OMSB Physician Exam cheat sheet

Acute STEMI reperfusion: primary PCI is preferred if achievable within 120 minutes of first medical contact; otherwise fibrinolysis within 30 minutes of door time (12 hours of symptom onset).

Heart failure with reduced EF: four pillars - ARNI/ACEi/ARB, evidence-based beta-blocker, MRA, and SGLT2 inhibitor - each reduces mortality; add loop diuretic for congestion only.

Atrial fibrillation stroke risk uses CHA2DS2-VASc (CHF, hypertension, age ≥75 =2, diabetes, stroke/TIA =2, vascular disease, age 65-74, female sex); anticoagulate at score ≥2 in men, ≥3 in women.

Acute pericarditis diagnosis needs 2 of 4: pleuritic chest pain, friction rub, diffuse ST elevation/PR depression, new or worsening effusion.

Aortic stenosis severity: severe if peak velocity ≥4 m/s, mean gradient ≥40 mmHg, or valve area ≤1.0 cm²; symptoms plus severe AS warrant valve replacement.

Hypertrophic cardiomyopathy: asymmetric septal hypertrophy, systolic murmur increased by Valsalva/standing and decreased by squatting; avoid vasodilators and dehydration.

Infective endocarditis: modified Duke criteria combine blood culture positivity and imaging (echo) as major criteria; obtain 3 culture sets before antibiotics in stable patients.

Wide-complex tachycardia is ventricular tachycardia until proven otherwise; hemodynamic instability mandates synchronized cardioversion.

Rapid sequence induction: preoxygenate, then induction agent plus neuromuscular blocker (succinylcholine 1-1.5 mg/kg or rocuronium 1-1.2 mg/kg) with cricoid pressure and no bag-mask ventilation.

Malignant hyperthermia: triggered by volatile agents and succinylcholine; treat with dantrolene 2.5 mg/kg IV, stop trigger, hyperventilate with 100% O2, and cool the patient.

Local anesthetic systemic toxicity: stop injection, secure airway, give 20% lipid emulsion 1.5 mL/kg bolus then infusion; avoid vasopressin, calcium channel blockers, and beta-blockers.

Succinylcholine is contraindicated in hyperkalemia risk states: burns >24-48 hours old, denervation injury, prolonged immobility, and crush injury.

MAC values are inversely related to potency; MAC is reduced by pregnancy, hypothermia, opioids, and increasing age, and increased by chronic alcohol use and hyperthermia.

Spinal anesthesia block height: hypotension from sympathectomy is treated with IV fluids and vasopressors; bradycardia from high block responds to atropine or epinephrine.

Difficult airway algorithm: optimize oxygenation, call for help, limit intubation attempts, use supraglottic rescue, and proceed to surgical airway if cannot intubate/cannot oxygenate.

Postoperative nausea and vomiting prophylaxis uses Apfel risk factors (female sex, nonsmoker, history of PONV, postoperative opioids); give 2+ antiemetics from different classes in high risk.

Glycolysis net yield per glucose: 2 ATP and 2 NADH in cytoplasm; pyruvate dehydrogenase produces 1 NADH and 1 acetyl-CoA per pyruvate.

TCA cycle per acetyl-CoA yields 3 NADH, 1 FADH2, and 1 GTP; oxidative phosphorylation gives ~2.5 ATP per NADH and ~1.5 ATP per FADH2.

Rate-limiting enzymes: hexokinase/glucokinase (glycolysis), phosphofructokinase-1 (glycolysis), pyruvate dehydrogenase, citrate synthase, and glycogen phosphorylase.

Urea cycle: carbamoyl phosphate synthetase I is the rate-limiting mitochondrial step; hyperammonemia with low BUN suggests a urea cycle defect.

Vitamin B1 (thiamine) is cofactor for pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase, and transketolase; deficiency causes Wernicke encephalopathy and beriberi.

Phenylketonuria: phenylalanine hydroxylase deficiency causes hyperphenylalaninemia, fair skin, musty odor, and intellectual disability; treat with low-phenylalanine diet.

