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BDS 3rd Year - General Surgery: Complete Exam Guide

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LONG QUESTIONS

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1. Fistula in Ano

Etiology

• Cryptoglandular (most common ~90%): Infection of the anal glands (located at the dentate line) spreads through the intersphincteric plane
• Specific infections: Tuberculosis, Crohn's disease, actinomycosis
• Trauma: Foreign bodies, injury
• Malignancy: Carcinoma of rectum/anal canal
• Radiation: Post-radiotherapy fistulas
• Obstetric injury

Classification (Parks Classification - Most Important)

Management

1. Fistulotomy (Lay-open): Opening the entire fistula tract - for low, simple intersphincteric fistulas; most common procedure
2. Fistulectomy: Complete excision of the tract (higher risk of incontinence if high fistula)
3. Seton placement:
   • Cutting seton: Gradually tightens, cuts through sphincter slowly (fibrous reaction forms around it)
   • Draining seton: Controls sepsis while awaiting definitive surgery
4. Advancement flap: Mucosal or anodermal flap to cover internal opening - for high complex fistulas
5. LIFT procedure (Ligation of Intersphincteric Fistula Tract): Sphincter-preserving; ligates and divides the tract at the intersphincteric plane
6. Fibrin glue/collagen plug: Minimally invasive; lower success rates

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2. Hypovolemic Shock (Most Asked)

Definition

Etiology

• Hemorrhagic: Trauma, GI bleed, ruptured aortic aneurysm, ectopic pregnancy
• Non-hemorrhagic: Burns (plasma loss), severe diarrhea/vomiting, diabetic ketoacidosis (dehydration), peritonitis (third-spacing)

Pathophysiology

• Sympathetic activation: tachycardia, vasoconstriction
• RAAS activation: sodium and water retention
• ADH release: water retention
• If not corrected: cellular ischemia → SIRS → MODS → death

Classification/Stages of Shock (ATLS - 4 Classes)

Exam tip: Class I and II - BP maintained (compensated shock). Class III onward - BP falls (decompensated).

Management

1. Airway + Oxygen
2. Two large-bore IV lines (14-16G in antecubital fossae)
3. IV fluid resuscitation: 2 liters Ringer's Lactate bolus (or Normal Saline)
4. Blood transfusion if inadequate response (for hemorrhagic shock)
5. Identify and control source of hemorrhage (pressure, tourniquet, surgical control)
6. Monitor: HR, BP, urine output (target >0.5 mL/kg/hr), CVP
7. Vasopressors (dopamine, norepinephrine) only if volume is adequate but BP remains low

• Rapid responder: Responds to initial bolus and stays stable - blood loss <20%
• Transient responder: Responds initially but deteriorates - ongoing bleeding
• Non-responder: No response - massive ongoing hemorrhage, needs emergency surgery

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3. Fluid Therapy in Burns (Parkland Formula)

Initial Assessment

Parkland Formula (Most Important)

• Fluid used: Ringer's Lactate (Hartmann's solution)
• First 8 hours: Give HALF of total calculated volume (time calculated from time of burn, NOT time of arrival)
• Next 16 hours: Give remaining HALF

• Total = 4 × 70 × 30 = 8,400 mL in first 24 hours
• First 8 hours: 4,200 mL
• Next 16 hours: 4,200 mL

Modified Brooke Formula

Monitoring Adequacy

• Urine output: 0.5-1 mL/kg/hr in adults (best indicator); 1 mL/kg/hr in children
• Inhalation injury: Add 30-50% to calculated volume
• Electrical burns: Target urine output 1-1.5 mL/kg/hr (myoglobinuria risk)

Important Points

• Burns <15% TBSA (adult) or <10% (child) - may manage with oral fluids
• Don't count 1st degree (superficial/epidermal) burns
• Fluid overload risk: Abdominal compartment syndrome, pulmonary edema

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4. Mandibular Fractures: Classification + Management

Classification

1. Symphysis/Parasymphysis - midline and 1 cm lateral
2. Body - between canine and angle
3. Angle - at the gonial angle (third molar region) - most common
4. Ramus - vertical part
5. Condyle - most common in children; subcondylar most frequent
6. Coronoid process - rare
7. Alveolar process

• Simple (closed), Compound (open into oral cavity), Comminuted, Pathological, Greenstick (children)

• Favorable: Muscle pull tends to reduce/maintain the fracture
• Unfavorable: Muscle pull tends to displace the fracture

Clinical Features

• Pain, swelling, trismus
• Malocclusion (most reliable sign)
• Step deformity at fracture site
• Anesthesia/paresthesia of lower lip (inferior alveolar nerve injury)
• Intraoral laceration, hematoma in floor of mouth
• Abnormal mobility of fragments

