Egyptian Board General Surgery cheat sheet

Inguinal canal boundaries: anterior = external oblique aponeurosis (reinforced laterally by internal oblique); posterior = transversalis fascia (reinforced medially by conjoint tendon); roof = internal oblique and transversus abdominis; floor = inguinal ligament.

Femoral triangle: lateral border sartorius, medial border adductor longus, superior border inguinal ligament; floor iliopectineus; femoral nerve lies outside the triangle, lateral to the artery.

Femoral sheath compartments medial to lateral: femoral vein, femoral canal, femoral artery (NAVEl from lateral to medial).

Cautery injury to the recurrent laryngeal nerve causes loss of all intrinsic laryngeal muscles except cricothyroid; unilateral injury = hoarseness, bilateral = airway obstruction.

Fever timing after surgery: immediate (<24 h) suggests necrotizing infection or atelectasis; 24-72 h suggests pneumonia or UTI; >72 h suggests wound, intra-abdominal abscess, or line sepsis.

Wound healing: hemostasis (0-2 days), inflammation (1-4 days), proliferation/fibroblast-driven collagen III (4-21 days), remodeling with collagen I replacement (21 days to 1 year); wound strength ~5% at 1 week, ~20% at 3 weeks, ~70-80% of normal at 1 year.

Liver biotransformation: phase I reactions via cytochrome P450 (oxidation, reduction, hydrolysis); phase II conjugation (glucuronidation, sulfation, acetylation) increases water solubility for renal or biliary excretion.

Collagen synthesis requires vitamin C as cofactor for prolyl and lysyl hydroxylase; deficiency (scurvy) causes defective cross-linking and wound dehiscence.

Local anesthetics: weak bases cross membranes in uncharged form; inflammation lowers pH, reducing the uncharged fraction and efficacy; adding bicarbonate raises pH and speeds onset.

Surgical site infection risk classification: clean <2%, clean-contaminated <10%, contaminated ~20%, dirty >40%; prophylactic antibiotic is given within 60 minutes before incision (120 minutes for vancomycin or fluoroquinolones) and redosed at 2 half-lives intraoperatively.

Fluid maintenance: 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); isotonic crystalloid 1-2 L for mild hypovolemia, 2-4 L for moderate, >4 L for severe.

Blood transfusion: one unit packed RBC raises hemoglobin ~1 g/dL or hematocrit ~3%; transfusion threshold generally restrictive (7 g/dL), liberal (8 g/dL) in cardiac disease.

Nutrition: resting energy expenditure estimated by Harris-Benedict equations or 25-30 kcal/kg/day; protein 1.2-1.5 g/kg/day in surgical stress; enteral feeding preferred over parenteral when gut works.

Wound healing by intention: primary (clean, approximated), secondary (open, granulation), tertiary (delayed primary closure after contamination control).

Anesthesia: MAC (minimum alveolar concentration) is the alveolar concentration at which 50% of patients do not move to surgical stimulus; propofol induction 1.5-2.5 mg/kg IV.

Hemostasis: primary hemostasis = platelet plug; secondary = coagulation cascade and fibrin; tertiary = fibrinolysis; heparin activates antithrombin III, warfarin inhibits vitamin K-dependent factors II, VII, IX, X.

Perioperative VTE prophylaxis: Caprini or Padua risk score; low-molecular-weight heparin or unfractionated heparin plus mechanical prophylaxis for moderate-high risk.

ATLS primary survey: Airway with cervical spine protection, Breathing and ventilation, Circulation with hemorrhage control, Disability (GCS), Exposure/environmental control; reassess after each intervention.

Hemorrhagic shock classes (70 kg adult): class I <15% blood loss, class II 15-30% (tachycardia, narrowed pulse pressure), class III 30-40% (hypotension, confusion), class IV >40% (lethargy, negligible urine output).

Damage control surgery triad: control hemorrhage and contamination, temporary abdominal closure, ICU resuscitation (permissive hypotension, hemostatic resuscitation); definitive repair after correction of hypothermia, acidosis, coagulopathy.

Massive transfusion protocol: balanced ratio of plasma:platelets:RBC approximately 1:1:1, with calcium replacement and tranexamic acid within 3 hours of injury.

Burns: Parkland formula = 4 mL × body weight (kg) × %TBSA burned in 24 h, half in first 8 h; rule of nines for adult TBSA; Lund-Browder for children.

FAST exam windows: pericardial, perihepatic (Morison's pouch), perisplenic, pelvic, and thoracic views; positive FAST in hemodynamically unstable patient is an indication for operative exploration.

Trauma lethal triad: hypothermia, acidosis, coagulopathy; corrected by warming, hemorrhage control, and balanced blood product resuscitation.