G6PD deficiency: X-linked; oxidative stress causes Heinz body hemolysis; avoid primaquine, dapsone, nitrofurantoin, and fava beans.

Lesch-Nyhan syndrome: HGPRT deficiency causes hyperuricemia, self-mutilation, and choreoathetosis; treat with allopurinol.

Permanent maxillary first molar typically has 3 roots and 4 canals (MB1, MB2, DB, palatal); mandibular first molar has 2 roots and 3 canals (mesial 2, distal 1).

Pulpal diagnosis: reversible pulpitis is provoked, sharp pain resolving after stimulus; irreversible pulpitis is spontaneous or lingering pain requiring root canal treatment.

Periodontal disease classification uses clinical attachment loss, probing depth, bleeding on probing, and radiographic bone loss; staging reflects severity and complexity.

Local anesthetic for mandibular molars: inferior alveolar nerve block with 2% lidocaine 1:100,000 epinephrine; buccal nerve block is needed for buccal soft tissue.

Dental trauma: avulsed permanent tooth should be replanted immediately or stored in milk/saline; splint flexibly for 2 weeks and consider tetanus prophylaxis.

Antibiotic prophylaxis before dental procedures is indicated for prosthetic heart valves, prior infective endocarditis, and certain congenital heart disease, not for routine joint prostheses.

Dental caries prevention: fluoride varnish 5% NaF every 3-6 months for high-risk patients; systemic fluoride reduces caries but risks fluorosis if excessive.

Oral lichen planus presents as reticular white striae (Wickham striae) on buccal mucosa; biopsy atypical or erosive lesions to exclude dysplasia or malignancy.

Psoriasis: well-demarcated erythematous plaques with silvery scale on extensor surfaces; Auspitz sign (pinpoint bleeding on scale removal) and Koebner phenomenon.

Atopic dermatitis: flexural distribution in adults, pruritus, personal/family atopy; first-line treatment is emollients plus topical corticosteroids.

Melanoma ABCDEs: Asymmetry, Border irregularity, Color variation, Diameter >6 mm, Evolving lesion; Breslow thickness is the strongest prognostic factor.

Basal cell carcinoma: pearly papule with telangiectasia, rolled border, and central ulceration; rarely metastasizes; treated by excision or Mohs surgery.

Pemphigus vulgaris: intraepidermal acantholysis, flaccid bullae, positive Nikolsky sign, IgG against desmoglein 1 and 3; treat with corticosteroids and rituximab.

Bullous pemphigoid: subepidermal blister, tense bullae, IgG against BP180/BP230; older adults; treat with topical or systemic corticosteroids.

Stevens-Johnson syndrome/toxic epidermal necrolysis: mucosal involvement plus epidermal detachment; SJS <10% body surface area, TEN >30%; withdraw culprit drug and give supportive care.

Erythema multiforme: target lesions, often herpes simplex triggered; mucosal involvement defines major form; treat underlying trigger and supportive care.

Anaphylaxis: intramuscular epinephrine 0.3-0.5 mg (1:1000) in the anterolateral thigh, repeat every 5-15 minutes; adjuncts include fluids, antihistamines, and corticosteroids.

Acute ischemic stroke: IV alteplase within 4.5 hours of last known well if no contraindications; mechanical thrombectomy for large vessel occlusion up to 24 hours in selected patients.

Sepsis bundle: measure lactate, obtain blood cultures before antibiotics, give broad-spectrum antibiotics within 1 hour for septic shock, and 30 mL/kg crystalloid for hypotension or lactate ≥4.

Tension pneumothorax: clinical diagnosis with hypotension, distended neck veins, absent breath sounds; immediate needle decompression followed by chest tube.

Opioid overdose: give naloxone 0.04-0.4 mg IV titrated to respiratory rate; observe for recurrent toxicity because naloxone half-life is shorter than most opioids.

Hyperkalemia with ECG changes: IV calcium gluconate for membrane stabilization, then insulin with glucose, beta-agonist, and dialysis for refractory cases.