Management

1. Resuscitation - airway, hemorrhage control
2. Reduction - restore normal anatomy
3. Retention (fixation) - maintain reduction
4. Rehabilitation

• Arch bars + wiring (Erich arch bar system)
• Used for: Simple, minimally displaced fractures, condylar fractures (especially in children)
• Duration: 4-6 weeks
• Disadvantage: Patient cannot eat normally; airway concerns

• Plates and screws (miniplates - Champy's technique)
• Indications: Displaced fractures, comminuted, failed closed reduction, bilateral fractures, edentulous patients, condylar fractures with significant displacement
• Approach: Intraoral or extraoral (submandibular incision for angle/body)
• Champy's lines of osteosynthesis: Single miniplate along the oblique line for angle fractures; two miniplates at symphysis

• Rarely used; for highly comminuted or infected fractures

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Principles of Fracture Healing

Primary (Direct) Healing

• Requires rigid fixation with compression plates
• Direct bone formation without callus
• Cutting cones (osteoclasts) traverse the fracture line, followed by osteoblasts

Secondary (Indirect) Healing - More common

1. Hematoma formation (0-48 hrs): Bleeding fills fracture gap; fibrin clot forms; inflammatory mediators released
2. Inflammatory phase (days 1-5): Granulation tissue replaces clot; macrophages, neutrophils; vasodilation
3. Soft callus stage (weeks 1-3): Fibroblasts and chondroblasts produce fibrocartilaginous callus; bridging between fragments
4. Hard callus stage (weeks 3-12): Cartilage calcifies and ossifies; woven bone replaces fibrocartilage
5. Remodeling (months to years): Woven bone replaced by lamellar bone; medullary canal restored; follows Wolff's law

Factors Affecting Healing

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5. Oral Cancer: Etiology, Clinical Features, Staging, Management

Etiology

• Tobacco (smoking + smokeless/chewing) - most important
• Alcohol (synergistic with tobacco - 15x risk)
• Betel nut (areca nut) chewing - particularly relevant in India/South Asia
• HPV 16 and 18 (oropharyngeal cancers, especially tonsillar/base of tongue)
• Chronic irritation: Ill-fitting dentures, jagged teeth
• Poor oral hygiene
• Sunlight (lip cancer)
• Nutritional deficiency: Iron deficiency (Plummer-Vinson syndrome predisposes), Vitamins A/C/E
• Pre-existing precancerous lesions (leukoplakia, erythroplakia, OSMF)
• Immune suppression

Histology

• Squamous cell carcinoma (SCC) - 95% of oral cancers
• Other: Adenocarcinoma (salivary glands), mucoepidermoid carcinoma, verrucous carcinoma

Clinical Features

• Non-healing ulcer (>2 weeks) - most important warning sign
• White or red patch that cannot be scraped off
• Painless initially; pain is a late feature

• Irregular, indurated (hard) ulcer with everted/raised edges
• Restricted mouth opening (trismus) - involvement of masticatory muscles
• Referred otalgia (ear pain via auriculotemporal nerve)
• Cervical lymphadenopathy (hard, fixed nodes)
• Loose teeth, altered speech, dysphagia
• Bleeding from lesion

Staging (TNM + AJCC)

• Stage I: T1N0M0
• Stage II: T2N0M0
• Stage III: T3N0 or T1-3N1
• Stage IV: T4 or N2-3 or M1

Management

• Wide local excision with 1-1.5 cm margins
• Neck dissection: Radical, modified radical, or selective (for N+ or N0 with >20% occult node risk)
• Reconstruction: Primary closure, local flaps, regional flaps (pectoralis major), free flaps (radial forearm, fibula for jaw)

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6. Precancerous Lesions

Leukoplakia

• Homogeneous: Uniform white, flat, well-defined - lowest malignant potential (~5%)
• Non-homogeneous:
  • Nodular (speckled): Mixed white and red patches
  • Verrucous: Thick, warty surface
  • Erythroleukoplakia: Red and white mixed - highest malignant potential (~40%)

• Hyperkeratosis without dysplasia
• Mild, moderate, severe dysplasia (carcinoma in situ)
• SCC

• Remove causative agent (stop tobacco/alcohol)
• Biopsy mandatory
• Small lesions: Surgical excision
• Larger: Laser ablation (CO2 laser), cryotherapy
• Vitamin A analogues (retinoids) - medical management
• Regular follow-up

Oral Submucous Fibrosis (OSMF)

• Areca nut (betel nut) chewing - primary cause
• Arecoline (alkaloid in areca nut) stimulates fibroblasts, increases collagen production, inhibits collagenase
• Genetic predisposition (HLA associations)
• Nutritional deficiency (iron, B vitamins)
• Autoimmune component (antinuclear antibodies)

