High-yield final pass

Surgery Rapid Review ⚑

Fast facts, exam traps, decision algorithms, numbers, operative cues, memory pearls, and active-recall prompts. Built to be scanned under pressure without turning back into a textbook.

General

🚨 Must Not Miss

  • Sepsis-3 Definitions: Sepsis is life-threatening organ dysfunction caused by a dysregulated host response (acute change in SOFA score β‰₯ 2). Septic Shock is sepsis with persisting hypotension requiring vasopressors to maintain MAP β‰₯ 65 mmHg AND serum lactate > 2$ mmol/L despite adequate fluid resuscitation (30 mL/kg crystalloid). The term "Severe Sepsis" is obsolete.
  • The 1-Hour Sepsis Bundle: 1) Measure lactate, 2) Blood cultures before antibiotics, 3) Broad-spectrum IV antibiotics, 4) 30 mL/kg crystalloid fluid bolus, 5) Vasopressors (Norepinephrine is 1st line). Never delay antibiotics/source control to wait for cultures.
  • Primary vs. Secondary Trauma Survey: ABCDE always comes first. If a patient is talking normally, Airway and Breathing are patent; jump immediately to Circulation. The Secondary Survey (head-to-toe, AMPLE history) only begins after the primary survey is complete and the patient is resuscitated.
  • Preoperative Risk: Severe, decompensated congestive heart failure (especially combined with severe anemia) carries the highest perioperative mortality risk, trumping recent MI or severe aortic stenosis.
  • Lethal Triad of Trauma: Hypothermia (halts coagulation enzymes <34$Β°C), Acidosis (interferes with factor complexes), and Coagulopathy. Resuscitate with Massive Transfusion Protocol (MTP) using a 1:1:1 ratio (PRBCs : FFP : Platelets) to prevent dilutional coagulopathy.
  • Metabolic Response to Injury: Severe trauma/burns trigger a massive counter-regulatory hormone release (catecholamines, cortisol, glucagon). This drives skeletal muscle breakdown and predictably causes hyperglycemia, not hypoglycemia.
  • Postoperative Fever (Early): Fever within 24-48 hours is overwhelmingly non-infectious. It is driven by systemic inflammation or atelectasis (decreased FRC from incisional pain/diaphragmatic stunning).
  • Abdominal Wound Dehiscence vs. Evisceration:
    • Dehiscence: Sudden, painless discharge of salmon-pink (serosanguinous) fluid at post-op days 7-10. This is a fascial dehiscence and a surgical emergency.
    • Evisceration: Bowel is externally exposed. Immediately cover with sterile, saline-soaked dressings and return the patient to the OR.
  • Nutritional Assessment: Prealbumin is the best marker for recent nutritional changes (half-life 2-3 days). However, the Subjective Global Assessment (SGA) is the most reliable overall clinical indicator of true nutritional status.
  • Acute Limb Ischemia: Sudden onset of a cold, pulseless limb requires immediate systemic anticoagulation (IV heparin bolus) before any imaging or transfer to the OR.

🎯 Past-Paper Hit List

Fluid & Acid-Base Derangements

  • Vomiting / Gastric Outlet Obstruction: Loss of HCl and potassium leads to hypochloremic hypokalemic metabolic alkalosis. Resuscitate with 0.9% Normal Saline + KCl.
  • Severe Diarrhea: Loss of bicarbonate leads to a normal anion gap metabolic acidosis (NAGMA).
  • Hypernatremia in Shock: If hypovolemic and unstable, resuscitate with 0.9% Normal Saline first, regardless of sodium levels. Correct sodium slowly (max 0.5 mEq/L/hr) to avoid cerebral edema.

Trauma & Resuscitation Concepts

  • FAST Exam Limitation: Excellent for rapid, bedside detection of free fluid (blood), but fundamentally cannot identify which specific solid organ is injured.
  • Stable Solid Organ Injury: In a hemodynamically stable patient with suspected splenic/hepatic trauma, a CT abdomen with IV contrast is the gold standard.
  • Penetrating Abdominal Trauma: High-velocity wounds transversing the mid-umbilicus most commonly injure the small bowel.
  • Non-Operative Management (NOM) Failure: In splenic trauma, a dropping hemoglobin requiring multiple blood transfusions mandates immediate splenectomy or angioembolization.

Infection & Wound Healing

  • Organisms: S. aureus (fight bites, though Eikenella is classic), Coagulase-negative Staph / S. epidermidis (central lines), E. coli (GI/GU sepsis).
  • C. difficile Treatment: Oral vancomycin or fidaxomicin. Alcohol-based sanitizers do not kill spores; soap and water handwashing is mandatory.
  • Wound Healing: Proliferative phase starts 2-3 days post-injury. Vitamin C is the essential cofactor for cross-linking collagen (prolyl/lysyl hydroxylase).
  • Necrotizing Soft Tissue Infections:
    • Gas Gangrene: C. perfringens, highly toxemic, destroys muscle rapidly.
    • Fournier's Gangrene: Perineal necrotizing fasciitis; classically spares the testicles because their blood supply comes directly from the aorta.

Transfusion Reactions & Anesthesia

  • Transfusions Under Anesthesia: Awake symptoms of Acute Hemolytic Transfusion Reactions are masked. Look for unexplained hypotension and diffuse microvascular oozing from the surgical field.
  • Transfusion Infections: Cytomegalovirus (CMV) transmits via donor leukocytes. Bacterial contamination is most common in Platelets (stored at room temperature).
  • Cadaveric Transplants: ABO blood group compatibility is the absolute first prerequisite to prevent hyperacute rejection.

🧭 Decision Algorithms

  • Tension Pneumothorax: Diagnosed clinically (hypotension, JVD, absent breath sounds, tracheal deviation). β†’ Immediate needle decompression (2nd ICS midclavicular). Do not wait for X-ray. Follow with chest tube.
  • Simple Pneumothorax: Stable patient. β†’ Tube thoracostomy. If air leak persists >3-5 days β†’ VATS with bleb excision and pleurodesis.
  • Suspected Peripheral Arterial Disease (PAD): Patient with claudication. β†’ Ankle-Brachial Index (ABI) first. If short (<3cm) SFA occlusion β†’ Percutaneous Transluminal Angioplasty.
  • Enteral vs. Parenteral Nutrition: Use the gut if it works! Enteral maintains gut integrity and prevents bacterial translocation. Mild acute pancreatitis is an indication for enteral feeding, not a contraindication. TPN is only for obstruction, high-output fistulas, or severe diarrhea.
  • Post-Hemorrhoidectomy Urinary Retention: Due to pain-induced pelvic floor reflex spasm. β†’ Ensure proper analgesia first. Do not jump to Foley or alpha-blockers.
  • Maxillofacial Fractures: Severe facial trauma in an unstable patient. β†’ Delay definitive repair. Wait until the patient is hemodynamically stabilized. Establish surgical airway (trach/cric) if airway is compromised.

βš”οΈ Classic Differentiators & Traps

  • Trap: Normal Saline is "normal". It is not. It contains 154 mEq/L Na+ and 154 mEq/L Cl-. Large volume resuscitation causes hyperchloremic metabolic acidosis.
  • Trap: Giving D5W provides adequate daily calories. 1 Liter of D5W contains only 50g of dextrose (~200 kcal), which is vastly insufficient to prevent catabolism.
  • Trap: TPN can be given via a peripheral IV. High-concentration dextrose (>900 mOsm / 20% Dextrose) must go through a central line. Peripherals cause severe chemical phlebitis.
  • Trap: Heart rate is part of qSOFA. It is not. qSOFA is SBP ≀ 100, RR β‰₯ 22, and GCS <15$. Heart rate is part of the older SIRS criteria.
  • Trap: Lowest GCS score is 0. The lowest GCS is 3. Eye opening to pain is 2. GCS ≀ 8 = Intubate.
  • Trap: Transfuse Platelets for ITP. Ineffective. Autoantibodies will immediately destroy the donor platelets.
  • Cardiogenic Shock vs. Hypovolemic Shock vs. Distributive Shock:
    • Hypovolemic: Low CVP, Low CO, High SVR.
    • Cardiogenic: High CVP, High PCWP, Low CO, High SVR. Contraindication: Pneumatic antishock garments (overloads failing heart).
    • Distributive (Early Sepsis): Low CVP, High CO, Low SVR (hyperdynamic).

πŸ”’ Numbers, Scores & Cutoffs

  • Thoracotomy Indications: Initial chest tube output >1500 mL, or >200 mL/hr for 2-4 consecutive hours. (Just >200 mL in 24 hours is not an indication).
  • Abdominal Compartment Syndrome (ACS): Intra-Abdominal Pressure (IAP) > 20 mmHg with new-onset organ dysfunction (e.g., oliguria, high airway pressures). Normal IAP is 5-7 mmHg.
  • Minimum Urine Output: 0.5 mL/kg/hour indicates adequate renal perfusion during resuscitation.
  • Transfusion Triggers: Transfuse if Hb < 7 g/dL in ICU/stable patients. Use 7-8 g/dL for stable variceal bleeders to avoid exacerbating portal hypertension.
  • Pediatric Maintenance Fluids (4-2-1 / 100-50-20 Rule): 100 mL/kg for first 10kg, 50 mL/kg for next 10kg, 20 mL/kg for remaining weight. (e.g., 35 kg child = 1000 + 500 + 300 = 1800 mL/day).
  • Tracheostomy Timing: Performed at 10-14 days for prolonged mechanical ventilation.
  • Tourniquet Time: Safe maximum inflation time is 2 hours (120 minutes) to prevent irreversible ischemic damage.
  • Prophylactic Antibiotics: Must be administered within 60 minutes prior to incision. Must be discontinued within 24 hours post-op.

πŸ› οΈ Operative / Procedural Must-Knows

  • Fasciotomy: The only definitive, limb-saving treatment for acute compartment syndrome. You must open all four lower leg compartments. Earliest clinical sign is pain on passive stretch.
  • Median Sternotomy: The optimal incision for broad access to the heart and great vessels in trauma.
  • Laparoscopy Insufflation (CO2): Stretching the peritoneum triggers a vagovagal reflex β†’ sinus bradycardia. Systemic absorption of CO2 causes respiratory acidosis. Increased intra-abdominal pressure compresses renal veins, causing transient oliguria.
  • Hernia Anatomy & Rules:
    • Femoral Hernia: High risk of strangulation due to narrow, rigid neck. Medial boundary is the lacunar ligament, lateral is the femoral vein.
    • Inguinal Hernia: Ilioinguinal nerve is most commonly injured in anterior repairs.
    • Antibiotics: Herniorrhaphy (suture only) = Class I, no antibiotics. Hernioplasty (mesh) = Foreign body, requires antibiotics.
  • Parotid Mass: Fine-needle aspiration (FNA) is the safest initial diagnostic step. Excisional/incisional biopsy is contraindicated due to facial nerve injury and tumor seeding risk.
  • Central Lines: Cannulation of the Left Internal Jugular Vein carries a unique risk of injuring the thoracic duct (chylothorax).
  • Surgical Wound Classification:
    • Class I (Clean): Uninfected, no resp/GI/GU entry.
    • Class II (Clean-Contaminated): Controlled entry (e.g., elective lap chole). Cefazolin is standard prophylaxis.
    • Class III (Contaminated): Gross spillage, breaks in sterile technique.
    • Class IV (Dirty/Infected): Pus, perforated viscera, old trauma.