Status epilepticus: benzodiazepine first (lorazepam 0.1 mg/kg or midazolam IM), then second-line antiseizure medication such as levetiracetam, valproate, or fosphenytoin.

Acute upper GI bleed: resuscitate, start proton pump inhibitor infusion, and perform endoscopy within 24 hours; consider tranexamic acid and massive transfusion protocol if unstable.

Hypertension: diagnose with repeated office readings ≥140/90 mmHg or ambulatory/home monitoring; start lifestyle change and pharmacotherapy based on risk and comorbidity.

Type 2 diabetes: metformin first-line unless contraindicated; add SGLT2 inhibitor or GLP-1 receptor agonist for atherosclerotic cardiovascular disease, heart failure, or chronic kidney disease.

Hyperlipidemia: statin intensity is guided by 10-year atherosclerotic cardiovascular disease risk; high-intensity statin for established disease or diabetes with risk factors.

Screening: colorectal cancer from age 45-75, cervical cancer from 21-65, breast cancer from 40-74, and lung cancer with low-dose CT for high-risk smokers.

Contraception: combined oral contraceptives are contraindicated with migraine with aura, smoking over age 35, and prior venous thromboembolism; use progestin-only or nonhormonal methods.

Depression: screen with PHQ-2/PHQ-9; first-line treatment is psychotherapy or SSRI; assess suicide risk and bipolar disorder before starting antidepressants.

Childhood immunization follows age-specific schedules; live vaccines are contraindicated in severe immunocompromise and pregnancy.

Osteoporosis: DEXA T-score ≤ -2.5 defines osteoporosis; treat with bisphosphonate, denosumab, or anabolic agent based on fracture risk.

Acute appendicitis: periumbilical pain migrating to right lower quadrant with McBurney point tenderness; ultrasound or CT confirms; treat with appendectomy or antibiotics in selected cases.

Bowel obstruction: air-fluid levels and dilated loops on plain film; initial management is IV fluids, nasogastric decompression, and serial examination; surgery for strangulation signs.

Cholecystitis: right upper quadrant pain, Murphy sign, fever, leukocytosis; ultrasound shows wall thickening and pericholecystic fluid; treat with antibiotics and cholecystectomy.

Hernia: reducible versus incarcerated versus strangulated; strangulation signs include severe pain, skin changes, and systemic toxicity requiring urgent surgery.

Trauma primary survey: airway with cervical spine protection, breathing, circulation with hemorrhage control, disability, and exposure; FAST exam for unstable patients.

Postoperative fever timing: within 48 hours consider atelectasis; days 3-5 consider urinary tract infection or pneumonia; days 5-7 consider surgical site infection or anastomotic leak.

Thyroidectomy complications: recurrent laryngeal nerve injury causes hoarseness; hypocalcemia from parathyroid injury presents with perioral numbness and Chvostek/Trousseau signs.

Breast cancer staging uses tumor size, nodal involvement, and metastasis; sentinel lymph node biopsy is standard for clinically node-negative axilla.

Iron deficiency anemia: low ferritin, low serum iron, high total iron-binding capacity, and high transferrin saturation index; treat underlying cause plus oral iron.

Anemia of chronic disease: low serum iron, low total iron-binding capacity, normal or high ferritin, and low transferrin saturation; treat the underlying disease.

Vitamin B12 deficiency causes macrocytic anemia with neurologic symptoms; folate deficiency causes macrocytic anemia without neurologic findings; replace before folate to avoid subacute combined degeneration.

Heparin-induced thrombocytopenia: platelet drop >50% at 5-10 days, thrombosis risk; stop heparin and start a non-heparin anticoagulant such as argatroban.

Disseminated intravascular coagulation: prolonged PT/aPTT, low fibrinogen, elevated D-dimer, schistocytes; treat the underlying cause and support with blood products.

Chronic myeloid leukemia: Philadelphia chromosome t(9;22) BCR-ABL; treat with tyrosine kinase inhibitors such as imatinib.