• Burning sensation in mouth (early) - especially with spicy food
• Blanching and stiffness of oral mucosa
• Trismus (restricted mouth opening) - hallmark symptom; fibrotic bands palpable in buccal mucosa
• Palpable fibrous bands
• Depapillation of tongue
• Uvula may become small and pale

• Cessation of areca nut/betel quid chewing - essential
• Medical:
  • Corticosteroid injections (intralesional triamcinolone) - reduces inflammation
  • Hyaluronidase injections
  • Lycopene, beta-carotene (antioxidants)
  • Vitamins A, C, E, B complex
  • Iron supplements
  • Pentoxifylline (vasodilator, reduces fibrosis)
• Surgical (for severe trismus):
  • Release of fibrous bands + split-thickness skin graft
  • Buccal fat pad grafting
  • Nasolabial flap
• Physiotherapy (mouth exercises after surgery)

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7. Approach to a Swelling (Clinical Examination)

Inspection

Palpation

1. Temperature: Warm (inflammatory/vascular), cold (ischemia)
2. Tenderness: Presence, degree, site
3. Size: More precise measurement
4. Surface: Smooth or irregular; lobulated
5. Edge/Border: Well-defined (cyst, lipoma) vs. ill-defined (infiltrating carcinoma)
6. Consistency:
   • Soft (lipoma, abscess)
   • Firm (fibroma, lymph node)
   • Hard (bone, calcified)
   • Fluctuant (fluid-filled - cyst, abscess)
   • Rubbery (lymphoma)
   • Stony hard (malignancy, calcified)
7. Reducibility: Can the swelling be reduced (hernia, varicocele)?
8. Compressibility: Blood/lymph can be compressed temporarily (hemangioma, lymphangioma)
9. Pulsatility:
   • Transmitted pulsations (overlying an artery)
   • Expansile pulsations (aneurysm - pushes fingers apart in two planes)
10. Transillumination: Fluid-filled, thin-walled cysts transilluminate (e.g., hydrocele, lymphangioma)
11. Plane of swelling: Skin, subcutaneous, deep fascia, muscle, bone
12. Mobility/Fixity: Free, tethered to skin, fixed to underlying structures
13. Regional lymph nodes: Always examine
14. Relation to underlying/overlying structures
15. Special tests: Fluctuation test, fluid thrill, slip sign (lipoma), etc.

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8. Classification of Tumors

By Behavior

By Tissue of Origin (Histogenesis)

Special Types

• Teratoma: From all 3 germ layers (totipotent cells)
• Hamartoma: Disorganized but normal tissue elements for that site
• Choristoma: Normal tissue in abnormal location
• Carcinoid: Neuroendocrine tumor (low-grade malignant)

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9. Goiter: Classification + Management

Definition

Classification

1. Physiological: Puberty, pregnancy
2. Simple/Colloid (Non-toxic):
   • Endemic goiter (iodine deficiency - most common cause worldwide)
   • Sporadic
3. Toxic Goiter:
   • Diffuse toxic (Graves' disease)
   • Toxic multinodular goiter
   • Toxic adenoma (Plummer's disease)
4. Autoimmune:
   • Hashimoto's thyroiditis (hypothyroid)
   • Graves' disease (hyperthyroid)
5. Inflammatory: De Quervain's (subacute), Riedel's (fibrous)
6. Neoplastic:
   • Benign: Follicular adenoma
   • Malignant: Papillary, Follicular, Medullary, Anaplastic carcinoma

• Grade 0: Not visible or palpable
• Grade 1: Palpable but not visible
• Grade 2: Visible and palpable

• Diffuse (uniform enlargement)
• Nodular (single/multinodular)

Thyroid Swelling Examination (Salient Points)

• Moves with swallowing - key feature (attached to pretracheal fascia)
• Pemberton's sign: Facial congestion on raising arms above head - SVC obstruction by goiter
• Berry's sign: Absence of carotid pulsation behind goiter
• Kocher's test: Trachea compression test

Management

• Small: Reassure; levothyroxine to suppress TSH
• Iodine supplementation (endemic)
• Surgery: For pressure symptoms, cosmesis, large goiter, suspected malignancy

1. Antithyroid drugs (Carbimazole/Propylthiouracil):
   • First-line in Graves' disease; block thyroid peroxidase
   • Propranolol (beta-blocker) for symptom control
2. Radioactive Iodine (RAI - I-131):
   • Preferred definitive treatment in adults
   • Destroys thyroid tissue
   • Contraindicated in pregnancy/children
3. Surgery (Total/Near-total thyroidectomy):
   • Indications: Large goiter with pressure symptoms, failed medical therapy, pregnancy, young patients, suspected malignancy, cosmesis

