic stays within the wound borders, while a keloid grows beyond the original wound margins. Post-burn contractures are best prevented by early physiotherapy, correct positioning, and splinting.""",

48: """FINAL MCQ SUMMARY - Complete Burns Review - Simple Explanation
This is the comprehensive final MCQ list for the entire burns section. It synthesizes all key points from Sections 11-14 in one place for rapid revision. The most important clinical distinctions to remember: Lund and Browder vs Rule of Nines - children always get Lund and Browder because their body proportions change with age. First-degree burns (sunburn-like) are NOT included in Parkland formula calculations. First-degree burns are painful and red but have NO blisters. Second-degree burns have blisters and are the most painful. Third-degree burns are painless and leathery. Escharotomy (cutting through eschar) is different from fasciotomy (cutting through fascia/muscle compartments) - escharotomy comes first, fasciotomy only if needed. Inhalation injury is more deadly than the burn itself in many cases. The initial first aid for any burn is cool running water for 20 minutes. After 3 weeks of non-healing, surgery (excision + grafting) is the answer. All these points are high-yield for KMU MCQ examinations.""",

49: """END OF DOCUMENT - Complete Review - Simple Explanation
This final page completes the Block N Surgery high-yield notes. The document has covered three comprehensive areas. Part I covered General Surgery foundation topics including WHO surgical safety checklist, informed consent, surgical incisions (Langer's lines, abdominal incision types), wound healing (primary, secondary, tertiary intention), suture techniques, drain management, diathermy (monopolar vs bipolar), laparoscopic and robotic surgery, perioperative fluid and electrolyte management, nutritional support (enteral vs TPN), and postoperative complications. Part II covered ERAS protocol in detail including preoperative optimization, intraoperative care, postoperative phases, and perioperative pain management using the WHO analgesic ladder. Part III covered Burns: classification by depth, TBSA calculation using Rule of Nines and Lund-Browder chart, Parkland formula for fluid resuscitation, escharotomy, topical agents (silver sulfadiazine, mafenide acetate), skin grafting, and early and late complications. These notes are a focused, high-yield revision resource for KMU Final Year MBBS Surgery exam. Made by Zakria Marwat.""",
}


def wrap_text_reportlab(c_obj, text, x, y, max_width, font_name, font_size, line_height):
    """Draw wrapped text and return the final y position."""
    words = text.split()
    lines = []
    current_line = []
    for word in words:
        test_line = ' '.join(current_line + [word])
        if c_obj.stringWidth(test_line, font_name, font_size) <= max_width:
            current_line.append(word)
        else:
            if current_line:
                lines.append(' '.join(current_line))
            current_line = [word]
    if current_line:
        lines.append(' '.join(current_line))

    current_y = y
    for line in lines:
        if current_y < 5:
            break
        c_obj.drawString(x, current_y, line)
        current_y -= line_height
    return current_y


def make_overlay(page_index, page_width, page_height):
    packet = io.BytesIO()
    c = canvas.Canvas(packet, pagesize=(page_width, page_height))

    # ── 1. Replace "Made by Haroon" in footer (all pages except page 0 which is image) ──
    if page_index > 0:
        # pdfplumber top=816.68 → RL y = page_height - 823.43
        text_y_rl = page_height - 823.5
        c.setFillColor(colors.white)
        c.setStrokeColor(colors.white)
        c.rect(255, text_y_rl - 1, 140, 12, fill=1, stroke=0)
        c.setFillColor(colors.black)
        c.setFont("Helvetica", 6.75)
        c.drawString(263, text_y_rl + 1.5, "Made by Zakria Marwat")

    # ── 2. Page 1 (index 0): cover image has "Haroon" baked in ──
    # We'll add a text label at the very bottom of the cover page
    if page_index == 0:
        # Add a footer bar at bottom of cover page
        c.setFillColor(colors.white)
        c.setStrokeColor(colors.white)
        # Cover bottom area - add white strip over potential "Haroon" text
        c.rect(0, 0, page_width, 40, fill=1, stroke=0)
        c.setFillColor(colors.HexColor("#1a1a2e"))
        c.setFont("Helvetica-Bold", 10)
        c.drawCentredString(page_width / 2, 14, "Made by Zakria Marwat")

    # ── 3. Add explanation box at bottom of every page ──
    explanation = EXPLANATIONS.get(page_index, "")
    if explanation:
        box_margin = 30
        box_width = page_width - (2 * box_margin)
        font_size = 6.5
        line_height = 8.5
        padding = 6

        # Count lines needed
        c.setFont("Helvetica", font_size)
        words = explanation.split()
        lines = []
        current_line = []
        for word in words:
            test_line = ' '.join(current_line + [word])
            if c.stringWidth(test_line, "Helvetica", font_size) <= box_width - 2 * padding:
                current_line.append(word)
            else:
                if current_line:
                    lines.append(' '.join(current_line))
                current_line = [word]
        if current_line:
            lines.append(' '.join(current_line))

        # Header line
        header = "PLAIN-ENGLISH EXPLANATION:"
        total_lines = 1 + len(lines)  # 1 for header + 1 gap
        box_height = (total_lines * line_height) + 2 * padding + line_height  # extra line_height for header gap

        # Position: just above the footer line
        # Footer "Made by" is at pdfplumber top ~816 → RL y ~ page_height - 816 = 26.88
        # Place box so it ends at y=32 (just above footer)
        box_bottom_y = 32
        box_top_y = box_bottom_y + box_height

        # Draw box background
        c.setFillColor(colors.HexColor("#f0f8ff"))  # light blue background
        c.setStrokeColor(colors.HexColor("#2e6da4"))
        c.setLineWidth(0.8)
        c.rect(box_margin, box_bottom_y, box_width, box_height, fill=1, stroke=1)

        # Draw header
        text_x = box_margin + padding
        text_y = box_top_y - padding - line_height
        c.setFillColor(colors.HexColor("#1a4a7a"))
        c.setFont("Helvetica-Bold", 6.5)
        c.drawString(text_x, text_y, header)

        # Draw explanation text
        text_y -= (line_height + 1)
        c.setFillColor(colors.HexColor("#1a1a1a"))
        c.setFont("Helvetica", font_size)
        for line in lines:
            if text_y < box_bottom_y + padding:
                break
            c.drawString(text_x, text_y, line)
            text_y -= line_height

    c.save()
    packet.seek(0)
    return packet


def main():
    import os
    os.makedirs("/tmp/workspace/pdf_edit", exist_ok=True)

    reader = PdfReader(INPUT_PDF)
    writer = PdfWriter()
    total = len(reader.pages)
    print(f"Processing {total} pages...")

    for i, page in enumerate(reader.pages):
        mb = page.mediabox
        pw = float(mb.width)
        ph = float(mb.height)

        overlay_packet = make_overlay(i, pw, ph)
        overlay_reader = PdfReader(overlay_packet)
        overlay_page = overlay_reader.pages[0]
        page.merge_page(overlay_page)
        writer.add_page(page)

        if (i + 1) % 10 == 0:
            print(f"  {i+1}/{total} pages done")

    with open(OUTPUT_PDF, "wb") as f:
        writer.write(f)

    size = os.path.getsize(OUTPUT_PDF)
    print(f"\nDone! Saved to: {OUTPUT_PDF}")
    print(f"File size: {size/1024:.1f} KB")


if __name__ == "__main__":
    main()

Successfully replaced 1 instance(s) of the string in '/tmp/workspace/pdf_edit/edit_pdf_v2.py'

"""
PDF Editor v3 - Adds diagrams/flowcharts to complex pages plus all previous edits:
  1. Replace "Made by Haroon" -> "Made by Zakria Marwat" on all pages incl cover
  2. Plain-English explanation box at bottom of every page
  3. Diagrams/flowcharts inserted on complex pages
"""

import io, math
from pypdf import PdfReader, PdfWriter
from reportlab.pdfgen import canvas
from reportlab.lib import colors
from reportlab.lib.colors import HexColor

INPUT_PDF  = "/tmp/workspace/attachments/2098dca5-f665-490c-9bd6-6a49cdacd54e/Block_N_Surgery_260721_185719.pdf"
OUTPUT_PDF = "/tmp/workspace/pdf_edit/Block_N_Surgery_ZakriaMarwat_v3.pdf"

PAGE_W = 595.92
PAGE_H = 842.88

# ── Colour palette ─────────────────────────────────────────────────────
C_BLUE_BG   = HexColor("#ddeeff")
C_BLUE_BRD  = HexColor("#2e6da4")
C_BLUE_HDR  = HexColor("#1a4a7a")
C_TEXT      = HexColor("#1a1a1a")
C_WHITE     = colors.white
C_ORANGE    = HexColor("#e07b00")
C_GREEN     = HexColor("#1a7a3c")
C_RED       = HexColor("#b01020")
C_PURPLE    = HexColor("#6a2a8a")
C_TEAL      = HexColor("#0a6a6a")
C_YELLOW_BG = HexColor("#fffbe6")
C_YELLOW_BD = HexColor("#c09000")
C_SALMON    = HexColor("#ffe4e1")
C_PINK_BD   = HexColor("#c06070")

