Complete MCQ Answers with Explanations

Q10. Laparoscopic liver resection - hypotension + drop in EtCO2 + no ventilator circuit break + minimal bleeding + ST changes

• Sudden hypotension
• Drop in end-tidal CO2 (gas lodges in pulmonary vasculature, reducing perfusion)
• ST changes (right heart strain/ischemia)

Q11. Malignant hyperthermia - laparoscopic cholecystectomy, hyperthermia + elevated EtCO2, treated with dantrolene

• (A) False - MH is autosomal dominant (not recessive), though multifactorial inheritance also occurs (Bradley & Daroff's Neurology)
• (B) False - Diagnosis is clinical; genetic analysis and muscle biopsy (caffeine-halothane contracture test) are confirmatory but not required for diagnosis
• (C) False - MH is more common in younger patients/children, not elderly
• (D) True - Delayed MH can occur up to 24 hours after anesthesia, especially with volatile agents that remain in tissue
• (E) False - With dantrolene treatment, mortality is ~5-10%; without it, historical mortality was up to 80%

Q12. Benzocaine spray - headache, dyspnea, SpO2 85%, SaO2 80%, PaO2 150 mmHg

Q13. 19-year-old with painful, swollen, red lateral nail fold - nail biting history, fever 103°F

• Nail biters harbor oral flora including anaerobic bacteria (Bacteroides, Fusobacterium, Eikenella)
• This distinguishes from typical paronychia which only needs skin flora coverage (Staph aureus)
• Because nail biting introduces mouth organisms, anaerobic coverage is required in addition to standard skin flora coverage
• Incision is at the lateral nail fold (not mid-pulp, which would be for felon)
• Fever 103°F indicates a significant infectious process requiring drainage + antibiotics (Miller's Review of Orthopaedics)

Q14. 2 cm lesion upper lip, shiny pearly nodule with rolled borders - most common skin cancer

Q15. 45-year-old shepherd, bottom lip lesion, red and brown plaque

Q18. 3-cm full-thickness cheek wound from flash burn - best skin graft

• Contract less
• Provide better cosmetic outcome
• Better match facial skin texture/color

Q19. Redness, pain, fluctuance in intergluteal cleft 4 cm posterior to anus, with hair

• Acute phase: incision and drainage
• The I&D should be performed lateral/off-midline to the intergluteal cleft (not in the cleft itself)
• Off-midline drainage heals faster with less recurrence than midline incision
• En bloc excision and flap reconstruction are for chronic/recurrent disease, not acute abscess (Textbook of Family Medicine; Roberts & Hedges' Clinical Procedures)

Q20. Most common organism causing burn sepsis

Q21. Electrical burn worker - discolored urine in minimal quantity, contact burns hands/feet/perineum, normal EKG

Q22. Respiratory distress - trachea deviated LEFT, absent breath sounds on RIGHT, tachycardia, feeble pulses

• Tracheal deviation away from affected side (deviated LEFT = tension on RIGHT)
• Absent breath sounds on the affected side (RIGHT)
• Hemodynamic instability (tachycardia, feeble pulses)

Q25. 8 cm from anal verge, pedunculated swelling, suspected carcinoma rectum - best test for early staging

• T-stage (depth of invasion through bowel wall layers)
• N-stage (perirectal lymph nodes)
• It is superior to CT for local T/N staging of early rectal cancer
• CT is better for distant metastasis (M-stage)
• PET-CT is for recurrence/metastasis
• CEA is a tumor marker, not a staging tool
• Colonoscopy is diagnostic, not staging

Q26. 32-year-old with thyroid lymphoma - disease confined to thyroid (no systemic spread)

• Localized disease (MALT type): radiotherapy alone is the standard
• More aggressive types (DLBCL): chemoradiotherapy (R-CHOP + RT)
• Surgery plays a limited role (mainly for diagnosis/decompression) Given the question specifies "no disease elsewhere" and asks for treatment, radiotherapy alone for localized thyroid lymphoma is the standard answer in surgical exams.