• Papillary (most common, best prognosis): Total thyroidectomy + RAI ablation
• Follicular: Total thyroidectomy + RAI
• Medullary: Total thyroidectomy + neck dissection (no RAI useful)
• Anaplastic (worst prognosis): Palliative; chemotherapy/radiotherapy

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10. Lymphadenopathy - Approach

Causes (mnemonic MINT-CRAP)

Clinical Approach

• Duration, associated fever, weight loss, night sweats (B symptoms of lymphoma)
• Sore throat, dental problems, scalp lesions
• Risk factors: TB contact, HIV risk, travel history
• Medications

Investigations

• CBC, ESR, CRP
• Mantoux test, chest X-ray (TB)
• HIV testing
• FNAC - first investigation for single enlarged node
• Excisional biopsy - if FNAC inconclusive
• CT neck/chest/abdomen
• PET scan (lymphoma staging)
• Bone marrow biopsy (hematological malignancy)

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11. Head Injury

Classification

• Mild: GCS 13-15
• Moderate: GCS 9-12
• Severe: GCS ≤8

1. Primary injury: Direct result of impact
   • Concussion, contusion, laceration, diffuse axonal injury (DAI)
2. Secondary injury: Develops after primary impact
   • Intracranial hematoma (EDH, SDH, ICH)
   • Brain edema, herniation, ischemia, infection

• EDH: Biconvex hyperdense (white) collection, does not cross suture lines
• Acute SDH: Crescent hyperdense collection; chronic SDH = hypodense (black)

• Mild TBI: Observation, neurological monitoring
• EDH >30 mL, thickness >15 mm, midline shift >5 mm: Urgent surgical evacuation (burr hole/craniotomy)
• Acute SDH with midline shift/deterioration: Urgent craniotomy
• ICP monitoring for severe TBI
• Mannitol (osmotic agent) for raised ICP
• Hyperventilation (temporary ICP reduction)

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12. Carcinoma Larynx

Etiology

• Cigarette smoking (most important)
• Alcohol
• Asbestos exposure
• HPV
• Radiation

Anatomy (relevant)

1. Glottis (vocal cord) - 60%; most common; BEST prognosis (poor lymphatic supply)
2. Supraglottis (above vocal cord) - 30%; worse prognosis (rich lymphatics, late presentation)
3. Subglottis (below vocal cord) - 10%; rarest; worst prognosis

Clinical Features

• Hoarseness (earliest symptom in glottic SCC) - hallmark; any hoarseness >3 weeks needs laryngoscopy
• Dysphagia (supraglottic)
• Dyspnea, stridor (advanced disease)
• Sore throat, referred otalgia
• Neck mass (lymph node metastasis)
• Hemoptysis
• Weight loss

Investigations

• Indirect laryngoscopy, fiber-optic laryngoscopy
• CT neck and chest
• Biopsy (definitive diagnosis)
• MRI (soft tissue involvement)

Staging (T staging)

• T1: Tumor limited to one subsite, normal cord mobility
• T2: Extended to other subsite or impaired mobility
• T3: Cord fixation or invasion of pre-epiglottic space
• T4: Invasion beyond larynx (thyroid cartilage, trachea, soft tissue of neck)

Management

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13. Hyperthyroidism

Definition

Etiology

• Graves' disease (diffuse toxic goiter) - most common (80%); autoimmune - TSH receptor antibodies (TRAb)
• Toxic multinodular goiter
• Toxic adenoma (Plummer's disease)
• Thyroiditis (De Quervain's) - transient
• Excess iodine (Jod-Basedow)
• Thyroid cancer (rare)
• TSH-secreting pituitary adenoma (rare)

Clinical Features

Investigations

• TSH low (most sensitive; suppressed in primary hyperthyroidism)
• T3, T4 elevated
• TRAb (positive in Graves')
• Radioactive iodine uptake scan: Diffuse uptake (Graves'), hot nodule (toxic adenoma)
• ECG: Sinus tachycardia, AF

Management

1. Antithyroid drugs:
   • Carbimazole (first-line in UK) or Methimazole - blocks peroxidase; inhibits T3/T4 synthesis
   • Propylthiouracil (PTU) - also blocks peripheral T4 → T3 conversion; preferred in pregnancy (first trimester) and thyroid storm
   • Duration: 12-18 months; 50% remission rate in Graves'
   • Side effects: Agranulocytosis (stop drug, urgent blood count), rash, hepatotoxicity (PTU)
2. Beta-blockers (Propranolol/Atenolol): Symptomatic control of tachycardia, tremor; does not affect thyroid hormone production
3. Radioactive Iodine (I-131):
   • Definitive treatment for Graves' and toxic MNG
   • Leads to hypothyroidism (requires lifelong levothyroxine)
   • Contraindicated: Pregnancy, breastfeeding, severe Graves' ophthalmopathy
4. Surgery (Total/Near-total thyroidectomy):
   • For large goiter, failed medical therapy, young patients, malignancy suspicion
   • Preoperative preparation: Antithyroid drugs for 6-8 weeks + Lugol's iodine 10 days pre-op (reduces vascularity)