Multiple myeloma: CRAB features (hypercalcemia, renal failure, anemia, bone lesions); serum protein electrophoresis shows M spike; treat with proteasome inhibitor-based regimens.

Sickle cell disease: hemoglobin S polymerization causes vaso-occlusion; acute chest syndrome is treated with oxygen, antibiotics, and exchange transfusion.

Coagulative necrosis: preserved tissue architecture with loss of nuclei, typical of ischemic infarction in heart, kidney, and spleen.

Caseous necrosis: friable cheesy appearance with granulomas; classic for tuberculosis and fungal infection.

Liquefactive necrosis: enzymatic digestion producing cystic spaces; typical of brain infarction and abscess.

Fat necrosis: saponification with chalky white deposits; seen in pancreatitis and breast trauma.

Fibrinoid necrosis: bright eosinophilic deposits in vessel walls; seen in immune vasculitis and malignant hypertension.

Metaplasia: reversible change of one mature cell type to another, such as squamous metaplasia of bronchial epithelium in smokers.

Dysplasia: disordered growth with nuclear atypia and loss of polarity, not yet invasive; severe dysplasia is carcinoma in situ.

Immunohistochemistry: cytokeratin marks epithelial tumors, vimentin marks mesenchymal tumors, and CD45 marks lymphoid neoplasms.

Diabetic ketoacidosis: hyperglycemia, ketonemia, and anion gap metabolic acidosis; treat with isotonic fluids, IV insulin infusion, and potassium replacement before insulin if K <3.3 mmol/L.

Hyperosmolar hyperglycemic state: glucose often >600 mg/dL, minimal ketosis, high osmolality, severe dehydration; treat with fluids and insulin.

Thyroid storm: fever, tachycardia, agitation, and altered mental status; treat with beta-blocker, thionamide, iodine after thionamide, and corticosteroids.

Adrenal crisis: hypotension, hyponatremia, hyperkalemia, and hypoglycemia; treat with IV hydrocortisone and fluids without waiting for confirmatory tests.

Nephrotic syndrome: proteinuria >3.5 g/day, hypoalbuminemia, edema, and hyperlipidemia; biopsy for adults to identify cause.

Cirrhosis complications: ascites managed with spironolactone plus furosemide; spontaneous bacterial peritonitis diagnosed by ascitic neutrophil count ≥250/mm³ and treated with third-generation cephalosporin.

Community-acquired pneumonia: CURB-65 (confusion, urea >7 mmol/L, respiratory rate ≥30, blood pressure low, age ≥65) guides site of care.

Rheumatoid arthritis: symmetric small joint polyarthritis with morning stiffness; anti-CCP is more specific than rheumatoid factor; treat early with methotrexate.

Gram-positive cocci in clusters with catalase and coagulase positivity indicate Staphylococcus aureus; MRSA requires vancomycin or linezolid.

Gram-positive cocci in chains, catalase negative, optochin sensitive indicate Streptococcus pneumoniae; treat with penicillin or ceftriaxone.

Gram-negative diplococci in neutrophils suggest Neisseria gonorrhoeae or meningitidis; culture on Thayer-Martin agar with CO2.

Gram-negative rods: lactose fermenters on MacConkey agar include E. coli and Klebsiella; non-lactose fermenters include Pseudomonas and Salmonella.

Clostridioides difficile: toxin-mediated colitis after antibiotics; treat with oral vancomycin or fidaxomicin; avoid antiperistaltic agents.

Tuberculosis: acid-fast bacilli on Ziehl-Neelsen stain; culture on Lowenstein-Jensen medium; treat with rifampin, isoniazid, pyrazinamide, and ethambutol.

Fungal infection: Candida pseudohyphae with germ tubes; Aspergillus shows septate hyphae with acute-angle branching; Mucor shows broad nonseptate hyphae.

Viral hepatitis serology: HBsAg indicates infection; anti-HBs indicates immunity; IgM anti-HBc indicates acute infection; HCV diagnosed by RNA PCR.