Q27. 12-year-old with road rash - skin rubbed off on road

• Thorough mechanical cleansing to remove embedded road debris (gravel, dirt, asphalt)
• Gentle brushing and irrigation with normal saline
• If debris is not removed, it becomes tattooed into healing skin permanently
• The wound itself does not require grafting acutely - clean abrasions generally heal by secondary intention
• Grafting decisions are made after wound assessment

Q28. 55-year-old farmer - longstanding mole changing in size, shape, color; crusting and bleeding; no lymphadenopathy

• Asymmetry, Border irregularity, Color change, Diameter increase, Evolution (change over time)
• Crusting and bleeding are signs of malignant transformation
• Longstanding mole (pre-existing nevus) transforming
• Farmer = chronic UV exposure (risk factor)
• No palpable lymph nodes does not exclude melanoma at this stage
• KA (keratoacanthoma) grows rapidly de novo; BCC is pearly; SCC doesn't typically arise from a mole

Q32. Stress response - which statement is FALSE?

• (A) True - it IS graded (proportional to severity of injury)
• (B) True - metabolism and nitrogen excretion correlate with degree of stress
• (C) True - physiological, metabolic, and immunological changes all occur
• (D) FALSE - The changes CAN be modified (by analgesia, anesthesia, nutritional support, beta-blockers, etc.)
• (E) True - the pituitary (via ACTH, ADH, GH) initiates the integrated neuroendocrine response

Q33. Preventable factors of mortality in high-risk patients

• (A) Pain and (D) Advanced age are NOT preventable factors - pain can be managed but is not a direct cause of mortality; age cannot be changed
• The preventable factors are system/process failures: inadequate monitoring, delayed intervention, inadequate critical care resources

Q34. Water homeostasis - TRUE statements

• (A) False - TBW in adult male is 60% of body weight (not 70%)
• (B) True - ICF = 2/3 of TBW; ECF = 1/3 of TBW
• (C) True - Plasma volume ~3L (part of the ~15L ECF)
• (D) False - TBW is LOWEST in elderly and obese individuals (more fat, less water); highest in lean young males
• (E) True - water moves freely via osmosis through aquaporins

Q35. Markers of malnutrition for TPN consideration

• Albumin (half-life ~21 days) - marker of chronic malnutrition
• Transthyretin/prealbumin (half-life ~2 days) - more sensitive marker of acute malnutrition
• Skin fold thickness - anthropometric measure of fat stores
• Weight loss >10% of body weight is significant
• (B) Urea - reflects protein catabolism/renal function, not a direct marker of malnutrition status

Q36. True statements about 0.9% normal saline

• (A) False - Normal saline has Na+ 154 mEq/L; plasma Na+ is 135-145 mEq/L. They are NOT identical
• (B) True - 0.9% NaCl has 154 mmol/L Na+ AND 154 mmol/L Cl- (equimolar)
• (C) False - Normal saline contains NO potassium
• (D) True - It contains no dextrose (unlike D5W or D5NS)
• (E) False - Normal saline is NOT the premier fluid for hypovolemia; it causes hyperchloremic metabolic acidosis with large volumes; balanced crystalloids (Lactated Ringer's) are preferred

Q37. FALSE statements about anastomosis

• (A) False - Large bowel anastomosis can be performed with either one-layer or two-layer technique; both are acceptable
• (B) True - tension-free anastomosis is mandatory
• (C) False - Both synthetic (polyglycolic acid, PDS) AND natural (catgut) sutures are used; the statement as written implies only synthetic should be used which is misleading
• (D) True - In vascular anastomosis, the needle passes from intima outward (inside-out) to prevent intimal dissection
• (E) True - Non-absorbable monofilament (polypropylene) is used for vascular anastomosis

