Iran General Surgery Board Exam cheat sheet

Body fluid: total body water ~60% of lean weight (40% ICF, 20% ECF); ECF splits into interstitial 15% and plasma 5% of body weight.

Maintenance fluids (4-2-1 rule): 4 mL/kg/h for first 10 kg, 2 mL/kg/h for next 10 kg, 1 mL/kg/h thereafter; correct deficits by volume status, not formula alone.

Anion gap = Na − (Cl + HCO3), normal 8–12 mEq/L; elevated gap with metabolic acidosis suggests ketoacidosis, lactate, uremia, or toxins.

Potassium: 1 mEq/L serum change ≈ 100–200 mEq total body deficit; ECG changes (peaked T, widened QRS) appear with hyperkalemia >6.5 mEq/L.

Wound healing phases: hemostasis (minutes), inflammation (0–3 days), proliferation/fibroplasia (3 days–3 weeks), remodeling (3 weeks–1 year); collagen type III is replaced by type I.

Surgical microbiology: Staphylococcus aureus and coagulase-negative staphylococci dominate skin flora; anaerobes (Bacteroides fragilis) dominate distal colon and perineal infections.

Nutrition: basal energy need ~25–30 kcal/kg/day and protein 1.2–1.5 g/kg/day in stressed surgical patients; enteral feeding is preferred when the gut works.

Pharmacology pearls: aminoglycosides are nephro/ototoxic and require renal dosing; metronidazole covers anaerobes; cephalosporins cover gram-positive skin flora for prophylaxis.

Preoperative risk: ASA physical status I–VI; ASA III–IV predicts higher perioperative morbidity and warrants optimization and anesthesia review.

Revised Cardiac Risk Index (RCRI) includes ischemic heart disease, heart failure, cerebrovascular disease, insulin-treated diabetes, renal impairment (creatinine >2 mg/dL), and high-risk surgery.

VTE prophylaxis: use Caprini score for general/abdominal surgery; low-molecular-weight heparin or unfractionated heparin plus mechanical prophylaxis when bleeding risk allows.

Surgical site infection prevention: administer prophylactic antibiotic within 60 minutes before incision (120 minutes for vancomycin/fluoroquinolones).

Anastomotic leak typically presents postoperative days 5–7 with fever, tachycardia, ileus, and rising inflammatory markers; CT with contrast is the initial imaging test.

Postoperative fever timing: atelectasis and drug reactions early; urinary and wound infection days 3–5; intra-abdominal abscess and anastomotic leak days 5–10; DVT after day 7.

Enhanced recovery after surgery (ERAS): early oral intake, multimodal opioid-sparing analgesia, early ambulation, and avoidance of routine nasogastric tubes.

Postoperative oliguria: first exclude hypovolemia and urinary retention; a bladder scan and fluid challenge precede diuretics or invasive monitoring.

Primary survey ABCDE: airway with cervical spine protection, breathing, circulation with hemorrhage control, disability (GCS/pupils), exposure with temperature control.

Hemorrhagic shock classes: class I <15% blood loss, class II 15–30% (tachycardia, narrowed pulse pressure), class III 30–40% (hypotension, confusion), class IV >40% (lethargy, anuria).

Permissive hypotension to systolic ~90 mmHg is used in penetrating trauma before hemorrhage control; avoid in traumatic brain injury, where cerebral perfusion pressure must be maintained.

Massive transfusion protocol: balanced 1:1:1 red cells:fresh frozen plasma:platelets; give tranexamic acid within 3 hours of injury.

FAST exam detects free intraperitoneal fluid; it is less sensitive for retroperitoneal, hollow viscus, and pelvic injuries.

Damage control laparotomy: stop bleeding, control contamination, temporary abdominal closure, then ICU resuscitation and planned re-exploration.

Tension pneumothorax is a clinical diagnosis treated with immediate needle decompression (2nd intercostal space midclavicular line or 5th intercostal space anterior axillary line) followed by tube thoracostomy.

Burn resuscitation: Parkland formula 4 mL/kg/% total body surface area lactated Ringer's in first 24 hours, half in first 8 hours; estimate TBSA with the rule of nines.

Appendicitis: migration of periumbilical pain to right lower quadrant, McBurney point tenderness, and leukocytosis; CT or ultrasound confirms when diagnosis is uncertain.

Small bowel obstruction: air-fluid levels and dilated loops on plain film; initial management is nasogastric decompression and intravenous fluids, with surgery for strangulation signs.

Colon cancer: right-sided lesions present with anemia and mass; left-sided lesions with obstruction and change in bowel habit; staging uses TNM and CT chest/abdomen/pelvis.

Incarcerated hernia with tenderness, irreducible mass, and systemic toxicity suggests strangulation and requires urgent surgery without manual reduction attempts.

Inguinal canal: deep ring is lateral to inferior epigastric vessels; indirect hernia passes through the deep ring, direct hernia through Hesselbach's triangle.

