بنك أسئلة USMLE الخطوة الثانية

اقرأ أسئلة عيّنة بنك أسئلة USMLE الخطوة الثانية

1. 1.A 58-year-old man presents with crushing substurnal chest pain for 40 minutes radiating to the left arm. He is diaphoretic. ECG shows 2 mm ST-segment elevation in leads II, III, and aVF. He is given aspirin and the cardiac catheterization laboratory is activated. Which of the following is the most appropriate next step in management?

   • أ.Perform primary percutaneous coronary interventionإجابة صحيحة
   • ب.Administer thrombolytic therapy
   • ج.Obtain a stress echocardiogram
   • د.Start high-dose statin and observe

   لماذا: This is an ST-elevation myocardial infarction (STEMI) with an inferior wall pattern. When available within 90 minutes, primary PCI is the preferred reperfusion strategy over thrombolysis. Rapid restoration of coronary blood flow limits infarct size and improves survival.

2. 2.A 65-year-old woman with an inferior STEMI develops hypotension with a blood pressure of 82/54 mm Hg. Her lungs are clear on auscultation and jugular venous pressure is elevated. ECG shows ST elevation in leads II, III, aVF. Which of the following is the most appropriate next step?

   • أ.Administer intravenous furosemide
   • ب.Administer intravenous normal saline bolusإجابة صحيحة
   • ج.Start intravenous nitroglycerin
   • د.Begin intravenous metoprolol

   لماذا: Hypotension with clear lungs and elevated JVP in an inferior MI suggests right ventricular infarction. RV infarction is preload dependent, so intravenous fluids are the initial treatment. Nitrates and diuretics reduce preload and can worsen hypotension and should be avoided.

3. 3.A 72-year-old man with hypertension presents with acute dyspnea. He has bibasilar crackles, an S3 gallop, and elevated jugular venous pressure. Chest x-ray shows pulmonary edema and blood pressure is 168/96 mm Hg. Oxygen saturation is 88 percent on room air. Which of the following is the most appropriate initial pharmacologic therapy?

   • أ.Intravenous furosemide and nitroglycerinإجابة صحيحة
   • ب.Oral beta-blocker
   • ج.Intravenous normal saline bolus
   • د.Broad-spectrum antibiotics

   لماذا: This is acute decompensated heart failure with pulmonary edema. Intravenous loop diuretics reduce volume overload and nitroglycerin reduces preload and afterload, relieving pulmonary congestion. Supplemental oxygen and diuresis are the cornerstones of initial management.

4. 4.A 60-year-old man presents with palpitations and lightheadedness. ECG shows an irregularly irregular rhythm with no discernible P waves at a ventricular rate of 140/min. Blood pressure is 138/82 mm Hg and he is otherwise stable. Symptoms began 2 hours ago. Which of the following is the most appropriate next step in management?

   • أ.Intravenous rate control with a beta-blocker or diltiazemإجابة صحيحة
   • ب.Intravenous adenosine
   • ج.Immediate synchronized cardioversion
   • د.Start warfarin and discharge

   لماذا: This is new-onset atrial fibrillation with rapid ventricular response in a hemodynamically stable patient. Rate control with an intravenous beta-blocker or non-dihydropyridine calcium channel blocker is the appropriate initial step. Cardioversion is reserved for hemodynamic instability or after anticoagulation considerations.

5. 5.A 45-year-old woman presents with sudden-onset dyspnea and pleuritic chest pain 5 days after a total knee replacement. Heart rate is 112/min, blood pressure 118/76 mm Hg, and oxygen saturation 91 percent. Her right calf is swollen and tender. Which of the following is the most appropriate next step in management?

   • أ.Obtain a D-dimer level
   • ب.Obtain a ventilation-perfusion scan first
   • ج.Start antibiotics for pneumonia
   • د.Begin empiric anticoagulation and obtain CT pulmonary angiographyإجابة صحيحة

   لماذا: High clinical probability of pulmonary embolism (recent surgery, DVT signs, tachycardia, hypoxia) warrants empiric anticoagulation while confirming with CT pulmonary angiography. D-dimer is not useful when pretest probability is high. Prompt anticoagulation prevents clot propagation.

