Cardiology
ID
Pulm
100
A 48-year-old woman is evaluated during a new-patient visit. She reports no symptoms. She is fairly sedentary but is trying to become more active by joining the local health club. She has noticed that she is “out of shape” but can cycle on a stationary bike with moderate intensity to the end of her 30-minute workout. Medical history is otherwise unremarkable. She takes no medications.
On physical examination, vital signs are normal. The estimated central venous pressure is 6 cm H2O. The apical impulse is not palpable. Cardiac examination reveals a grade 2/6 midsystolic murmur localized to the left sternal border without radiation. The murmur does not change with respiration or handgrip but does diminish in intensity with standing. The S2 is physiologically split. There are no clicks. The lungs are clear to auscultation. Peripheral pulses are normal in volume and contour. No edema is present.
Which of the following is the most appropriate management?
A Cardiac magnetic resonance imaging
B Transesophageal echocardiography
C Transthoracic echocardiography
D Routine clinical follow-up without imaging
Answer & Critique Correct Answer: D
Educational Objective: Diagnose a benign heart murmur.
Key Point
Short, soft systolic murmurs (grade <3) that are well localized to the left sternal border and are not associated with symptoms often do not require further investigation.
The most appropriate management is routine clinical follow-up without imaging. Cardiac murmurs result from increased blood flow across a normal orifice (such as with anemia, thyrotoxicosis, pregnancy, or atrial septal defect), turbulent flow through a narrowed orifice (such as with aortic stenosis or mitral stenosis), or regurgitant flow through an incompetent valve (such as with aortic regurgitation or mitral regurgitation). Timing in the cardiac cycle, chest wall location, radiation, intensity, configuration, duration, and pitch all assist in the differential diagnosis.
Not all systolic murmurs are pathologic. Asymptomatic patients with short, soft systolic murmurs (grade <3) well localized to the left sternal border and associated with normal heart sounds do not usually require further investigation. Benign murmurs typically decrease in intensity with standing. The presence of any diastolic or continuous murmur, cardiac symptoms (chest pain, dyspnea, syncope), or abnormalities on examination (clicks, abnormal S2, abnormal pulses) requires evaluation by echocardiography.
Various interventions may alter the intensity of murmurs. The murmur of hypertrophic cardiomyopathy may increase with standing or Valsalva maneuver; both maneuvers decrease venous return, which decreases left ventricular chamber size and increases the degree of obstruction. The click and murmur of mitral valve prolapse may move earlier in systole and increase in intensity as left ventricular volume decreases (standing or Valsalva maneuver). Aortic outflow murmurs increase in intensity in the beat following a premature ventricular contraction due to increased left ventricular volume. Murmurs of mitral regurgitation, ventricular septal defect, and aortic regurgitation increase with handgrip because of increased cardiac output and peripheral resistance. Right-sided heart murmurs may increase during inspiration due to increased venous return.
Characteristics of the S2 may assist in determining the diagnosis or the severity of a valvular lesion. A fixed split of S2 (present during inspiration and expiration instead of only inspiration) results from a delay in right ventricular emptying and is strongly associated with atrial septal defect. A paradoxical split of S2 (present during expiration) indicates a delay in left ventricular emptying, such as with severe aortic stenosis. Presence of a physiologic split (present during inspiration) is helpful for excluding severe aortic stenosis.
Because this patient likely has a benign systolic heart murmur and is asymptomatic, imaging with echocardiography or cardiac magnetic resonance imaging is not necessary.
100
A 25-year-old woman is hospitalized with a 4-day history of fever and cough productive of brown sputum. She is at 14 weeks' gestation with her first pregnancy. Medical history is significant for mild persistent asthma. Medications are an albuterol inhaler, beclomethasone inhaler, and a prenatal vitamin.
On physical examination, temperature is 38.2 °C (100.8 °F), blood pressure is normal, pulse rate is 122/min, and respiration rate is 24/min. Oxygen saturation is 94% breathing ambient air. Crackles are heard at the left lung base on pulmonary auscultation.
Chest radiograph shows a left lower lobe infiltrate.
Which of the following is the most likely cause of pneumonia in this patient?
A Escherichia coli
B Klebsiella pneumonia
C Listeria monocytogenes
D Staphylococcus aureus
E Streptococcus pneumoniae
Answer & CritiqueCorrect Answer: E
Educational Objective: Evaluate community-acquired pneumonia in a pregnant patient.
Key Point:
The microbiology of community-acquired pneumonia in pregnancy is similar to that seen in the general population; among patients requiring hospitalization, the most common pathogens are Streptococcus pneumoniae, Haemophilus influenzae, and atypical organisms, including Legionella species, Chlamydia pneumoniae, and Mycoplasma pneumonia.
