A 48-year-old man comes to the emergency department with a 4-day history of shortness of breath and fever. He is a chronic injection drug user. He has a history of a rash secondary to penicillin but has been treated previously for skin abscesses with cephalexin.
His temperature is 38.5 C (101.4 F). Cardiac examination reveals a faint diastolic murmur at the left sternal border. Skin examination shows needle track marks on both arms.
All 4 bottles of blood cultures obtained on admission grow Staphylococcus aureus (methicillin-susceptible). Intravenous cefazolin is initiated. A transthoracic echocardiogram reveals a 0.9 cm aortic valve vegetation with mild aortic regurgitation and normal left ventricular ejection fraction. On the third day of hospitalization, he is intermittently febrile and develops respiratory failure. Endotracheal intubation and mechanical ventilation is initiated. Chest x-ray reveals bilateral alveolar opacities consistent with pulmonary edema.
Which of the following is the best next step in the management of this patient?

Question

A 48-year-old man comes to the emergency department with a 4-day history of shortness of breath and fever.  He is a chronic injection drug user.  He has a history of a rash secondary to penicillin but has been treated previously for skin abscesses with cephalexin.
His temperature is 38.5 C (101.4 F).  Cardiac examination reveals a faint diastolic murmur at the left sternal border.  Skin examination shows needle track marks on both arms.
All 4 bottles of blood cultures obtained on admission grow Staphylococcus aureus (methicillin-susceptible).  Intravenous cefazolin is initiated.  A transthoracic echocardiogram reveals a 0.9 cm aortic valve vegetation with mild aortic regurgitation and normal left ventricular ejection fraction.  On the third day of hospitalization, he is intermittently febrile and develops respiratory failure.  Endotracheal intubation and mechanical ventilation is initiated.  Chest x-ray reveals bilateral alveolar opacities consistent with pulmonary edema.
Which of the following is the best next step in the management of this patient?

Quizplus · Accepted Answer

11ec193a_9649_5adc_853d_a33656014c6b_MD0002_00 This patient with aortic valve endocarditis was initially appropriately treated with intravenous antibiotics. However, his sudden clinical deterioration with respiratory failure and pulmonary edema suggests a mechanical complication of endocarditis. The most common cause of acute congestive heart failure (CHF) in patients with infective endocarditis is valvular insufficiency, either due to valve leaflet perforation or worsening regurgitation. The best next step for evaluation is a transesophageal echocardiogram (TEE). TEE is superior to TTE (transthoracic echocardiogram) for detecting complications such as leaflet perforation, aneurysm formation, and secondary infection of other valve structures. Refractory CHF due to mitral or aortic valvular insufficiency from an infected valve is an indication for surgery. (Choice A) Early CHF in a patient with endocarditis is not an indication of microbiologic treatment failure. Moreover, addition of gentamicin is not recommended for the treatment of native valve endocarditis as the risk of nephrotoxicity outweighs the potential benefit. (Choice B) Rifampin is used as an essential component of the antibiotic regimen for treatment of staphylococcal prosthetic valve endocarditis. However, it is not recommended for native valve endocarditis. (Choice C) Vancomycin is recommended for the treatment of methicillin-resistant Staphylococcus endocarditis. However, this patient has a methicillin-susceptible Staphylococcus aureus strain and switching antibiotics is not indicated. (Choice D) A CT scan of the chest will likely reveal bilateral pulmonary edema as seen on the chest x-ray, but would not show valvular pathology and is unlikely to add additional diagnostic information. TEE is more appropriate for definitive diagnosis in this setting. Educational objective: Transesophageal echocardiogram is highly sensitive for the diagnosis of infective endocarditis and its complications; it should be obtained early in patients with suspected complications or sudden clinical deterioration. __________ References: The importance of secondary mitral valve involvement in primary aortic valve endocarditis; the mitral kissing vegetation. (http://www.ncbi.nlm.nih.gov/pubmed/11741365) The diagnostic utility of transthoracic echocardiography for the diagnosis of infective endocarditis in the real world of the Italian Registry on Infective Endocarditis. (http://www.ncbi.nlm.nih.gov/pubmed/23489364)

A 48-Year-Old Man Comes to the Emergency Department with a 4-Day