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PANCE practice questions

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Question 1Cardiovascular system

A 58-year-old man has crushing chest pain and ST-segment elevation in leads V1 through V4. Which coronary artery is most likely occluded?

  1. LAD artery Correct answer.
  2. Right coronary artery
  3. Left main coronary artery
  4. Left circumflex artery

Explanation

ST elevation in V1-V4 localizes ischemia to the anterior and septal walls, which are supplied by the left anterior descending artery. Right coronary occlusion produces inferior changes, and circumflex occlusion produces lateral changes.

Question 2Cardiovascular system

A 70-year-old man has exertional syncope and a harsh systolic murmur. Which description best fits aortic stenosis?

  1. Holosystolic murmur at the apex that radiates to the axilla
  2. Mid-diastolic rumbling murmur with an opening snap
  3. Early diastolic decrescendo murmur at the left upper sternal border
  4. Crescendo-decrescendo systolic murmur radiating to the carotids Correct answer.

Explanation

Aortic stenosis produces a crescendo-decrescendo systolic ejection murmur at the right upper sternal border that radiates to the carotids. Exertional syncope is a classic symptom of severe aortic stenosis.

Question 3Cardiovascular system

A 30-year-old has sharp pleuritic chest pain that worsens when supine. Which ECG finding is most consistent with acute pericarditis?

  1. ST elevation in leads II, III, and aVF
  2. Diffuse ST elevation with PR-segment depression Correct answer.
  3. ST depression in leads V1-V3 with tall R waves
  4. ST elevation in leads V1-V4 with reciprocal depression

Explanation

Acute pericarditis causes diffuse concave ST elevation and PR depression because of epicardial inflammation. The changes are not limited to a single coronary territory.

Question 4Cardiovascular system

A 68-year-old with dyspnea and bilateral rales has which blood test most useful for supporting a diagnosis of heart failure?

  1. BNP level Correct answer.
  2. Creatine kinase-MB level
  3. Serum troponin level
  4. Plasma D-dimer level

Explanation

BNP is released from stretched ventricular myocardium and is useful for supporting or excluding heart failure in a patient with dyspnea. Troponin and CK-MB reflect myocardial injury, while D-dimer reflects thrombosis.

Question 5Cardiovascular system

A 55-year-old Black man has stage 2 hypertension without diabetes or chronic kidney disease. Which agent is an appropriate first-line choice?

  1. Amlodipine Correct answer.
  2. Metoprolol
  3. Lisinopril
  4. Spironolactone

Explanation

Guidelines recommend a thiazide-type diuretic or a calcium channel blocker as initial therapy for many Black adults with hypertension. ACE inhibitors are less effective as monotherapy in this group unless chronic kidney disease or diabetes is present.

Question 6Cardiovascular system

A 28-year-old woman has a regular narrow-complex tachycardia at 180 beats/min and is hemodynamically stable. Which is the first-line acute pharmacologic therapy?

  1. Intravenous adenosine Correct answer.
  2. Intravenous amiodarone
  3. Intravenous digoxin
  4. Intravenous diltiazem

Explanation

Adenosine transiently blocks the atrioventricular node and terminates most paroxysmal supraventricular tachycardias. It is preferred in stable narrow-complex tachycardia after vagal maneuvers fail.

Question 7Cardiovascular system

A 65-year-old smoker has calf cramping with walking and diminished pedal pulses. Which test is the best initial diagnostic study for peripheral artery disease?

  1. Exercise treadmill testing
  2. Ankle-brachial index Correct answer.
  3. CT angiography
  4. Duplex ultrasonography

Explanation

The ankle-brachial index is a simple, noninvasive first-line test for peripheral artery disease, with a value below 0.90 considered abnormal. Imaging is used mainly for anatomic planning when revascularization is considered.

Question 8Cardiovascular system

A 40-year-old with fever and a new regurgitant murmur is suspected of having infective endocarditis and is hemodynamically stable. What should be obtained before starting antibiotics?

  1. Transesophageal echocardiography
  2. Urine culture
  3. Three sets of blood cultures from separate sites Correct answer.
  4. Erythrocyte sedimentation rate

Explanation

In suspected infective endocarditis, multiple blood culture sets should be drawn from separate venipuncture sites before antibiotics are started. This increases the yield and identifies the pathogen so therapy can be tailored.