Streptococcus pneumoniae is the most likely cause of this patient's community-acquired pneumonia (CAP). Pneumonia is the most common cause of fatal nonobstetric infection in pregnancy. The microbiology of CAP in pregnancy is similar to that seen in the general population. Among patients requiring hospitalization, the most common pathogens are S. pneumoniae, Haemophilus influenzae, and atypical organisms, including Legionella species, Chlamydia pneumoniae, and Mycoplasma pneumoniae. Empiric treatment of pregnant patients is similar to that in nonpregnant adults, although quinolones and tetracyclines are relatively contraindicated because of the potential for teratogenic effects. In addition to these common bacterial causes of CAP, pregnant women are at increased risk for serious viral pneumonia from influenza virus and varicella-zoster virus, so it is recommended that pregnant women receive seasonal influenza vaccination.
Gram-negative bacteria, including Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter species, Escherichia coli, and Enterobacter species, are rarely implicated in CAP, including among pregnant women hospitalized for pneumonia. Most patients with CAP caused by gram-negative bacteria have a predisposing risk factor, such as bronchiectasis, cystic fibrosis, or COPD, and develop severe pneumonia necessitating admission and care in the ICU.
Pregnancy causes a decrease in T-cell function, and pregnant women are at increased risk for severe Listeria infections, including meningitis and sepsis. However, Listeria rarely causes pulmonary infection and would be an unlikely cause of infection in this patient.
Staphylococcus aureus is an increasingly recognized cause of CAP, with risk factors including antecedent viral infection or injection drug use. Maternal S. aureus infection can occur perinatally, related to delivery, surgery, or indwelling lines, but remains a rare cause of CAP in the prenatal period.
100
A 46-year-old man is evaluated for 6 months of exertional dyspnea, fatigue, and ankle edema. Recently he experienced near-syncope walking up two flights of stairs. He has no other medical problems and takes no medications.
On physical examination, blood pressure is 106/70 mm Hg, pulse rate is 94/min, and respiration rate is 18/min. Oxygen saturation is 90% breathing ambient air. On cardiac examination, a prominent jugular venous a wave is present along with widened splitting of S2. Lung examination is unremarkable.
A transthoracic echocardiogram demonstrates a normal size left ventricle with ejection fraction of 65% and right ventricular enlargement. The estimated pulmonary artery systolic pressure is 58 mm Hg. Spirometry, lung volumes, and ventilation-perfusion scan are unremarkable; DLCO is 42% of predicted. CT angiogram of the chest is negative for pulmonary embolism and interstitial lung disease. Right heart catheterization demonstrates a mean pulmonary arterial pressure of 36 mm Hg, with no change with inhaled nitric oxide. Pulmonary capillary wedge pressure is normal.
Which of the following is the most appropriate treatment?
A Bosentan
B Diltiazem
C Metoprolol
D Pirfenidone
Answer & CritiqueCorrect Answer: A
Educational Objective: Treat pulmonary arterial hypertension.
Key Point
Before administering advance therapy for patients with pulmonary arterial hypertension (PAH), particularly idiopathic PAH, vasoreactivity testing directs agent selection by identifying those who may respond to calcium channel blockers.
The most appropriate treatment is bosentan. This patient has pulmonary hypertension most consistent with Group 1 (pulmonary arterial hypertension [PAH]), based upon the right heart catheterization demonstrating high pulmonary arterial pressures in the absence of left-sided heart failure, lung disease, and venous thromboembolic disease. Before administering advanced therapy for patients with PAH, vasoreactivity testing with nitric oxide is performed to identify those who may respond to calcium channel blockers (CCBs). CCBs are desirable therapy because they are less expensive and have fewer side effects than other forms of advanced therapy. Failure to achieve a favorable hemodynamic response with nitric oxide predicts unresponsiveness to CCBs and the need for other advanced therapy. The endothelin receptor antagonist bosentan is one of many oral pulmonary vasoactive drugs that is indicated in PAH in patients with negative vasoreactivity testing, such as this patient, some of which have been shown to increase exercise capacity and improve echocardiographic parameters.
CCBs such as diltiazem may be used in the setting of PAH when a response to a vasodilator such as nitric oxide is demonstrated during right heart catheterization. When a response is not found, CCBs are not indicated.
β-Blockers such as metoprolol do not have a proved role specific to PAH, though they might be used as an adjunct agent for supraventricular tachyarrhythmias that are common in this population.
Pirfenidone is an antifibrotic agent indicated for the treatment of idiopathic pulmonary fibrosis. Pulmonary hypertension is frequently observed in patients with idiopathic pulmonary fibrosis, but pirfenidone would not be indicated for a patient with PAH without idiopathic pulmonary fibrosis.