# ════════════════════════════════════════════════════════════════════════
#  HELPER DRAWING UTILITIES
# ════════════════════════════════════════════════════════════════════════

def rounded_rect(c, x, y, w, h, r=4, fill_color=None, stroke_color=None, lw=0.8):
    if fill_color:
        c.setFillColor(fill_color)
    if stroke_color:
        c.setStrokeColor(stroke_color)
        c.setLineWidth(lw)
    c.roundRect(x, y, w, h, r, fill=1 if fill_color else 0,
                stroke=1 if stroke_color else 0)

def draw_box(c, x, y, w, h, label, sub=None,
             bg=C_BLUE_BG, border=C_BLUE_BRD, label_color=C_BLUE_HDR,
             label_fs=7, sub_fs=6, r=4):
    rounded_rect(c, x, y, w, h, r, bg, border)
    c.setFillColor(label_color)
    c.setFont("Helvetica-Bold", label_fs)
    c.drawCentredString(x + w/2, y + h/2 + (3 if sub else 0), label)
    if sub:
        c.setFont("Helvetica", sub_fs)
        c.setFillColor(C_TEXT)
        c.drawCentredString(x + w/2, y + h/2 - 5, sub)

def arrow_right(c, x1, y, x2, color=C_BLUE_BRD, lw=1.2):
    c.setStrokeColor(color)
    c.setLineWidth(lw)
    c.line(x1, y, x2 - 4, y)
    # arrowhead
    p = c.beginPath()
    p.moveTo(x2, y)
    p.lineTo(x2 - 5, y + 3)
    p.lineTo(x2 - 5, y - 3)
    p.close()
    c.setFillColor(color)
    c.drawPath(p, fill=1, stroke=0)

def arrow_down(c, x, y1, y2, color=C_BLUE_BRD, lw=1.2):
    c.setStrokeColor(color)
    c.setLineWidth(lw)
    c.line(x, y1, x, y2 + 4)
    p = c.beginPath()
    p.moveTo(x, y2)
    p.lineTo(x - 3, y2 + 5)
    p.lineTo(x + 3, y2 + 5)
    p.close()
    c.setFillColor(color)
    c.drawPath(p, fill=1, stroke=0)

def section_title(c, x, y, text, fs=7.5, color=C_BLUE_HDR):
    c.setFillColor(color)
    c.setFont("Helvetica-Bold", fs)
    c.drawString(x, y, text)

def wrap_draw(c, text, x, y, max_w, fs=6, lh=7.5, color=C_TEXT):
    c.setFont("Helvetica", fs)
    c.setFillColor(color)
    words = text.split()
    line = []
    cur_y = y
    for w in words:
        test = ' '.join(line + [w])
        if c.stringWidth(test, "Helvetica", fs) <= max_w:
            line.append(w)
        else:
            if line:
                c.drawString(x, cur_y, ' '.join(line))
                cur_y -= lh
            line = [w]
    if line:
        c.drawString(x, cur_y, ' '.join(line))
        cur_y -= lh
    return cur_y

# ════════════════════════════════════════════════════════════════════════
#  DIAGRAM FUNCTIONS  (each returns the y consumed / lowest y drawn)
# ════════════════════════════════════════════════════════════════════════

def diagram_who_checklist(c, left, top, width):
    """3-phase WHO checklist horizontal flowchart."""
    bw, bh = 115, 52
    gap = 20
    total = 3*bw + 2*gap
    start_x = left + (width - total) / 2
    y_box = top - bh

    section_title(c, left, top + 2, "DIAGRAM: WHO Surgical Safety Checklist — 3 Phases", color=C_BLUE_HDR)

    phases = [
        ("SIGN IN", "Before anaesthesia\n• Patient identity\n• Site marked?\n• Anaesthesia check\n• Pulse oximeter", HexColor("#c8e6c9"), HexColor("#2e7d32"), HexColor("#1b5e20")),
        ("TIME OUT", "Before skin incision\n• Team introductions\n• Confirm patient/site\n• Antibiotic given?\n• Imaging displayed", HexColor("#fff9c4"), C_YELLOW_BD, HexColor("#5d4037")),
        ("SIGN OUT", "Before leaving OR\n• Procedure recorded\n• Instrument count OK\n• Specimens labelled\n• Recovery handover", HexColor("#fce4ec"), C_PINK_BD, HexColor("#880e4f")),
    ]

    for i, (title, body, bg, bd, tc) in enumerate(phases):
        bx = start_x + i * (bw + gap)
        rounded_rect(c, bx, y_box, bw, bh, 5, bg, bd, 1)
        c.setFillColor(tc)
        c.setFont("Helvetica-Bold", 7.5)
        c.drawCentredString(bx + bw/2, y_box + bh - 11, title)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", 5.8)
        for j, line in enumerate(body.split('\n')[1:]):   # skip first empty
            c.drawString(bx + 5, y_box + bh - 22 - j*7, line)
        if i < 2:
            ax = bx + bw
            arrow_right(c, ax, y_box + bh/2, ax + gap, color=bd)

    # Label underneath
    c.setFillColor(HexColor("#555555"))
    c.setFont("Helvetica-Oblique", 5.5)
    c.drawCentredString(left + width/2, y_box - 6, "Primary purpose: Improve communication & teamwork among surgical, anaesthetic, and nursing teams.")
    return y_box - 12


def diagram_burns_classification(c, left, top, width):
    """Burns depth classification — 3 columns with skin layer indicators."""
    section_title(c, left, top + 2, "DIAGRAM: Burns Classification by Depth", color=C_RED)

    bw = (width - 30) / 3
    bh = 80
    y_box = top - bh - 2
    gap = 15

    cols = [
        ("1st DEGREE\nSuperficial", "Epidermis only",
         ["• Erythema (redness)", "• Painful & warm", "• NO blisters", "• Heals in 3-5 days"],
         HexColor("#fff3e0"), HexColor("#e65100"), HexColor("#bf360c")),
        ("2nd DEGREE\nPartial-Thickness", "Epidermis + Dermis",
         ["• Fluid-filled BLISTERS", "• Moist wound surface", "• Very PAINFUL", "• Intact nerve endings"],
         HexColor("#fce4ec"), HexColor("#c62828"), HexColor("#880e4f")),
        ("3rd DEGREE\nFull-Thickness", "Epidermis + Dermis\n+ beyond",
         ["• Dry, leathery eschar", "• White / charred", "• PAINLESS (nerves gone)", "• Requires skin graft"],
         HexColor("#f3e5f5"), HexColor("#6a1b9a"), HexColor("#4a148c")),
    ]

    for i, (title, sub, bullets, bg, bd, tc) in enumerate(cols):
        bx = left + i * (bw + gap)
        rounded_rect(c, bx, y_box, bw, bh, 5, bg, bd, 1)
        c.setFillColor(tc)
        c.setFont("Helvetica-Bold", 6.8)
        for j, tl in enumerate(title.split('\n')):
            c.drawCentredString(bx + bw/2, y_box + bh - 10 - j*8, tl)
        c.setFillColor(HexColor("#555555"))
        c.setFont("Helvetica-Oblique", 5.5)
        c.drawCentredString(bx + bw/2, y_box + bh - 27, sub)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", 5.8)
        for k, b in enumerate(bullets):
            c.drawString(bx + 5, y_box + bh - 38 - k*8, b)

    # Pain scale bar
    bar_y = y_box - 14
    c.setFillColor(HexColor("#333333"))
    c.setFont("Helvetica-Bold", 5.8)
    c.drawString(left, bar_y, "Pain level:")
    for i, (label, col) in enumerate([("Painful", HexColor("#ff8f00")),
                                        ("Very Painful", HexColor("#d32f2f")),
                                        ("PAINLESS", HexColor("#6a1b9a"))]):
        bx = left + i * (bw + gap)
        rounded_rect(c, bx + bw//4, bar_y - 9, bw//2, 9, 3, col, col)
        c.setFillColor(C_WHITE)
        c.setFont("Helvetica-Bold", 5.2)
        c.drawCentredString(bx + bw/2, bar_y - 3, label)
    return bar_y - 16


def diagram_wound_healing(c, left, top, width):
    """3 types of wound intention — vertical flow."""
    section_title(c, left, top + 2, "DIAGRAM: Types of Wound Healing", color=C_GREEN)

    bw = (width - 20) / 3
    bh = 48
    gap = 10
    y_box = top - bh - 4

    types = [
        ("PRIMARY\nINTENTION", ["Clean wound", "Edges stitched together", "Heals fast, thin scar"],
         HexColor("#e8f5e9"), HexColor("#2e7d32")),
        ("SECONDARY\nINTENTION", ["Open wound / infected", "Heals by granulation", "Slower, wider scar"],
         HexColor("#fff8e1"), HexColor("#f57f17")),
        ("TERTIARY\nINTENTION", ["Contaminated wound", "Left open → cleaned", "Closed surgically later"],
         HexColor("#fce4ec"), HexColor("#c62828")),
    ]

    for i, (title, bullets, bg, bd) in enumerate(types):
        bx = left + i * (bw + gap)
        rounded_rect(c, bx, y_box, bw, bh, 5, bg, bd, 1)
        c.setFillColor(bd)
        c.setFont("Helvetica-Bold", 6.5)
        for j, t in enumerate(title.split('\n')):
            c.drawCentredString(bx + bw/2, y_box + bh - 11 - j*8, t)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", 5.8)
        for k, b in enumerate(bullets):
            c.drawString(bx + 5, y_box + bh - 28 - k*7.5, b)

    c.setFillColor(HexColor("#555555"))
    c.setFont("Helvetica-Oblique", 5.5)
    c.drawCentredString(left + width/2, y_box - 6,
                        "Day 2 post-injury: Neutrophils → Macrophages take over (coordinate debridement & remodelling)")
    return y_box - 12


def diagram_eras(c, left, top, width):
    """ERAS 3-phase pathway."""
    section_title(c, left, top + 2, "DIAGRAM: ERAS Pathway — 3 Phases", color=C_TEAL)