Question 9Cardiovascular system

A 72-year-old man with nonvalvular atrial fibrillation also has hypertension, giving a CHA2DS2-VASc score of 2. Which management is recommended?

  1. Start aspirin alone
  2. No antithrombotic therapy
  3. Start apixaban Correct answer.
  4. Start aspirin plus clopidogrel

Explanation

A CHA2DS2-VASc score of 2 or more in a man warrants oral anticoagulation, and a direct oral anticoagulant is preferred over warfarin for nonvalvular atrial fibrillation. Antiplatelet therapy alone is inadequate for stroke prevention in this setting.

Question 10Cardiovascular system

A 20-year-old athlete has syncope and a harsh systolic murmur at the left lower sternal border that intensifies with Valsalva. Which diagnosis is most likely?

  1. Hypertrophic cardiomyopathy Correct answer.
  2. Degenerative mitral valve regurgitation
  3. Calcific aortic stenosis with syncope
  4. Congenital ventricular septal defect

Explanation

Hypertrophic cardiomyopathy causes dynamic left ventricular outflow tract obstruction that worsens when preload falls during Valsalva, so the murmur intensifies. Syncope in a young athlete is a classic presentation.

Question 11Cardiovascular system

A 60-year-old with a large pericardial effusion has hypotension and muffled heart sounds. Which finding is most consistent with cardiac tamponade?

  1. Widened pulse pressure
  2. Bounding peripheral pulses
  3. Pulsus alternans
  4. Pulsus paradoxus Correct answer.

Explanation

Cardiac tamponade impairs right ventricular filling during inspiration, producing an exaggerated inspiratory fall in systolic blood pressure known as pulsus paradoxus. It is part of the clinical picture that also includes hypotension and muffled heart sounds.

Question 12Cardiovascular system

A 55-year-old with diabetes and an LDL cholesterol level of 190 mg/dL is starting lipid-lowering therapy. Which is the first-line agent?

  1. High-intensity statin Correct answer.
  2. Ezetimibe monotherapy
  3. Fenofibrate monotherapy
  4. Extended-release niacin

Explanation

Statins are first-line therapy for LDL lowering and reduction of atherosclerotic cardiovascular risk. A patient with diabetes and markedly elevated LDL should receive a high-intensity statin.

Question 13Cardiovascular system

A 70-year-old with syncope has an ECG showing intermittent dropped QRS complexes without progressive PR prolongation. What is the definitive management?

  1. Observation with repeat ECG
  2. Atropine administration
  3. Permanent pacemaker Correct answer.
  4. Beta-blocker therapy

Explanation

This pattern is Mobitz type II second-degree atrioventricular block, which reflects infranodal conduction disease and can progress suddenly to complete heart block. Permanent pacing is the definitive treatment.

Question 14Cardiovascular system

A 60-year-old with sudden tearing chest pain and unequal arm blood pressures is hemodynamically stable. Which is the best initial imaging study?

  1. Transthoracic echocardiography
  2. CT angiography of the chest Correct answer.
  3. Chest radiography
  4. Exercise stress testing

Explanation

CT angiography of the chest is highly sensitive and specific for detecting an intimal flap in aortic dissection and is the preferred initial study in a stable patient. Transthoracic echocardiography visualizes only limited portions of the aorta.

Question 15Cardiovascular system

A 35-year-old immigrant from a developing country has dyspnea, an opening snap, and a diastolic rumble at the apex. Which cause is most likely?

  1. Mitral valve prolapse
  2. Aortic regurgitation
  3. Active infective endocarditis
  4. Rheumatic heart disease Correct answer.

Explanation

Rheumatic heart disease is the leading cause of mitral stenosis worldwide and produces leaflet thickening, commissural fusion, an opening snap, and a mid-diastolic rumble. The history of immigration from an endemic area supports this diagnosis.

Question 16Cardiovascular system

A 78-year-old taking digoxin has nausea, confusion, and bradycardia. Which finding is most characteristic of digoxin toxicity?

  1. Diffuse ST-segment elevation
  2. Markedly shortened PR interval
  3. Visual halos Correct answer.
  4. Tall peaked T waves

Explanation

Digoxin toxicity classically causes gastrointestinal, neurologic, and visual symptoms, including yellow-green halos. Bradyarrhythmias and heart block are common, and hypokalemia predisposes to toxicity.

Question 17Cardiovascular system

A patient on long-term amiodarone requires monitoring for which adverse effect?