Open pneumothorax: three-sided dressing (vented chest seal) and chest tube placed away from the wound; tension pneumothorax needs immediate needle decompression in the 5th intercostal space anterior axillary line.

Right upper quadrant pain with Murphy sign suggests acute cholecystitis; first-line imaging is abdominal ultrasound; cholecystectomy is definitive treatment, ideally within 72 hours of presentation.

Choledocholithiasis: elevated alkaline phosphatase, bilirubin, and dilated common bile duct on ultrasound; MRCP or ERCP for diagnosis and clearance before cholecystectomy.

Acute pancreatitis: diagnose with 2 of 3 (characteristic pain, lipase >3× upper limit of normal, imaging); initial management is aggressive isotonic fluid resuscitation, analgesia, and early enteral nutrition.

Glasgow (Imrie) score and Ranson criteria predict severity of acute pancreatitis; modified Atlanta classification distinguishes interstitial edematous from necrotizing pancreatitis, and mild, moderately severe, severe.

Peptic ulcer disease: H. pylori eradication with triple or quadruple therapy; perforation presents with pneumoperitoneum and requires omental (Graham) patch repair.

Colorectal cancer: right-sided presents with iron-deficiency anemia and mass; left-sided with obstruction and change in bowel habit; staging by TNM; adjuvant chemotherapy for node-positive disease.

Portal hypertension: portal pressure >10-12 mmHg; varices form above 12 mmHg; first-line management of acute variceal bleeding is octreotide plus endoscopic band ligation and prophylactic antibiotics.

Splenectomy indications: trauma with hemodynamic instability, hereditary spherocytosis, ITP refractory to medical therapy, splenic abscess; post-splenectomy vaccination against encapsulated organisms (pneumococcus, meningococcus, Haemophilus influenzae type b).

Small bowel obstruction: most common cause is adhesions; initial management is nasogastric decompression, IV fluids, and serial abdominal exams; surgery for strangulation signs (fever, tachycardia, peritoneal signs, closed-loop).

Thyroid nodule: TSH first, then ultrasound; fine-needle aspiration based on ultrasound features (TI-RADS); Bethesda categories guide management from benign observation to total thyroidectomy.

Papillary thyroid carcinoma: most common, lymphatic spread, excellent prognosis, radioactive iodine for selected high-risk cases; medullary carcinoma arises from parafollicular C cells and secretes calcitonin, associated with MEN2.

Post-thyroidectomy hypocalcemia: monitor calcium and PTH; symptoms include perioral numbness, Chvostek and Trousseau signs; treat with IV calcium gluconate and oral calcitriol.

Primary hyperparathyroidism: elevated calcium with inappropriately normal or elevated PTH; most common cause is a single parathyroid adenoma; sestamibi scan and ultrasound for localization; surgery is definitive.

Adrenal incidentaloma: assess for hormonal hypersecretion (cortisol, aldosterone, metanephrines) and imaging characteristics; surgical resection for functional tumors or size >4-6 cm.

Pheochromocytoma: episodic hypertension, headache, palpitations, diaphoresis; diagnosed by plasma free metanephrines; alpha-blockade (phenoxybenzamine) before beta-blockade to avoid unopposed alpha stimulation.

Carcinoid syndrome: serotonin-secreting neuroendocrine tumor, usually with liver metastases; flushing, diarrhea, bronchospasm; diagnosed by urinary 5-HIAA and chromogranin A; somatostatin analogues for control.

MEN1 (Wermer syndrome): parathyroid, pituitary, and pancreatic neuroendocrine tumors; MEN2A: medullary thyroid carcinoma, pheochromocytoma, parathyroid hyperplasia; RET proto-oncogene mutation.

Breast cancer screening: mammography every 1-2 years starting age 40-50 depending on guideline; diagnostic workup for palpable mass includes ultrasound and core needle biopsy.

Breast cancer receptor status: estrogen receptor, progesterone receptor, and HER2; triple-negative has worst prognosis and lacks targeted endocrine or HER2 therapy; HER2-positive benefits from trastuzumab.

Sentinel lymph node biopsy: indicated for clinically node-negative invasive breast cancer; uses blue dye and/or radiolabeled colloid; if positive, axillary lymph node dissection or regional radiation may follow.

Modified radical mastectomy removes breast, pectoralis major fascia, and axillary contents; simple mastectomy removes breast only; lumpectomy plus radiation is equivalent survival to mastectomy for early-stage disease.

Breast abscess: ultrasound-guided aspiration or incision and drainage; lactation-associated abscess often due to Staphylococcus aureus; continue breastfeeding or pumping on the affected side.

Soft tissue sarcoma: most common in extremities; MRI for local staging; biopsy along the limb axis; wide local excision with negative margins; radiation for high-grade or large tumors.