Q38. Advantages of minimal access surgery (laparoscopy)

• (A) True - smaller incisions
• (B) True - less tissue trauma = less pain
• (C) False - Operating time is often LONGER with laparoscopy (more complex setup, longer learning curve)
• (D) True - magnified, high-definition camera provides better visualization than open surgery in some cases
• (E) False - Operating theatre costs are actually HIGHER for laparoscopy (expensive equipment, disposables)

Q39. Gases used to provide pneumoperitoneum

• CO2 is the standard gas - highly soluble, non-combustible, rapidly absorbed
• Helium has been used as an alternative (less physiologic effects on acid-base, useful in patients with pulmonary disease)
• (A) Methane - not used (flammable, dangerous)
• (D) Nitrous oxide - historically used but abandoned (supports combustion, risk with electrocautery)
• (E) Argon - not used for pneumoperitoneum

Q40. Complications of creating pneumoperitoneum

Q41. Life and death decisions - TRUE statements

• (A) False - Surgeons are NOT always obliged to provide life-sustaining treatment; futile treatment, patient advance directives, and DNR orders exist
• (B) True - Withholding treatment requires collegial decision-making and detailed documentation
• (C) True - The doctrine of double effect - adequate pain relief in terminal malignancy is ethically appropriate even if it may hasten death
• (D) False - Confidentiality is NOT absolute; it can be breached to prevent serious harm to others

Q42. FALSE statements in orthopedic imaging

• (A) False - Synovitis is a soft-tissue finding detected by MRI or ultrasound, NOT plain X-ray
• (B) True - MR arthrography IS ideal for articular cartilage damage
• (C) True - MRI IS ideal for staging malignant bone tumors
• (D) True - X-ray is the first investigation for destructive bone lesions
• (E) True - US IS used to examine soft tissue masses
• (F) False - Plain film shows only late changes (joint space narrowing, periosteal reaction); joint aspiration and synovial fluid culture are the gold standard for acute septic arthritis

Q43. Antibiotic prophylaxis NOT considered

• (A) Prosthetic heart valves - high risk for endocarditis
• (B) Previous endocarditis - highest risk group
• (C) Severe neutropenia - immunocompromised
• (D) Chronic liver disease undergoing variceal sclerotherapy - risk of bacteremia/SBP

Q44. NOT risk factors for post-ERCP pancreatitis

• (A) Young age - TRUE risk factor
• (B) Difficult cannulation - TRUE risk factor
• (D) Pancreatic sphincterotomy - TRUE risk factor
• (E) Balloon dilation of biliary sphincter - TRUE risk factor
• (C) Increased bilirubin - Elevated bilirubin is actually associated with lower risk of PEP (dilated CBD from obstruction makes cannulation easier and sphincter is already open)

Q45. TRUE statements about immunohistochemistry (IHC)

• (A) Partially true but misleading - IHC is more than "just a special staining method"; it specifically uses antigen-antibody reactions (making B the better answer)
• (B) True - IHC uses specific antibodies against cellular antigens (e.g., ER/PR in breast cancer)
• (C) True - Used to classify tumor type (cytokeratin for carcinoma, S-100 for melanoma, CD markers for lymphoma)
• (D) True - e.g., HER2 status guides trastuzumab therapy; ER/PR guides hormonal therapy

Q46. Surgical risks in a diabetic patient

• (A) True - Hyperglycemia impairs neutrophil function, complement, and opsonization
• (B) True - Diabetics have accelerated atherosclerosis and autonomic neuropathy (silent MI risk is high)
• (C) Pressure sore - while diabetics are at higher risk due to neuropathy, this is not a primary surgical risk per se
• (D) True - Impaired collagen synthesis, microvascular disease, and neuropathy all impair wound healing
• (E) Pain control - diabetics may have altered pain perception (neuropathy) but "pain control" is not a surgical risk in the classic sense