• Treat with: PTU high dose, iodine (Lugol's), hydrocortisone, propranolol, cooling, supportive care

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SHORT QUESTIONS

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Stages of Shock

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Cross-Matching

1. Major cross-match (most important): Recipient's serum + donor's RBCs - tests for antibodies in recipient against donor cells
2. Minor cross-match: Donor's serum + recipient's RBCs - tests for antibodies in donor against recipient
3. In-silico (electronic cross-match): Computer-based using blood bank records

1. ABO + Rh typing (forward and reverse)
2. Antibody screening (indirect Coombs test)
3. Cross-match (major)

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Massive Transfusion

• Dilutional coagulopathy (loss of clotting factors)
• Dilutional thrombocytopenia
• Hypothermia (use blood warmers)
• Hypocalcemia (citrate in stored blood chelates calcium - give IV calcium)
• Hyperkalemia (RBC breakdown releases K+)
• Metabolic acidosis
• TRALI (Transfusion-Related Acute Lung Injury)
• TACO (Transfusion-Associated Circulatory Overload)
• ABO/Rh incompatibility reactions
• Citrate toxicity (in liver failure - can't metabolize citrate)

• Cryoprecipitate for fibrinogen (<1.5 g/L)
• Tranexamic acid (antifibrinolytic) early in trauma (within 3 hours)

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Le Fort Fractures

• Dish-face deformity
• CSF rhinorrhea (Le Fort II, III - dural tear)
• Bilateral periorbital ecchymosis ("Panda eyes/Raccoon eyes")
• Malocclusion

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Complications of Fractures

• Hemorrhage, shock
• Nerve injury
• Vascular injury (ischemia)
• Wound/open fracture infection
• Fat embolism (48-72 hrs after long bone fracture: confusion, hypoxia, petechiae)
• Compartment syndrome (5 P's: Pain, Pallor, Pulselessness, Paraesthesia, Paralysis - treat with FASCIOTOMY)

• Malunion (healed in wrong position)
• Non-union (failure to heal >4-6 months; types: hypertrophic, atrophic, infected)
• Delayed union
• Avascular necrosis (head of femur, scaphoid, talus - watershed areas)
• Contractures (Volkmann's ischemic contracture - forearm after compartment syndrome)
• Post-traumatic arthritis
• Myositis ossificans (heterotopic ossification)
• Osteomyelitis (open fractures)

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Immobilization Methods

1. Plaster of Paris (POP): Calcium sulfate hemihydrate; exothermic setting; used for casting
2. Fiberglass cast: Lighter, water-resistant alternative
3. Splint: Partial cast; allows swelling
4. External fixation: Pins through bone connected by external frame; open/infected fractures
5. Traction:
   • Skin traction (sticky traction) - limited force
   • Skeletal traction (pin through bone - Steinmann pin, Kirschner wire)
   • Types: Fixed traction (Thomas splint), Balanced traction
6. Internal fixation:
   • Plates and screws (ORIF)
   • Intramedullary nails (IMN) - femur, tibia fractures
   • Kirschner wires (K-wires)
   • Dynamic Hip Screw (DHS) - femoral neck fractures
7. Functional bracing: Allows joint movement while fracture heals (tibial shaft)

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TNM Staging

• T: Primary tumor size/extent (T0 to T4)
• N: Regional lymph node involvement (N0 to N3)
• M: Distant metastasis (M0 = absent, M1 = present)
• p prefix = pathological staging (after surgery)
• c prefix = clinical staging
• Stage grouping: I to IV based on T, N, M combinations

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Biopsy in Oral Cancer

1. Incisional biopsy: Remove a representative piece from the lesion - preferred for large lesions
2. Excisional biopsy: Remove entire lesion - for small lesions (<1 cm)
3. Punch biopsy: For flat lesions
4. Brush biopsy / cytology: Screening tool, not definitive

• Include representative tissue with some normal margin
• Include area of most abnormal appearance (erythroplakia component, indurated area)
• Avoid necrotic center (non-diagnostic)
• Must include subepithelial connective tissue (depth)
• No prior cauterization/electrosurgery
• Avoid crushing with forceps
• Use Toluidine blue as vital stain to guide biopsy site (stains dysplastic/malignant tissue blue)

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Benign vs Malignant Tumor

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Signs of Malignancy (in a swelling/ulcer)