200
A 65-year-old woman is evaluated during a routine examination. She was diagnosed with a cardiac murmur in early adulthood. She is active, healthy, and without symptoms. She takes no medications.
On physical examination, vital signs are normal. A grade 3/6 holosystolic murmur preceded by multiple clicks is present at the apex. Physical findings are otherwise unremarkable.
An echocardiogram demonstrates a left ventricular ejection fraction of 50%. The left ventricle is moderately dilated with an end-systolic dimension of 42 mm. Myxomatous degeneration of the mitral valve is present with severe regurgitation due to posterior leaflet prolapse.
Which of the following is the most appropriate next step in management?
A Serial clinical and echocardiographic evaluations
B Surgical mitral valve repair
C Surgical mitral valve replacement
D Transcatheter mitral valve repair
Answer & CritiqueCorrect Answer: B
Educational Objective: Treat degenerative mitral regurgitation with surgical mitral valve repair.
Key Point
Mitral valve repair is strongly recommended for chronic severe primary mitral regurgitation in symptomatic patients with left ventricular ejection fraction greater than 30%, asymptomatic patients with left ventricular dysfunction, and patients undergoing another cardiac surgical procedure.
The most appropriate next step in management is surgical mitral valve repair. Myxomatous degeneration of the mitral valve is common, affecting 1% to 2% of the general population. In 10% of patients, the valvular lesion can progress, become life threatening, and require surgery. The only definitive therapy for severe mitral regurgitation is mitral valve surgery. Options are mitral valve repair, mitral valve replacement with preservation of part or all of the mitral apparatus, and mitral valve replacement with removal of the mitral apparatus. Mitral valve repair is generally preferred to valve replacement because it is associated with improved survival in retrospective studies. Mitral valve repair is strongly recommended for chronic severe primary mitral regurgitation in (1) symptomatic patients with left ventricular ejection fraction greater than 30%, (2) asymptomatic patients with left ventricular dysfunction (left ventricular ejection fraction of 30%-60% and/or left ventricular end-systolic diameter ≥40 mm), and (3) patients undergoing another cardiac surgical procedure. Additionally, mitral valve repair is reasonable in asymptomatic patients with chronic severe primary mitral regurgitation who have new-onset atrial fibrillation or pulmonary hypertension (pulmonary artery systolic pressure >50 mm Hg). Notably, a left ventricular ejection fraction of 60% or less is used in defining left ventricular systolic dysfunction in mitral regurgitation because ventricular emptying into the left atrium contributes to the relatively lower afterload conditions and higher ejection fraction despite impaired left ventricular performance.
Serial evaluations every 6 to 12 months are recommended for patients with severe mitral regurgitation who do not have indications for surgery. This patient meets the criteria for surgery; therefore, serial evaluations would not be appropriate at this time.
Many patients who could benefit from mitral valve repair are denied surgery because of high surgical risk, advanced age, or comorbid conditions. A catheter-based device can improve mitral valve function by delivering a clip percutaneously to approximate the valve leaflet edges and improve leaflet coaptation at the origin of the mitral regurgitation jet. The device is approved for patients with significant symptomatic degenerative mitral regurgitation for whom mitral valve surgery poses a prohibitive risk. This patient is healthy and does not have comorbid conditions that would significantly increase surgical risk; therefore, transcatheter repair is not indicated.
200
A 55-year-old man is evaluated in the hospital for antibiotic management of a diabetic foot ulcer. He was hospitalized 3 days ago for debridement of a draining great toe ulcer. A radiograph of the left foot showed osteomyelitis of the great toe. Empiric piperacillin-tazobactam was started after debridement of the ulcer, and a bone biopsy was obtained intraoperatively. Medical history is significant for diabetes mellitus with nephropathy. Medications are metformin, insulin glargine, and piperacillin-tazobactam. Today the patient is clinically improved.
On physical examination, vital signs are normal. A large, deep plantar ulcer penetrates to the bone of the left great toe with minimal surrounding erythema and no evidence of necrotic tissue.
The bone culture grows Pseudomonas aeruginosa (sensitive to piperacillin-tazobactam, ceftazidime, ciprofloxacin, aztreonam, and tobramycin) and Bacteroides fragilis.
Which of the following is the most appropriate management?
A Add tobramycin to piperacillin-tazobactam
B Switch piperacillin-tazobactam to aztreonam
C Switch piperacillin-tazobactam to ceftazidime
D Switch piperacillin-tazobactam to oral ciprofloxacin and metronidazole
Answer & CritiqueCorrect Answer: D
Educational Objective: Manage conversion of intravenous antimicrobial therapy to oral antimicrobial therapy.