    bw = (width - 20) / 3
    bh = 72
    gap = 10
    y_box = top - bh - 4

    phases = [
        ("PRE-OPERATIVE", [
            "• No prolonged fasting",
            "• Solids up to 6h before",
            "• Clear fluids up to 2h",
            "• Carb-loading drinks",
            "• Correct anaemia/DM",
            "• Optimize comorbidities",
        ], HexColor("#e3f2fd"), HexColor("#1565c0")),
        ("INTRA-OPERATIVE", [
            "• Minimally invasive Sx",
            "• Goal-directed fluids",
            "• Opioid-sparing analgesia",
            "• Regional nerve blocks",
            "• Maintain normothermia",
            "• Short-acting anaesthesia",
        ], HexColor("#f3e5f5"), HexColor("#6a1b9a")),
        ("POST-OPERATIVE", [
            "• Early oral feeding",
            "• Early mobilisation",
            "• No routine NG tube",
            "• Remove catheter early",
            "• Avoid excess drains",
            "• Multimodal analgesia",
        ], HexColor("#e8f5e9"), HexColor("#1b5e20")),
    ]

    for i, (title, bullets, bg, bd) in enumerate(phases):
        bx = left + i * (bw + gap)
        rounded_rect(c, bx, y_box, bw, bh, 5, bg, bd, 1.2)
        c.setFillColor(bd)
        c.setFont("Helvetica-Bold", 7)
        c.drawCentredString(bx + bw/2, y_box + bh - 11, title)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", 5.8)
        for k, b in enumerate(bullets):
            c.drawString(bx + 5, y_box + bh - 21 - k*7.8, b)
        if i < 2:
            arrow_right(c, bx + bw, y_box + bh/2, bx + bw + gap, color=bd)

    c.setFillColor(HexColor("#555555"))
    c.setFont("Helvetica-Oblique", 5.5)
    c.drawCentredString(left + width/2, y_box - 6,
                        "Goal: Maintain normal physiology ▸ Reduce surgical stress response ▸ Faster recovery ▸ Shorter hospital stay")
    return y_box - 12


def diagram_analgesic_ladder(c, left, top, width):
    """WHO Analgesic Ladder — 3 steps as a pyramid/staircase."""
    section_title(c, left, top + 2, "DIAGRAM: WHO Analgesic Ladder", color=C_ORANGE)

    step_h = 24
    pad = 4
    y_cur = top - 6
    steps = [
        ("STEP 3 — SEVERE PAIN", "Strong Opioids (e.g., Morphine)", HexColor("#ffccbc"), HexColor("#bf360c"), 0),
        ("STEP 2 — MODERATE PAIN", "Weak Opioids (e.g., Tramadol) + Step 1 drugs", HexColor("#fff9c4"), HexColor("#f57f17"), 20),
        ("STEP 1 — MILD PAIN", "Non-Opioids: Paracetamol + NSAIDs (baseline always)", HexColor("#c8e6c9"), HexColor("#2e7d32"), 40),
    ]

    for title, sub, bg, bd, indent in steps:
        bx = left + indent
        bw = width - 2*indent
        rounded_rect(c, bx, y_cur - step_h, bw, step_h, 3, bg, bd, 1)
        c.setFillColor(bd)
        c.setFont("Helvetica-Bold", 6.5)
        c.drawString(bx + 6, y_cur - 10, title)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", 5.8)
        c.drawString(bx + 6, y_cur - 20, sub)
        y_cur -= step_h + pad

    # Tramadol note
    c.setFillColor(C_ORANGE)
    c.setFont("Helvetica-Oblique", 5.5)
    c.drawCentredString(left + width/2, y_cur - 3,
                        "Tramadol: Weak μ-opioid + Serotonin/Noradrenaline reuptake inhibitor | Morphine: Step 3 severe pain (e.g., bone mets)")
    return y_cur - 10


def diagram_parkland(c, left, top, width):
    """Parkland formula step-by-step flowchart."""
    section_title(c, left, top + 2, "DIAGRAM: Parkland Formula — Burn Fluid Resuscitation", color=C_PURPLE)

    bh = 20
    bw_main = width - 40
    bx = left + 20
    y = top - 8

    steps = [
        ("STEP 1: Calculate Total Fluid", "Formula: 4 mL  ×  Body Weight (kg)  ×  %TBSA (2nd + 3rd degree only)",
         HexColor("#e8eaf6"), HexColor("#3949ab")),
        ("STEP 2: Split into Two Halves", "First 8 hours → give 50%  |  Next 16 hours → give 50%",
         HexColor("#fce4ec"), HexColor("#c62828")),
        ("STEP 3: Start Timing from INJURY (not arrival)", "Clock starts at the time of the burn, not when patient reaches hospital",
         HexColor("#fff8e1"), HexColor("#f57f17")),
        ("STEP 4: Fluid of Choice = Ringer's Lactate", "Composition similar to extracellular fluid; lactate corrects metabolic acidosis",
         HexColor("#e8f5e9"), HexColor("#2e7d32")),
    ]

    for i, (title, sub, bg, bd) in enumerate(steps):
        rounded_rect(c, bx, y - bh, bw_main, bh, 3, bg, bd, 0.8)
        c.setFillColor(bd)
        c.setFont("Helvetica-Bold", 6.2)
        c.drawString(bx + 6, y - 8, title)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", 5.8)
        c.drawString(bx + 6, y - 16, sub)
        if i < len(steps) - 1:
            arrow_down(c, bx + bw_main/2, y - bh - 1, y - bh - 7, color=bd)
        y -= bh + 10

    # Example box
    ex_y = y - 4
    rounded_rect(c, left, ex_y - 16, width, 16, 3, HexColor("#f3e5f5"), C_PURPLE, 0.8)
    c.setFillColor(C_PURPLE)
    c.setFont("Helvetica-Bold", 5.8)
    c.drawString(left + 5, ex_y - 7, "Example: 80kg adult, 50% burns → 4×80×50 = 16,000 mL  |  First 8h = 8,000 mL (1,000 mL/hr)  |  Next 16h = 8,000 mL")
    c.setFont("Helvetica", 5.5)
    c.setFillColor(C_TEXT)
    c.drawString(left + 5, ex_y - 14, "Monitor with hourly urine output: Adults 0.5–1 mL/kg/hr  |  Children 1–2 mL/kg/hr  |  Electrical burns 1–1.5 mL/kg/hr")
    return ex_y - 22


def diagram_laparoscopy(c, left, top, width):
    """Laparoscopy key facts — concept map style."""
    section_title(c, left, top + 2, "DIAGRAM: Laparoscopic Surgery — Key Concepts", color=C_TEAL)

    bw2 = (width - 12) / 2
    bh2 = 34
    y = top - 8
    items = [
        ("CO₂ Pneumoperitoneum", "Non-combustible + highly blood-\nsoluble → safe gas embolism risk\nMax pressure: 15 mmHg",
         HexColor("#e3f2fd"), HexColor("#1565c0")),
        ("Advantages", "Less trauma  •  Smaller scars\nShorter stay  •  Faster recovery\nBetter cosmesis",
         HexColor("#e8f5e9"), HexColor("#2e7d32")),
        ("Absolute Contraindication", "Uncontrolled coagulopathy\n(bleeding disorder) = cannot\ncontrol haemorrhage laparoscopically",
         HexColor("#ffccbc"), HexColor("#bf360c")),
        ("Vagal Bradycardia", "Rapid peritoneum stretch →\nvagus nerve → bradycardia/arrest\nRx: Desufflate + Atropine IV",
         HexColor("#fce4ec"), HexColor("#c62828")),
    ]

    for i, (title, body, bg, bd) in enumerate(items):
        bx = left + (i % 2) * (bw2 + 12)
        by = y - (i // 2) * (bh2 + 8)
        rounded_rect(c, bx, by - bh2, bw2, bh2, 4, bg, bd, 0.8)
        c.setFillColor(bd)
        c.setFont("Helvetica-Bold", 6.5)
        c.drawString(bx + 5, by - 10, title)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", 5.8)
        for j, line in enumerate(body.split('\n')):
            c.drawString(bx + 5, by - 20 - j*7, line)

    return y - 2 * (bh2 + 8) - 12


def diagram_diathermy(c, left, top, width):
    """Monopolar vs Bipolar diathermy comparison."""
    section_title(c, left, top + 2, "DIAGRAM: Monopolar vs Bipolar Diathermy", color=HexColor("#5d4037"))

    bw2 = (width - 12) / 2
    bh2 = 62
    y_box = top - bh2 - 8

    # Monopolar
    rounded_rect(c, left, y_box, bw2, bh2, 5, HexColor("#fff3e0"), HexColor("#e65100"), 1)
    c.setFillColor(HexColor("#bf360c"))
    c.setFont("Helvetica-Bold", 7)
    c.drawCentredString(left + bw2/2, y_box + bh2 - 12, "MONOPOLAR")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 6)
    for j, line in enumerate([
        "• Current: instrument → body → pad",
        "• Powerful; used for cutting/coagulation",
        "• DANGER: pacemakers, metal implants",
        "  (current arcs to metal/disrupts pacing)",
        "• Avoid in: ICDs, cochlear implants",
    ]):
        c.drawString(left + 5, y_box + bh2 - 22 - j*8, line)

    # Bipolar
    bx2 = left + bw2 + 12
    rounded_rect(c, bx2, y_box, bw2, bh2, 5, HexColor("#e8f5e9"), HexColor("#2e7d32"), 1)
    c.setFillColor(HexColor("#1b5e20"))
    c.setFont("Helvetica-Bold", 7)
    c.drawCentredString(bx2 + bw2/2, y_box + bh2 - 12, "BIPOLAR")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 6)
    for j, line in enumerate([
        "• Current: tip ↔ tip of forceps only",
        "• Does NOT travel through body",
        "• SAFE with pacemakers & implants",
        "  (current stays localised)",
        "• Preferred in: cardiac device patients",
    ]):
        c.drawString(bx2 + 5, y_box + bh2 - 22 - j*8, line)