• Raised, everted, rolled edges (SCC)
• Indurated base and edges
• Sloughing/necrotic floor
• Fixed to underlying structures
• Regional lymphadenopathy (hard, fixed)
• Satellite nodules
• Bleeding on touch

• Unexplained weight loss, anorexia
• Cachexia (malignant cachexia - cytokine-driven)
• Anemia of chronic disease
• Paraneoplastic syndromes

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Cyst vs Tumor

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Lymph Node Examination

1. Inspect for visible swelling
2. Palpate systematically (all groups bilateral):
   • Submental, submandibular, parotid
   • Pre and post auricular, occipital
   • Anterior cervical (along SCM, IJV)
   • Posterior cervical (behind SCM)
   • Supraclavicular (Virchow's node on left)
   • Axillary, inguinal
3. Note: Size, number, consistency (soft/firm/hard/rubbery), tenderness, mobility/fixity, matting, skin changes over it, surface character

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Sialolithiasis

• Wharton's duct is long (5 cm), runs upward against gravity
• Saliva is more alkaline and mucous-rich (higher calcium content)
• Orifice is at floor of mouth (wider, more contaminated)
• Duct bends over mylohyoid muscle

• Painful swelling of the gland at meal times (postprandial pain and swelling)
• Obstruction symptoms: swelling subsides between meals
• Pus from duct orifice (secondary infection)
• Stone palpable bimanually in floor of mouth

• Plain X-ray (80% of submandibular stones are radio-opaque)
• Ultrasonography
• CT scan (best)
• Sialography (shows filling defect - now less used)

• Small stones near orifice: Milking/massage + warm fluids + sialogogues
• Duct stones: Sialolithotomy (intraoral incision and extraction)
• Gland stones / recurrent disease: Submandibular gland excision
• Parotid: Stenson's duct accessible intraorally; parotidectomy if intraglandular

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Parotid Swelling - Causes

• Acute bacterial parotitis (Staphylococcus aureus - dehydrated elderly)
• Viral: Mumps (bilateral, tender, child)
• Chronic recurrent parotitis
• Sarcoidosis (Heerfordt syndrome)
• Sjogren's syndrome

• Parotid duct stone (rare, <20% of sialoliths)

• Benign: Pleomorphic adenoma (most common parotid tumor, 70%)
• Benign: Warthin's tumor (adenolymphoma - bilateral, smokers, males)
• Malignant: Mucoepidermoid carcinoma (most common parotid malignancy), Acinic cell, Adenoid cystic carcinoma
• Lymphoma, metastatic deposits

• Branchial cyst (within parotid)
• HIV-associated cysts

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Facial Nerve in Parotid Surgery

• Nerve exits the stylomastoid foramen
• Divides into upper (temporofacial) and lower (cervicofacial) divisions in the parotid
• Further divides into 5 branches: Temporal, Zygomatic, Buccal, Marginal Mandibular, Cervical (mnemonic: Ten Zebras Bought My Car)

• Tragal pointer (cartilage of tragus points to main trunk ~1 cm medially and inferiorly) - most reliable
• Posterior belly of digastric (nerve lies just above it)
• Tympanomastoid suture (nerve 6-8 mm deep)
• Mastoid process and styloid process

• Facial nerve palsy (temporary ~10%, permanent ~1%) - most feared complication
• Frey's syndrome (auriculotemporal nerve syndrome): Sweating and flushing over cheek during eating (gustatory sweating) - due to aberrant regeneration of parasympathetic fibers to sweat glands
• Salivary fistula
• Hematoma, infection
• Great auricular nerve damage (numbness of earlobe)

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Thyroid Swelling Examination

1. Inspection: Neck midline swelling; moves with swallowing and protrusion of tongue (distinguishes thyroid from non-thyroid)
2. Palpation (from behind patient):
   • Size, shape, surface, consistency
   • Single nodule vs multinodular
   • Tenderness
   • Mobility - moves with swallowing
   • Tracheal position (deviation)
3. Percussion: Over sternum for retrosternal extension
4. Auscultation: Bruit over thyroid (Graves' disease - hypervascular)
5. Pemberton's sign: Raise arms above head → facial congestion, cyanosis = SVC obstruction by retrosternal goiter
6. Kocher's test: Lateral pressure on each side of thyroid → stridor if tracheal narrowing
7. Berry's sign: Loss of carotid pulsation behind enlarged thyroid lobe
8. Cervical lymph nodes: For malignancy
9. Check for thyroid status: Pulse rate, tremor, eye signs (exophthalmos, lid lag), reflexes, temperature

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Complications of Thyroidectomy

• Primary hemorrhage (within 24 hrs) - may cause airway compromise by hematoma compressing trachea (EMERGENCY - remove clips/sutures at bedside)
• Airway obstruction (hematoma, tracheomalacia)
• Thyroid storm (in uncontrolled hyperthyroidism)