Q47. Roux-en-Y for carcinoma stomach localized to:

Q48. Reducing unpleasant dreams/emergence phenomena from ketamine

Q49. IV anesthetic associated with highest incidence of nausea and vomiting

• Etomidate has the highest incidence of PONV among IV induction agents (~30-40%)
• Propofol actually has antiemetic properties and reduces PONV
• Ketamine has moderate emetic potential
• Midazolam has minimal emetic potential and mild antiemetic properties

Q50. Hyperdense on CT scan

• Hyperdense (bright/white): bone, fresh/acute blood (hyperdense due to globin protein), calcifications, contrast, foreign bodies
• Isodense: brain parenchyma, subacute blood
• Hypodense (dark): fat, air, edema, old infarcts, CSF
• Gas/fluid/swelling = hypodense; brain parenchyma = isodense

Q51. Femoral hernia passes:

• Medial to the femoral vein
• Lateral to the lacunar ligament
• Below the inguinal ligament
• Posterior to the inguinal ligament (NOT anterior)
• Posterior to Cooper's ligament (NOT posterior to it)

Q52. 5x5 cm sacral ulcer with slough, tissue loss through sacral fascia

• Stage 1: Intact skin, non-blanchable erythema
• Stage 2: Partial thickness, shallow open ulcer/blister
• Stage 3: Full thickness skin loss, subcutaneous fat visible, no fascia exposure
• Stage 4: Full thickness tissue loss with exposed bone, tendon, or fascia
• Unstageable: covered by slough/eschar (cannot determine depth)

Q53. Hemorrhage 2 hours after cholecystectomy

• Primary: occurs at time of operation
• Reactionary: within 24 hours of surgery (usually 4-6 hours) - occurs as blood pressure normalizes, dislodging clots from inadequately ligated vessels
• Secondary: 7-14 days post-op, due to infection/sepsis eroding vessel walls

Q54. Metabolic disturbance in Infantile Hypertrophic Pyloric Stenosis (IHPS)

• HCl (hydrochloric acid) from gastric juice → hypochloremia + metabolic alkalosis
• The kidney initially compensates by excreting HCO3- with Na+, but as volume depletion worsens, it prioritizes Na+ retention over acid-base balance
• K+ is lost in urine (aldosterone-driven Na+/K+ exchange) and via vomiting → hypokalemia
• Paradoxical aciduria occurs despite alkalosis (kidney excretes H+ to save Na+ and K+)

Summary Answer Key

Q55. Diabetic patient - scrotal erythema, bullae, foul-smelling discharge, high-grade fever

• Scrotal erythema progressing to bullae and skin necrosis
• Foul-smelling discharge (anaerobic organisms produce gas and putrid odor)
• Systemic sepsis (high-grade fever)
• Polymicrobial infection (aerobes + anaerobes acting synergistically)

• Meleney's synergistic gangrene affects post-op abdominal wounds, not scrotum
• Gas gangrene (Clostridium) typically follows trauma/surgery with crepitus
• Cellulitis lacks bullae and foul discharge
• Epididymo-orchitis lacks skin necrosis and is a less severe presentation

Q56. Buerger's disease is associated with:

Q57. 5-year-old, 4 cm incised wound on right cheek from shaving blade, bleeding

• Face has excellent blood supply = low infection risk, excellent healing
• Facial wounds should be closed within the "golden period" (6-8 hours, extended to 12-24 hours for face due to rich vascularity)
• Cosmetic outcome on the face is a priority - primary closure gives the best result
• A shaving blade creates a clean-cut incised wound, not a contaminated one
• Sending home with pressure dressing alone risks poor cosmesis and ongoing bleeding
• Delayed primary closure is for contaminated/infected wounds

Q58. GST to left thigh - large medial hematoma, weak distal pulses, foot paresis, paresthesia

• Weak distal pulses (ischemia)
• Motor deficit (unable to move foot)
• Sensory deficit (paresthesia)