    # VS badge
    c.setFillColor(HexColor("#37474f"))
    c.setFont("Helvetica-Bold", 9)
    c.drawCentredString(left + bw2 + 6, y_box + bh2/2, "VS")

    return y_box - 8


def diagram_fluid_types(c, left, top, width):
    """Ringer's Lactate vs Normal Saline comparison."""
    section_title(c, left, top + 2, "DIAGRAM: IV Fluid Comparison", color=HexColor("#00695c"))

    bw2 = (width - 12) / 2
    bh2 = 65
    y_box = top - bh2 - 8

    # RL
    rounded_rect(c, left, y_box, bw2, bh2, 5, HexColor("#e3f2fd"), HexColor("#1565c0"), 1)
    c.setFillColor(HexColor("#0d47a1"))
    c.setFont("Helvetica-Bold", 7)
    c.drawCentredString(left + bw2/2, y_box + bh2 - 12, "RINGER'S LACTATE")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 6)
    rl_lines = [
        "Na⁺: 130 mEq/L  |  Cl⁻: 109 mEq/L",
        "K⁺: 4 mEq/L     |  Ca²⁺: 3 mEq/L",
        "Lactate → Bicarbonate (liver)",
        "✓ Corrects metabolic acidosis",
        "✓ Best for: burns, haemorrhagic shock",
        "✓ Less hyperchloraemia than NS",
    ]
    for j, line in enumerate(rl_lines):
        c.drawString(left + 5, y_box + bh2 - 23 - j*7, line)

    # NS
    bx2 = left + bw2 + 12
    rounded_rect(c, bx2, y_box, bw2, bh2, 5, HexColor("#fff9c4"), HexColor("#f57f17"), 1)
    c.setFillColor(HexColor("#e65100"))
    c.setFont("Helvetica-Bold", 7)
    c.drawCentredString(bx2 + bw2/2, y_box + bh2 - 12, "NORMAL SALINE (0.9%)")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 6)
    ns_lines = [
        "Na⁺: 154 mEq/L  |  Cl⁻: 154 mEq/L",
        "K⁺: 0 mEq/L     |  No potassium",
        "No lactate / bicarbonate buffer",
        "✗ Large volumes → Hyperchloraemic",
        "  metabolic acidosis",
        "Use: drug dilution, hyponatraemia",
    ]
    for j, line in enumerate(ns_lines):
        c.drawString(bx2 + 5, y_box + bh2 - 23 - j*7, line)

    return y_box - 8


def diagram_incisions(c, left, top, width):
    """Abdominal incisions quick reference table."""
    section_title(c, left, top + 2, "DIAGRAM: Common Abdominal Incisions — Summary", color=HexColor("#004d40"))

    rows = [
        ("Midline", "Vertical, linea alba", "Emergency/trauma", "Fastest; HIGHEST hernia risk"),
        ("Kocher's", "Oblique, subcostal", "Cholecystectomy/liver", "Muscle-cutting; painful"),
        ("Gridiron", "Oblique, RIF", "Appendectomy", "Muscle-splitting; LOW hernia"),
        ("Lanz", "Transverse, RIF", "Appendectomy", "Better cosmesis than Gridiron"),
        ("Pfannenstiel", "Transverse, suprapubic", "C-section/gynaecology", "Hidden; very strong closure"),
    ]

    col_ws = [70, 90, 95, width - 70 - 90 - 95 - 10]
    headers = ["Incision", "Direction/Site", "Main Use", "Key Feature"]
    col_x = [left, left+col_ws[0]+2, left+col_ws[0]+col_ws[1]+4, left+col_ws[0]+col_ws[1]+col_ws[2]+6]
    row_h = 10
    hdr_y = top - 10

    # Header row
    rounded_rect(c, left, hdr_y - 2, width, row_h + 2, 2, HexColor("#004d40"), HexColor("#004d40"))
    c.setFillColor(C_WHITE)
    c.setFont("Helvetica-Bold", 6)
    for i, h in enumerate(headers):
        c.drawString(col_x[i] + 2, hdr_y + 1, h)

    for r, (name, loc, use, note) in enumerate(rows):
        by = hdr_y - row_h - r * (row_h + 2) - 4
        bg = HexColor("#e0f2f1") if r % 2 == 0 else HexColor("#f1f8e9")
        rounded_rect(c, left, by - 2, width, row_h + 2, 1, bg, HexColor("#aaaaaa"), 0.4)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", 5.8)
        for i, val in enumerate([name, loc, use, note]):
            c.drawString(col_x[i] + 2, by + 1, val)

    return hdr_y - row_h * (len(rows)+1) - 20


def diagram_hyperkalemia(c, left, top, width):
    """Hyperkalemia ECG changes + treatment flow."""
    section_title(c, left, top + 2, "DIAGRAM: Hyperkalemia — ECG Changes & Treatment", color=C_RED)

    # ECG changes sequence
    bw = (width - 20) / 3
    bh = 36
    gap = 10
    y_box = top - bh - 8

    stages = [
        ("EARLY", ["Peaked T waves", "(tall, narrow)"], HexColor("#fff9c4"), HexColor("#f9a825")),
        ("MODERATE", ["P waves flatten", "QRS widens"], HexColor("#ffe0b2"), HexColor("#e65100")),
        ("SEVERE", ["Sine-wave QRS", "Risk of VF/arrest"], HexColor("#ffccbc"), HexColor("#c62828")),
    ]

    for i, (stage, lines, bg, bd) in enumerate(stages):
        bx = left + i * (bw + gap)
        rounded_rect(c, bx, y_box, bw, bh, 4, bg, bd, 1)
        c.setFillColor(bd)
        c.setFont("Helvetica-Bold", 7)
        c.drawCentredString(bx + bw/2, y_box + bh - 11, stage)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", 6)
        for j, l in enumerate(lines):
            c.drawCentredString(bx + bw/2, y_box + bh - 22 - j*8, l)
        if i < 2:
            arrow_right(c, bx + bw, y_box + bh/2, bx + bw + gap)

    # Treatment box
    tx_y = y_box - 14
    rounded_rect(c, left, tx_y - 18, width, 18, 4, HexColor("#e8f5e9"), HexColor("#2e7d32"), 1)
    c.setFillColor(HexColor("#1b5e20"))
    c.setFont("Helvetica-Bold", 6.5)
    c.drawString(left + 5, tx_y - 8, "TREATMENT:  10% IV Calcium Gluconate  →  Stabilises myocardium  (does NOT lower K⁺)")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 5.8)
    c.drawString(left + 5, tx_y - 16, "Then: Insulin + Dextrose (drives K⁺ into cells)  |  Salbutamol nebuliser  |  Calcium Resonium  |  Dialysis if renal failure")
    return tx_y - 24


def diagram_consent(c, left, top, width):
    """Informed consent components + exception flowchart."""
    section_title(c, left, top + 2, "DIAGRAM: Informed Consent — Components & Exceptions", color=HexColor("#1a237e"))

    # Components box
    comp_bh = 46
    comp_bw = width * 0.52
    y_comp = top - comp_bh - 8
    rounded_rect(c, left, y_comp, comp_bw, comp_bh, 4, HexColor("#e8eaf6"), HexColor("#3949ab"), 1)
    c.setFillColor(HexColor("#1a237e"))
    c.setFont("Helvetica-Bold", 6.5)
    c.drawString(left + 4, y_comp + comp_bh - 11, "SURGEON MUST EXPLAIN:")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 6)
    items = ["• Diagnosis", "• Nature of procedure", "• Benefits & Risks",
             "• Alternatives available", "• Possible conversion (e.g., lap → open)"]
    for j, item in enumerate(items):
        c.drawString(left + 4, y_comp + comp_bh - 21 - j*7, item)

    # Exception flow
    ex_bw = width - comp_bw - 12
    ex_x = left + comp_bw + 12
    rounded_rect(c, ex_x, y_comp, ex_bw, comp_bh, 4, HexColor("#fce4ec"), HexColor("#c62828"), 1)
    c.setFillColor(HexColor("#880e4f"))
    c.setFont("Helvetica-Bold", 6.5)
    c.drawString(ex_x + 4, y_comp + comp_bh - 11, "IMPLIED CONSENT (Emergency):")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 6)
    exc_items = ["• Life/limb-threatening emergency", "• Patient unconscious/incapacitated",
                 "• No surrogate available", "→ Proceed without explicit consent"]
    for j, item in enumerate(exc_items):
        c.drawString(ex_x + 4, y_comp + comp_bh - 21 - j*7, item)

    c.setFillColor(HexColor("#555555"))
    c.setFont("Helvetica-Oblique", 5.5)
    c.drawCentredString(left + width/2, y_comp - 6,
                        "Ethical basis: Respect for patient autonomy | Surgeon (not nurse/resident) is responsible for consent")
    return y_comp - 12


def diagram_burn_management(c, left, top, width):
    """Initial burn management ATLS flow."""
    section_title(c, left, top + 2, "DIAGRAM: Initial Burn Management — ATLS Approach", color=HexColor("#4a148c"))

    bh = 18
    bw_full = width - 20
    bx = left + 10
    y = top - 8

    steps = [
        ("A — AIRWAY", "Inhalation injury? → Hoarseness/stridor → Immediate endotracheal intubation + high-flow O₂",
         HexColor("#e3f2fd"), HexColor("#1565c0")),
        ("B — BREATHING", "Circumferential chest burns → Escharotomy to allow chest expansion",
         HexColor("#f3e5f5"), HexColor("#6a1b9a")),
        ("C — CIRCULATION", "Major burns → Parkland formula → Ringer's Lactate IV → Target urine 0.5–1 mL/kg/hr",
         HexColor("#fce4ec"), HexColor("#c62828")),
        ("FIRST AID", "Cool with running water 20 min | Remove clothing/jewellery | NO ice, butter, or toothpaste",
         HexColor("#e8f5e9"), HexColor("#2e7d32")),
    ]