Key Point
Intravenous-to-oral antibiotic switching should be considered in patients who have an intact and functioning gastrointestinal tract, whose clinical status is improving, and who are not being treated for an infection for which parenteral therapy is preferred.
This patient's therapy should be switched from intravenous piperacillin-tazobactam to oral ciprofloxacin and metronidazole. He has a diabetic foot ulcer and osteomyelitis of the left great toe caused by Pseudomonas aeruginosa and Bacteroides fragilis. Ciprofloxacin and metronidazole have excellent bioavailability and will penetrate bone adequately with oral administration. Continuing intravenous therapy offers no advantage for this patient, and intravenous therapy has risks that include developing a venous catheter–associated bloodstream infection. Intravenous-to-oral antibiotic switching should be considered in patients who have an intact and functioning gastrointestinal tract, whose clinical status is improving, and who are not being treated for an infection for which parenteral therapy is preferred (for example, endocarditis or meningitis). Common infectious scenarios for which a switch from intravenous to oral therapy should be considered include community-acquired pneumonia, bacterial peritonitis, pyelonephritis, septic arthritis, and skin and soft tissue infections. When switching from a parenteral to an oral antibiotic agent, the bioavailability of the oral antibiotics must be considered.
A second antipseudomonal agent is not required for this patient's osteomyelitis. He also has kidney disease, which should discourage use of an aminoglycoside. Therefore, adding tobramycin while continuing intravenous antibiotic therapy would not be the best management for this patient who can de-escalate to oral therapy.
Although aztreonam and ceftazidime have good antipseudomonal activity, neither agent has any anaerobic activity to cover B. fragilis.
200
A 62-year-old woman is evaluated in the emergency department for worsening dyspnea on exertion during the last 2 weeks. She has a history of severe COPD and an FEV1 of 45% of predicted. She has a cough productive of yellow sputum and wheezing during the same time period. She has a 20-pack-year history of smoking but quit 10 years ago. Her albuterol inhaler and nebulizer have provided temporary relief at home. Current medications are umeclidinium/vilanterol, mometasone, and albuterol.
On physical examination, temperature is normal, blood pressure is 132/64 mm Hg, pulse rate is 110/min, and respiration rate is 30/min. Oxygen saturation is 90% on 6 L/min of oxygen by nasal cannula. Cardiopulmonary examination reveals tachycardia, tachypnea with accessory muscle use, and decreased breath sounds throughout with a prolonged expiratory phase and end expiratory wheezes. She has no jugular venous distention or edema.
Laboratory studies reveal an arterial PCO2 of 46 mm Hg (6.11 kPa). Complete blood count, serum electrolytes , and blood glucose are normal.
A chest radiograph shows hyperinflated lungs with flattening of the diaphragms but no infiltrate.
Which of the following is the most appropriate next additional test?
A CT pulmonary angiogram
B Electrocardiogram
C Sputum culture
D Sputum Gram stain
Answer & CritiqueCorrect Answer: B
Educational Objective: Evaluate an acute exacerbation of COPD.
Key Point
The first steps in managing a patient with a presumed COPD exacerbation are to confirm the diagnosis and to evaluate other causes of the acute presentation.
An electrocardiogram should be obtained for this patient to evaluate other causes of her acute presentation, such as acute myocardial infarction, arrhythmia, and atrial fibrillation. The first steps in managing a patient with a presumed COPD exacerbation are to confirm the diagnosis. Studies helpful in the evaluation may include pulse oximetry to assess oxygenation or guide oxygen therapy; a chest radiograph to rule out an alternative diagnosis; a complete blood count to identify the presence of polycythemia, anemia, or leukocytosis; arterial blood gas studies; a biochemical panel to assess for electrolyte and glycemic abnormalities; and an electrocardiogram to evaluate tachycardia (as in this patient) and for other possible cardiac comorbidity. This patient has already had a chest radiograph and appropriate laboratory studies but an electrocardiogram is also indicated.
Patients with pulmonary embolism (PE) can present with symptoms similar to a COPD exacerbation. Because of this, pretest probability models such as the Wells criteria have been developed and validated to assist in clinical decision making. Patients who have a low pretest probability for PE using the Wells criteria, such as this patient, and who meet all Pulmonary Embolism Rule-Out Criteria do not need further testing to rule out PE. Physicians should obtain a D-dimer assay in patients with intermediate pretest probability for PE or for those with a low pretest probability for PE who do not meet all Pulmonary Embolism Rule-Out Criteria. In these patients, imaging studies should not be used for initial evaluation.