🧠 Memory Pearls

  • 6 W's of Post-Op Fever:
    • Wind (Atelectasis/Pneumonia, Days 1-2)
    • Water (UTI, Day 3)
    • Walking (DVT/PE, Day 4)
    • Wound (Infection, Days 5-7)
    • Waste (Abscess/C.diff, Days 7+)
    • Wonder drugs
  • 6 P's of Acute Limb Ischemia: Pain, Pallor, Pulselessness, Paresthesia, Paralysis, Poikilothermia (cold).
  • Beck's Triad (Cardiac Tamponade): Hypotension, muffled heart sounds, distended neck veins.
  • AMPLE History: Allergies, Medications, Past medical history/Pregnancy, Last meal, Events/Environment.
  • CREST Syndrome: Calcinosis, Raynaud's, Esophageal dysmotility, Sclerodactyly, Telangiectasia.
  • Kwashiorkor vs. Marasmus: Kwashiorkor = Protein malnutrition (edema, ascites). Marasmus = Caloric/Energy malnutrition (wasted, old-man appearance).
  • Strap Muscle Innervation ("TIE"): Thyrohyoid is Innervated Extra (by C1 hitchhiking on CN XII, bypassing the ansa cervicalis).

βœ… Final 20-Minute Self-Test

Q: What is the first maneuver for a trauma patient with a GCS of 6 who is hypotensive and bleeding from the thigh? β†’ A: Secure the airway (Intubate; GCS ≀ 8). ABCDE sequence always applies.

Q: A post-op day 8 laparotomy patient complains of sudden, painless, salmon-pink fluid draining from the incision. Diagnosis and next step? β†’ A: Fascial dehiscence. Immediately take back to the OR for closure to prevent evisceration.

Q: What is the hemodynamic profile of early septic shock? β†’ A: Low CVP, Low SVR, High Cardiac Output (hyperdynamic state).

Q: A trauma patient has a chest tube placed that immediately drains 1,600 mL of blood. What is the next step? β†’ A: Urgent thoracotomy (>1500 mL initial drainage is an absolute indication).

Q: What is the best test to diagnose underlying osteomyelitis in a diabetic foot ulcer? β†’ A: Probe-to-bone test.

Q: A patient on TPN suddenly becomes wildly hyper- and hypoglycemic (glucose intolerant) with a normal white count. What should you suspect? β†’ A: Occult line sepsis.

Q: You suspect a splenic laceration in a hemodynamically unstable patient. What test do you perform? β†’ A: FAST exam (If positive β†’ Ex-Lap). Do not send an unstable patient to the CT scanner.

Q: A patient requires massive blood transfusion. What electrolyte abnormality is most likely to occur and why? β†’ A: Hypocalcemia (Citrate toxicity; citrate in stored blood chelates serum calcium).

Q: What is the mechanism of metabolic acidosis in a patient with an un-resuscitated bowel perforation? β†’ A: High serum lactate. Poor tissue perfusion (shock) leads to anaerobic metabolism and lactic acid buildup.

Q: An asthmatic child swallows a coin. Is this an absolute contraindication to placing a nasogastric tube? β†’ A: No. Severe facial trauma, strictures, or esophageal ruptures are contraindications. Swallowed foreign bodies are not.

Q: What structure is most at risk of injury when placing a left internal jugular central venous catheter? β†’ A: Thoracic duct.

Q: Post-operative patient day 1 with a fever of 38.4Β°C. Lungs have decreased breath sounds at the bases. Best management? β†’ A: Incentive spirometry and pain control (diagnosis is atelectasis). Do not start antibiotics.

Q: A patient sustains a high-velocity gunshot wound directly through the umbilicus. What organ is most likely injured? β†’ A: Small bowel.

Q: What is the gold standard antibiotic for clean-contaminated biliary tract surgery? β†’ A: First-generation cephalosporin (Cefazolin).

Q: What is the most definitive clinical indicator of true nutritional status? β†’ A: Subjective Global Assessment (SGA). Prealbumin is useful, but clinical SGA is superior.

Gastrointestinal

🚨 Must Not Miss

  • Staging GI Malignancies: Endoscopic Ultrasound (EUS) is the absolute gold standard and single most accurate modality for determining T-stage (depth of invasion) and N-stage (local nodes) in esophageal, gastric, and pancreatic cancers.
  • The Ulcer Biopsy Rule: Gastric ulcers carry a high risk of malignancy and must be endoscopically biopsied at their margins. Primary duodenal ulcers are overwhelmingly benign and do not require routine biopsy.
  • H. pylori Pathophysiology: It is a microaerophilic organism that survives stomach acid by producing urease, which generates ammonia to neutralize the acid environment. It is not acidophilic.
  • Adenoma-Carcinoma Sequence: The universal initiating event for colorectal cancer is the mutation of the APC tumor suppressor gene (chromosome 5q21).
  • Internal Hernias: These are a classic, specific complication of Roux-en-Y Gastric Bypass (RYGB) due to created mesenteric defects. They are impossible after a Laparoscopic Sleeve Gastrectomy (SG) because no mesenteric defects are made.
  • Meckel's Diverticulum: The most common cause of massive, painless lower GI bleeding in infants/toddlers (due to ulceration from ectopic gastric mucosa). It is a "true" diverticulum (contains all three bowel wall layers), unlike colonic diverticula which are "false".
  • Gallstones Post-Bariatric Surgery: Rapid weight loss causes profound cholesterol mobilization, supersaturating the bile and heavily predisposing patients to gallstone formation.
  • Acute Pancreatitis Diagnosis: Requires 2 out of 3: (1) Classic epigastric pain radiating to the back, (2) Lipase/Amylase >3x upper limit of normal, (3) Characteristic CT findings.
  • Fatal Post-Splenectomy Complication: Overwhelming Post-Splenectomy Infection (OPSI) is primarily caused by encapsulated organisms, most lethally Streptococcus pneumoniae. Risk peaks in the first 2 years post-op.

🎯 Past-Paper Hit List

  • Achalasia Diagnostics: Barium swallow shows a "bird's beak," but High-Resolution Esophageal Manometry is the gold standard (showing aperistalsis and incomplete LES relaxation).
  • Gastric Cancers (Lauren Classification):
    • Diffuse (Linitis Plastica): Younger patients, equal male:female ratio, Blood type A, inherited CDH1/E-cadherin mutations, signet ring cells. Submucosal infiltration (rigid stomach).
    • Intestinal: Older men, environmentally driven (H. pylori, high nitrates), sporadic.
  • Emphysematous Cholecystitis: Classically affects elderly diabetic men. Caused by gas-forming organisms (Clostridium perfringens). It is often acalculous and requires emergent surgical source control.
  • Carcinoid Tumors: Midgut (ileal) carcinoids have the highest metastatic potential (regional LNs/liver) and are multifocal ~30% of the time. Systemic symptoms (flushing, bronchospasm, diarrhea) signify Carcinoid Syndrome, driven by serotonin.
  • GI Lymphoma: The GI tract is the most common extranodal site. Primary treatment is systemic chemoradiation (e.g., R-CHOP). Surgery is strictly for complications (perforation, refractory bleeding).
  • Colorectal Cancer Prognosis: Assuming no distant metastasis, the regional lymph node status (N-stage) is the single most important prognostic factor.
  • Hepatic Adenoma vs. FNH: Hepatic adenomas are strongly linked to OCP use, are hypervascular, and can bleed or turn malignant. Focal Nodular Hyperplasia (FNH) has a central stellate scar and zero malignant potential.
  • MEN-1 Syndrome: Suspect in any patient with refractory peptic ulcers (Gastrinoma) and hypercalcemia (Parathyroid adenoma).
  • Post-Op Bleeding Indicator: A progressively rising BUN without a proportional rise in creatinine strongly indicates ongoing internal GI bleeding (blood protein digestion).

🧭 Decision Algorithms

  • GERD Workup:
    • First step: Trial of empirical PPIs.
    • Next step (if refractory/atypical/pre-fundoplication): 24-hour pH monitoring.
  • Bariatric Surgery Selection:
    • Obese + Severe GERD: RYGB (Sleeve gastrectomy worsens GERD).
    • Obese + Sweet Eater: RYGB (triggers dumping syndrome, providing negative reinforcement).
    • Maximum weight loss/T2DM cure needed: BPD/DS (highest efficacy, but highest mortality).
  • Hepatic Adenoma Management:
    • Initial: Stop OCPs.
    • Definitive: Surgical resection if >5 cm or symptomatic.
    • Rule: NEVER biopsy due to severe hemorrhage risk.
  • Incidental Gallbladder Carcinoma (post-cholecystectomy):
    • T1a (lamina propria only): Simple cholecystectomy is curative.
    • T1b (muscularis) or deeper: Requires radical cholecystectomy + lymphadenectomy.
  • Acute Severe Ulcerative Colitis:
    • Start maximal medical therapy (IV steroids). If refractory by Day 5 β†’ Urgent subtotal colectomy with end ileostomy (prevents toxic megacolon).
  • Complicated Appendicitis (Abscess):
    • If a walled-off abscess is seen on CT β†’ IV antibiotics + image-guided percutaneous drainage β†’ Interval appendectomy in 6–8 weeks.
  • Splenic Trauma:
    • Hemodynamically Stable + Kehr sign (referred shoulder pain): CT abdomen to grade injury.
    • Hemodynamically Unstable: FAST exam β†’ Emergent exploratory laparotomy.

βš”οΈ Classic Differentiators & Traps

  • Trap - Barium/Scope in Diverticulitis: Colonoscopy and barium enemas are strictly contraindicated during acute diverticulitis due to a massive risk of iatrogenic perforation.
  • Trap - Ranson Criteria: Amylase is used for pancreatitis diagnosis, but it does NOT correlate with disease severity and is NOT part of the Ranson criteria.
  • Trap - Child-Pugh Score: Uses PT/INR to assess synthetic function, NOT PTT. AST/ALT are also NOT part of the score.
  • Trap - Normal Endoscopy in GERD: A normal endoscopy does NOT rule out GERD. ~60% of patients have Non-Erosive Reflux Disease (NERD).
  • Trap - Diverticular vs Cancer Bleeding: Diverticulosis causes massive, acute, painless lower GI arterial bleeding. Uncomplicated colon cancer causes chronic, occult bleeding (microcytic anemia).
  • Differentiator - Crohn's vs. Ulcerative Colitis:
    • Crohn's: Transmural, skip lesions, non-caseating granulomas, creeping fat, rectal sparing. Smoking worsens it.
    • UC: Superficial mucosal, continuous from rectum, crypt abscesses, "lead pipe" colon. Smoking paradoxically decreases severity.
  • Trap - Splenomegaly in ITP: In Immune Thrombocytopenic Purpura, the spleen is generally not palpably enlarged. A massively palpable spleen points to leukemia, lymphoma, or portal hypertension.
  • Trap - Hernia Anatomy: Femoral hernias present below the inguinal ligament. Inguinal hernias present above the inguinal ligament.
  • Differentiator - Internal vs. External Hemorrhoids: Internal (above dentate line, viscerally innervated, painless bleeders). External (below dentate line, squamous epithelium, somatically innervated, highly painful if thrombosed).