  1. Gingival hyperplasia
  2. Pulmonary fibrosis Correct answer.
  3. Nephrotoxicity
  4. Ototoxicity

Explanation

Amiodarone accumulates in the lungs, thyroid, liver, and cornea and can cause potentially fatal pulmonary fibrosis. Patients need periodic pulmonary, thyroid, hepatic, and ophthalmologic monitoring.

Question 18Cardiovascular system

A 45-year-old woman has unilateral leg swelling after surgery. Which is the best initial diagnostic test for deep vein thrombosis?

  1. MRI of the lower extremity
  2. Plasma D-dimer assay
  3. Contrast venography of the leg
  4. Compression ultrasound Correct answer.

Explanation

Venous compression ultrasound is the preferred initial test for suspected proximal deep vein thrombosis and diagnoses it by showing noncompressibility of the vein. D-dimer is nonspecific in postoperative patients.

Question 19Cardiovascular system

Which finding best distinguishes NSTEMI from unstable angina?

  1. Elevated troponin Correct answer.
  2. Pathologic Q waves
  3. ST-segment elevation on ECG
  4. Elevated CK-MB

Explanation

Both NSTEMI and unstable angina cause ischemia without persistent ST elevation, but NSTEMI produces myocardial necrosis that releases troponin. ST elevation defines STEMI, and Q waves indicate established infarction.

Question 20Cardiovascular system

A 10-year-old has migratory polyarthritis and fever two weeks after streptococcal pharyngitis. Which is a major Jones criterion?

  1. Low-grade fever
  2. Polyarthralgia without arthritis
  3. Elevated erythrocyte sedimentation rate
  4. Subcutaneous nodules Correct answer.

Explanation

The major Jones criteria are carditis, polyarthritis, chorea, erythema marginatum, and subcutaneous nodules. Arthralgia, fever, and elevated inflammatory markers are minor criteria.

Question 21Cardiovascular system

A 70-year-old with an anterior STEMI has a blood pressure of 78/50 mm Hg, cold extremities, and Killip class IV heart failure. Which management is most appropriate?

  1. Dobutamine infusion alone
  2. High-dose nitroglycerin infusion
  3. Rapid bolus of intravenous normal saline
  4. Norepinephrine plus revascularization Correct answer.

Explanation

Cardiogenic shock after myocardial infarction requires vasopressor support to maintain perfusion and urgent revascularization of the infarct-related artery. Large fluid boluses can worsen pulmonary edema.

Question 22Cardiovascular system

Which finding is most associated with chronic severe aortic regurgitation?

  1. Fixed split S2
  2. Systolic ejection murmur at the base
  3. Bounding pulses with head bobbing Correct answer.
  4. Narrow pulse pressure

Explanation

Chronic severe aortic regurgitation creates a large stroke volume and rapid diastolic runoff, producing a wide pulse pressure, bounding water-hammer pulses, and head bobbing. These are signs of a hyperdynamic circulation.

Question 23Cardiovascular system

A 50-year-old with prior tuberculosis has right heart failure, a pericardial knock, and preserved ejection fraction. Which diagnosis is most likely?

  1. Constrictive pericarditis Correct answer.
  2. Right ventricular infarction
  3. Cardiac tamponade
  4. Restrictive cardiomyopathy

Explanation

Constrictive pericarditis causes a rigid pericardium that impairs diastolic filling, producing right heart failure, a pericardial knock, and preserved ejection fraction. Tuberculosis is a classic risk factor.

Question 24Cardiovascular system

A 65-year-old with a mechanical aortic valve develops fever and a new murmur three weeks after surgery. Which organism is most likely?

  1. Enterococcus faecalis
  2. Staphylococcus aureus Correct answer.
  3. Viridans group streptococci
  4. HACEK organisms

Explanation

Early prosthetic valve endocarditis, occurring within 60 days of surgery, is most often caused by staphylococci acquired during the perioperative period. Staphylococcus aureus is a common and virulent cause.

Question 25Cardiovascular system

A 55-year-old with a Stanford type A aortic dissection is diagnosed. What is the definitive management?

  1. Intravenous thrombolysis
  2. Pericardiocentesis
  3. Beta-blocker therapy and observation
  4. Emergent surgical repair Correct answer.

Explanation

Type A dissection involves the ascending aorta and can rapidly cause tamponade, aortic regurgitation, or malperfusion, so emergent surgical repair is required. Beta blockers are an important initial medical measure but are not definitive.