Skin cancer: basal cell carcinoma most common, rarely metastasizes; squamous cell carcinoma can metastasize; melanoma staged by Breslow thickness and sentinel node biopsy for thickness >1 mm or ulceration.

Breast cancer staging: TNM; stage I-II operable; stage III locally advanced, neoadjuvant chemotherapy often used; stage IV metastatic, systemic therapy is palliative.

Peripheral arterial disease: ankle-brachial index <0.9 indicates disease; <0.4 suggests critical limb ischemia; claudication is treated with supervised exercise and risk-factor modification; rest pain, ulceration, or gangrene require revascularization.

Acute limb ischemia (6 Ps: pain, pallor, pulselessness, paresthesia, paralysis, poikilothermia): immediate IV heparin and vascular surgery consult; embolectomy or thrombolysis; irreversible ischemia with paralysis and rigor may require amputation.

Abdominal aortic aneurysm: elective repair for diameter ≥5.5 cm, rapid growth >0.5 cm in 6 months, or symptomatic; ultrasound surveillance for smaller aneurysms; endovascular repair preferred in high-risk patients.

Carotid stenosis: symptomatic stenosis 70-99% benefits from carotid endarterectomy; 50-69% considered; medical management for asymptomatic stenosis <70%.

Deep vein thrombosis: diagnosed by compression ultrasound; anticoagulation with low-molecular-weight heparin or direct oral anticoagulant; duration 3 months for provoked, longer for unprovoked or cancer-associated.

Varicose veins: great saphenous vein incompetence; treatment options include compression, endovenous laser or radiofrequency ablation, and sclerotherapy.

Lung cancer: non-small cell (adenocarcinoma, squamous, large cell) most common; small cell is centrally located and treated primarily with chemotherapy and radiation; staging by CT and PET-CT, mediastinoscopy for mediastinal nodes.

Chest tube: placed in the triangle of safety (anterior border of latissimus dorsi, lateral border of pectoralis major, line superior to the horizontal level of the nipple, apex below the axilla); underwater seal with or without suction.

Hypertrophic pyloric stenosis: nonbilious projectile vomiting at 3-6 weeks of age; hypochloremic, hypokalemic metabolic alkalosis; diagnosis by ultrasound showing pyloric muscle thickness ≥3 mm; treatment is pyloromyotomy after correction of electrolytes.

Intussusception: colicky pain, currant-jelly stool, sausage-shaped mass; diagnosis by ultrasound (target sign); first-line treatment is air or barium enema reduction; surgery if peritonitis or failed reduction.

Biliary atresia: persistent jaundice beyond 2 weeks of life with acholic stools and direct hyperbilirubinemia; diagnosis by HIDA scan and liver biopsy; Kasai portoenterostomy is performed ideally before 60 days of life.

Necrotizing enterocolitis: premature infants, feeding intolerance, bloody stools, pneumatosis intestinalis; treatment is bowel rest, nasogastric decompression, antibiotics, and surgery for perforation.

Undescended testis: orchidopexy recommended by 6-18 months of age to reduce malignancy and infertility risk; testis may be palpable in the inguinal canal or intra-abdominal.

Testicular torsion: sudden severe scrotal pain, high-riding testis, absent cremasteric reflex; diagnosis is clinical; treatment is urgent detorsion and bilateral orchidopexy; salvage rate decreases after 6 hours.

Hypospadias: ventral urethral meatus, dorsal hood, and ventral curvature (chordee); avoid neonatal circumcision; surgical repair at 6-18 months of age.

Wilms tumor: most common renal tumor in children, usually presents with abdominal mass; staging by imaging; treatment is nephrectomy plus chemotherapy; associated with WT1 mutation and syndromes (WAGR, Beckwith-Wiedemann).

Tumor suppressor genes: p53 (guardian of the genome), RB, APC, BRCA1/2; oncogenes: RAS, MYC, HER2; two-hit hypothesis for tumor suppressor inactivation.

TNM staging: T = primary tumor size and invasion, N = regional lymph nodes, M = distant metastasis; stage grouping determines prognosis and treatment.

Renal transplantation: end-stage renal disease with GFR <15; workup includes ABO compatibility, HLA matching, crossmatch, and viral screening; immunosuppression with calcineurin inhibitor (tacrolimus) plus mycophenolate and corticosteroids.

Liver transplantation: indications include decompensated cirrhosis (MELD score), hepatocellular carcinoma within Milan criteria (single tumor ≤5 cm or up to 3 tumors each ≤3 cm), and acute liver failure; living donor or deceased donor graft.

Transplant rejection: hyperacute (preformed antibodies, minutes to hours), acute cellular (days to weeks, T-cell mediated), chronic (months to years, fibrosis and graft loss).