πŸ”’ Numbers, Scores & Cutoffs

  • Bariatric Surgery Indications: BMI β‰₯ 40, or BMI β‰₯ 35 with severe obesity-related comorbidities. (Note: Asia-Pacific criteria are lower: β‰₯ 37, or β‰₯ 32 with comorbidities).
  • Gastric Cancer Resection Margin: 6 cm.
  • FAP Cancer Risk: Familial Adenomatous Polyposis carries a 100% lifetime risk of colorectal cancer.
  • OPSI Incidence: Risk of OPSI after trauma splenectomy is very low (0.1%–0.5%).
  • Intragastric Balloon Limit: Maximum dwell time is 6 months (deflation leads to fatal bowel obstruction).
  • Ranson Admission Criteria: Age >55, WBC >16,000, Blood glucose >200 mg/dL, LDH >350, AST >250.
  • Atlanta Criteria (Organ Failure in AP): GI bleeding >500cc/24h, SBP ≀90 mmHg, PaO2 ≀60%, Creatinine β‰₯2 mg/dL.
  • Hinchey Staging (Diverticulitis):
    • I: Phlegmon/uncomplicated.
    • II: Walled-off pelvic abscess.
    • III: Purulent peritonitis.
    • IV: Fecal peritonitis.

πŸ› οΈ Operative / Procedural Must-Knows

  • Esophagectomy Conduits: The stomach is the most common conduit, mobilized on the right gastroepiploic artery pedicle. Never place a pre-op PEG tube (destroys the pedicle).
  • Fundoplication: The wrap must be tension-free and use the fundus (not the body). Nissen = 360Β°. Toupet = 270Β° posterior. Dor = Anterior.
  • Whipple Procedure (Pancreaticoduodenectomy): Removes pancreatic head, duodenum, gallbladder, distal bile duct. Requires 3 anastomoses: Pancreaticojejunostomy, Hepaticojejunostomy, Gastrojejunostomy.
  • Hartmann's Procedure: Resection of the diseased sigmoid colon, creation of an end colostomy, and closure of a blind rectal pouch. Used for emergent Hinchey III/IV diverticulitis.
  • Strictureplasty (Crohn's): Used to preserve bowel length. Heineke-Mikulicz for short strictures (≀5–7 cm); Finney for longer strictures (10–15 cm).
  • Splenectomy Vaccination Timing: For elective cases, administer pneumococcal, meningococcal, and Hib vaccines 2–4 weeks before surgery.
  • Goodsall’s Rule (Fistulas): External openings anterior to the transverse line and <3 cm from the verge run straight to the nearest crypt. Openings posterior, or anterior but >3 cm away, track in a curve to the posterior midline.
  • Gastrinoma Triangle: Bounded by the cystic/common hepatic duct junction, the D2/D3 duodenal junction, and the neck/body of the pancreas. Most gastrinomas are found in the duodenum!

🧠 Memory Pearls

  • Gastric Cancers: "Diffuse is in your DNA" (Blood type A, CDH1). "Intestinal is environmental" (H. pylori, nitrates).
  • Child-Pugh Score: "Pour Another Beer At Eleven" (PT/INR, Ascites, Bilirubin, Albumin, Encephalopathy).
  • Ranson Admission Criteria: GA LAW (Glucose, AST, LDH, Age, WBC).
  • Acute Pancreatitis Causes: I GET SMASHED (Gallstones, Ethanol, Trauma, Steroids, Mumps, Autoimmune, Scorpion sting, Hypercalcemia/Hypertriglyceridemia, ERCP, Drugs).
  • Pancreatic Cysts by Age:
    • SCA = Senior females (benign, microcystic).
    • MCN = Middle-aged mothers (macrocystic, tail, malignant potential).
    • SPT = School-aged young females (solid/cystic, excise).
  • Bariatric Surgeries:
    • Sleeve = Slices fundus, Stops ghrelin, Spikes GERD.
    • RYGB = Reduces Reflux, Rewires bowel (creates internal hernias).
  • Crohn's Disease Features: "Trans" = Transmural inflammation, Trans-GI tract (mouth to anus), Trans-tissue (fistulas).
  • Gallstone Ileus: Rigler's Triad (PBE) = Pneumobilia, Bowel obstruction, Ectopic gallstone.
  • Neuroendocrine Tumors:
    • Glucagonoma 4Ds: Dermatitis, Diabetes, Diarrhea, DVT.
    • VIPoma WDHA: Watery Diarrhea, Hypokalemia, Achlorhydria.

βœ… Final 20-Minute Self-Test

Q: What is the absolute best staging modality for determining T- and N-stage in esophageal/gastric cancer? β†’ A: Endoscopic Ultrasound (EUS).

Q: A patient presents with acute diverticulitis. Should you order a colonoscopy to confirm? β†’ A: No. It is strictly contraindicated due to the high risk of perforation.

Q: Which type of bariatric surgery reliably cures "sweet eaters" and why? β†’ A: Roux-en-Y Gastric Bypass (RYGB), because consuming concentrated sweets triggers dumping syndrome (negative reinforcement).

Q: A young woman on OCPs is found to have a 6 cm hypervascular liver mass. What is the diagnosis and should you biopsy it? β†’ A: Hepatic adenoma. NEVER biopsy due to the risk of massive hemorrhage.

Q: What vascular pedicle is used to mobilize the stomach during an esophagectomy? β†’ A: The right gastroepiploic artery.

Q: A 65-year-old diabetic male presents with RUQ pain and gas in the gallbladder wall on CT. Diagnosis and culprit organism? β†’ A: Emphysematous cholecystitis, most commonly caused by Clostridium perfringens.

Q: You diagnose acute severe ulcerative colitis. The patient is on Day 5 of IV steroids with no improvement. Next step? β†’ A: Urgent subtotal colectomy with end ileostomy.

Q: A patient has fasting hypoglycemia, low blood glucose, and symptom relief with IV glucose. If labs show high insulin and low C-peptide, what is the diagnosis? β†’ A: Factitious (exogenous) hypoglycemia. (An endogenous insulinoma would have high C-peptide).

Q: What is the most important modifiable risk factor that increases both the onset and post-operative recurrence of Crohn's disease? β†’ A: Smoking.

Q: A patient develops an internal hernia after bariatric surgery. Did they have a Sleeve Gastrectomy or a Gastric Bypass? β†’ A: Gastric Bypass (RYGB). Sleeve gastrectomies do not create mesenteric defects.

Q: Which gastric cancer is associated with Blood Type A, signet ring cells, and younger patients? β†’ A: Diffuse type (Linitis Plastica).

Q: When managing a walled-off appendiceal abscess seen on CT, what is the sequence of treatment? β†’ A: IV antibiotics + image-guided percutaneous drainage, followed by an interval appendectomy in 6–8 weeks.

Q: An external anal fistula opening is found 2 cm anterior to the transverse line. How will the tract run according to Goodsall's Rule? β†’ A: Straight into the nearest crypt.

Cardiothoracic

🚨 Must Not Miss

  • Embolic vs. Thrombotic Ischemia: Embolic Acute Limb Ischemia (ALI) strikes suddenly in a "clean" vessel (no history of claudication). Thrombotic ALI is gradual, superimposed on chronic Peripheral Arterial Disease (PAD) with well-developed collaterals.
  • Critical Limb Ischemia (CLI): The limb-threatening end-stage of PAD. Diagnosed by ischemic rest pain (classically worse at night when lying flat), non-healing ulcers, or gangrene.
  • Tetralogy of Fallot (ToF): The degree of cyanosis and overall prognosis are dictated entirely by the severity of the Right Ventricular Outflow Tract obstruction (pulmonary stenosis). This stenosis also protects the lungs from pulmonary hypertension.
  • Mitral Stenosis Hemodynamics: Because an isolated stenotic mitral valve restricts blood flow into the left ventricle, the LV is underfilled and doing less work. Therefore, LV hypertrophy does NOT occur. It causes LA enlargement, A-Fib, and pulmonary hypertension instead.
  • Tension Pneumothorax is purely clinical: Hypotension, absent breath sounds, tracheal deviation away from the affected side, and distended neck veins (obstructive shock). Waiting for a chest X-ray is absolutely contraindicated.
  • Thoracic vs. Abdominal Aortic Risks: Atherosclerosis is the #1 cause of descending thoracic AND abdominal aortic aneurysms. However, hypertension is the #1 risk factor for aortic dissections.
  • The Anterior Mediastinum "4 Ts": Thymoma (Myasthenia Gravis), Teratoma/Germ Cell (check AFP/Ξ²-hCG), Thyroid (ectopic), and Terrible Lymphoma.
  • DVT and Pulmonary Embolism: Outpatient DVT management with DOACs or LMWH is routine; not all DVTs require admission. The most life-threatening acute complication is PE, while the long-term sequela is post-thrombotic syndrome.

🎯 Past-Paper Hit List

  • PAD Medical Therapy: Aspirin is vital for cardiovascular secondary prevention, but it does not improve claudication distance. Supervised exercise improves walking distance and muscle metabolic efficiency, but does not change the resting Ankle-Brachial Index (ABI).
  • Surgical Aortic Valves:
    • Mechanical: For young, healthy patients (<50-60y); extremely durable but require lifelong warfarin. Early post-insertion mortality is typically thromboembolic.
    • Tissue (Bioprosthetic): For elderly patients (>65y), high bleeding risk, or women desiring pregnancy (since warfarin is teratogenic).
  • TAVR Indications: Transcatheter Aortic Valve Replacement is the gold standard for frail patients with severe, symptomatic aortic stenosis who are at prohibitive risk for open surgery.
  • Iatrogenic Vascular Complications:
    • Intra-Aortic Balloon Pump (IABP): Lower limb ischemia is the most common complication due to occlusion of the femoral artery by the large catheter.
    • Post-PCI Groin Mass: Palpable thrill + continuous bruit + venous engorgement/edema = Iatrogenic AV Fistula (a pseudoaneurysm lacks the dramatic venous signs).
  • Chest Tube Air Leaks: If an air leak persists for >3–5 days post-chest tube placement for a pneumothorax, it has failed conservative management. The definitive next step is Video-Assisted Thoracoscopic Surgery (VATS) with bleb stapling and pleurodesis.
  • Esophageal Cancer Resectability: Regional lymph node involvement (N1-3) does not mean the tumor is unresectable. These patients receive neoadjuvant chemoradiation followed by esophagectomy. Direct invasion of the aorta or trachea makes it unresectable.