Question 26Cardiovascular system

A 58-year-old man with an ejection fraction of 30% and New York Heart Association class III symptoms is already taking a beta blocker and an ACE inhibitor at target doses. Which additional agent has been shown to reduce all-cause mortality in this setting?

  1. Spironolactone Correct answer.
  2. Diltiazem
  3. Amlodipine
  4. Furosemide

Explanation

Aldosterone receptor antagonists reduce mortality and heart failure hospitalization in patients with reduced ejection fraction and moderate-to-severe symptoms already treated with standard therapy. Diuretics such as loop agents relieve congestion but have no mortality benefit, and non-dihydropyridine calcium channel blockers are negatively inotropic and should be avoided in reduced ejection fraction. Dihydropyridine calcium channel blockers are considered neutral rather than mortality-reducing.

Question 27Pulmonary system

A 24-year-old woman with asthma uses her rescue inhaler three times a week and wakes with cough twice a month. Spirometry shows an FEV1 of 85% predicted. Which agent is the most appropriate first-line controller?

  1. Low-dose inhaled corticosteroid Correct answer.
  2. Montelukast as monotherapy
  3. Long-acting beta-2 agonist as monotherapy
  4. Scheduled daily short-acting beta-2 agonist

Explanation

In persistent asthma, inhaled corticosteroids are the most effective anti-inflammatory controller and the preferred first-line therapy at every severity step. Short-acting beta-2 agonists are for rescue relief only, and long-acting beta-2 agonists are never used as monotherapy in asthma because of the risk of unopposed bronchoconstriction.

Question 28Pulmonary system

A 31-year-old man is struck in the chest and becomes acutely dyspneic and hypotensive. He has distended neck veins, absent breath sounds on the right, and hyperresonance to percussion on the right. What is the most appropriate immediate step?

  1. Perform needle decompression of the right hemithorax Correct answer.
  2. Place a chest tube only after CT confirmation
  3. Obtain a chest radiograph before any intervention
  4. Administer nebulized albuterol and observe

Explanation

Tension pneumothorax is a clinical diagnosis, and treatment must never be delayed for imaging. Immediate needle decompression, followed by tube thoracostomy, relieves the obstructed venous return and prevents cardiovascular collapse.

Question 29Pulmonary system

A 2-year-old child has failure to thrive, recurrent bulky greasy stools, and repeated respiratory infections. Which test is the diagnostic standard for the suspected condition?

  1. Sweat chloride test Correct answer.
  2. Serum immunoreactive trypsinogen level
  3. Routine sputum culture
  4. Nasal nitric oxide measurement

Explanation

Cystic fibrosis is confirmed by a sweat chloride concentration above 60 mmol/L on adequate pilocarpine iontophoresis testing, with values of 30 to 59 mmol/L considered intermediate. Immunoreactive trypsinogen is a newborn screening tool, not a confirmatory test.

Question 30Pulmonary system

A 48-year-old obese man with a 20-inch neck circumference snores loudly, has witnessed apneas, and falls asleep while driving. Which test is the reference standard for establishing the diagnosis?

  1. Epworth Sleepiness Scale score
  2. Overnight pulse oximetry alone
  3. A one-week empiric CPAP trial
  4. Attended in-laboratory polysomnography Correct answer.

Explanation

Attended polysomnography is the reference standard for obstructive sleep apnea because it quantifies apneas and hypopneas per hour and measures oxygen saturation. Home sleep apnea testing is an acceptable alternative only in patients with a high pretest probability and no significant cardiopulmonary comorbidity.

Question 31Pulmonary system

Which clinical definition establishes chronic bronchitis in a patient with a chronic obstructive pulmonary disease phenotype?

  1. Productive cough for at least 3 months in each of 2 consecutive years Correct answer.
  2. Permanent bronchial dilation with daily purulent sputum
  3. Irreversible airflow obstruction on post-bronchodilator spirometry
  4. Progressive dyspnea with a reduced diffusing capacity

Explanation

Chronic bronchitis is defined clinically as a productive cough present for at least 3 months in each of 2 consecutive years. The definition is symptom-based, whereas emphysema is defined by permanent enlargement of airspaces and airflow obstruction by spirometry.

Question 32Pulmonary system

A 19-year-old with asthma presents with wheezing, a respiratory rate of 30/min, and an oxygen saturation of 90% on room air. Which medication should be given first?