A sputum culture or Gram stain is not routinely used to assess COPD exacerbations as it rarely changes management. For patients with a confirmed COPD exacerbation with cough, increased sputum, and dyspnea, antibiotics are usually initiated regardless of the results of the sputum Gram stain or culture.
300
A 72-year-old woman is evaluated during a routine office visit. She has a 3-year history of heart failure with preserved ejection fraction and a long history of hypertension. She has exertional dyspnea with walking around the house, almost nightly paroxysmal nocturnal dyspnea, and peripheral edema. Cardiac catheterization performed 2 years ago revealed normal coronary arteries. Medications are hydrochlorothiazide and diltiazem.
On physical examination, the patient is afebrile, blood pressure is 136/82 mm Hg, pulse rate is 48/min, and respiration rate is 18/min. There is jugular venous distention. An S4 is present. Pulmonary examination reveals no wheezes or crackles. Peripheral edema is noted.
Laboratory studies are significant for a serum creatinine level of 1.2 mg/dL (106.1 µmol/L) and a serum sodium level of 139 mEq/L (139 mmol/L).
Which of the following is the most appropriate management?
A Add ivabradine.
B Add valsartan.
C Discontinue hydrochlorothiazide and diltiazem and start furosemide.
D Refer for pacemaker placement.
Answer & CritiqueCorrect Answer: C
Educational Objective: Treat heart failure with preserved ejection fraction.
Key Point:
The cornerstone of treatment for patients with heart failure with preserved ejection fraction is diuretic therapy to maintain euvolemia.
The most appropriate management is to discontinue hydrochlorothiazide and diltiazem and start furosemide. This elderly woman with heart failure with preserved ejection fraction (HFpEF) has signs and symptoms of volume overload in the setting of bradycardia. The cornerstone of treatment for patients with HFpEF is diuretic therapy to maintain euvolemia. Antihypertensive agents should also be used to maintain normal blood pressure in the setting of hypertension. Despite treatment with hydrochlorothiazide, this patient has evidence of volume overload, and she should be switched to furosemide for more efficacious diuresis. This patient is also taking diltiazem, which may be causing her bradycardia, and this agent should be discontinued. If the patient's heart rate fails to improve, she should be referred for pacemaker placement.
Ivabradine is a sinus node modulator that reduces heart failure–associated hospitalizations in select heart failure patients; however, it is indicated as therapy only in patients with a reduced left ventricular ejection fraction and heart rate higher than 70/min while receiving β-blocker therapy.
Although ACE inhibitors, angiotensin receptor blockers (such as valsartan), β-blockers, and aldosterone antagonists have been studied for the treatment of HFpEF, no drugs have been shown to reduce morbidity or mortality in these patients. Most recently, in the TOPCAT trial, there was no difference in the primary combined endpoint of death, aborted cardiac arrest, or heart failure hospitalization with spironolactone compared with placebo; however, spironolactone was associated with a reduction in heart failure hospitalizations. Notably, a retrospective analysis showed that spironolactone reduced the incidence of cardiovascular death and heart failure hospitalization in patients in the Americas compared with those in Eastern Europe, likely because of different patient demographic characteristics across regions.
Pacemaker placement would be indicated only for symptomatic bradycardia in the absence of a reversible cause; the response to diltiazem discontinuation should be assessed before pacemaker placement is considered in this patient.
300
A 47-year-old woman is evaluated in the hospital for pyelonephritis not responding to antibiotic therapy. Five days ago she was evaluated in an urgent care center for abdominal and back pain, nausea, fever, and dysuria. She was started on oral ciprofloxacin for a urinary tract infection (UTI). Symptoms did not respond to this treatment, and two days ago, she was hospitalized. Acute pyelonephritis was diagnosed, and she was treated with intravenous fluids, vancomycin, and cefepime. Since hospitalization, her clinical condition has deteriorated, with continued fever and worsening flank pain. She also has stage 2 chronic kidney disease, recurrent UTIs, and a 6-year history of poorly controlled type 2 diabetes mellitus. Medications are amoxicillin, metformin, and insulin glargine.
On physical examination, temperature is 38.2 °C (100.8 °F), blood pressure is 130/60 mm Hg, pulse rate is 106/min, and respiration rate is 22/min. Abdominal examination reveals diminished bowel sounds, bilateral costovertebral angle tenderness, and suprapubic pain. Other examination findings are unremarkable.
Laboratory studies:
Hemoglobin
11 g/dL (110 g/L)
Leukocyte count
21,000/µL (21 × 109/L) with 91% neutrophils and 9% lymphocytes
Platelet count
167,000/µL (167 × 109/L)
Creatinine
1.8 mg/mL (159 µmol/L)
Urinalysis
10 erythrocytes/hpf, leukocytes too numerous to count, many yeast forms, trace protein, and 4+ glucose.