🧭 Decision Algorithms

  • Vascular Trauma Triage:
    • Hard signs (pulsatile bleeding, expanding hematoma, absent pulse, bruit/thrill) β†’ Direct to OR for exploration.
    • Soft signs (diminished pulse, non-expanding hematoma, proximity) β†’ Perform ABI.
    • ABI > 0.9 β†’ Observe. ABI < 0.9 β†’ CTA.
  • Acute Limb Ischemia (Rutherford Categories):
    • Stages I & IIa (Viable/Marginal): Urgent revascularization.
    • Stage IIb (Immediately Threatened): Absent arterial Doppler, partial motor/sensory loss β†’ Emergency surgical embolectomy (Fogarty catheter) + IV Heparin.
    • Stage III (Non-viable): Profound paralysis, rigor mortis, fixed mottling β†’ Primary amputation. (Revascularization here causes lethal reperfusion syndrome).
  • Trauma Thoracotomy Thresholds (Chest Tube Output):
    • β†’ Immediate return of >1500 cc blood.
    • β†’ Ongoing output of >200 cc/hr for 2–4 consecutive hours.
  • Acute Aortic Dissection Medical Control:
    • Step 1: IV Beta-blockers (Reduce HR <60 bpm to decrease shear stress).
    • Step 2: IV Vasodilators (Reduce SBP <120 mmHg). Never drop BP before HR, as reflex tachycardia will tear the aorta further.
  • Empyema Management:
    • Stage 1 (Exudative): Thoracentesis/chest tube + antibiotics.
    • Stage 2 (Fibropurulent) & 3 (Organizing): Chest tube is insufficient. Requires intrapleural fibrinolytics (tPA/DNase), VATS, or thoracotomy with decortication.

βš”οΈ Classic Differentiators & Traps

  • Pneumothorax vs. Hemothorax Physical Exam: Both have decreased breath sounds. Pneumothorax is hyperresonant to percussion and has decreased tactile fremitus (trap: don't choose "increased fremitus"). Hemothorax is dull to percussion.
  • CABG vs. PCI: CABG is the absolute standard of care for left main coronary disease, complex triple-vessel disease, or multivessel disease combined with reduced LVEF (<50%) or diabetes.
  • Ductal-Dependent Lesions Trap: You must KEEP the patent ductus arteriosus (PDA) OPEN to sustain life until surgery. Give Prostaglandin E1 (Alprostadil). Indomethacin/ibuprofen will close it and kill the patient.
  • Ruptured AAA Timing Trap: A ruptured abdominal aortic aneurysm has no conservative window. It is an absolute indication for emergent surgical/endovascular repair. Do not select answers offering a "12-hour window."
  • Pancoast Tumor Operability: Pancoast (superior sulcus) tumors are predominantly squamous cell carcinomas. Horner's syndrome or extensive brachial plexus invasion are contraindications to primary surgery; management shifts to concurrent chemoradiation.

πŸ”’ Numbers, Scores & Cutoffs

  • ABI Ranges:
    • Normal: >0.9$
    • Claudication: 0.5 - 0.9
    • Rest pain (CLI): <0.50 (often 0.21 - 0.49$)
    • Tissue Loss/Gangrene: <0.20$
    • Trap: Diabetics/ESRD patients have calcified vessels β†’ Falsely elevated ABI (>1.25).
  • Ischemia Tolerance: Irreversible tissue damage occurs beyond 6 hours of warm ischemia.
  • Aortic Aneurysm Surgical Thresholds: β‰₯ 5.5 cm for sporadic/bicuspid TAA, or β‰₯ 5.0 cm in Marfan syndrome. Rupture risk spikes dramatically at 6.0 cm.
  • Coronary Anatomy Dominance: Right-dominant (85%) means RCA supplies the posterior descending artery (PDA). Left-dominant (10%) means the circumflex (LCx) supplies the PDA.
  • Vein Graft Failure: CABG graft failure between 1 month and 1 year is almost exclusively caused by intimal hyperplasia (smooth muscle proliferation).
  • Pleural Fluid Cutoffs: A parapneumonic effusion requires drainage (complicated) if pH < 7.20 or Glucose < 40.
  • Lung Resection Limits: An FEV1 < 800 ml or DLCO < 60% precludes surgery. Goal post-op FEV1 is β‰₯ 1000 ml.

πŸ› οΈ Operative / Procedural Must-Knows

  • Aortic Cross-Clamping Complication: The most devastating complication of descending thoracic aortic repair is paraplegia secondary to ischemia of the anterior spinal artery (Artery of Adamkiewicz).
  • Vascular Repair Conduit: For severe arterial trauma (AAST Grade IV/V) where primary repair is impossible, the autologous greater saphenous vein (GSV) is the interposition graft of choice.
  • Fasciotomy: Prophylactic double-incision fasciotomy is mandatory after successful reperfusion of prolonged limb ischemia (>4–6 hours) to prevent compartment syndrome.
  • Post-Pneumonectomy Empyema: A patient post-pneumonectomy who develops a dropping/changing air-fluid level on CXR, fever, and copious sputum has a bronchopleural fistula. The definitive next step is diagnostic thoracentesis.
  • Surgical Approaches:
    • Median Sternotomy: Standard for penetrating cardiac trauma in stable/semi-stable OR patients.
    • Chamberlain Procedure (Anterior Mediastinotomy): 2nd/3rd intercostal parasternal incision to biopsy anterior mediastinal masses.
    • VATS Positioning: Lateral decubitus with one 4-6cm utility incision and multiple small ports.

🧠 Memory Pearls

  • 6 P's of Acute Limb Ischemia: Pain, Pallor, Pulselessness, Paresthesia, Paralysis, Poikilothermia.
  • Embolism vs. Thrombosis: Embolism = Explosive onset, Empty (clean) vessels. Thrombosis = Time (gradual), Terrible vessels (claudication hx).
  • Tetralogy of Fallot: PROVe β€” Pulmonary stenosis, RVH, Overriding aorta, VSD.
  • Beck’s Triad for Tamponade: The 3 D's β€” Decreased BP, Distant heart sounds, Distended jugular veins.
  • Thoracotomy Rule: 1500 or 200 (Immediate out the door, or per hour for a few more).
  • Empyema Stages: Every Fool Organizes (Exudative β†’ Fibropurulent β†’ Organizing).
  • Tension PTX: Pushes everything AWAY (trachea/mediastinum shift to the normal side).

βœ… Final 20-Minute Self-Test

1. A patient presents with an ABI of 1.35. What is the diagnosis and pathophysiology? β†’ Falsely elevated ABI due to severely calcified, non-compressible arteries (classic in Diabetes or ESRD).

2. What is the single most important lifestyle intervention for a patient with claudication? β†’ Smoking cessation.

3. A trauma patient has a tension pneumothorax. You are preparing to intubate. What must you do FIRST? β†’ Immediate needle decompression or chest tube placement. (Positive pressure ventilation will worsen the obstructive shock and cause cardiac arrest).

4. A neonate has a ductal-dependent cardiac lesion. What medication must be initiated instantly? β†’ Prostaglandin E1 (Alprostadil) to keep the PDA open.

5. What is the strict order of medical management in Acute Aortic Dissection? β†’ 1st: IV Beta-blockers (lower HR < 60). 2nd: IV Vasodilators (lower SBP < 120).

6. A patient with isolated severe mitral stenosis undergoes echocardiography. What will the Left Ventricle look like? β†’ Normal or small (No Left Ventricular Hypertrophy, because the LV is underfilled and pressure-protected by the stenotic valve).

7. A 60-year-old diabetic male with multivessel coronary disease and an LVEF of 40% needs revascularization. CABG or PCI? β†’ CABG is the standard of care for multivessel disease + Diabetes + reduced EF.

8. Patient has an acute embolic occlusion of the superficial femoral artery. Vascular exam reveals absent pulses, total paralysis of the foot, profound sensory loss, and rigor mortis. What is the management? β†’ Primary amputation (Rutherford Stage III). Revascularization will cause lethal reperfusion injury.

9. A patient's saphenous vein graft fails 6 months after CABG. What is the most likely biological cause? β†’ Intimal hyperplasia.

10. A Pancoast tumor is diagnosed in a patient who also exhibits ptosis, miosis, and anhidrosis on the ipsilateral side. Is this patient a candidate for immediate surgical resection? β†’ No. Horner's syndrome indicates sympathetic ganglion invasion, a contraindication to primary surgery. (Requires chemoradiation).

11. What finding absolutely separates Critical Limb Ischemia (CLI) from severe intermittent claudication? β†’ Ischemic rest pain (often waking the patient at night) or tissue loss (ulcers/gangrene). Claudication strictly stops with rest.

12. A patient with a right-sided chest tube for pneumothorax continues to have a persistent air leak on day 6. What is the definitive next step? β†’ VATS (Video-Assisted Thoracoscopic Surgery) with bleb stapling and pleurodesis.

Pediatric

🚨 Must Not Miss

  • Volvulus = Absolute Emergency: Sudden bilious vomiting in a neonate is midgut volvulus until proven otherwise. Delaying surgery is catastrophic.
  • CDH is a Physiologic, NOT Surgical, Emergency: Congenital Diaphragmatic Hernia pathology hinges on pulmonary hypoplasia and right-to-left shunting (pulmonary hypertension). You must stabilize ventilation and pulmonary hemodynamics before operative repair.
  • HPS Resuscitation Precedes Surgery: Hypertrophic Pyloric Stenosis presents with projectile nonbilious vomiting, causing a classic hypochloremic, hypokalemic metabolic alkalosis. IV fluid resuscitation and electrolyte correction are mandatory before taking the patient to the OR.
  • Omphalocele vs. Gastroschisis:
    • Omphalocele: Midline sac present. High mortality driven by a 50–70% association with severe congenital anomalies (cardiac defects, Trisomies 13/18/21).
    • Gastroschisis: Right-sided, no sac, matted/exposed bowel. Highly associated with younger maternal age and bowel atresias, but not typically systemic syndromes.
  • Pediatric Hernias Need No Mesh: Pediatric indirect hernias are caused by a patent processus vaginalis (PPV) with normal musculature. The standard of care is a herniotomy (high ligation of the sac). Bassini repairs or mesh hernioplasties are practically never used.
  • Tumor Palpation Danger: Do not vigorously palpate a suspected Wilms’ tumor on physical exam. Rough palpation can rupture the tumor, cause massive hemorrhage, and instantly upstage the patient to Stage III.
  • First-Line for Hemangiomas: Problematic, vision-threatening, or airway-compromising infantile hemangiomas are treated immediately with oral propranolol.