    for i, (title, sub, bg, bd) in enumerate(steps):
        rounded_rect(c, bx, y - bh, bw_full, bh, 3, bg, bd, 0.8)
        c.setFillColor(bd)
        c.setFont("Helvetica-Bold", 6.2)
        c.drawString(bx + 4, y - 8, title)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", 5.8)
        c.drawString(bx + 4, y - 16, sub)
        if i < len(steps) - 1:
            arrow_down(c, bx + bw_full/2, y - bh - 1, y - bh - 6, color=bd)
        y -= bh + 9

    return y - 4


def diagram_topical_agents(c, left, top, width):
    """Silver Sulfadiazine vs Mafenide Acetate."""
    section_title(c, left, top + 2, "DIAGRAM: Topical Burn Agents Comparison", color=HexColor("#880e4f"))

    bw2 = (width - 12) / 2
    bh2 = 60
    y_box = top - bh2 - 8

    # SSD
    rounded_rect(c, left, y_box, bw2, bh2, 5, HexColor("#e8eaf6"), HexColor("#3949ab"), 1)
    c.setFillColor(HexColor("#1a237e"))
    c.setFont("Helvetica-Bold", 7)
    c.drawCentredString(left + bw2/2, y_box + bh2 - 12, "Silver Sulfadiazine (SSD)")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 5.8)
    for j, line in enumerate([
        "• Most widely used topical agent",
        "• Partial + full-thickness burns",
        "✗ Contraindicated on FACE",
        "✗ Sulfa allergy, G6PD deficiency",
        "✗ Pregnancy at term",
        "⚠ Causes transient leukopenia (CBC)",
    ]):
        c.drawString(left + 5, y_box + bh2 - 22 - j*7, line)

    # Mafenide
    bx2 = left + bw2 + 12
    rounded_rect(c, bx2, y_box, bw2, bh2, 5, HexColor("#fff8e1"), HexColor("#f57f17"), 1)
    c.setFillColor(HexColor("#e65100"))
    c.setFont("Helvetica-Bold", 7)
    c.drawCentredString(bx2 + bw2/2, y_box + bh2 - 12, "Mafenide Acetate")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 5.8)
    for j, line in enumerate([
        "• Excellent tissue penetration",
        "• Deep wounds + ear/cartilage burns",
        "✓ Works on thick eschar",
        "✗ PAINFUL on application",
        "✗ Inhibits carbonic anhydrase",
        "  → Metabolic acidosis + hyperventilation",
    ]):
        c.drawString(bx2 + 5, y_box + bh2 - 22 - j*7, line)

    return y_box - 8


def diagram_neuropathic(c, left, top, width):
    """Neuropathic pain management flow."""
    section_title(c, left, top + 2, "DIAGRAM: Neuropathic Pain — Features & Management", color=HexColor("#4a148c"))

    bw2 = (width - 12) / 2
    bh2 = 48
    y_box = top - bh2 - 8

    # Features
    rounded_rect(c, left, y_box, bw2, bh2, 5, HexColor("#f3e5f5"), C_PURPLE, 1)
    c.setFillColor(C_PURPLE)
    c.setFont("Helvetica-Bold", 6.8)
    c.drawCentredString(left + bw2/2, y_box + bh2 - 12, "FEATURES")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 6)
    for j, line in enumerate([
        "• Burning / shooting pain",
        "• Tingling / electric shocks",
        "• Often opioid-RESISTANT",
        "Examples: tumour nerve invasion,",
        "  phantom limb, chemo neuropathy",
    ]):
        c.drawString(left + 5, y_box + bh2 - 22 - j*7.5, line)

    # Treatment
    bx2 = left + bw2 + 12
    rounded_rect(c, bx2, y_box, bw2, bh2, 5, HexColor("#e8f5e9"), HexColor("#2e7d32"), 1)
    c.setFillColor(HexColor("#1b5e20"))
    c.setFont("Helvetica-Bold", 6.8)
    c.drawCentredString(bx2 + bw2/2, y_box + bh2 - 12, "1st LINE TREATMENT")
    c.setFillColor(C_TEXT)
    c.setFont("Helvetica", 6)
    for j, line in enumerate([
        "• Pregabalin (Lyrica)",
        "• Gabapentin",
        "Mechanism: α2δ calcium channel",
        "  ligands → reduce nerve firing",
        "Add on top of standard analgesia",
    ]):
        c.drawString(bx2 + 5, y_box + bh2 - 22 - j*7.5, line)