Urine culture results show 10,000 colony-forming units of Candida glabrata. Blood culture results are negative.
A CT scan of the abdomen with contrast shows bilateral perinephric stranding, no masses, and no renal abscesses.
Which of the following is the most likely diagnosis?
A Acute diverticulitis
B Antibiotic-resistant bacterial pyelonephritis
C Candida pyelonephritis
D Renal infarction
Answer & CritiqueCorrect Answer: C
Educational Objective: Diagnose invasive candidiasis.
Key Point
In patients with invasive candidiasis, therapy with an oral azole (if the Candida species is susceptible) or amphotericin B should be initiated immediately; the total duration of therapy should be 10 to 14 days.
This patient has Candida pyelonephritis, a form of invasive candidiasis. She has several risk factors for candidiasis, such as recently taking broad-spectrum antibiotics, uncontrolled diabetes mellitus, and a history of recurrent urinary tract infections. These risk factors, in combination with the findings of yeast, leukocytes, and erythrocytes in the urine, is classic for this infection. Although the urine culture only grew 10,000 colony-forming units of Candida glabrata, the colony count may not correlate with active infection in Candida infections of the urinary tract. Thus, antifungal therapy with amphotericin B should be initiated immediately. After identification of the species, the antifungal agent may be de-escalated to an oral azole if the Candida species is susceptible to azoles. The total duration should be 10 to 14 days of antifungal therapy.
Acute diverticulitis may present with the same manifestations this patient had. However, the bilateral flank pain and the lack of abdominal pain make diverticulitis less likely. In addition, the urinalysis results showing leukocytes too numerous to count and the classic CT scan finding of perinephric stranding point to a kidney infection.
Antibiotic-resistant bacterial pyelonephritis is a possibility and could explain her progressive symptoms despite appropriate antibiotic therapy for pyelonephritis. However, this diagnosis is excluded by the patient's urine culture, which showed only Candida species.
Patients with acute kidney infarction typically present with acute flank pain or generalized abdominal pain, often associated with nausea and vomiting and, less commonly, with fever; hematuria is present in one-third of patients. Over half of kidney infarctions are cardioembolic, and atrial fibrillation is commonly found in patients with this diagnosis. A contrast-enhanced CT scan will show a wedge-shaped perfusion defect. This patient's normal abdominal contrast-enhanced CT scan and urinalysis argue against kidney infarction.
300
A 72-year-old woman is evaluated in the hospital for a pneumothorax. The patient has severe, oxygen-dependent COPD complicated by several exacerbations. She was hospitalized 72 hours ago with abrupt onset of chest pain and dyspnea. Chest radiography confirmed the presence of a large left-sided pneumothorax and a thoracostomy tube was placed. She had 90% expansion of the lung following thoracostomy.
On physical examination, the patient is frail appearing but comfortable. Vital signs are normal. Oxygen saturation is 96% breathing 3 L/min of oxygen through nasal cannula. Pulmonary examination reveals diminished but present breath sounds bilaterally. A left thoracostomy tube is in place.
Chest radiograph demonstrates resolution of pneumothorax with a thoracostomy tube in place.
Which of the following is the most appropriate management?
A Clamp thoracostomy tube
B Place thoracostomy tube to high suction
C Pleurodesis
D Remove thoracostomy tube
Answer & CritiqueCorrect Answer: C
Educational Objective: Treat secondary spontaneous pneumothorax with chemical pleurodesis.
Key Point
Recurrence prevention with pleurodesis is recommended after the first occurrence of secondary spontaneous pneumothorax.
The most appropriate management of this patient with severe COPD and secondary pneumothorax is pleurodesis. Pneumothorax (air in the pleural space) can occur spontaneously, as a result of trauma, or iatrogenically. Spontaneous pneumothorax is further characterized as a primary spontaneous pneumothorax (PSP) in a person without underlying lung disease or a secondary spontaneous pneumothorax (SSP) in a person with underlying lung disease. Patients presenting with SSP are at higher risk for persistent air leak, further expansion of the pneumothorax, or pneumothorax recurrence due to their underlying lung disease. Intervention to prevent recurrence includes both chemical and mechanical pleurodesis, which is recommended in all patients with SSP and after the second occurrence of a PSP. In patients with SSP the cause of persistent air leak following pneumothorax is usually subpleural bullae or cysts. Additional interventions are required to close the leak. For patients who are surgical candidates, video-assisted thoracoscopic surgery (VATS) is recommended to locate and staple or resect blebs followed by mechanical pleurodesis. Patients who cannot tolerate surgery are treated with blood patch or chemical pleurodesis. These procedures are designed to seal the leak and prevent recurrence of pneumothorax. A blood patch is performed by injecting a quantity of the patient's blood into the thoracostomy tube. Chemical pleurodesis is performed by instilling tetracycline or one of its derivatives or specialized talc powder through the thoracostomy tube. Success rate for chemical pleurodesis ranges from 60% to 90% but it is not as effective as mechanical pleurodesis using VATS.