🎯 Past-Paper Hit List

  • VACTERL Echocardiograms: Cardiac defects are a core VACTERL association. Always obtain an echo before anesthetizing/operating on a neonate with Esophageal Atresia (EA/TEF) or anorectal malformations.
  • Hirschsprung Disease Histology: Beyond classic aganglionosis, the key adjunctive exam finding on a rectal biopsy is the loss of calretinin staining in the affected segment.
  • CDH Traps: Diaphragmatic eventration (abnormally thinned but intact diaphragm) presents identically to CDH clinically and radiographically. Also, fetal surgery (FETO) for CDH is strictly contraindicated if severe concomitant anomalies (cardiac/chromosomal) exist.
  • Foreign Body "Stealth" Presentations:
    • Uncomplicated esophageal meat boluses typically present with a completely normal physical and respiratory exam.
    • Conversely, a large esophageal coin can compress the highly compliant posterior membranous tracheal wall, causing atypical respiratory symptoms (stridor, wheezing, recurrent cough).
  • Button Battery vs. Coin: A button battery on AXR shows a "double contour" or "halo sign." If in the esophagus = emergent endoscopic removal (liquefaction necrosis within 1 hour). If in the stomach and asymptomatic = observe.
  • Cleft Palate Hearing Loss: Causes acquired conductive hearing loss via recurrent otitis media (Eustachian tube dysfunction), NOT congenital sensorineural hearing loss.
  • Hypospadias Traps: The most common locations are distal (glandular/coronal), not proximal. Classically presents as spraying of the urinary stream. Circumcision is strictly contraindicated as the dorsal hooded foreskin is needed for reconstruction.
  • VUR Surgical Indications: Primary VUR is treated medically first. Ureteral reimplantation is indicated for breakthrough UTIs despite continuous prophylactic antibiotics, or Grade IV/V reflux with recurrent UTIs and renal scarring.

🧭 Decision Algorithms

  • Neonatal Intestinal Obstruction:
    • Step 1: Hemodynamic stabilization (NPO, NGT, IVF).
    • Step 2: Differentiate uncomplicated vs. complicated. E.g., Uncomplicated meconium ileus β†’ Gastrografin enema (diagnostic & therapeutic). Complicated β†’ OR.
  • Undescended Testis (UDT):
    • Unilateral palpable: Dartos pouch orchiopexy.
    • Unilateral non-palpable: Diagnostic laparoscopy (gold standard to locate intra-abdominal/vanishing testes).
    • Bilateral non-palpable: Check baseline FSH/LH and perform an hCG stimulation test to rule out anorchia before surgical exploration.
  • Intussusception:
    • Start NPO, NGT, IVF.
    • Stable / no peritonitis β†’ Hydrostatic/pneumatic enema (85% success).
    • Shock, peritonitis, or enema failure β†’ Laparoscopic/Open manual retrograde "milking."
  • Incarcerated Hernia:
    • Stable β†’ Sedate, apply continuous manual pressure to reduce. If successful, admit for elective repair in 24–48 hours.
    • Peritonitis / Shock / Strangulation β†’ Do not reduce. Emergent surgery.
  • Imperforate Anus Imaging:
    • Wait 24 hours to allow swallowed air to traverse the gut.
    • Perform a prone cross-table lateral radiograph (invertogram) to measure the distance between the rectal gas pouch and perineum.
  • Airway Foreign Body:
    • Clinical suspicion β†’ Expiratory CXR (shows hyperinflation/air trapping on the affected side due to a one-way valve effect) β†’ Rigid bronchoscopy.

βš”οΈ Classic Differentiators & Traps

  • Esophageal Atresia Gas Patterns: Most common is Type C (proximal EA, distal TEF), which has stomach gas. Type A (isolated EA) is unique: the AXR shows a completely gasless abdomen.
  • Distal Anorectal Malformations: A rectoperineal fistula is a "low" defect. Because it is highly distal, vomiting occurs much later in the clinical course and is initially non-bilious, differentiating it from high obstructions.
  • EA/TEF Timing Trap: Definitive primary repair is the goal, but delay repair (opt for a staged approach with a gastrostomy) if the neonate is extremely premature, hemodynamically unstable, or has severe concomitant life-threatening anomalies.
  • UPJ Obstruction vs. VUR: Due to prenatal screening, most UPJOs are diagnosed as asymptomatic fetal hydronephrosis. A Micturating Cystourethrogram (MCUG/VCUG) is mandatory during workup to rule out coexisting or mimicking Vesicoureteral Reflux (VUR).
  • Wilms Tumor Staging Trap: Staging a newly diagnosed Wilms tumor requires a contrast-enhanced CT of the abdomen AND chest (lung is the most common site of metastasis).
  • Neuroblastoma Age Paradox: Infants (<1 year) actually have a better prognosis.

πŸ”’ Numbers, Scores & Cutoffs

  • Meckel Diverticulum Rule of 2s:
    • 2% prevalence.
    • 2:1 male-to-female ratio.
    • Presents by age 2 (~50% of symptomatic cases).
    • Located 2 feet from the ileocecal valve.
    • 2 inches long.
    • Contains 2 types of ectopic mucosa (gastric = bleeding, pancreatic).
  • HPS Ultrasound Criteria: Muscle thickness β‰₯ 4 mm; Pyloric channel length β‰₯ 16 mm.
  • Bochdalek Hernia: 80–85% occur on the left side.
  • Pediatric Burns: Partial-thickness burns >10% TBSA mandate burn unit admission.
  • VUR Submucosal Tunnel: The normal, protective functional ratio of submucosal ureteral tunnel length to ureter diameter is 5:1.
  • UPJO Pyeloplasty Indications (MAG3 Scan): Differential renal function drops <40%, or drainage T1/2 is >20 mins.

πŸ› οΈ Operative / Procedural Must-Knows

  • Ladd's Procedure (for Malrotation):
    1. Counterclockwise detorsion.
    1. Division of Ladd's bands.
    1. Broadening the mesentery.
    1. Prophylactic appendectomy.
    1. Placing small bowel on the right, colon on the left.
  • Ramstedt Pyloromyotomy (for HPS): Incision of the circular muscle down to, but not including, the submucosa. The mucosa must remain intact and bulge out. Mucosal perforation (1–2%) is the most tested intra-op complication.
  • Duodenal Atresia Repair: Requires a diamond-shaped duodenoduodenostomy to prevent strictures.
  • Kasai Portoenterostomy (for Biliary Atresia): A Roux-en-Y jejunal limb is anastomosed directly to the transected porta hepatis. Trap: Despite success, 2/3 still eventually require a liver transplant.
  • Rigid vs Flexible Bronchoscopy: Rigid bronchoscopy is the absolute procedure of choice for pediatric airway foreign bodies (provides superior airway control, ventilation, and a larger working channel).
  • Hypospadias Repair: Done before 18 months. Includes chordee release, urethral plate tubularization (Snodgrass), and reconstruction using the dorsal foreskin.

🧠 Memory Pearls

  • VACTERL Associations: Vertebral, Anorectal, Cardiac, TEF, Renal, Limb.
  • Double Bubble: Duodenal atresia (or midgut volvulus).
  • Corkscrew Sign: Midgut volvulus on Upper GI series.
  • String Sign: Thin streak of contrast passing through the narrowed pyloric channel in HPS on Upper GI series.
  • Ground-Glass / Soap Bubble (Neuhauser's sign): Meconium ileus (classic for Cystic Fibrosis).
  • Target / Donut / Pseudokidney Sign: Intussusception on ultrasound.
  • Dance Sign: Empty right iliac fossa on palpation due to the cecum telescoping away (intussusception).
  • Triangular Cord Sign: Fibrous cone of tissue at the porta hepatis on ultrasound (Biliary atresia).
  • "Blueberry Muffin" Baby: Stage MS Neuroblastoma (skin/liver/marrow mets in infants <18 months)β€”paradoxically has a high spontaneous regression rate!
  • "Dumb-bell" Tumor: Neuroblastoma extending from the retroperitoneum/mediastinum through the intervertebral foramen, compressing the spinal cord.

βœ… Final 20-Minute Self-Test

Q: A neonate presents with frothy drooling and choking on the first feed. AXR shows a completely gasless abdomen. Diagnosis? β†’ Isolated Esophageal Atresia (Type A).

Q: Sudden bilious vomiting in a 2-day old neonate. Most likely diagnosis? β†’ Midgut volvulus (surgical emergency).

Q: 4-week-old with non-bilious projectile vomiting. What metabolic derangement is expected? β†’ Hypochloremic, hypokalemic metabolic alkalosis (HPS).

Q: A pathognomonic X-ray finding for Necrotizing Enterocolitis (NEC)? β†’ Pneumatosis intestinalis (gas in the bowel wall).

Q: Medical first-line treatment for an infant with a vision-threatening facial hemangioma? β†’ Oral propranolol.

Q: What is the gold standard diagnostic step for a unilateral, non-palpable undescended testis? β†’ Diagnostic laparoscopy.

Q: A child with intussusception has failed pneumatic enema reduction and is hemodynamically stable. Next step? β†’ Surgical reduction (Laparoscopic or Open retrograde milking).

Q: Imaging modality required to definitively stage a Wilms Tumor? β†’ Contrast-enhanced CT of the abdomen AND chest.

Q: A neonate with VACTERL syndrome is scheduled for esophageal atresia repair. What screening test must be done prior to surgery? β†’ Echocardiogram (to rule out severe cardiac defects).

Q: 3-year-old swallowed a coin. X-ray shows it in the stomach. Vitals are normal. Next step? β†’ Observation and reassurance.

Q: Histological hallmark of Hirschsprung disease on rectal biopsy (besides aganglionosis)? β†’ Loss of calretinin staining.

Q: Most commonly tested intra-operative complication of a Ramstedt Pyloromyotomy? β†’ Mucosal perforation.

Q: Procedure of choice for retrieving a suspected peanut from a toddler's airway? β†’ Rigid bronchoscopy.

Q: Ultrasound findings of a target sign and pseudokidney sign. Diagnosis? β†’ Intussusception.

Endocrine

🚨 Must Not Miss

  • Most Lethal Thyroid Surgery Complication: Postoperative expanding neck hematoma. It causes rapid airway compromise via venous and tracheal compression. Treatment is immediate bedside decompression (opening the wound), do not wait for the OR.
  • Pheochromocytoma Pre-Op Rule: Always initiate alpha-blockade (phenoxybenzamine) first. Administering beta-blockers prior to alpha-blockade triggers unopposed alpha-stimulation, leading to severe vasoconstriction, hypertensive crisis, and acute heart failure.
  • Cervical / Parotid Mass Biopsy Rule: Never do an initial excisional or incisional biopsy on a firm, isolated cervical node in a smoker (suspected SCC) or a parotid mass with facial nerve palsy. It disrupts surgical planes and risks tumor seeding/nerve damage. The absolute first step is Fine Needle Aspiration (FNA).
  • Follicular Neoplasms (Bethesda 4): FNA cannot distinguish between a benign follicular adenoma and malignant follicular carcinoma. Malignancy is strictly defined by capsular or vascular invasion (requires tissue architecture). A Bethesda 4 FNA mandates a diagnostic hemithyroidectomy.
  • MEN Syndrome Divider: Pheochromocytoma is strictly a feature of MEN 2A and 2B. It is never seen in MEN 1.
  • Asymptomatic Primary Hyperparathyroidism (HPT) Surgery Indications: Age < 50 years old or Serum Calcium >1.0 mg/dL above the upper limit of normal.
  • Charcot vs. Cellulitis: An acutely red, hot, swollen, painless (neuropathic) diabetic foot is acute Charcot Neuro-osteoarthropathy until proven otherwise. Treatment is strict immobilization (Total Contact Cast), not antibiotics, unless there is an open ulcer/systemic infection.