6. 6.A 68-year-old man with a 50 pack-year smoking history presents with worsening cough, increased sputum purulence, and dyspnea over 3 days. He has diffuse wheezing and prolonged expiration. Temperature is 37.2 C and oxygen saturation is 90 percent. Which of the following is the most appropriate treatment regimen?

   • أ.Inhaled bronchodilators, systemic corticosteroids, and antibioticsإجابة صحيحة
   • ب.Inhaled corticosteroids alone
   • ج.Intravenous furosemide
   • د.Immediate intubation

   لماذا: This is an acute exacerbation of COPD with the cardinal features of increased dyspnea, sputum volume, and sputum purulence. Treatment includes short-acting bronchodilators, systemic corticosteroids, and antibiotics when purulence is present. Oxygen is titrated to avoid CO2 retention.

7. 7.A 24-year-old woman with asthma presents with acute shortness of breath and wheezing. She is speaking in short phrases, respiratory rate is 28/min, and oxygen saturation is 93 percent. After initial albuterol nebulization, she remains symptomatic. Which of the following is the most appropriate next step?

   • أ.Start a long-acting beta-agonist
   • ب.Add systemic corticosteroids and continue bronchodilatorsإجابة صحيحة
   • ج.Obtain a chest CT
   • د.Administer intravenous magnesium as first-line

   لماذا: In a moderate-to-severe asthma exacerbation that is not resolving with initial short-acting beta-agonist therapy, systemic corticosteroids should be added early to reduce airway inflammation. Continued bronchodilators and oxygen are also given. Magnesium is reserved for severe refractory cases.

8. 8.A 55-year-old man presents with fever, productive cough, and right-sided pleuritic chest pain. Chest x-ray shows a right lower lobe consolidation. He has no comorbidities and vital signs are stable with oxygen saturation of 95 percent. Which of the following is the most appropriate management?

   • أ.Outpatient oral amoxicillin or a macrolideإجابة صحيحة
   • ب.Obtain a chest CT before treatment
   • ج.Admit for intravenous antibiotics
   • د.Start oseltamivir

   لماذا: This is community-acquired pneumonia in a previously healthy outpatient with low severity (low CURB-65 score). Outpatient oral therapy with amoxicillin or a macrolide is appropriate. Hospitalization is reserved for higher severity scores or comorbidities.

9. 9.A 70-year-old man presents with progressive exertional dyspnea and a harsh crescendo-decrescendo systolic murmur at the right upper sternal border radiating to the carotids. He reports one episode of syncope. Echocardiography shows severe aortic stenosis. Which of the following is the most appropriate management?

   • أ.Start a vasodilator such as nitroprusside
   • ب.Begin diuretics and observe
   • ج.Perform balloon valvuloplasty as definitive therapy
   • د.Aortic valve replacementإجابة صحيحة

   لماذا: Symptomatic severe aortic stenosis (angina, syncope, or heart failure) is an indication for aortic valve replacement, which is the only effective definitive therapy. Vasodilators are dangerous because of the fixed outflow obstruction. Valvuloplasty is only a temporizing bridge.

10. 10.A 30-year-old man presents with sharp, positional chest pain that improves when leaning forward and worsens when lying supine. He had a recent viral illness. A pericardial friction rub is heard, and ECG shows diffuse ST-segment elevation with PR depression. Which of the following is the most appropriate treatment?

    • أ.High-dose NSAIDs and colchicineإجابة صحيحة
    • ب.Immediate coronary angiography
    • ج.Systemic anticoagulation
    • د.Thrombolytic therapy

    لماذا: This is acute viral pericarditis, characterized by pleuritic positional chest pain, a friction rub, and diffuse ST elevation with PR depression. First-line treatment is NSAIDs plus colchicine, which reduces symptoms and recurrence. Anticoagulation is avoided due to hemorrhagic pericardial risk.