Clamping or removing the thoracostomy tube would not be appropriate because the patient has a secondary spontaneous pneumothorax and the likelihood of recurrence is high.
Placing the thoracostomy tube to high suction would not be appropriate because high levels of suction can increase the risk for reexpansion and pulmonary edema; in addition, the pneumothorax has resolved so no additional suction is needed.
400
A 68-year-old man is evaluated for a 2-month history of exertional dyspnea. Medical history is significant for diabetes mellitus, hypertension, and hyperlipidemia. Medications are lisinopril, hydrochlorothiazide, metformin, and atorvastatin.
On physical examination, vital signs are normal. Oxygen saturation is 99% breathing ambient air. Cardiopulmonary examination shows a regular rhythm and a paradoxically split S2. There is no peripheral edema.
An electrocardiogram is shown.
Which of the following is the most appropriate diagnostic test to perform next?
A Adenosine single-photon emission CT
B Coronary artery calcium scoring
C Exercise single-photon emission CT
D Exercise electrocardiography
Correct Answer: A
Educational Objective: Evaluate for coronary artery disease in a patient with left bundle branch block on a baseline electrocardiogram.
Key Point
In patients with left bundle branch block, the preferred diagnostic test for coronary artery disease is a vasodilator stress test because myocardial perfusion imaging with exercise or dobutamine stress may result in a false-positive perfusion defect in the basilar septum.
Adenosine single-photon emission CT is the most appropriate next diagnostic test. This patient with several cardiovascular risk factors has exertional dyspnea, which may be an angina equivalent, and he should undergo stress testing to evaluate for coronary artery disease (CAD). Because his electrocardiogram (ECG) shows left bundle branch block, ST-segment changes with exercise cannot be used to evaluate for the presence of obstructive CAD. He must undergo stress testing with additional imaging, such as nuclear perfusion imaging or stress echocardiography. Exercise is typically the preferred mode of stress because of the additional functional information it provides. However, in the case of left bundle branch block, myocardial perfusion imaging with exercise or dobutamine stress may result in a false-positive perfusion defect in the basilar septum, and these stressors should be avoided. Instead, vasodilator stress testing should be used. Vasodilators, such as dipyridamole, regadenoson, and adenosine, produce hyperemia and a flow disparity between myocardium supplied by unobstructed vessels and myocardium supplied by the stenotic vessel (due to the inability of the distal vasculature to dilate).
Coronary artery calcium scoring, which quantifies the amount of calcium in the walls of the coronary arteries, would document the presence of atherosclerotic disease in this symptomatic patient with risk factors, but it would not determine whether there is obstructive CAD. Although the absence of any coronary artery calcification has been shown to have a high specificity for the absence of obstructive CAD, trials evaluating coronary artery calcium scoring have typically focused on primary prevention in asymptomatic patients.
ECG Criteria for LBBB.
- QRS duration ≥ 120ms
- Dominant S wave in V1 and V2
- Broad monophasic R wave in lateral leads (I, aVL, V5-6)
- Absence of Q waves in lateral leads
- Prolonged R wave peak time > 60ms in leads V5-6
400
A 42-year-old man is evaluated in the hospital for increased pain and drainage from a previously healed surgical wound over the left fibula. He underwent open reduction and internal fixation of a fracture 4 weeks ago. The patient has undergone incision and surgical debridement of the wound. A bone culture revealed methicillin-sensitive Staphylococcus aureus. Medical history is otherwise noncontributory, and his only medication is ibuprofen for pain.
On physical examination, vital signs are normal. A surgical wound over the left lateral leg is well approximated with no erythema or drainage.
A plain radiograph before debridement shows nonunion of the fracture with screws and K-wires in place.
Which of the following is the most appropriate treatment?
A Cefazolin
B Cefazolin and rifampin
C Ceftaroline
D Vancomycin and rifampin
Answer & CritiqueCorrect Answer: B
Educational Objective: Treat osteomyelitis associated with orthopedic hardware.
Key Point
Rifampin should be used in combination with another antistaphylococcal agent when managing Staphylococcus aureus osteomyelitis in the setting of orthopedic hardware if the hardware cannot be removed.