🎯 Past-Paper Hit List

  • Primary vs. Secondary HPT:
    • Primary: 80-85% single adenoma. Labs: High Ca, High PTH, Low Phosphate.
    • Secondary: Normal physiologic response to hypocalcemia (e.g., CKD, Vitamin D deficiency). Labs: Low/Normal Ca, High PTH.
  • Thyroid Cancer Profiles:
    • Papillary: Most common (80–85%), pediatric, radiation-associated, multifocal lymphatic spread, Psammoma bodies.
    • Follicular: Iodine-deficient areas, unifocal, hematogenous spread (lungs, bone).
    • Medullary: Parafollicular C-cells, secretes calcitonin, deposits amyloid (Congo Red stain), 25% MEN 2A/2B (RET mutations).
    • Anaplastic: Elderly, highly aggressive, rapid stridor/invasion, fatal in months.
  • Adrenal Syndromes:
    • Conn's Syndrome (Primary Hyperaldosteronism): Hypertension, hypernatremia, hypokalemia. Renin is profoundly suppressed (low).
    • Addison's Disease: Lack of mineralocorticoids/glucocorticoids. Profound sodium wasting, fluid depletion, and severe hypotension (never hypertension).
    • Insulinoma: High insulin, hypoglycemia (causing catecholamine surge: anxiety/palpitations), appropriately high C-peptide.
    • Glucagonoma: Triad of mild new-onset diabetes, necrolytic migratory erythema (scaling rash on legs/groin), and a pancreatic tail mass.
  • Salivary Gland Masses:
    • Pleomorphic Adenoma: Most common overall / most common benign. Slow-growing, painless.
    • Warthin's Tumor: Older smoking males, parotid only, 10% bilateral, essentially 0% malignancy risk.
    • Mucoepidermoid Carcinoma: Most common salivary malignancy.
    • Adenoid Cystic Carcinoma: Minor salivary gland/submandibular malignancy; notorious for perineural invasion and distant lung mets.
  • Sialolithiasis: Recurrent submandibular swelling specifically upon eating. Submandibular gland is most prone due to thick/mucinous saliva and uphill Wharton’s duct.
  • Tracheo-innominate Fistula: A brisk "sentinel" bright red bleed from a tracheostomy site 1–2 weeks post-procedure.

🧭 Decision Algorithms

Thyroid Nodule Workup

  1. Discover nodule β†’ First step: Check TSH.
  1. If TSH is Low: Order Radioactive Iodine Uptake (RAIU) scan.
    • "Hot" nodule β†’ Hyperfunctioning (rarely malignant) β†’ Hemithyroidectomy definitively treats toxic adenoma.
    • "Cold" nodule β†’ Proceed to FNA.
  1. If TSH is Normal/Elevated: Proceed straight to Ultrasound-guided FNA (if β‰₯ 1 cm or highly suspicious ultrasound features).

Primary Hyperaldosteronism Management

  1. Labs confirm high Aldo / low Renin.
  1. Imaging shows bilateral adrenal nodules.
  1. Next Step: Adrenal Venous Sampling (AVS) (distinguishes unilateral adenoma from bilateral hyperplasia).
    • Lateralizes to one side: Unilateral adrenalectomy.
    • Bilateral overproduction: Medical management with Spironolactone (bilateral adrenalectomy causes Addisonian crisis).

Diabetic Foot Ischemia Workup

  1. Check Ankle-Brachial Index (ABI).
    • ABI > 1.30: Poorly compressible, calcified vessels (common in DM). Needs toe pressures.
    • ABI 0.90 – 1.30: Normal.
    • ABI < 0.50: Severe ischemia. Mandates urgent vascular imaging (angio) for revascularization prior to any elective debridement/amputation.

βš”οΈ Classic Differentiators & Traps

  • Trap: Excisional Biopsy of the Parotid: Suspect malignancy if a parotid mass presents with facial nerve palsy. Never do an incisional biopsy (seeds tumor/damages nerve). Do an FNA. Surgery is superficial parotidectomy with facial nerve preservation.
  • Trap: Adrenal Adenoma & Hypokalemia: Marked hypokalemia is uncharacteristic of Cushing's (cortisol). If you see severe hypokalemia, think Primary Hyperaldosteronism or ectopic ACTH.
  • Trap: Orthostatic Hypotension in Pheochromocytoma: This is caused by severely contracted intravascular volume due to chronic, massive alpha-adrenergic vasoconstriction, not catecholamine withdrawal.
  • Trap: Clonidine Suppression Test: Clonidine suppresses normal sympathetics. If catecholamine levels drop >50% after clonidine, it is not a pheochromocytoma (autonomous tumors do not suppress).
  • Trap: Subcentimeter Thyroid Nodules: FNA is generally not indicated for nodules < 10 mm unless they have extremely suspicious ultrasound features or the patient has high-risk history (radiation).
  • Trap: Diabetic Foot Hygiene: Instruct patients not to soak feet (causes maceration) and not to apply lotion between the toes (promotes fungal growth).

πŸ”’ Numbers, Scores & Cutoffs

  • Primary HPT Surgical Thresholds (Asymptomatic): Age < 50, Calcium > 1.0 mg/dL above ULN.
  • Adrenal CT Hounsfield Units (HU):
    • Benign, lipid-rich adenoma: < 10 HU (with >60% contrast washout).
    • Suspicious for malignancy/pheo: > 30 HU.
  • Adrenal Incidentaloma Surgery Criteria: Size > 5 cm, functionally active, or rapid growth.
  • Diabetic Foot Mortality: 5-year mortality after a diabetic lower limb amputation is 68% (worse than many common cancers).
  • Rule of 80s (Salivary Tumors): 80% are in the parotid (80% of these are benign). Conversely, 80% of minor salivary gland tumors are malignant.
  • Pheochromocytoma "Rule of 10s": 10% bilateral, 10% malignant, 10% extra-adrenal, 10% familial, 10% pediatric.
    • Pediatric Trap: In kids, it’s a roughly 25% rate of being bilateral, familial, or extra-adrenal.
  • Carotid Body Tumors: Malignancy rate is < 10%.

πŸ› οΈ Operative / Procedural Must-Knows

  • Post-Op Thyroid Feeding: The GI tract is not entered. Feeding can begin immediately upon recovery from anesthesia (assuming intact swallowing); do not wait for bowel sounds.
  • Parathyroid Anatomy: The Inferior Thyroid Artery supplies the majority of blood to all four parathyroid glands.
  • Post-Thyroidectomy Hypocalcemia: Perioral numbness and muscle cramps signify parathyroid injury/devascularization. Treat immediately with IV/PO calcium and Vitamin D.
  • Hungry Bone Syndrome: Profound, rapid hypocalcemia post-parathyroidectomy or severe Graves' surgery. Due to massive skeletal calcium uptake once PTH/thyrotoxicosis is removed.
  • Medullary Thyroid Carcinoma (MTC) Surgery: Prophylactic central compartment (Level VI) lymph node dissection is universally recommended during the initial total thyroidectomy.
  • Parotidectomy Landmarks: The main trunk of the facial nerve is identified using the tragal pointer (cartilaginous EAC) and the posterior belly of the digastric muscle.
  • Posterior Retroperitoneal Adrenalectomy: Avoids intra-abdominal adhesions and allows bilateral surgery without repositioning. Constraint: Tiny working space; strictly reserved for tumors < 5 cm.
  • Distal Submandibular Stone Extraction: A stone ≀ 1 cm from Wharton's duct opening is best managed transorally by cutting directly over the duct (sialodochotomy).
  • Diabetic Ulcer Debridement: Always sharply debride the thick rim of hyperkeratotic callus surrounding the ulcer to allow epithelialization. If there is a fluctuant abscess, actively drain it before debriding necrotic tissue.

🧠 Memory Pearls

  • MEN 1 = 3 P's: Parathyroid, Pituitary, Pancreas (Gastrinoma most common). No Pheo!
  • Papillary Carcinoma = The "P"s: Popular (80%), Pediatric, Psammoma bodies, Palpable lymph nodes (lymphatic spread).
  • Follicular Carcinoma = The "F"s: Far-away spread (hematogenous), Females, FNA is Fruitless (needs tissue architecture).
  • Hurthle Cell: Abundant eosinophilic cytoplasm (mitochondria), not eosinophilic WBCs.
  • Adrenal Cortex Zones (GFR = Salt, Sugar, Sex):
    • Glomerulosa β†’ Salt (Aldosterone)
    • Fasciculata β†’ Sugar (Cortisol)
    • Reticularis β†’ Sex (Androgens)
  • Warthin's Tumor = "W"s: Wrinkled, White male, Who smokes, with a Watery-cystic parotid mass.
  • MIAMI (Lymphadenopathy): Malignancies, Infectious, Autoimmune, Miscellaneous, Iatrogenic.
  • Charcot Stages (Eichenholtz): Development (acute/fragmentation), Coalescence (subacute), Reconstruction (chronic/rocker-bottom).
  • SINBAD Ulcer Score: Site, Ischemia, Neuropathy, Bacterial infection, Area, Depth.

βœ… Final 20-Minute Self-Test

Q: A 45-year-old has an asymptomatic calcium of 11.2 mg/dL (Normal: 8.5-10.5). Is surgery indicated? β†’ Yes. Age < 50 is an absolute indication, regardless of the calcium level. (Calcium >11.5 would be the secondary indication).

Q: A thyroid FNA returns as Bethesda 4 (Follicular Neoplasm). Next best step? β†’ Diagnostic hemithyroidectomy. FNA cannot rule out capsular invasion.

Q: A 65-year-old smoker presents with a firm, painless 3cm mass in the right neck. Next step? β†’ FNA cytology. Never perform an excisional biopsy on a suspected SCC cervical node.

Q: What is the most sensitive and specific imaging modality for localizing a hyperfunctioning parathyroid adenoma? β†’ Technetium-99m Sestamibi scan.

Q: A patient with suspected pheochromocytoma is given a beta-blocker first. What happens? β†’ Hypertensive crisis / acute heart failure due to unopposed alpha-adrenergic vasoconstriction. Always give alpha-blockade (phenoxybenzamine) first.

Q: A patient presents with mild new-onset diabetes, a scaling erythematous rash on the groin, and a pancreatic mass. Diagnosis? β†’ Glucagonoma (the rash is necrolytic migratory erythema).

Q: An adrenal mass is found on CT. It is 2 cm, functionally inactive, and measures 4 Hounsfield Units. Management? β†’ Observation. (<3 cm, non-functional, and <10 HU indicates a benign lipid-rich adenoma).

