NBME Comprehensive Clinical Science 2 — Questions and Answers
Question 1: A 65-year-old man with crushing chest pain and ST elevation in leads II, III, and aVF arrives at a PCI-capable hospital. BP 110/70, HR 95. What is the most appropriate next step?
- Administer IV thrombolytics
- Perform emergency primary PCI (Correct answer)
- Start IV heparin and admit to CCU
- Obtain serial troponins and echocardiogram
Correct answer: Perform emergency primary PCI
Primary PCI is the preferred reperfusion strategy for inferior STEMI when available within 90 minutes of first medical contact.
Question 2: A 50-year-old woman 3 days post-total hip replacement develops acute dyspnea, pleuritic chest pain, and tachycardia (HR 118). SpO2 is 90% on room air. BP is 105/70. What is the most likely diagnosis?
- Hospital-acquired pneumonia
- Pulmonary embolism (Correct answer)
- Acute NSTEMI
- Spontaneous pneumothorax
Correct answer: Pulmonary embolism
Pulmonary embolism classically presents with acute dyspnea, pleuritic chest pain, and hypoxia following prolonged immobilization or orthopedic surgery.
Question 3: A 72-year-old diabetic man presents with altered mental status and fruity breath. ABG shows pH 7.18, pCO2 22, HCO3 8 mEq/L. Blood glucose is 520 mg/dL with urine ketones. What is the first priority in management?
- IV insulin infusion at 0.1 units/kg/hr
- IV normal saline fluid resuscitation (Correct answer)
- Sodium bicarbonate infusion
- Potassium supplementation
Correct answer: IV normal saline fluid resuscitation
Aggressive IV fluid resuscitation with normal saline corrects dehydration and must precede insulin administration in DKA.
Question 4: A 55-year-old woman with sepsis develops oozing from IV sites, petechiae, platelets 38,000/μL, prolonged PT and PTT, low fibrinogen, and schistocytes on peripheral smear. What is the most likely diagnosis?
- Immune thrombocytopenic purpura
- Heparin-induced thrombocytopenia
- Disseminated intravascular coagulation (Correct answer)
- Thrombotic thrombocytopenic purpura
Correct answer: Disseminated intravascular coagulation
DIC in sepsis presents with consumption of clotting factors and platelets causing simultaneous bleeding and thrombosis, with low fibrinogen distinguishing it from TTP.
Question 5: A 60-year-old man develops sudden severe 'thunderclap' headache described as the worst of his life, followed by neck stiffness and photophobia. CT head is normal. What is the most appropriate next step?
- MRI brain with gadolinium
- Lumbar puncture (Correct answer)
- Empiric antibiotics for bacterial meningitis
- Cerebral angiography
Correct answer: Lumbar puncture
A normal CT in a patient with thunderclap headache requires lumbar puncture to detect xanthochromia or RBCs, confirming subarachnoid hemorrhage.
Question 6: A 25-year-old woman with 6 weeks of amenorrhea presents with right lower quadrant pain and a positive urine pregnancy test. Pelvic ultrasound shows no intrauterine pregnancy and a 2.5 cm right adnexal mass. What is the diagnosis?
- Ruptured ovarian cyst
- Acute appendicitis
- Ectopic pregnancy (Correct answer)
- Ovarian torsion
Correct answer: Ectopic pregnancy
A positive beta-hCG with no intrauterine pregnancy on ultrasound and an adnexal mass is an ectopic pregnancy until proven otherwise.
Question 7: A 48-year-old man with alcoholic cirrhosis develops fever, abdominal pain, and worsening encephalopathy. Paracentesis reveals a PMN count of 380 cells/mm³. What is the most appropriate treatment?
- Emergent surgical drainage of peritoneal cavity
- IV cefotaxime (Correct answer)
- IV ampicillin-sulbactam
- Oral ciprofloxacin and outpatient follow-up
Correct answer: IV cefotaxime
Spontaneous bacterial peritonitis (PMN ≥250 cells/mm³) is treated with IV third-generation cephalosporins such as cefotaxime without waiting for culture results.
NBME Comprehensive Clinical Science 2
A 65-year-old man with crushing chest pain and ST elevation in leads II, III, and aVF arrives at a PCI-capable hospital.
BP 110/70, HR 95.
What is the most appropriate next step?