Cefazolin and rifampin are appropriate therapy for treatment of methicillin-sensitive Staphylococcus aureus (MSSA) osteomyelitis associated with orthopedic hardware. Identification of the causative pathogen, administration of adequate antimicrobials for a prolonged duration, surgical debridement (if warranted), and removal of orthopedic prosthetic devices (if feasible) influence the success of osteomyelitis treatment. Optimal management of this patient's infection includes hardware removal; however, this is not possible because the fracture has not yet healed. Hardware-associated infections caused by S. aureus are difficult to eradicate because of the biofilm that forms on the hardware. First-line treatment of MSSA osteomyelitis consists of a β-lactam agent such as cefazolin; a randomized controlled trial and systematic review of the literature have demonstrated that if infected hardware cannot be removed, the addition of rifampin increases the chances of therapeutic success compared with an antistaphylococcal agent alone.
Although cefazolin has activity against MSSA as well as good bone penetration, it would not be an appropriate therapeutic option for the treatment of hardware-associated osteomyelitis without the addition of rifampin.
Ceftaroline has coverage for MSSA, methicillin-resistant S. aureus, and Enterobacteriaceae, but it is unnecessarily broad coverage for the treatment of this patient's MSSA infection.
Vancomycin, a bacteriostatic agent, is less effective than β-lactam agents for the treatment of MSSA and is typically restricted to patients with drug intolerance or allergy.
400
A 36-year-old woman is evaluated for dry cough and progressive dyspnea that limits her ability to exercise. She initially presented 8 weeks ago with cough, fever, sputum production, and dyspnea. A chest radiograph at that time revealed left-lower-lobe opacities; she was diagnosed with pneumonia and treated with azithromycin but had little improvement in her symptoms. Her fever and sputum production have resolved. She is a nonsmoker.
On physical examination, vital signs are normal. Lungs are clear to auscultation.
Repeat chest radiograph reveals patchy opacities bilaterally and several nodular densities that are peripherally predominant in different locations than previous radiographs. High-resolution CT scan of the chest shows extensive ground-glass changes bilaterally with several areas of nodular consolidation that are peripherally predominant and along bronchovascular bundles.
Which of the following is the most likely diagnosis?
A Acute HIV infection
B Community-acquired pneumonia
C Cryptogenic organizing pneumonia
D Idiopathic pulmonary fibrosis
Answer & CritiqueCorrect Answer: C
Educational Objective: Diagnose cryptogenic organizing pneumonia.
Key Point
A typical presentation of cryptogenic organizing pneumonia includes cough, fever, and malaise for 6 to 8 weeks that does not respond to antibiotics; patchy opacities on chest radiograph; and ground-glass opacities on CT scan that are peripherally distributed; glucocorticoids are first-line therapy.
The most likely diagnosis is cryptogenic organizing pneumonia. This patient has a subacute history of progressive dyspnea and persistent cough after an initial history consistent with community-acquired pneumonia. Despite treatment with appropriate antibiotic therapy, she now has clear evidence of new opacities that are located in different areas, are peripherally predominant, and coalesce along broncho-vascular bundles. These findings are consistent with a diagnosis of organizing pneumonia, which involves proliferation of granulation tissue within alveolar ducts, alveolar spaces, and surrounding areas of chronic inflammation. There are many known causes of this pattern, including acute infections and autoimmune disorders like rheumatoid arthritis. The term cryptogenic organizing pneumonia is reserved for individuals who have this pattern but do not have a clear associated cause. Patients with cryptogenic organizing pneumonia will typically present with a 6-to-8-week history of symptoms that mimic community-acquired pneumonia. Typically, an initial empiric treatment of infection is given but fails; subsequently, noninfectious causes are considered. This patient has a subacute illness that began with viral symptoms, persistent and progressive cough and dyspnea that are not responsive to past antibiotics, and radiographic findings typical of cryptogenic organizing pneumonia. Patients with cryptogenic organizing pneumonia respond well to glucocorticoids. Glucocorticoids are slowly tapered during the subsequent 6 months.
Acute HIV is unlikely in this patient who initially presented with symptoms of community-acquired pneumonia and whose fever has resolved. Although acute HIV symptoms are not specific, the most common presentation includes persistence of symptoms including fever.
Recurrent community-acquired pneumonia is also unlikely in this patient who was appropriately treated with azithromycin and whose symptoms have partially improved with resolution of the fever and sputum production.
Idiopathic pulmonary fibrosis (IPF) is a disease that affects older patients (the mean age of presentation is in the mid- to late 60s) and presents with chronic (longer than 6 months) symptoms of dry cough and shortness of breath. This patient's presentation is not consistent with these criteria, making a diagnosis of IPF unlikely.