Hepatocellular carcinoma: surveillance with ultrasound plus alpha-fetoprotein every 6 months in cirrhotic patients; treatment options include resection, ablation, transarterial chemoembolization, and transplantation.

Chemotherapy principles: log-kill hypothesis, cell cycle specificity, combination therapy to reduce resistance; common toxicities include myelosuppression, mucositis, and alopecia.

Graft-versus-host disease occurs in hematopoietic stem cell transplant, not solid organ transplant; solid organ transplant recipients are at risk for opportunistic infections (CMV, PJP, EBV-driven post-transplant lymphoproliferative disorder).

Laparoscopic pneumoperitoneum: CO2 insufflation to 12-15 mmHg; physiological effects include hypercapnia, respiratory acidosis, decreased venous return, and increased vagal tone; contraindications include severe cardiopulmonary disease and hemodynamic instability.

Veress needle insertion at Palmer's point (2 cm below left costal margin in midclavicular line) is preferred in patients with prior abdominal surgery or suspected adhesions.

Laparoscopic trocar placement: primary port at umbilicus (open Hasson technique for prior surgery), secondary ports under direct vision; avoid epigastric vessels (inferior epigastric artery runs medial to the deep inguinal ring).

Robotic surgery: three-dimensional vision, tremor filtration, and articulating instruments; disadvantages include lack of tactile feedback, cost, and setup time; used in prostatectomy, hysterectomy, and colorectal surgery.

Energy devices: monopolar (cutting and coagulation), bipolar (coagulation with less lateral spread), ultrasonic (harmonic scalpel, protein denaturation), and advanced bipolar (LigaSure); avoid monopolar near bowel or nerves.

Intraoperative cholangiogram: performed during cholecystectomy to identify common bile duct stones and anatomy; identifies aberrant biliary anatomy and prevents bile duct injury.

Critical view of safety in cholecystectomy: only two structures (cystic duct and cystic artery) entering the gallbladder, hepatocystic triangle cleared of fat and fibrous tissue, and lower third of gallbladder separated from liver bed.

Laparoscopic conversion to open: indications include inability to visualize anatomy, uncontrolled bleeding, suspected malignancy requiring open resection, and hemodynamic instability.

Informed consent elements: diagnosis, nature of procedure, risks and benefits, alternatives, and consequences of refusal; documented by the operating surgeon.

Capacity assessment: patient must understand information, appreciate consequences, reason through options, and communicate a choice; if absent, surrogate decision-maker or best-interest standard applies.

WHO surgical safety checklist: sign-in (before induction), time-out (before incision), sign-out (before leaving OR); reduces surgical morbidity and mortality.

Never events: wrong-site surgery, retained foreign body, wrong patient, wrong procedure; root cause analysis is required after a sentinel event.

Error types: active errors (sharp end, frontline) versus latent errors (blunt end, system factors); Swiss cheese model of accident causation.

Research methodology: randomized controlled trial is the gold standard for causal inference; blinding reduces bias; intention-to-treat analysis preserves randomization.

Statistics: sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives); positive predictive value depends on prevalence.

Surgical education: Halsted model (see one, do one, teach one) replaced by competency-based training; simulation and deliberate practice improve technical skills; ACGME core competencies include patient care, medical knowledge, practice-based learning, interpersonal skills, professionalism, and systems-based practice.

History and physical: OLDCARTS (onset, location, duration, character, aggravating/associated factors, relieving factors, timing, severity); review of systems and past medical, surgical, family, and social history.

Abdominal examination sequence: inspection, auscultation (before palpation to avoid altering bowel sounds), percussion, palpation; peritoneal signs include rebound tenderness, guarding, and rigidity.

Imaging choice: ultrasound for gallbladder, thyroid, and scrotal pathology; CT for acute abdomen, trauma, and staging; MRI for soft tissue, brain, and spinal cord; plain films for obstruction and perforation (free air under diaphragm).

Evidence hierarchy: systematic reviews and meta-analyses > randomized controlled trials > cohort studies > case-control studies > case series > expert opinion.

Likelihood ratios: positive LR = sensitivity / (1 - specificity); negative LR = (1 - sensitivity) / specificity; LR >10 or <0.1 significantly changes probability.

Number needed to treat (NNT) = 1 / absolute risk reduction; number needed to harm (NNH) = 1 / absolute risk increase.

Confidence interval: 95% CI indicates range in which the true effect lies with 95% probability; if CI crosses 1 for relative risk or odds ratio, result is not statistically significant.

Clinical practice guidelines: GRADE system rates quality of evidence and strength of recommendation; guidelines should be adapted to local resources and patient preferences.