Q: A patient develops a brisk, bright red bleed from a tracheostomy site 10 days post-placement. Diagnosis? β†’ Tracheo-innominate fistula.

Q: A diabetic patient has a painless, red, hot, swollen foot without systemic signs of infection. Most likely diagnosis and immediate management? β†’ Acute Charcot neuro-osteoarthropathy. Treat with strict immobilization (Total Contact Cast).

Q: Following a total thyroidectomy, the patient complains of tingling around the lips and muscle cramps. What is the cause? β†’ Hypocalcemia due to inadvertent parathyroid injury or devascularization. Treat with Calcium and Vitamin D.

Plastic

🚨 Must Not Miss

  • The Macrophage is King: Neutrophils arrive first (24–48h), but macrophages (48–72h) are the most critical cells for wound healing. (Exception: In perfectly clean surgical wounds, PMNs are not strictly required).
  • Flaps vs. Grafts: Grafts rely 100% on the recipient bed's blood supply. You must use a flap (which brings its own blood supply) to cover bare bone, bare tendon, exposed hardware, or pressure ulcers.
  • Burn Resuscitation Gold Standard: Strict hourly urine output is the single most reliable indicator of adequate fluid resuscitation (Goal: 0.5–1.0 mL/kg/hr for adults).
  • No Prophylactic Antibiotics: They are strictly contraindicated in both acute burns and frostbite. They do not prevent sepsis; they actively select for deadly Pseudomonas species.
  • Cleft Palate Feeding: The neuromuscular swallowing mechanism (deglutition) is completely intact. Feeding difficulty is purely due to the inability to create negative suction pressure and nasal regurgitation.
  • Bites are Dirty: Never primarily close a human bite (fight bite) or heavily contaminated wound. Debride, irrigate, and leave open for delayed primary closure to prevent deep space abscesses or septic arthritis.
  • Melanoma Prognosis: Absolute depth of invasion in millimeters (Breslow thickness) is the single most important prognostic indicator.
  • Felon vs. Antibiotics: A felon (pulp space infection) is a closed-compartment syndrome of the fingertip. Antibiotics alone are always the wrong answer; mandatory treatment is surgical Incision and Drainage (I&D).

🎯 Past-Paper Hit List

  • The Hematoma Trap: Hematoma/seroma is the #1 cause of skin graft failure. Meshed grafts have a better take rate than unmeshed (sheet) grafts because the mesh allows fluid drainage.
  • Vitamin Wound Interactions: Vitamin A and C accelerate healing (Vitamin A can even reverse steroid-induced healing delays). However, high-dose Vitamin E impairs collagen synthesis and delays healing.
  • Inhalation Injury Diagnosis: Initial CXR and ABG are notoriously normal. The diagnostic gold standard is direct visualization via flexible fiberoptic bronchoscopy.
  • The Burn Hemoconcentration Trap: A high Hb/Hct in a fresh burn patient indicates severe plasma leak (third spacing) and under-resuscitation, not fluid overload.
  • Hemangioma Intervention: Usually observed to involution, but if an infantile hemangioma obstructs the visual axis, you must treat immediately (propranolol) to prevent deprivation amblyopia.
  • Cleft Palate Hearing Loss: It is acquired, not congenital. Defective tensor veli palatini insertion causes Eustachian tube dysfunction, leading to chronic otitis media. (Requires myringotomy tubes).
  • Skin Tumor Mimic: Keratoacanthoma rapidly grows and clinically/histologically mimics Squamous Cell Carcinoma (SCC), not Basal Cell Carcinoma (BCC).
  • Fistula Tract Length: A long enterocutaneous fistula tract (>2 cm) is actually a good predictor of spontaneous closure, whereas a short tract is less likely to close.

🧭 Decision Algorithms

  • Burn Fluid Resuscitation (First 24 Hours):
    • Determine volume: Parkland Formula (4 mL Γ— kg Γ— %TBSA).
    • Timing: Give 50% of total volume in the first 8 hours from the time of injury (subtract transport time!). Give the remaining 50% over the next 16 hours.
    • Fluid choice: Purely crystalloids (Lactated Ringer's). Avoid early colloids (worsens edema).
  • Chemical Burn Management:
    • Acid/Alkali: Immediate, copious water irrigation. Never neutralize (causes exothermic thermal burn).
    • Elemental Metal (Na, K): Smother with sand or mineral oil. Never use water (combusts/explodes).
  • Cleft Surgery Timing:
    • Cleft Lip: Repair at ~3 months (Rule of 10s must be met).
    • Cleft Palate: Repair at 9–18 months. Balances normal midface maxillary growth (favors delay) with optimal speech/VPI prevention (favors early).
  • Frostbite Protocol:
    • Rapid rewarming in circulating water bath (40–42Β°C) β†’ Analgesia β†’ Elevation β†’ Tetanus toxoid.
    • Do NOT: Rub the tissue, prescribe Abx, or do early amputation (wait for late demarcation).
  • Melanoma Biopsy:
    • Suspected lesion β†’ Excisional biopsy with 1–2 mm margins.
    • Do NOT: Shave, punch, freeze, or cauterize (destroys architecture needed for Breslow depth).

βš”οΈ Classic Differentiators & Traps

  • Alkali vs. Acid Burns: Alkalis are "Liquid Liars" causing liquefactive necrosis (penetrates deep, requires 1–2 hours of irrigation). Acids cause coagulative necrosis (forms a protective eschar barrier).
  • Electrical vs. Thermal Burns: Electrical skin injury is just the "tip of the iceberg." Bone resistance generates massive heat killing deep muscle. Look for hyperkalemia, myoglobinuria, compartment syndrome, and violently induced fractures.
  • STSG vs. FTSG (Skin Grafts):
    • Split-Thickness (STSG): Better take rate (less tissue to feed). Worse cosmesis. Donor site heals by adnexal regeneration.
    • Full-Thickness (FTSG): Worse take rate (thick tissue needs rich blood supply). Better cosmesis/function (retains hair/sweat).
  • Ulcer Topography:
    • Venous: Painless, medial malleolus ("gaiter zone"), irregular, lipodermatosclerosis.
    • Arterial: Painful, punched-out smooth margins, pale base, distal/toes, absent pulses.
    • Neuropathic (Diabetic): Plantar surface (metatarsal heads), thick hyperkeratotic callus.
  • Compartment Syndrome Trap: Do not wait for loss of distal pulses (irreversible late sign). Diagnose via pain out of proportion or absolute pressure >40 mmHg.
  • Escharotomy vs. Fasciotomy:
    • Escharotomy: Cut through dead skin (eschar) to relieve tourniquet effect in circumferential 3rd-degree burns.
    • Fasciotomy: Cut through deep fascia to treat true compartment syndrome (electrical burns/crush).

πŸ”’ Numbers, Scores & Cutoffs

  • Max Wound Tensile Strength: Heals to maximum 80% of unwounded skin strength over several months.
  • Compartment Syndrome Threshold: Fasciotomy indicated if pressure >40 mmHg.
  • Rule of Nines (Adults): Head = 9%, Arms = 9% each, Legs = 18% each, Anterior Trunk = 18%, Posterior Trunk = 18%, Genitals = 1%. (Never include 1st-degree burns in TBSA!)
  • Lund-Browder (Pediatrics): An infant's head is massive = 18–19% of TBSA.
  • Cleft Lip Rule of 10s: Wait until 10 weeks, 10 lbs, and 10 g/dL Hb before repairing.
  • Frostbite Rewarming Temp: Strictly 40–42Β°C.
  • Felon Incision Safety: Must start 3–5 mm distal to the DIP joint crease to avoid penetrating the flexor tendon sheath.

πŸ› οΈ Operative / Procedural Must-Knows

  • Tangential Burn Excision: Early excision and grafting decreases sepsis and mortality. Major risks: Massive intraoperative blood loss and hypothermia.
  • Pressure Sore Coverage: Surgery will fail if underlying mechanics, moisture, or malnutrition aren't fixed. Diagnose underlying osteomyelitis with direct bone biopsy, not a surface swab.
  • Felon I&D Dissection: Once the skin is incised, you must use blunt dissection (hemostat) to physically break the vertical fibrous septa and evacuate all loculated pus.
  • Nail Trephination: Subungual hematomas covering >50% of the nail bed risk underlying distal phalanx fractures. Decompress by melting a hole through the nail plate with a heated wire.
  • Sarcoma Resection: Soft tissue sarcomas possess a pseudocapsule. You must widely excise outside this capsule; leaving it guarantees local recurrence.
  • Paronychia Drainage: Elevate the lateral nail fold parallel to the nail plate. Do not make a formal skin incision or remove the nail (unless subungual tracking is present).

🧠 Memory Pearls

  • Wound Healing Collagen: Type III is laid down early, but is replaced by Type I (which is number ONE for strength).
  • FRIEND (Factors preventing fistula closure): Foreign body, Radiation, Inflammation/Infection, Epithelialization, Neoplasm, Distal obstruction.
  • Ulcer Edges:
    • Punched out = Peripheral arterial
    • Rolled = Basal cell carcinoma
    • Everted = Squamous cell carcinoma
    • Undermined = PressUre or TB
  • Lip Cancers: BCC = Below the eyes (Upper lip); SCC = Sunny side (Lower lip).
  • Fight Bite Flora: Eikenella – think "I-can-yell-a" after taking a punch to the mouth.
  • Pain is a Good Thing: Blanches + hurts = 2nd degree (heals). Painless + leathery white = 3rd degree (needs excision/graft).
  • Electric Shock = Hidden Clock: The skin looks fine, but massive deep muscle necrosis is ticking underneath.

βœ… Final 20-Minute Self-Test

  1. What is the single best clinical indicator of adequate burn fluid resuscitation?
    • Strict hourly urine output (0.5–1.0 mL/kg/hr).
  1. Which cells are the most critical for driving the wound healing process?
    • Macrophages (peak at 48–72 hours).
  1. What type of graft is mandatory for covering bare bone or tendon?
    • A flap (brings its own intrinsic blood supply).
  1. What is the primary cause of skin graft failure?
    • Hematoma/seroma collection under the graft.
  1. A patient arrives 4 hours after a 40% TBSA burn. How should the Parkland volume be administered?
    • The first 50% must be given over the remaining 4 hours (the 8-hour window starts from the time of injury).
  1. What electrolyte abnormality is a major threat in electrical burns?
    • Hyperkalemia (due to massive deep muscle necrosis).
  1. What is the initial management for a chemical burn caused by elemental sodium?
    • Smother with sand or mineral oil (Water will cause an explosion).
  1. What is the definitive treatment for an infantile hemangioma obstructing the visual axis?
    • Systemic propranolol (or steroids).
  1. Why do cleft palate patients suffer from hearing loss?
    • Eustachian tube dysfunction (due to abnormal tensor veli palatini insertion) causing chronic otitis media.
  1. What is the most important prognostic factor in melanoma?
    • Breslow thickness (absolute depth of invasion in mm).
  1. What is the correct immediate management for frostbite?
    • Rapid rewarming in a 40–42Β°C circulating water bath.
  1. Which vitamin impairs collagen synthesis and delays wound healing when taken in high doses?
    • Vitamin E.
  1. What is the defining rule for managing a human "fight bite" to the hand?
    • Never close primarily; irrigate and leave open for delayed primary closure (risk of Eikenella infection).
  1. When performing an I&D for a felon, where must the proximal end of the incision stop?
    • 3–5 mm distal to the DIP joint crease (to avoid iatrogenic septic tenosynovitis of the flexor sheath).
  1. What is the most common cause of mortality following severe burns?
    • Respiratory failure secondary to bronchopneumonia (inhalation injury).