• Hypocalcemia (most common complication): Due to inadvertent parathyroid gland removal or devascularization → tetany, positive Chvostek's sign (facial nerve tapping), Trousseau's sign (carpal spasm with BP cuff). Treat with IV calcium gluconate, then oral calcium + Vitamin D
• Recurrent laryngeal nerve (RLN) injury: Unilateral RLN injury → hoarseness; Bilateral → aphonia + respiratory distress (tracheostomy needed)
• External laryngeal nerve injury: Loss of high-pitched voice (singer's nerve - Semon's law)
• Wound infection

• Hypothyroidism: Post total thyroidectomy; requires lifelong levothyroxine
• Hypoparathyroidism (permanent)
• Keloid scar
• Recurrence (of toxic goiter/malignancy)

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Tubercular Lymphadenitis

• Mycobacterium tuberculosis
• Starts as reactive lymphadenopathy → caseation necrosis → collar-stud abscess (pus tracks through deep fascia, creating abscess with narrow neck between deep and superficial compartments)
• Cold abscess: No overlying signs of acute inflammation (cold, painless)

• Cervical nodes most commonly affected (posterior triangle)
• Multiple, matted nodes
• Painless initially → cold abscess → collar-stud abscess → discharging sinus

• FNAC (shows caseating granulomas, Langerhans giant cells)
• AFB stain and culture (gold standard)
• Mantoux test (often positive)
• PCR (rapid, sensitive)
• Chest X-ray (rule out pulmonary TB)
• Excisional biopsy (if FNAC inconclusive)

• Anti-TB therapy: HRZE for 2 months (Intensive phase), then HR for 4-7 months (Continuation phase)
• H = Isoniazid, R = Rifampicin, Z = Pyrazinamide, E = Ethambutol
• Surgical: Excision for large nodes, cold abscess drainage, discharging sinus excision

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Hodgkin vs Non-Hodgkin Lymphoma

• Stage I: Single lymph node region
• Stage II: 2+ regions, same side of diaphragm
• Stage III: Both sides of diaphragm
• Stage IV: Disseminated extranodal involvement

• HL: ABVD chemotherapy (Adriamycin, Bleomycin, Vinblastine, Dacarbazine) ± radiotherapy
• NHL: CHOP regimen ± rituximab (R-CHOP for CD20+ B-cell)

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Glasgow Coma Scale (GCS)

• 3-8 = Severe TBI (Intubate! GCS ≤8, intubate)
• 9-12 = Moderate
• 13-15 = Mild

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Concussion

• Brief loss of consciousness (<30 min) or no LOC
• Post-traumatic amnesia (<24 hours)
• Confusion, disorientation, headache, dizziness
• No focal neurological deficit
• CT/MRI: Normal (structural imaging is normal by definition)

• Physical and cognitive rest
• Avoid returning to sport/activity too soon (risk of second impact syndrome)
• Gradual return-to-play protocol (stepwise)
• No specific pharmacological treatment

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Tonsillitis

• Commonest organisms: Streptococcus pyogenes (Group A beta-haemolytic) - most important; also Adenovirus, EBV
• Features: Sore throat, fever, dysphagia, odynophagia, tonsillar enlargement, exudate on tonsils, cervical lymphadenopathy
• Complications: Peritonsillar abscess (quinsy), rheumatic fever, post-streptococcal glomerulonephritis, retropharyngeal abscess
• Treatment: Penicillin V / Amoxicillin; Azithromycin if allergic; avoid Ampicillin (can cause rash in EBV)

• Recurrent acute episodes, persistent sore throat, halitosis, hypertrophied tonsils with crypts

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Indications of Tonsillectomy

• Obstructive sleep apnea (OSA) from tonsillar hypertrophy
• Peritonsillar abscess (quinsy) - after 6 weeks
• Suspicion of malignancy (unilateral enlargement)
• Diphtheria carrier not responding to antibiotics

• ≥7 episodes of tonsillitis in 1 year
• ≥5 episodes/year for 2 consecutive years
• ≥3 episodes/year for 3 consecutive years

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Dehydration

• Isotonic (most common): Equal loss of water and sodium (diarrhea, vomiting)
• Hypertonic: Water loss > sodium loss (diabetes insipidus, inadequate oral intake)
• Hypotonic: Sodium loss > water loss (excess sweating replaced with plain water)

• Mild/moderate: Oral rehydration therapy (ORS)
• Severe: IV fluids (Normal saline 0.9% or Ringer's Lactate)
• Reassess and adjust

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IV Fluids

• Human albumin (4.5%, 20%)
• Hydroxyethyl starch (Voluven)
• Gelatin solutions (Gelofusine, Haemaccel)
• Dextran
• FFP, blood products