  1. Intravenous aminophylline
  2. Inhaled corticosteroid alone
  3. Intravenous antibiotic therapy
  4. Inhaled short-acting beta-2 agonist Correct answer.

Explanation

Inhaled short-acting beta-2 agonists are the first-line therapy for acute bronchospasm because they produce rapid bronchodilation with a wide safety margin. Corticosteroids are added early to treat inflammation, but they have no immediate bronchodilator effect.

Question 33Pulmonary system

Which spirometric finding confirms persistent airflow limitation consistent with COPD?

  1. Pre-bronchodilator FEV1 below 80% of predicted
  2. Post-bronchodilator FEV1/FVC ratio below 0.80
  3. Diffusing capacity below 60% of predicted
  4. Post-bronchodilator FEV1/FVC ratio below 0.70 Correct answer.

Explanation

A post-bronchodilator FEV1/FVC ratio below 0.70 in a patient with symptoms and risk factors establishes the diagnosis of COPD. The fixed ratio is the accepted spirometric criterion, and the FEV1 percentage predicted is then used for severity grading.

Question 34Pulmonary system

A previously healthy 42-year-old man has community-acquired pneumonia and will be treated as an outpatient. He has no comorbidities, no recent antibiotic use, and no drug allergies. Which regimen is most appropriate?

  1. High-dose amoxicillin monotherapy Correct answer.
  2. Vancomycin plus piperacillin-tazobactam
  3. Levofloxacin plus metronidazole
  4. Azithromycin plus ceftriaxone

Explanation

For otherwise healthy outpatients with community-acquired pneumonia, high-dose amoxicillin or doxycycline is recommended first-line because Streptococcus pneumoniae remains the dominant pathogen. Combination or broad-spectrum regimens are reserved for patients with comorbidities or recent antibiotic exposure.

Question 35Pulmonary system

A 34-year-old woman presents with pleuritic chest pain and dyspnea three days after a long flight. She is tachycardic but has no hemoptysis, immobilization, prior venous thromboembolism, or cancer. Her age-adjusted D-dimer returns normal. What is the next step?

  1. Proceed to ventilation-perfusion scanning
  2. Proceed to CT pulmonary angiography
  3. No further imaging is required Correct answer.
  4. Start empiric anticoagulation

Explanation

In a patient with a low pretest probability and a negative age-adjusted D-dimer, pulmonary embolism is effectively excluded and no imaging or anticoagulation is indicated. This strategy safely avoids unnecessary radiation and bleeding risk.

Question 36Pulmonary system

A 30-year-old nurse has a positive interferon-gamma release assay, a normal chest radiograph, and no symptoms. Which regimen is appropriate for this patient?

  1. Weekly isoniazid plus rifapentine for 12 weeks Correct answer.
  2. Four-drug therapy for 6 months
  3. Rifampin plus isoniazid for 2 weeks
  4. Isoniazid alone for 4 weeks

Explanation

Latent tuberculosis infection is treated with short-course rifamycin-based regimens such as 12 weeks of weekly isoniazid plus rifapentine, or alternative 3- to 4-month rifamycin regimens. Four-drug therapy is reserved for active tuberculosis disease.

Question 37Pulmonary system

A 38-year-old nonsmoker has emphysema that is most prominent in the lung bases. Which test is most likely to establish the underlying cause?

  1. Serum ceruloplasmin level
  2. Sweat chloride concentration
  3. Sputum culture for Pseudomonas aeruginosa
  4. Serum alpha-1 antitrypsin level Correct answer.

Explanation

Early-onset emphysema with basilar, panacinar involvement in a nonsmoker suggests alpha-1 antitrypsin deficiency, which is confirmed by serum alpha-1 antitrypsin levels with phenotyping. Smoking-related emphysema is typically upper-lobe and centrilobular.

Question 38Pulmonary system

A 63-year-old smoker with small cell lung cancer is admitted with confusion and a serum sodium of 118 mEq/L. He is euvolemic, and urine osmolality is elevated. What is the most appropriate initial therapy?

  1. Intravenous furosemide alone
  2. Hypertonic saline for all patients
  3. Emergent radiation to the pituitary gland
  4. Fluid restriction Correct answer.