    return y_box - 8


# ════════════════════════════════════════════════════════════════════════
#  EXPLANATIONS (same as v2)
# ════════════════════════════════════════════════════════════════════════
EXPLANATIONS = {
0:  "COVER PAGE — These are high-yield Block-N Surgery notes for KMU Final Year MBBS students, covering General Surgery, Plastic Surgery (Burns), and Surgical Foundation topics. Designed to help you revise the 15 MCQs that appear in the Block-N Surgery paper. Made by Zakria Marwat.",
1:  "TABLE OF CONTENTS — This document has three parts. Part I covers General Surgery foundation topics: patient safety, WHO checklist, incisions, wound healing, sutures, drains, diathermy, laparoscopic and robotic surgery, fluids, electrolytes, nutrition, and postoperative complications. Part II covers ERAS protocol and perioperative pain management with the WHO analgesic ladder. Part III covers Burns: classification by depth, TBSA calculation (Rule of Nines and Lund-Browder), Parkland formula for fluid resuscitation, escharotomy, topical agents, surgical management, and early/late complications.",
2:  "WHO SURGICAL SAFETY CHECKLIST — The WHO checklist is like a pilot's pre-flight check for surgeons. It has three phases. Sign In happens before the patient goes to sleep under anaesthesia — the team checks identity, site, and equipment. Time Out is the most critical step, performed just before the first skin cut — the whole team pauses and verbally confirms the patient's name, the procedure, and the surgical site. Sign Out happens before the patient leaves theatre — the team confirms the procedure was completed and no instruments are missing. Its main goal is improving communication between the surgical team. Another key safety rule: always check the patient's ID bracelet twice before giving any medication.",
3:  "INFORMED CONSENT — Consent means the patient agrees to the surgery after fully understanding it. The operating surgeon (not a nurse or junior doctor) is personally responsible for obtaining it. They must explain the diagnosis, nature of the procedure, risks, benefits, and alternatives. The ethical foundation is respect for patient autonomy — every competent adult can decide what happens to their body. One practical rule: if laparoscopic surgery might need to be converted to open surgery, the patient must be informed and must consent to both possibilities before entering theatre. Exception: implied consent in true emergencies when the patient is unconscious and no family member is available — life-saving surgery can proceed.",
4:  "SKIN INCISIONS AND LANGER'S LINES — Langer's Lines run along the natural orientation of collagen fibres in the skin. Cuts made along these lines heal with thin, neat scars because the skin is not being pulled apart by underlying muscle forces. Cuts made across these lines result in wide, raised, or ugly scars. Good incision planning means: providing safe access to the target organ, being extensible if needed, avoiding major nerves/vessels, and preferring muscle-splitting (separating fibres) over muscle-cutting (cutting across fibres) to preserve strength and reduce pain.",
5:  "ABDOMINAL INCISIONS — Surgeons have several standard ways to open the abdomen. Midline (linea alba): fastest, most flexible, highest hernia risk. Paramedian: lower hernia risk than midline; slower. Kocher's (subcostal): for gallbladder/liver; cuts through muscle so it is painful. Gridiron (McBurney's): for appendix; muscle-splitting so very low hernia risk. Lanz: transverse in right iliac fossa; better cosmesis than Gridiron. Pfannenstiel: curved above pubis for caesarean sections; cosmetically hidden and very strong closure. The choice depends on the urgency, organ being accessed, and patient factors.",
6:  "PATIENT POSITIONING — Rose's position involves hyperextending (bending back) the neck. It is specifically used during thyroidectomy to push the thyroid gland forward and give the surgeon excellent access to the front of the neck. Correct positioning is critical to prevent nerve injuries and pressure sores during long operations.",
7:  "WOUND HEALING — There are three types. Primary intention: clean wound, edges sutured together, heals quickly with minimal scarring. Secondary intention: wound left open (often because it is infected), heals slowly from inside out through granulation tissue formation. Tertiary intention (delayed primary closure): contaminated wound initially left open, dressed, then surgically closed days later once clean. By day 2, macrophages replace neutrophils as the dominant healing cells — they coordinate debridement and tissue remodelling. The most common factor preventing wound healing is local tissue infection.",
8:  "SUTURES, DRAINS, AND DIATHERMY — Vicryl (Polyglactin 910) is an absorbable suture that dissolves in 60–90 days via hydrolysis. The Vertical Mattress Suture provides excellent tension distribution and keeps wound edges everted — preferred for abdominal closure in obese patients. Redivac drains are removed after 24 hours or when output is minimal. Clavien-Dindo Grade III complication means the problem requires surgical/endoscopic/radiological intervention. Diathermy uses high-frequency electricity. Monopolar: current travels through the whole body — dangerous with pacemakers. Bipolar: current stays between the two forceps tips — safe with pacemakers.",
9:  "DIATHERMY AND IMAGING BASICS — Monopolar diathermy passes current through the patient's body to a grounding pad. It is contraindicated in patients with cardiac pacemakers, ICDs, or metallic implants. Bipolar diathermy flows only between the two tips of the instrument — safe for pacemaker patients. X-rays weaken (attenuate) as they pass through tissue of varying densities. CT scans deliver far more radiation than plain X-rays. Ultrasound is radiation-free: a piezoelectric crystal vibrates when electricity is applied, producing high-frequency sound waves that create images.",
10: "LAPAROSCOPY — PRINCIPLES — Laparoscopy is keyhole surgery through small ports. CO₂ gas inflates the abdomen to create working space (pneumoperitoneum). CO₂ is chosen because it is non-combustible (safe with diathermy) and dissolves rapidly in blood (minimises gas embolism risk). Maximum safe inflation pressure is 15 mmHg — higher pressure compresses the inferior vena cava and reduces cardiac output. Advantages: smaller wounds, less pain, shorter stay, faster recovery. Disadvantages: no tactile feedback, limited movement, steep learning curve.",
11: "LAPAROSCOPY — CONTRAINDICATIONS AND COMPLICATIONS — Absolute contraindication to elective laparoscopy: uncontrolled coagulopathy (bleeding disorder). Vagal bradycardia complication: rapid CO₂ inflation stretches the peritoneum, triggering the vagus nerve, which slows the heart suddenly — treatment is to deflate immediately and give IV atropine. If major bleeding cannot be controlled laparoscopically, immediate conversion to open surgery is mandatory. Robotic surgery adds 3D vision, tremor filtration, and 7 degrees of instrument freedom — most advanced minimally invasive option.",
12: "LAPAROSCOPY — KEY MCQ POINTS — WHO Checklist: improves communication. Time Out: between anaesthesia and incision. Langer's Lines: follow them for better scars. Midline: highest hernia risk. Rose's position: thyroidectomy. Vicryl: 60–90 days. Monopolar: avoid with pacemakers. Bipolar: safe with pacemakers. Absolute laparoscopy contraindication: coagulopathy. CO₂: non-combustible, blood-soluble. Max 15 mmHg. Bradycardia → desufflate + atropine. Robotic: most advanced.",
13: "SECTION 5 — INFORMED CONSENT (DETAILED) — Informed consent is a full communication process, not just a signature. The surgeon personally explains: diagnosis, procedure, benefits, risks, complications, alternatives, and must answer all questions. Ethically it respects patient autonomy. Practical MCQ point: a patient scheduled for laparoscopic cholecystectomy must also consent to possible open conversion before surgery.",
14: "CONSENT EXCEPTIONS AND MCQ SUMMARY — Implied consent applies only when: (1) surgery is immediately life/limb-saving, (2) patient is unconscious or incapacitated, AND (3) no surrogate decision-maker is present. It does NOT apply to elective procedures. The operating surgeon — not a nurse or junior — must always obtain consent. These three conditions must ALL be met simultaneously for implied consent.",
15: "TOP MCQ POINTERS — Sections 1–5 — Key facts: WHO checklist improves communication. Time Out is between anaesthesia and incision. Surgeon obtains consent. Informed consent respects autonomy. Langer's Lines give better scars. Midline incision has highest hernia risk. Rose's position for thyroidectomy. Primary/secondary/tertiary wound healing. Vicryl absorbs in 60–90 days. Vertical mattress for obese laparotomy closure. Day 2: macrophages dominate healing. Monopolar contraindicated with pacemakers. CO₂ for pneumoperitoneum at max 15 mmHg. Uncontrolled coagulopathy is absolute contraindication to laparoscopy. Implied consent in true emergencies only.",
16: "SECTION 6 — PERIOPERATIVE FLUIDS — ECF deficit is the most common perioperative fluid problem, caused by blood loss, gut losses, or pre-op fasting. Ringer's Lactate is the preferred resuscitation fluid — its composition is similar to extracellular fluid, its lactate converts to bicarbonate (corrects acidosis), and it causes less hyperchloraemia than Normal Saline. Normal Saline (0.9% NaCl) contains 154 mEq/L each of sodium and chloride. Given in large volumes it causes hyperchloraemic metabolic acidosis — excess chloride disturbs acid-base balance. Ringer's Lactate has potassium; Normal Saline has none.",
17: "ELECTROLYTE DISORDERS — Three common postoperative problems: (1) Normal anion gap metabolic acidosis from severe diarrhoea — bicarbonate-rich fluid lost, chloride retained. (2) Metabolic alkalosis from vomiting or NG suction — HCl lost, blood becomes alkaline, potassium and chloride depleted. (3) SIADH hyponatraemia — surgical stress causes excess ADH, kidneys retain water, sodium dilutes. Treatment for mild/stable SIADH: restrict free water intake — do not give more IV fluid. These electrolyte patterns are favourite MCQ topics.",
18: "HYPERKALEMIA — ECG CHANGES — High potassium (hyperkalaemia) can stop the heart. ECG changes progress in order: first, peaked tall T-waves appear; next, P-waves flatten or disappear; finally, QRS widens (slow ventricular conduction). This is a medical emergency. First treatment: IV 10% Calcium Gluconate — this stabilises the cardiac membrane and protects the heart from arrhythmia. Critically, calcium gluconate does NOT lower the potassium level — it just protects the heart while other measures (insulin-dextrose, salbutamol, Calcium Resonium, dialysis) work to actually remove excess potassium.",
19: "MCQ SUMMARY — FLUIDS AND ELECTROLYTES — Key facts: ECF deficit is the most common perioperative fluid problem. Ringer's Lactate preferred for hemorrhagic shock, burns, and severe dehydration. Normal Saline contains 154 mEq/L Na⁺ and Cl⁻; no potassium. Large NS volumes cause hyperchloraemic metabolic acidosis. RL has potassium; NS does not. Diarrhoea causes normal anion gap acidosis. Vomiting/NG suction causes metabolic alkalosis. SIADH treated with fluid restriction. IV Calcium Gluconate stabilises the heart in hyperkalaemia but does not lower K⁺.",
20: "SECTION 7 — NUTRITIONAL SUPPORT — Enteral nutrition (feeding through the gut) is always preferred because it preserves gut mucosal integrity and prevents intestinal atrophy. Feeding jejunostomy is preferred when the oesophagus is blocked (e.g., corrosive burns, obstructing cancer) because an NG tube could perforate the damaged oesophagus. Enteral feeding is contraindicated in active severe GI bleeding and high-output proximal fistulas. TPN (Total Parenteral Nutrition) delivers all nutrients into a central vein when the gut cannot be used — for short bowel syndrome, high-output fistula, or non-functional bowel.",
21: "TPN — COMPOSITION, MONITORING, COMPLICATIONS — TPN composition: 70% dextrose (energy), 10% amino acids (protein), 20% lipid emulsion (essential fatty acids). Absolute contraindication: active systemic infection (sepsis) — bacteria can colonise the central line. Daily monitoring: CBC, serum urea, electrolytes. Major complication of central line insertion: pneumothorax (collapsed lung) — presents with sudden dyspnoea and chest pain after insertion. Refeeding syndrome: dangerous metabolic complication in malnourished patients fed too rapidly — causes hypophosphataemia, hypokalaemia, and hypomagnesaemia.",
22: "MCQ SUMMARY — NUTRITION — Key facts: Enteral preferred over parenteral (preserves gut). Feeding jejunostomy for oesophageal obstruction/burns. GI bleeding = contraindication to enteral feeding. TPN for non-functional gut. Active sepsis = absolute TPN contraindication. Monitor CBC, urea, electrolytes daily during TPN. Pneumothorax after central line — confirm with CXR. Refeeding syndrome: hypophosphataemia + hypokalaemia + hypomagnesaemia in malnourished patients.",
23: "SECTION 8 — POSTOPERATIVE CARE — Functional status (METs) is the best predictor of perioperative outcome in elderly patients — those who can do moderate daily activities have lower risk. ERAS (Enhanced Recovery After Surgery) is a care bundle that speeds recovery: minimal fasting (clear fluids up to 2 hours pre-op), early oral feeding, early mobilisation, avoid routine NG tubes/drains/catheters. The most reliable sign the bowel has returned to function after abdominal surgery is passage of flatus.",
24: "POSTOPERATIVE COMPLICATIONS PART 1 — Early fever (first 24h): most common cause is atelectasis (partial lung collapse under anaesthesia). SSI prevention: antibiotics within 1 hour of incision, hair clipping not shaving, early catheter removal, normothermia. Wound abscess: pain, erythema, fluctuance, pus — treatment is incision and drainage. Necrotising fasciitis: rapidly spreading deep infection with high fever, purple skin, bullae — caused by Group A Streptococcus or mixed organisms — surgical emergency. Paralytic ileus: temporary bowel paralysis after surgery — managed with NPO, NG decompression, IV fluids, electrolyte correction.",
25: "POSTOPERATIVE COMPLICATIONS PART 2 — MI within 6 months is the strongest predictor of postoperative cardiac complications. Chronic hepatitis C without coagulopathy is NOT a contraindication to elective surgery. Hold oral hypoglycaemic drugs on the day of major surgery while the patient is fasting. Reactionary haemorrhage: occurs within 24 hours, classically 4–6 hours post-surgery, when rising blood pressure dislodges a ligature or clot. Diagnosis: bedside FAST ultrasound scan.",