Breast

🚨 Must Not Miss

These are the highest-yield foundational concepts you must have locked down before walking into the exam.

  • Unilateral, Bloody Nipple Discharge: An intraductal papilloma is the single most common cause. Do not immediately assume cancer, but it still requires surgical excision for definitive diagnosis and treatment.
  • Phyllodes Tumor Biology: These behave like sarcomas. They spread hematogenously (most commonly to lungs and bone). Because lymph node metastasis is exceedingly rare (less than 5%), a formal axillary lymph node dissection (ALND) is rarely needed.
  • Paget's Disease of the Breast: This represents the migration of underlying malignant adenocarcinoma cells (Paget cells) into the nipple epidermis. It is a marker of underlying breast cancer. Clinically, it presents as a unilateral, scaly, crusty nipple lesion that lacks vesicles and does not itch.
  • Medullary Carcinoma Paradox: Typically presents as a "triple-negative" tumor and shows high-grade, poorly differentiated histology on pathology. Paradoxically, despite these aggressive markers, it carries a more favorable prognosis than standard invasive ductal carcinoma.
  • High-Risk Premalignancy: Atypical ductal hyperplasia (ADH) carries the highest relative risk for developing invasive breast cancer among benign breast lesions, increasing the risk by 4 to 5 times.
  • Gynecomastia vs. Pseudo-gynecomastia: Pseudo-gynecomastia (lipomastia) is composed purely of adipose tissue without any true glandular proliferation. Because there is no glandular tissue, it is completely unresponsive to anti-estrogen therapy like Tamoxifen.
  • Spinal Metastases Pathway: Breast cancer spreads to the axial skeleton directly via the valveless vertebral venous plexus, known as Batson's plexus.

🎯 Past-Paper Hit List

Themes that show up year after year in multiple-choice scenarios.

  • Advanced Cancer Signs (T4): You must recognize the physical exam findings of T4 direct local invasion. Skin dimpling (caused by fibrosis and retraction of Cooper's ligaments), peau d'orange (caused by dermal lymphatic blockage), skin ulceration, and chest wall fixation all automatically upgrade the tumor to T4.
  • Arm Edema vs. Local Invasion: Ipsilateral arm edema is a sign of regional nodal lymphatic obstruction in the axilla (or a known complication of previous axillary surgery/radiation). It is NOT a sign of direct contiguous local invasion of the primary breast tumor.
  • Staging Calculation Trap: The T-stage of a breast tumor is determined strictly by the size of the invasive component. You must ignore the size of any surrounding in situ component. For example, a 3.2 cm DCIS lesion that contains a 0.9 cm invasive focus is staged as T1b, not T2.
  • Receptor Status and Targeted Therapy:
    • HER2/neu overexpression implies aggressive tumor biology. It is targeted by Trastuzumab (Herceptin).
    • ER+/HER2- tumors derive massive benefit from endocrine therapies (Tamoxifen for premenopausal women, Aromatase inhibitors for postmenopausal women).
  • Lactational Abscess Management: Treat with standard incision and drainage (I&D) alongside antibiotics. The heavily tested teaching point: strictly advise the patient to continue breastfeeding or pumping from the affected breast. This prevents milk stasis and promotes clearance of the infection.
  • Recurrence Timeline: The vast majority of breast cancer recurrences (especially in triple-negative and HER2+ subtypes) occur within the first 5 years post-treatment.

🧭 Decision Algorithms

Step-by-step logic for the most commonly tested clinical scenarios.

  • Symptomatic Simple Cyst:
    • Presentation: Painful, palpable, clinically fluctuant mass.
    • Action: Fine Needle Aspiration (FNA).
    • Why: It is both diagnostic (confirms simple fluid) and therapeutic (collapses the cyst for immediate pain relief).
  • BI-RADS 3 (Probably Benign):
    • Risk: Malignancy risk is <2%.
    • Action: Short-interval follow-up imaging (repeat mammogram at 6 months). Do not biopsy unless changes occur.
  • BI-RADS 4 (Suspicious for Malignancy):
    • Risk: Requires tissue diagnosis.
    • Action: If the lesion is non-palpable and detected only on mammogram (e.g., a cluster of microcalcifications), the gold standard next step is a stereotactic mammogram-guided core needle biopsy.
  • Early-Stage Breast Cancer (T1/T2, Node-Negative):
    • Action: Breast-conserving surgery (lumpectomy / wide local excision) + Sentinel Lymph Node Biopsy (SLNB) + Postoperative radiotherapy.
    • Rule: If the SLNB is negative, complete axillary lymph node dissection (ALND) is strictly contraindicated.
  • Locally Advanced / Inflammatory Breast Cancer (T4):
    • Action: Neoadjuvant systemic chemotherapy β†’ Modified radical mastectomy β†’ Post-mastectomy radiotherapy.
    • Rule: Never operate first on inflammatory or locally advanced breast cancer. You must downstage the tumor and clear micrometastases with neoadjuvant chemotherapy first.

βš”οΈ Classic Differentiators & Traps

Subtle distinctions examiners use to misdirect you.

  • Invasive vs. In Situ Skin Lesions:
    • Trap: Assuming basal cell carcinoma is in situ because it rarely metastasizes. Basal cell carcinoma is an invasive skin malignancy.
    • True In Situ: Bowen's disease, Erythroplasia of Queyrat, and Paget's disease of the breast are true in situ carcinomas.
  • Radiation Dermatitis vs. Permanent Damage:
    • Trap: Patients presenting with severe erythema and desquamation following breast radiotherapy.
    • Truth: This is a very common acute side effect, but it is temporary. It resolves within weeks of completing treatment and is not a permanent condition.
  • Nipple Eczema vs. Paget's Disease:
    • Eczema: Usually bilateral, itchy, and responds to topical steroids.
    • Paget's: Usually unilateral, lacks vesicles, does not itch, and fails to resolve with topical steroids.

πŸ”’ Numbers, Scores & Cutoffs

The exact digits you need to memorize.

  • BI-RADS 3 Malignancy Risk: <2%
  • Phyllodes Lymph Node Metastasis Rate: <5%
  • Lymphedema Rate: 20–30% (Ipsilateral arm lymphedema is the most dreaded chronic complication of a complete ALND).
  • ADH Cancer Risk: 4 to 5 times relative risk of developing invasive breast cancer.
  • Recurrence Window: 5 years (highest risk period).
  • TNM Staging (T-Stage sizes):
    • T1: < 2 cm
    • T2: 2 to 5 cm
    • T3: > 5 cm
    • T4: Any size with direct extension to chest wall or skin (ulceration, macroscopic nodules, peau d'orange).
  • TNM Staging (N2a): Axillary lymph nodes that are described on exam as "matted to each other" or "fixed" are automatically staged as N2a.

πŸ› οΈ Operative / Procedural Must-Knows

Anatomy danger zones and surgical procedure specifics.

  • Intercostobrachial Nerve Injury: This nerve is frequently sacrificed or stretched during axillary dissection. Injury results in the classic postoperative complaint of numbness or paresthesia along the medial aspect of the upper arm.
  • Long Thoracic Nerve Injury: Runs along the serratus anterior muscle. If injured during axillary clearance, the patient will develop a "winged scapula."
  • Hadfield’s Operation: A major terminal duct excision procedure. It is the surgical treatment of choice for chronic recurrent periductal mastitis, severe duct ectasia, or mammillary fistulas.
  • Skin-Sparing Mastectomy: A technique that excises only the nipple-areolar complex (NAC) and the underlying breast tissue, leaving the native breast skin envelope intact. This facilitates excellent cosmetic results during immediate autologous flap or implant reconstruction.

🧠 Memory Pearls

Mental shortcuts for rapid recall.

  • Batson's Back: Batson's plexus = Breast to Back (spine metastases).
  • Phyllodes Acts Like a Sarcoma: Fleshy, leaf-like tumor. Spreads via Blood to Bone and Breathing (lungs). Bypasses lymphatics.
  • T-Staging Rule of 2s and 5s: T1 < 2 cm, T2 = 2 to 5 cm, T3 > 5 cm, T4 = Chest wall/Skin.

βœ… Final 20-Minute Self-Test

Cover the answers on the right and test your recall.

  1. What is the most common cause of unilateral, bloody nipple discharge? β†’ Intraductal papilloma
  1. Which benign breast lesion carries a 4-5x relative risk for developing invasive breast cancer? β†’ Atypical ductal hyperplasia (ADH)
  1. Why is a formal axillary lymph node dissection rarely needed for a Phyllodes tumor? β†’ It spreads hematogenously; lymph node metastasis is <5%
  1. A patient has a 4.0 cm DCIS lesion with a 1.5 cm invasive ductal carcinoma. What is the T-stage? β†’ T1c (Staging is based ONLY on the invasive component: 1.5 cm is < 2 cm)
  1. What is the initial management for a painful, palpable, and fluctuant simple breast cyst? β†’ Fine Needle Aspiration (FNA)
  1. What is the recommended next step for a BI-RADS 4 cluster of microcalcifications seen only on mammography? β†’ Stereotactic mammogram-guided core needle biopsy
  1. A patient presents with inflammatory breast cancer (T4). What is the first step in the treatment algorithm? β†’ Neoadjuvant systemic chemotherapy (Never operate first)
  1. Ipsilateral arm edema in a breast cancer patient indicates what? β†’ Regional nodal lymphatic obstruction (NOT direct local tumor invasion)
  1. Which nerve is injured if a patient complains of medial upper arm numbness after an axillary dissection? β†’ Intercostobrachial nerve
  1. Which nerve is injured if a patient develops a winged scapula post-mastectomy? β†’ Long thoracic nerve
  1. What surgical procedure is indicated for a mammillary fistula or severe chronic periductal mastitis? β†’ Hadfield’s Operation (major terminal duct excision)
  1. What specific advice regarding breastfeeding must be given to a woman being treated for a lactational breast abscess? β†’ Continue breastfeeding/pumping to prevent milk stasis
  1. Clinically, how do you differentiate Paget's disease of the breast from eczema? β†’ Paget's is usually unilateral, lacks vesicles, and does not itch
  1. Which paradoxical breast cancer subtype is triple-negative and poorly differentiated but carries a favorable prognosis? β†’ Medullary carcinoma
  1. What venous plexus allows breast cancer to metastasize directly to the axial skeleton? β†’ Batson's plexus
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