Anorectal disease: internal hemorrhoids are above the dentate line and painless; external hemorrhoids are below and painful when thrombosed; fistula-in-ano follows Goodsall's rule.

Gastric cancer: adenocarcinoma is most common; distal lesions are associated with Helicobacter pylori, and total gastrectomy requires Roux-en-Y reconstruction with D2 lymphadenectomy in fit patients.

Peptic ulcer bleeding: high-risk stigmata (active spurting, visible vessel) require endoscopic hemostasis plus high-dose proton pump inhibitor infusion.

Child–Pugh score uses bilirubin, albumin, INR, ascites, and encephalopathy; class C carries prohibitive operative risk for major hepatic resection.

MELD score uses bilirubin, INR, and creatinine (with sodium in MELD-Na) to predict mortality and prioritize liver transplantation.

Acute cholecystitis: right upper quadrant pain, Murphy sign, and ultrasound showing wall thickening, pericholecystic fluid, or stones; early laparoscopic cholecystectomy is preferred.

Choledocholithiasis: magnetic resonance cholangiopancreatography or endoscopic retrograde cholangiopancreatography (ERCP) for common bile duct stones; ERCP with sphincterotomy is therapeutic.

Acute pancreatitis: diagnosis requires two of three criteria (typical pain, lipase >3× upper limit, imaging); early management is aggressive fluids, analgesia, and enteral nutrition.

Pancreatic adenocarcinoma: most common in the head, causing painless jaundice and a double-duct sign; Whipple resection is offered only for resectable disease without vascular invasion.

Splenic injury: hemodynamically stable patients with contained injury may be managed nonoperatively with monitoring; unstable patients need laparotomy or angioembolization.

Portal hypertension: variceal bleeding is managed with octreotide, antibiotics, and endoscopic band ligation; transjugular intrahepatic portosystemic shunt (TIPS) is a rescue option.

Thyroid nodule: fine-needle aspiration cytology is the initial diagnostic test; Bethesda categories guide surgery versus observation.

Papillary thyroid carcinoma spreads via lymphatics and has excellent prognosis; medullary carcinoma arises from parafollicular C cells and secretes calcitonin.

Post-thyroidectomy hypocalcemia: monitor calcium and symptoms; bilateral recurrent laryngeal nerve injury causes stridor and requires immediate airway management.

Primary hyperparathyroidism: elevated calcium with inappropriately elevated parathyroid hormone; sestamibi scan and ultrasound localize adenoma before focused parathyroidectomy.

Adrenal incidentaloma: assess for hormonal hypersecretion (cortisol, aldosterone, metanephrines) and size; lesions >4 cm or with suspicious imaging warrant resection.

Pheochromocytoma: episodic hypertension, headache, and diaphoresis; alpha-blockade precedes beta-blockade to avoid unopposed vasoconstriction.

Insulinoma: fasting hypoglycemia with elevated insulin and C-peptide; localization with endoscopic ultrasound and selective arterial calcium stimulation.

Breast cancer: triple assessment (clinical exam, imaging, core biopsy); sentinel lymph node biopsy is standard for clinically node-negative axilla.

Abdominal aortic aneurysm: repair when diameter ≥5.5 cm, growth >1 cm/year, or symptomatic; endovascular repair is preferred when anatomy permits.

Acute limb ischemia: the six Ps (pain, pallor, pulselessness, paresthesia, paralysis, poikilothermia); immediate heparinization and urgent revascularization.

Peripheral arterial disease: ankle-brachial index <0.9 supports diagnosis; claudication is managed with exercise and antiplatelet therapy before intervention.

Carotid endarterectomy is indicated for symptomatic stenosis 70–99% and selected asymptomatic stenosis ≥60% in acceptable surgical risk.

Deep vein thrombosis: duplex ultrasound is the diagnostic test; anticoagulation is first-line, with catheter-directed thrombolysis for extensive iliofemoral thrombosis.

Varicose veins: duplex mapping identifies saphenofemoral or saphenopopliteal incompetence; endovenous ablation is first-line for symptomatic reflux.

Vascular access: radiocephalic arteriovenous fistula is preferred for hemodialysis; rule of 6s (flow >600 mL/min, diameter >6 mm, depth <6 mm).

Lymphedema: managed with compression, manual drainage, and skin care; surgery is reserved for refractory cases.

Lung cancer: non-small cell is most common; staging with CT and PET-CT; mediastinal lymph node sampling is required when nodes are enlarged.

Solitary pulmonary nodule: spiculated margins, growth, and size >8 mm raise concern; PET-CT and biopsy or resection follow risk assessment.

Pneumothorax: large or symptomatic requires tube thoracostomy; persistent air leak >5 days or recurrent pneumothorax suggests surgical pleurodesis.

Empyema: staged (exudative, fibrinopurulent, organizing); early drainage and antibiotics, with decortication when loculated.

Mediastinal masses: anterior compartment masses include thymoma, teratoma, thyroid, and lymphoma; posterior masses are usually neurogenic.