Q59. Heavy smoker, chest trauma, ABGs: PaCO2 46, PaO2 <60, pH 7.34, Hb 14.5

• PaO2 <60 mmHg on room air (Type I - hypoxemic), OR
• PaCO2 >45 mmHg with respiratory acidosis (Type II - hypercapnic)

Q60. Beck's triad in pericardial tamponade

1. Hypotension (reduced cardiac output as pericardial fluid compresses the heart)
2. Distended neck veins / JVD (elevated JVP due to impaired venous return)
3. Muffled/distant heart sounds (fluid cushions heart sounds)

Q61. Massive hemothorax - indication for urgent thoracotomy

• Initial drainage ≥1500 ml of blood on chest tube insertion, OR
• Ongoing hemorrhage >200 ml/hour for 2-4 hours

Q62. Burn percentage for whole anterior chest and abdomen

• Anterior chest (thorax): 9%
• Anterior abdomen: 9%
• Total anterior trunk = 18%

Q63. Parkland formula for fluid requirement in burns

• Half given in first 8 hours (from time of burn)
• Remaining half given over next 16 hours

Q64. X-ray indicated in primary survey (ATLS)

1. Chest X-ray - identifies pneumothorax, hemothorax, widened mediastinum
2. Pelvis X-ray - identifies pelvic fractures (major source of occult hemorrhage)
3. Lateral cervical spine (in older ATLS versions; now often replaced by CT)

Q65. 40-year-old mason, fall onto right shoulder and neck, cervical spine fracture, severe shock

• Loss of sympathetic tone → vasodilation → hypotension
• Loss of cardiac sympathetic innervation → bradycardia (distinguishes from hypovolemic shock which causes tachycardia)
• Classic presentation: hypotension + bradycardia + warm extremities after spinal cord injury
• The mechanism (fall onto shoulder and neck) + cervical fracture + "swelling at nape of neck" = cervical spinal cord injury → neurogenic shock

Q66. 1 week post-wound - fibroblasts migrating and synthesizing collagen

1. Hemostasis: minutes to hours (platelet plug, coagulation)
2. Inflammation: 0-5 days (neutrophils, macrophages)
3. Proliferation: days 5-21 - fibroblasts proliferate, synthesize collagen (type III initially), granulation tissue forms, angiogenesis, epithelialization
4. Maturation/Remodeling: 21 days to 2 years - type III collagen replaced by type I, scar contracts

Q67. Stress response after major trauma - identify INCORRECT statement

• Adequate analgesia
• Regional anesthesia
• Nutritional support
• Beta-blockade
• Corticosteroids (in some contexts)

Q68. Inhalational anesthetic causing most arrhythmias

• Ventricular ectopics
• Ventricular fibrillation (especially with exogenous epinephrine)
• Bradycardia

Q69. Ketamine emergence - hallucinations and vivid dreams

Q70. Gallstones on ultrasound appearance

• Hyperechoic (bright white) - calcium/cholesterol reflects sound strongly
• Posterior acoustic shadowing - the stone blocks transmission of ultrasound, creating a dark "shadow" behind it
• Mobile with position change (gravity-dependent)

Q71. Most specific radiological finding of chronic osteomyelitis (Garré's)

• Sequestrum - a piece of dead, necrotic bone separated from living bone; it appears as a dense fragment within the medullary cavity on X-ray. This is the most specific finding for chronic osteomyelitis
• Involucrum - new bone formation surrounding the sequestrum (also specific)
• Hyperostosis and periostitis are non-specific findings
• Bone destruction is seen in many bone pathologies

Q72. Solution commonly used for blood storage

• Saline - maintains volume
• Adenine - substrate for ATP synthesis (preserves red cell metabolism)
• Glucose - energy substrate for red cells
• Mannitol - stabilizes red cell membrane, reduces hemolysis

Summary Answer Key