Explanation

Small cell lung cancer commonly causes paraneoplastic syndrome of inappropriate antidiuretic hormone, and the first-line treatment for euvolemic hyponatremia is fluid restriction. Hypertonic saline is reserved for severe symptomatic hyponatremia because of the risk of osmotic demyelination.

Question 39Pulmonary system

Which pulmonary function test result pattern characterizes a restrictive lung disease?

  1. Reduced total lung capacity with a normal or increased FEV1/FVC ratio Correct answer.
  2. Increased diffusing capacity with a normal total lung capacity
  3. Reduced FEV1/FVC ratio with an increased residual volume
  4. Normal spirometry with an isolated reduction in peak expiratory flow

Explanation

Restrictive disease reduces lung volumes, so total lung capacity falls while the FEV1/FVC ratio is preserved or even elevated because both values decline proportionally. Obstruction, by contrast, lowers the FEV1/FVC ratio and often raises residual volume.

Question 40Pulmonary system

A 71-year-old man with a recent stroke and dysphagia develops fever and a right lower lobe infiltrate. Which empiric antibiotic regimen best covers the likely pathogens?

  1. Aztreonam
  2. Azithromycin monotherapy
  3. Vancomycin monotherapy
  4. Ampicillin-sulbactam Correct answer.

Explanation

Aspiration pneumonia in a patient with dysphagia typically involves mixed oral anaerobes and enteric gram-negative organisms. Ampicillin-sulbactam provides appropriate anaerobic and gram-negative coverage for this setting.

Question 41Pulmonary system

A 29-year-old woman presents with anterior uveitis, painful erythematous nodules on her shins, and bilateral ankle arthritis. Chest imaging shows bilateral hilar adenopathy. What is the most likely diagnosis?

  1. Hypersensitivity pneumonitis
  2. Hodgkin lymphoma
  3. Tuberculous lymphadenitis
  4. Sarcoidosis (Löfgren syndrome) Correct answer.

Explanation

The triad of erythema nodosum, bilateral hilar lymphadenopathy, and polyarthritis constitutes Löfgren syndrome, a form of acute sarcoidosis with an excellent prognosis. When the triad is fully present, the diagnosis can be made clinically without biopsy.

Question 42Pulmonary system

Which set of findings meets the Berlin definition of acute respiratory distress syndrome?

  1. PaO2/FiO2 of 350 while breathing room air
  2. Unilateral consolidation with a normal PaO2/FiO2
  3. Respiratory failure fully explained by left ventricular failure
  4. PaO2/FiO2 of 200 on PEEP of at least 5 cm H2O with bilateral opacities Correct answer.

Explanation

The Berlin definition requires acute onset within 1 week, bilateral opacities not fully explained by cardiac failure, and a PaO2/FiO2 ratio of 300 or less while receiving at least 5 cm H2O of positive end-expiratory pressure. Severity is graded by the ratio, with 200 or less on PEEP indicating moderate disease.

Question 43Pulmonary system

A pleural effusion is sampled; serum protein is 7.0 g/dL, serum lactate dehydrogenase is 200 U/L, and the upper limit of normal for serum lactate dehydrogenase is 200 U/L. Which pleural fluid result classifies the effusion as exudative by Light's criteria?

  1. Pleural fluid lactate dehydrogenase of 90 U/L
  2. Pleural fluid glucose of 95 mg/dL
  3. Pleural fluid pH of 7.45
  4. Pleural fluid protein of 4.4 g/dL Correct answer.

Explanation

Light's criteria classify an effusion as exudative when any one of three thresholds is met: a pleural-to-serum protein ratio above 0.5, a pleural-to-serum lactate dehydrogenase ratio above 0.6, or a pleural lactate dehydrogenase greater than two-thirds of the serum upper limit of normal. A pleural protein of 4.4 g/dL gives a ratio of 0.63 and therefore meets exudative criteria.

Question 44Pulmonary system

A 68-year-old man has 2 years of progressive exertional dyspnea and fine basilar inspiratory crackles. Which high-resolution CT pattern is most consistent with the suspected diagnosis?

  1. Bilateral hilar lymphadenopathy with nodularity along the bronchovascular bundles
  2. Subpleural, basal-predominant honeycombing with traction bronchiectasis Correct answer.
  3. Upper-lobe centrilobular emphysema
  4. Centrilobular nodules with tree-in-bud branching

Explanation

Idiopathic pulmonary fibrosis produces a usual interstitial pneumonia pattern on high-resolution CT, consisting of subpleural, basal-predominant reticulation, honeycombing, and traction bronchiectasis with minimal ground-glass opacity. This pattern allows a confident diagnosis without surgical biopsy.