• 100 mL/kg for first 10 kg + 50 mL/kg for next 10 kg + 20 mL/kg for each kg >20 kg

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Electrolyte Imbalance

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Acidosis vs Alkalosis / ABG Basics

• pH: 7.35-7.45
• PaCO2: 35-45 mmHg
• HCO3-: 22-26 mEq/L
• PaO2: 80-100 mmHg
• SaO2: 95-100%
• BE: -2 to +2

1. Look at pH: <7.35 = acidosis; >7.45 = alkalosis
2. Look at PaCO2: Elevated = respiratory acidosis; Low = respiratory alkalosis
3. Look at HCO3: Low = metabolic acidosis; High = metabolic alkalosis
4. Check for compensation

• High anion gap metabolic acidosis (MUDPILES): Methanol, Uremia, DKA, Propylene glycol, Isoniazid, Lactic acidosis, Ethylene glycol, Salicylates

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Tuberculosis (TB)

• Sputum AFB smear (3 samples), culture (gold standard - Lowenstein-Jensen medium)
• GeneXpert MTB/RIF (rapid PCR, detects rifampicin resistance)
• Chest X-ray: Upper lobe infiltrates, cavitation
• Mantoux (TST), IGRA (QuantiFERON)

• Intensive phase: HRZE × 2 months
• Continuation phase: HR × 4 months
• Drug-resistant TB: Longer regimens with second-line drugs

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HIV Basics

1. Acute HIV infection (seroconversion illness) - fever, rash, lymphadenopathy, 2-6 weeks after exposure
2. Chronic asymptomatic infection (clinical latency) - CD4 decline over years
3. AIDS: CD4 <200 cells/mm³ OR AIDS-defining illness

• Universal precautions, double gloving
• Post-exposure prophylaxis (PEP) within 72 hours of needlestick
• Avoid unnecessary procedures; higher infection/wound healing risk

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Ulnar Nerve Injury

1. Medial epicondyle (cubital tunnel) - most common
2. Wrist (canal of Guyon) - e.g., cyclist's palsy

• Hypothenar muscles (ADM, ODM, FDM)
• All palmar and dorsal interossei
• 3rd and 4th lumbricals (ring and little)
• Adductor pollicis (Froment's sign: can't pinch paper without flexing thumb IP joint)

• Low (at wrist): Claw hand more pronounced (clawing of ring and little fingers - "ulnar paradox")
• High (at elbow): Flexor digitorum profundus to ring/little also lost → less clawing paradoxically

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Wrist Drop

• Humeral shaft fracture (most common)
• "Saturday night palsy" / "Park bench palsy" - compression in axilla (crutch) or upper arm (falling asleep on arm)
• Penetrating injuries

• Wrist extensors (ECRL, ECRB, ECU)
• Finger extensors (EDC, EI, EDM)
• Thumb extensors and abductor (ECRB, APL, EPL, EPB)
• Brachioradialis (elbow flexion in mid-prone position)

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Common Surgical Specimens

1. Appendix - appendectomy (most common surgical specimen)
2. Gallbladder - cholecystectomy
3. Colorectal resections - right hemicolectomy, sigmoid colectomy
4. Mastectomy specimens (breast)
5. Thyroid (thyroidectomy specimens)
6. Lymph node - biopsy specimens
7. Hernia sac - open/laparoscopic hernia repair
8. Tonsils (tonsillectomy)
9. Skin biopsies - melanoma, SCC
10. Prostate - TURP chips, prostatectomy

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Sutures and Needles

Types of Sutures

• Monofilament: Less infection risk, harder to tie, cuts through tissue
• Multifilament (braided): Easier to tie, better knot security, more infection risk (harbors bacteria)

Types of Needles

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Local Anesthesia

• 1:80,000 or 1:100,000 concentration
• Prolongs duration, reduces systemic absorption, reduces bleeding
• Contraindicated: Uncontrolled thyrotoxicosis, severe cardiac disease, pheochromocytoma, end-arteries (fingers, toes, nose, penis, ears)

Complications of Local Anesthesia

• Hematoma (intravascular injection)
• Nerve damage (direct trauma, intraneural injection)
• Infection
• Broken needle (rare, with sudden movement)
• Trismus (inferior alveolar nerve block)

• Intravascular injection (most dangerous):
  • CNS: Perioral tingling, tinnitus → confusion → seizures → CNS depression → coma
  • CVS: Bradycardia, hypotension, cardiac arrest (bupivacaine particularly cardiotoxic)
• Allergic reaction: True allergy rare (more to preservatives - paraben); anaphylaxis
• Methaemoglobinaemia (prilocaine overdose)
• Syncope (vasovagal - most common "reaction" in dental practice)

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Types of Biopsy + Indications

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