Esophageal cancer: adenocarcinoma of distal esophagus is linked to Barrett's esophagus; squamous cell carcinoma is linked to smoking and alcohol.

Tracheal obstruction: stridor indicates significant narrowing; management includes rigid bronchoscopy, stenting, or resection with primary anastomosis.

Chest wall: flail chest with paradoxical motion is managed with analgesia and ventilation; rib fixation is considered for severe displacement.

Hypertrophic pyloric stenosis: projectile nonbilious vomiting at 3–6 weeks, palpable olive, hypochloremic hypokalemic metabolic alkalosis; treat with pyloromyotomy after correction.

Intussusception: colicky pain, currant-jelly stool, and target sign on ultrasound; pneumatic or hydrostatic reduction is first-line if no peritonitis.

Biliary atresia: conjugated hyperbilirubinemia in the neonate; Kasai hepatic portoenterostomy before 60 days improves native liver survival.

Congenital diaphragmatic hernia: respiratory distress with scaphoid abdomen; initial management is decompression and gentle ventilation, surgery after stabilization.

Necrotizing enterocolitis: premature infants with feeding intolerance, bloody stools, and pneumatosis intestinalis; treat with bowel rest, antibiotics, and surgery for perforation.

Undescended testis: orchidopexy is recommended by 6–12 months of age to reduce malignancy and infertility risk.

Wilms tumor: abdominal mass in a young child; nephrectomy after chemotherapy for bilateral or large tumors; staging guides adjuvant therapy.

Pediatric trauma: children compensate with tachycardia before hypotension; hypotension indicates decompensated shock and requires immediate resuscitation.

Kidney transplant: living donor grafts have superior outcomes; immunosuppression includes induction and maintenance with calcineurin inhibitor, antimetabolite, and steroid.

Liver transplant: indications include decompensated cirrhosis, hepatocellular carcinoma within Milan criteria, and fulminant hepatic failure.

Rejection: hyperacute (minutes, preformed antibodies), acute cellular (days–weeks, T-cell mediated), and chronic (months–years, fibrosis).

Oncologic surgery principles: en bloc resection with negative margins (R0), adequate lymph node sampling, and multidisciplinary tumor board discussion.

Breast cancer staging: tumor size, nodal status, and receptor status (estrogen receptor, progesterone receptor, HER2) guide systemic therapy.

Colorectal cancer: adjuvant chemotherapy for stage III disease; liver metastases may be resected when disease is limited and margins achievable.

Pancreas transplant: indicated for brittle diabetes with renal failure, often combined as simultaneous pancreas-kidney transplant.

Graft-versus-host disease occurs after hematopoietic stem cell transplant, not solid organ transplant; solid organ recipients develop graft rejection instead.

Laparoscopic insufflation: carbon dioxide is preferred; pneumoperitoneum pressure 12–15 mmHg; physiologic effects include hypercapnia, reduced venous return, and vagal response.

Laparoscopic cholecystectomy: critical view of safety (two structures entering gallbladder) is required before clipping; avoid injury to the common bile duct.

Robotic surgery: advantages include tremor filtration, three-dimensional visualization, and articulated instruments; limitations include cost and lack of haptic feedback.

Endoscopy: screening colonoscopy detects and removes adenomas; therapeutic endoscopy includes hemostasis, dilation, stenting, and endoscopic mucosal resection.

Interventional radiology: angioembolization controls hemorrhage; percutaneous drainage treats abscesses; biliary stenting relieves obstruction.

Laparoscopic hernia repair: transabdominal preperitoneal (TAPP) and totally extraperitoneal (TEP) approaches; mesh placement in the preperitoneal space reduces recurrence.

Laparoscopic converted to open surgery when anatomy is unclear, bleeding is uncontrolled, or malignancy requires en bloc resection.

Enhanced imaging: intraoperative cholangiography and indocyanine green fluorescence help identify biliary anatomy and perfusion.

Informed consent requires capacity, disclosure of risks/benefits/alternatives, and voluntary agreement; emergency treatment may proceed when consent is impossible and delay risks death.

Medical error disclosure: patients should be told about harmful errors; disclosure supports trust and is required by professional standards.

Confidentiality: patient information may be shared only with consent or when required by law (reportable diseases, court order, imminent harm).

Iranian medical regulations: the Medical Council of the Islamic Republic of Iran (Sazman-e Nezam Pezeshki) oversees licensure and professional discipline.

Patient safety: hand hygiene, surgical safety checklist (sign in, time out, sign out), and medication reconciliation reduce preventable harm.

Quality improvement: Plan-Do-Study-Act cycles and root cause analysis address system failures rather than individual blame.

Communication: use structured handover (SBAR) and closed-loop communication in the operating room and ward.

Ethical principles: autonomy, beneficence, nonmaleficence, and justice guide decisions when values conflict; substituted judgment applies for incapacitated patients.