Question 45Pulmonary system

A 66-year-old with chronic obstructive pulmonary disease presents with worsening dyspnea, a pH of 7.28, and a PaCO2 of 68 mm Hg despite maximal bronchodilators and controlled oxygen. Which intervention most clearly reduces mortality?

  1. Chest physiotherapy with assisted coughing
  2. Adding inhaled ipratropium to the nebulizer regimen
  3. Noninvasive positive-pressure ventilation Correct answer.
  4. High-flow nasal cannula as a substitute for ventilatory support

Explanation

Noninvasive positive-pressure ventilation reduces intubation rates and mortality in acute hypercapnic exacerbations of chronic obstructive pulmonary disease with respiratory acidosis. It should be started early in patients with an arterial pH of 7.35 or less and hypercapnia who can protect their airway.

Question 46Pulmonary system

A 27-year-old man has chronic productive cough, recurrent sinusitis, and dextrocardia. Semen analysis shows immotile sperm. Which diagnosis best explains this constellation?

  1. Post-infectious bronchiolitis obliterans
  2. Alpha-1 antitrypsin deficiency
  3. Allergic bronchopulmonary aspergillosis
  4. Primary ciliary dyskinesia Correct answer.

Explanation

Primary ciliary dyskinesia impairs mucociliary clearance, producing bronchiectasis, chronic sinusitis, and male infertility from immotile sperm. When accompanied by situs inversus, the combination is known as Kartagener syndrome.

Question 47Musculoskeletal system

A 45-year-old man presents with a 12-hour history of severe pain, swelling, and redness of the first metatarsophalangeal joint. Arthrocentesis yields cloudy fluid, and polarized light microscopy shows needle-shaped intracellular crystals that appear yellow when aligned parallel to the compensator. Which diagnosis is most likely?

  1. Septic arthritis
  2. Hydroxyapatite crystal disease
  3. Gout Correct answer.
  4. Calcium pyrophosphate deposition disease

Explanation

Needle-shaped, negatively birefringent monosodium urate crystals are diagnostic of gout, and the first metatarsophalangeal joint is the classic site of a flare. Calcium pyrophosphate crystals are rhomboid and positively birefringent.

Question 48Musculoskeletal system

A 2-year-old girl is brought to the clinic after her father lifted her by the hand while she resisted. She now holds her right arm slightly flexed and refuses to use it. There is no swelling, deformity, or point tenderness, and radiographs are normal. Which of the following is the most appropriate management?

  1. Refer urgently for orthopedic surgical evaluation
  2. Reduce the radial head by supination and flexion Correct answer.
  3. Apply a long arm cast for 4 weeks
  4. Obtain an MRI of the elbow

Explanation

This is a radial head subluxation (nursemaid's elbow), caused by longitudinal traction on the extended pronated arm. It is reduced in the office by supinating the forearm and flexing the elbow, after which the child typically resumes use within minutes.

Question 49Musculoskeletal system

A 52-year-old woman reports 6 months of burning and tingling in the thumb, index, and middle fingers that wakes her at night and improves when she shakes her hand. Examination shows atrophy of the thenar eminence. Which nerve is affected?

  1. Median nerve Correct answer.
  2. Radial nerve
  3. Posterior interosseous nerve
  4. Ulnar nerve

Explanation

The median nerve supplies sensation to the thumb, index, middle, and radial half of the ring finger and innervates the thenar muscles, so nocturnal paresthesias with thenar wasting localizes to it. Symptoms are caused by compression at the carpal tunnel.

Question 50Musculoskeletal system

A 13-year-old soccer player has 2 months of anterior knee pain localized just below the patella. The pain worsens with running and jumping and improves with rest. Examination reveals a prominent, tender bony bump at the tibial tuberosity without effusion or ligamentous instability. Which diagnosis is most likely?

  1. Sinding-Larsen-Johansson disease
  2. Patellar tendinopathy
  3. Osteochondritis dissecans of the femoral condyle
  4. Osgood-Schlatter disease Correct answer.

Explanation

Osgood-Schlatter disease is traction apophysitis of the tibial tubercle occurring in skeletally immature adolescents during a growth spurt. It produces focal tenderness and a bony prominence at the tibial tuberosity that worsens with activity.