26: "POSTOPERATIVE COMPLICATIONS PART 3 — Perioperative anticoagulation: low-risk patients — stop warfarin, restart after surgery, no bridging needed. High-risk patients (metallic valves, recent DVT) — stop warfarin, bridge with LMWH injections. Acute haemolytic transfusion reaction: most commonly caused by clerical/identification error (wrong blood given to wrong patient). Heparin reversal: specific antidote is IV Protamine Sulfate. Neurogenic shock: spinal cord injury causes hypotension WITH bradycardia (sympathetic tone lost). Non-oliguric AKI: kidneys damaged but still produce >1500 mL/day of dilute urine.",
27: "MCQ SUMMARY — POSTOPERATIVE CARE — Functional status predicts outcome. ERAS: early mobilisation, early oral feeding, minimal fasting. Passage of flatus = bowel function returned. First 24h fever = atelectasis. SSI prevention = antibiotics within 1 hour. Wound abscess = incision and drainage. Necrotising fasciitis = Group A Streptococcus. Ileus = NPO + NG decompression. MI within 6 months = highest cardiac risk. Hold oral hypoglycaemics on surgery day. Reactionary haemorrhage at 4–6 hours → FAST scan. High-risk warfarin = LMWH bridging. Transfusion reaction = clerical error. Protamine reverses heparin. Neurogenic shock = hypotension + bradycardia.",
28: "SECTION 9 — ERAS PROTOCOL — Enhanced Recovery After Surgery (ERAS) is an evidence-based bundle of care interventions across three phases. Preoperative: solids allowed up to 6 hours before surgery; clear fluids up to 2 hours; carbohydrate-loading drinks reduce postoperative insulin resistance and patient hunger; correct anaemia and optimise diabetes before surgery. Intraoperative: prefer laparoscopic/robotic surgery; goal-directed fluid therapy (not too much, not too little); opioid-sparing multimodal analgesia with regional nerve blocks. Postoperative: early oral feeding, early mobilisation, avoid NG tubes/drains/catheters — all these together reduce complications and shorten hospital stay.",
29: "ERAS INTRAOPERATIVE AND POSTOPERATIVE — Goal-directed fluid therapy means giving precise amounts of IV fluid guided by cardiac output monitoring — neither restricting too much (causing poor organ perfusion) nor overloading (causing oedema). Multimodal opioid-sparing analgesia combines regional nerve blocks with paracetamol and NSAIDs, reducing opioid side effects like ileus and sedation. Postoperative ERAS principles: resume oral diet within 24 hours after most surgeries, mobilise the patient the same day or next day, and avoid inserting routine NG tubes, catheters, or surgical drains unless specifically indicated.",
30: "SECTION 10 — POSTOPERATIVE PAIN PHYSIOLOGY — Uncontrolled pain activates the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system, releasing catecholamines (adrenaline, noradrenaline) and cortisol. Effects: Cardiovascular — hypertension, tachycardia, increased myocardial oxygen demand, risk of heart attack. Respiratory — shallow breathing, poor cough, atelectasis, hypoxaemia, secondary pneumonia. Gastrointestinal — reduced gut motility, prolonged ileus. Metabolic — hyperglycaemia, lipolysis, catabolic wasting state. This shows why pain control is not just about comfort — it directly prevents serious postoperative complications.",
31: "WHO ANALGESIC LADDER — Step 1 (mild pain): Paracetamol + NSAIDs. Step 2 (moderate pain): add Tramadol. Tramadol is a weak μ-opioid receptor agonist that also inhibits serotonin and norepinephrine reuptake — dual mechanism. Step 3 (severe pain): strong opioids like Morphine, for severe acute pain such as metastatic bone pain. Modern analgesia is multimodal: combine drugs from different steps to achieve better control with lower doses of each drug, reducing side effects. Always use the lowest effective step first.",
32: "NEUROPATHIC PAIN — Burning, shooting, electric-shock, tingling pain caused by nerve damage itself rather than tissue injury. Causes: tumour invading nerve, phantom limb post-amputation, chemotherapy neuropathy, diabetic nerve damage. Key characteristic: resistant to standard opioids and NSAIDs. First-line adjuvant treatment: Pregabalin or Gabapentin — these are alpha-2-delta calcium channel ligands that reduce abnormal neuronal firing. Add them on top of standard analgesics. Also: Methotrexate causes painful oral ulcers (mucositis) by blocking folate. Management: increase folic acid supplementation, continue methotrexate if blood tests are normal.",
33: "MCQ SUMMARY — ERAS AND PAIN MANAGEMENT — ERAS goal: reduce surgical stress, speed recovery, shorten stay. Cornerstones: early mobilisation + early oral feeding. Carbohydrate loading: clear drinks up to 2 hours pre-op reduce insulin resistance. Prolonged fasting (>6h) should be avoided. Postoperative pain activates HPA axis (catecholamines + cortisol). WHO Step 3 severe pain: Morphine. Tramadol: weak opioid + serotonin/norepinephrine reuptake inhibitor. Neuropathic pain: opioid-resistant; treated with Pregabalin/Gabapentin. Methotrexate mucositis: increase folic acid.",
34: "SECTION 11 — BURNS CLASSIFICATION — Burns are graded by depth of skin destruction. First-degree: epidermis only; red, painful, no blisters (like sunburn). Second-degree: epidermis + dermis; blisters, moist, VERY painful because nerve endings intact. Deep second-degree: into reticular dermis; less sensation, high risk of hypertrophic scarring. Third-degree: full destruction of epidermis + entire dermis, may reach muscle/bone; dry, leathery, white or charred, completely PAINLESS because all nerve endings destroyed. Burn depth may take 3–5 days to fully declare itself as the zone of stasis can progress to necrosis.",
35: "BURNS — DEPTH AND ZONE OF STASIS — The zone of stasis surrounds the dead central area of a burn. It has damaged blood flow but is not yet irreversibly dead. Without proper resuscitation, it converts to full necrosis and the burn deepens. This is why aggressive early resuscitation and avoiding infection are critical. Burn depth assessment requires 3–5 days for accuracy. Deep partial-thickness burns healing beyond 3–4 weeks have a high risk of hypertrophic (raised, thick) scarring and require surgical management.",
36: "SECTION 12 — TBSA CALCULATION — TBSA (Total Body Surface Area burned) determines fluid requirements and prognosis. For children: use Lund and Browder Chart — adjusts percentages for age-related body proportions (a child's head is proportionally larger). For adults: use Wallace Rule of Nines — Head and neck 9%; each upper limb 9%; anterior trunk 18%; posterior trunk 18%; each lower limb 18%; perineum 1%; total = 100%. Only second- and third-degree burns are counted in TBSA. First-degree burns (like sunburn) are excluded from fluid calculations.",
37: "PARKLAND FORMULA — Total fluid for first 24 hours = 4 mL × weight (kg) × %TBSA. Only 2nd and 3rd degree burns counted. Fluid of choice: Ringer's Lactate. Give 50% in first 8 hours and 50% over next 16 hours. The 8-hour clock starts from the time of injury, not hospital arrival. Example: 30 kg child, 30% burns → 4×30×30 = 3,600 mL; first 8h = 1,800 mL. Example: 80 kg adult, 50% burns → 4×80×50 = 16,000 mL; first 8h = 8,000 mL = 1,000 mL/hr. Monitor with hourly urine output: Adults 0.5–1 mL/kg/hr; Children 1–2 mL/kg/hr.",
38: "RESUSCITATION MONITORING — The gold standard for monitoring burn resuscitation adequacy is hourly urine output. Target: Adults 0.5–1 mL/kg/hr; Children 1–2 mL/kg/hr; high-voltage electrical burns 1–1.5 mL/kg/hr (to flush myoglobin). If urine output drops (oliguria), increase Ringer's Lactate infusion rate. Do NOT give diuretics to treat oliguria during burn resuscitation — diuretics mask the problem and worsen hypovolaemia. Oliguria almost always means the patient is under-resuscitated.",
39: "SECTION 13 — INITIAL BURN MANAGEMENT — Immediate first aid: Cool burn with cool running water for 20 minutes (not ice, not cold water — these cause frostbite; not butter or toothpaste — these trap heat and cause infection). Remove clothing and jewellery before swelling starts. Never peel away melted/adherent clothing. Give tetanus toxoid to all partial- and full-thickness burn patients if not up to date. In hospital: follow ATLS — Airway first, then Breathing, then Circulation. Assess the airway BEFORE evaluating burn size. Signs of inhalation injury: hoarseness, stridor, wheezing → immediate intubation.",
40: "INHALATION INJURY AND ESCHAROTOMY — Inhalation injury from enclosed fires is the worst prognostic factor in burns — it greatly increases mortality. Signs (hoarseness, stridor, wheezing, dyspnoea) demand immediate endotracheal intubation + high-flow oxygen before airway oedema closes the airway. Escharotomy: circumferential third-degree burns create inelastic dead skin (eschar) that acts like a tourniquet as underlying tissues swell. Surgical release (escharotomy) cuts through the eschar along medial and lateral borders of the limb. No anaesthesia needed — third-degree burns have no nerve endings in the eschar. Similarly, chest wall circumferential burns restrict breathing and need escharotomy.",
41: "TOPICAL BURN AGENTS — Dead eschar has no blood supply so systemic antibiotics cannot reach it — topical agents applied directly to the wound are used. Silver Sulfadiazine (SSD/Flamazine): most widely used; partial and full-thickness burns; transient leukopenia (monitor CBC); contraindicated on face, in sulfa allergy, G6PD deficiency, pregnancy at term. Mafenide Acetate: superior tissue penetration; used for deep wounds and ear/cartilage burns; painful on application; inhibits carbonic anhydrase → metabolic acidosis and compensatory hyperventilation.",
42: "LONG-TERM SURGICAL MANAGEMENT — Burns not healing within 3 weeks need surgery: (1) Tangential excision — shave off dead tissue layer by layer until healthy bleeding tissue appears. (2) Split-thickness skin grafting — harvest thin healthy skin from donor site using a dermatome and apply it over the excised wound. Benefits: prevents infection, minimises hypertrophic scarring, prevents contractures, speeds wound closure. Physiotherapy starts early: active joint exercises, correct positioning, and pressure garments (worn continuously for months) to prevent contractures and hypertrophic scarring.",
43: "SECTION 14 — EARLY COMPLICATIONS — Inhalation injury: single most important negative prognostic factor in burns; causes respiratory failure and increases mortality. Burn shock: major burns trigger massive systemic inflammation → capillary permeability increases → plasma leaks into tissues → hypovolaemia → burn shock. This is why Parkland formula fluids are critical in the first 24 hours. High-voltage electrical burns (>1,000 Volts): extensive muscle necrosis → massive myoglobin release into blood → myoglobin blocks kidney tubules → myoglobinuric AKI. Urine appears dark red/brown. Treatment: aggressive fluids to maintain urine output 1–1.5 mL/kg/hr.",
44: "LATE COMPLICATIONS — Hypertrophic scarring: thick, raised, red, itchy scar that stays within the wound margins — common after deep partial-thickness burns healing beyond 3–4 weeks. Prevention: pressure garments, silicone sheets, physiotherapy. Different from keloid scars, which grow beyond the original wound margins. Post-burn contractures: scar tissue contracts as it matures, pulling joints into fixed, bent positions — reduces joint movement and causes permanent deformity. Prevention: early physiotherapy, splinting (keeping joints in extension), pressure garments. Treatment when established: surgical contracture release + skin grafting.",
45: "MCQ SUMMARY — BURNS PART 1 — Lund and Browder: children (age-adjusted proportions). Rule of Nines: adults. Hourly urine output: gold standard for resuscitation. Ringer's Lactate: fluid of choice. ATLS ABC first, then assess burns. Third-degree: dry, leathery, painless, white or charred. Second-degree: painful, fluid-filled blisters. Inhalation injury: immediate intubation + O₂. Burn depth: assess at 3–5 days. Inhalation injury: worst prognostic factor. Oliguria during resuscitation: increase crystalloid, NOT diuretics. High-voltage: >1,000V; causes myoglobinuria and AKI.",
46: "MCQ SUMMARY — BURNS PART 2 — Parkland formula: 4 × kg × %TBSA; 50% in first 8h (from time of injury). SSD: most common topical agent; avoid on face; avoid in sulfa allergy. Mafenide: better penetration; painful; causes metabolic acidosis. Escharotomy: no anaesthesia needed (third-degree burns are insensate). Fasciotomy: needed if deep compartment pressure >30 mmHg after escharotomy, or high-voltage electrical burns. Non-healing deep burns at 3 weeks: tangential excision + split-thickness skin grafting. Physiotherapy and pressure garments prevent contractures. Post-burn contractures: surgical release + skin grafting.",
47: "BURNS — FINAL MCQ REVIEW — Hypertrophic scar stays within wound borders; keloid extends beyond. Both are prevented with pressure garments and physiotherapy. Burn shock results from massive plasma leakage through inflamed, leaky capillaries — not haemorrhage. Electrical burns >1,000V cause rhabdomyolysis → myoglobin in urine (myoglobinuria) → AKI. Treat with high-volume IV fluids and high target urine output. The goal of split-thickness skin grafting after tangential excision is to close the wound permanently, reduce infection risk, minimise scarring, and prevent contractures. Early physiotherapy is as important as surgery.",
48: "COMPREHENSIVE BURNS SUMMARY — Distinguishing features: First-degree (epidermis only) = painful, red, no blisters — excluded from Parkland calculations. Second-degree (partial-thickness) = most painful; fluid-filled blisters — INCLUDED in Parkland. Third-degree (full-thickness) = painless, leathery, charred — INCLUDED. Escharotomy ≠ Fasciotomy — escharotomy cuts through the dead skin layer; fasciotomy cuts through the muscle compartment fascia. Inhalation injury is more lethal than the visible burn area in many cases. Initial first aid is always cool running water for 20 minutes. After 3 weeks of non-healing: surgery is the answer. All high-yield for KMU MCQ exams.",
49: "END OF DOCUMENT — FINAL REVIEW — This completes the Block N Surgery high-yield notes by Zakria Marwat. The document comprehensively covers: WHO checklist, informed consent, skin incisions, wound healing, diathermy, laparoscopic and robotic surgery, perioperative fluids and electrolytes, nutritional support, postoperative care and complications, ERAS protocol, perioperative pain management with the WHO analgesic ladder, and complete burns management including classification, TBSA calculation, Parkland formula, escharotomy, topical agents, skin grafting, and early/late complications. These notes target all 15 KMU Block-N Surgery MCQs. Best of luck in your exams!",
}

