A 19-year-old male with no past medical history presented to the emergency room with pelvic fracture after being hit by a car. A central line was placed for administering vasopressors and volume resuscitation. Three days later, the patient became febrile, and blood cultures were obtained revealing Staphylococcus aureus. Vancomycin was started, and repeat blood cultures 2 days later are negative. Transthoracic echocardiogram is unremarkable.
Which of the following is the next best step?
Correct Answer: C
This patient with likely Staphylococcus aureus catheter-related blood stream infection (CRBSI) without evidence of endocarditis should have catheters removed and receive antibiotic therapy for 14 days. Salvage therapy using catheter exchange over a guidewire or antibiotic lock therapy should generally be avoided, given increased morbidity, mortality, treatment failure, and recurrence in patients with Staphylococcus aureus CRBSI. In spite of a negative transthoracic echocardiogram, a transesophageal echocardiogram is necessary in patients with signs or symptoms of endocarditis, prior history of endocarditis, positive blood cultures after 72 hours despite appropriate antibiotic treatment, a previously placed port or other indwelling vascular device, hemodialysis, a prosthetic valve, cardiac structural and valvular abnormalities, an implantable pacemaker, an intravenous drug abuse, and absence of a reasonable reason for infection.
References:
A 74-year-old male with end-stage renal disease (ESRD) and recent pulmonary embolism on apixaban presents to the intensive care unit from dialysis clinic with a 6-day history of fevers and chills. He received hemodialysis through a tunneled central venous catheter. Blood cultures drawn in the emergency room are all positive for gram-positive cocci that are later identified as coagulase-negative Staphylcoccus (CNS). The patient is hemodynamically stable with significant thrombocytopenia to 15 and is methicillin-resistant Staphylococcus aureus (MRSA) negative.
What is the next best step in this patient’s management?
Correct Answer: A
This patient likely has CNS CRBSI. Central line removal is often advocated but is controversial in the setting of CNS CRBSI especially in hemodynamically stable and immunocompetent patients without signs of infection and foreign bodies. Salvage therapy using antibiotic lock therapy or a guidewire exchange of his tunneled dialysis catheter can be considered as an alternative treatment for catheter removal especially given this patient’s significant coagulopathy and risk for complications related to removing and placing a new central line. For organisms other than Staphylococcus aureus and candida, repeat blood cultures are not necessary unless salvage therapy has been used to ensure resolution of bacteremia. Antibiotic course is typically 7 days if the catheter is removed and 14 days if salvage therapy is used. CNS CRBSI should be initially treated with vancomycin until sensitivities return because of the high incidence of resistance to methicillin, cephalosporins, and many other antibiotics. Echocardiogram is not necessary in the setting of CNS CRBSI unless there is persistent bacteremia.
A 67-year-old male with an implantable cardioverter defibrillator (ICD) is admitted with urosepsis. Blood cultures reveal methicillinsensitive Staphylococcus aureus, and transesophageal echocardiogram reveals a 1.9 cm mass on the ICD lead with no evidence of endocarditis.
Which of the following is the MOST appropriate management regarding this patient’s ICD and leads?
Correct Answer: B
Patients with cardiac implantable electronic devices should have complete system (ie, leads and device) explanted if blood cultures are positive, and there are valvular and/or lead vegetations seen on echocardiography. Interventional transvenous lead extractions can be performed for vegetations <2 cm on leads, whereas surgical extraction should be considered if vegetations are >2 cm because of risk for pulmonary embolism. Reimplantation can be considered when blood cultures are negative for at least 72 hours but often times is not necessary, given that many patients no longer meet current criteria for device implantation.
Reference:
A 79-year-old female with ESRD presents to the intensive care unit with 7 days of worsening dyspnea on exertion, lower extremity edema, malaise, and chest pain that radiates toward the left shoulder that is worse with inspiration. Vitals are:
Electrocardiogram (EKG) reveals ST elevations in leads I, II, III, aVF, and aVL.
What is the MOST common etiology of this patient’s condition?
This patient is describing signs and symptoms of acute pericarditis, which most commonly occurs because of a viral infection with patients often recalling a nonspecific prodrome of fever, malaise, and pleuritic chest pain that radiates toward the left shoulder and is worse with inspiration and relieved by leaning forward. The other choices describe other less frequent causes of acute pericarditis. ST elevations are diffusely seen in all or many EKG leads in acute pericarditis and can be differentiated from a ST elevation myocardial infarction by not having ST depressions in reciprocal leads (ie, ST elections in both high lateral leads I and aVL and reciprocal inferior leads II, III, and aVF).
A 69-year-old female with history of rheumatic mitral stenosis presents to the intensive care unit with 5 days of fevers and night sweats, malaise, and multiple small erythematous lesions on the soles of the feet. The patient develops an escalating pressor requirement, and a bedside echocardiogram reveals severe mitral regurgitation that was not seen a month earlier on a formal echocardiogram.
Which of the following is the MOST likely organism to be isolated from blood cultures?
Correct Answer: D
This patient satisfies the Duke criteria for the diagnosis of endocarditis with the major criteria satisfied by endocardial involvement assessed with echocardiogram and the three minor criteria satisfied by the patient’s fevers, Janeway lesions, and predisposing heart condition of rheumatic heart disease. The most common organisms for endocarditis from most to least common include Staphylococcus aureus (31%), viridans Streptococcus (17%), CNS (11%), Enterococci (11%), Streptococcus bovis (7%), other Streptococci (5%), fungi (2%), gram-negative HACEK bacilli (2%), and gramnegative non-HACEK bacilli (2%). Endocardial involvement as a major criteria can be satisfied by new valvular regurgitant lesions, vegetations, abscesses, or dehiscence of prosthetic valves.
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