# ════════════════════════════════════════════════════════════════════════
#  DIAGRAM ASSIGNMENT: page_index -> (function, y_start_from_top_of_page)
#  y_start is in pdfplumber coords (top from page top);
#  convert to reportlab: rl_y = PAGE_H - pdfplumber_top
# ════════════════════════════════════════════════════════════════════════

# After examining free space, we place diagrams starting at these RL y-coords
# (well below the existing page content and above the explanation box)
DIAGRAMS = {
    # page_index: (function, rl_top_y, left_margin, width)
    2:  (diagram_who_checklist,     170, 30, 535),   # WHO Checklist — 162pt free
    3:  (diagram_consent,           130, 30, 535),   # Consent
    7:  (diagram_wound_healing,     115, 30, 535),   # Wound Healing — 94pt free
    9:  (diagram_diathermy,         170, 30, 535),   # Diathermy
    10: (diagram_laparoscopy,       335, 30, 535),   # Laparoscopy — 321pt free
    11: (diagram_laparoscopy,       165, 30, 535),   # Laparoscopy continued
    16: (diagram_fluid_types,       335, 30, 535),   # Fluid types — 321pt free
    17: (diagram_fluid_types,       145, 30, 535),   # Electrolytes
    18: (diagram_hyperkalemia,      130, 30, 535),   # Hyperkalemia
    28: (diagram_eras,              140, 30, 535),   # ERAS
    29: (diagram_eras,              140, 30, 535),   # ERAS continued
    30: (diagram_analgesic_ladder,  255, 30, 535),   # Analgesic Ladder — 253pt free
    31: (diagram_analgesic_ladder,  135, 30, 535),   # Neuropathic pain
    32: (diagram_neuropathic,       130, 30, 535),   # Neuropathic
    34: (diagram_burns_classification, 110, 28, 539), # Burns classification — ample space
    35: (diagram_burns_classification, 105, 28, 539), # Burns depth
    37: (diagram_parkland,          135, 30, 535),   # Parkland formula
    39: (diagram_burn_management,   120, 30, 535),   # Burn management ATLS
    40: (diagram_burn_management,   115, 30, 535),   # Inhalation/escharotomy
    41: (diagram_topical_agents,    120, 30, 535),   # Topical agents
    5:  (diagram_incisions,         115, 30, 535),   # Incisions table
}


# ════════════════════════════════════════════════════════════════════════
#  OVERLAY BUILDER
# ════════════════════════════════════════════════════════════════════════

def make_overlay(page_index, page_width, page_height):
    packet = io.BytesIO()
    c = canvas.Canvas(packet, pagesize=(page_width, page_height))

    # 1. Cover page Haroon fix
    if page_index == 0:
        c.setFillColor(C_WHITE)
        c.setStrokeColor(C_WHITE)
        c.rect(0, 0, page_width, 40, fill=1, stroke=0)
        c.setFillColor(HexColor("#1a1a2e"))
        c.setFont("Helvetica-Bold", 10)
        c.drawCentredString(page_width / 2, 14, "Made by Zakria Marwat")

    # 2. Replace "Made by Haroon" footer on content pages
    if page_index > 0:
        text_y_rl = page_height - 823.5
        c.setFillColor(C_WHITE)
        c.setStrokeColor(C_WHITE)
        c.rect(255, text_y_rl - 1, 145, 12, fill=1, stroke=0)
        c.setFillColor(colors.black)
        c.setFont("Helvetica", 6.75)
        c.drawString(263, text_y_rl + 1.5, "Made by Zakria Marwat")

    # 3. Draw diagram if assigned to this page
    if page_index in DIAGRAMS:
        fn, rl_top, left, width = DIAGRAMS[page_index]
        fn(c, left, rl_top, width)

    # 4. Explanation box
    explanation = EXPLANATIONS.get(page_index, "")
    if explanation:
        box_margin = 30
        box_width = page_width - 2 * box_margin
        fs, lh, pad = 6.3, 8.2, 5

        c.setFont("Helvetica", fs)
        words = explanation.split()
        lines = []
        cur = []
        for w in words:
            test = ' '.join(cur + [w])
            if c.stringWidth(test, "Helvetica", fs) <= box_width - 2*pad:
                cur.append(w)
            else:
                if cur: lines.append(' '.join(cur))
                cur = [w]
        if cur: lines.append(' '.join(cur))

        total_lines = 1 + len(lines)  # header + body
        box_h = total_lines * lh + 2*pad + lh
        box_bottom = 32

        rounded_rect(c, box_margin, box_bottom, box_width, box_h, 4, C_BLUE_BG, C_BLUE_BRD, 0.8)
        ty = box_bottom + box_h - pad - lh
        c.setFillColor(C_BLUE_HDR)
        c.setFont("Helvetica-Bold", 6.5)
        c.drawString(box_margin + pad, ty, "PLAIN-ENGLISH EXPLANATION:")
        ty -= (lh + 1)
        c.setFillColor(C_TEXT)
        c.setFont("Helvetica", fs)
        for line in lines:
            if ty < box_bottom + pad: break
            c.drawString(box_margin + pad, ty, line)
            ty -= lh

    c.save()
    packet.seek(0)
    return packet


# ════════════════════════════════════════════════════════════════════════
#  MAIN
# ════════════════════════════════════════════════════════════════════════

def main():
    import os
    os.makedirs("/tmp/workspace/pdf_edit", exist_ok=True)
    reader = PdfReader(INPUT_PDF)
    writer = PdfWriter()
    total = len(reader.pages)
    print(f"Processing {total} pages...")

    for i, page in enumerate(reader.pages):
        mb = page.mediabox
        pw, ph = float(mb.width), float(mb.height)
        ovl = make_overlay(i, pw, ph)
        ovl_reader = PdfReader(ovl)
        page.merge_page(ovl_reader.pages[0])
        writer.add_page(page)
        if (i+1) % 10 == 0:
            print(f"  {i+1}/{total}")

    with open(OUTPUT_PDF, "wb") as f:
        writer.write(f)
    size = os.path.getsize(OUTPUT_PDF)
    print(f"\nDone! {OUTPUT_PDF}  ({size/1024:.0f} KB)")


if __name__ == "__main__":
    main()