focus. Patients with ABE often have no initial murmur or may have a new/rapidly changing
cardiac murmur. With lung ABE, often there has been sufficient time for valvular damage to
manifest with a cardiac murmur. In patients without bacteremia there is no rationale to get a
TTE/TEE to rule out ABE, the vegetation is an incidental finding and not diagnostic of ABE.
Sterile vegetations, i.e., marantic endocarditis, may occur in association with malignancy and
nonmalignant disorders, e.g., Libman–Saks endocarditis. The diagnosis of MSSA/MRSA is
based on demonstrating a continuous/high-grade bacteremia in a patient with vegetation by
cardiac. A cardiac murmur may or may not be present. In non-IVDAs, the fever in ABE is
usually 1028 F (1,13,36,39) (Tables 4 to 6).
The treatment of MSSA/MRSA ABE is for four to six weeks. For MSSA ABE, treatment is
usually with oxacillin, nafcillin, or first-generation cephalosporin, e.g., cephazolin. In penicillin-
allergic patients with MSSA ABE/MRSA ABE, quinupristin/dalfopristin, minocycline, linezolid,
or daptomycin have been used. Because therapy of MRSA/MSSA is prolonged, i.e., four to six
weeks, oral therapy for all or part of the therapy is desirable. The only two oral antibiotics
available to treat MRSA ABE orally are minocycline and linezolid (37,39–51) (Tables 7 to 10).
Vancomycin is inferior tob-lactam therapy of MSSA bacteremia/ABE. For MRSA
bacteremia/ABE, vancomycin has been associated with acquired resistance/therapeutic
failures. Vancomycin serum levels are unhelpful in avoiding nephrotoxicity or optimizing
therapeutic outcomes (44–56).
Nafcillin plus gentamicin or rifampin is not more effective than nafcillin alone against
MSSA. Combination therapy for MSSA/MRSA has no demonstrated benefit. Vancomycin plus
rifampin is often antagonistic (46–51,56). Vancomycin is not nephrotoxic even when combined
with aminoglycosides. In terms of pharmacokinetic and pharmacodynamic (PK/PD)Table 4 Infectious Complications of CVCsI. CVC related bacteremias
A. Diagnostic features
l Bacteremia of intermittent and of variable duration/intensity (1/4, 1/2, 2/4)
l Temperatures usually 1028 F
B. Therapy
l Remove CVC
l Antibiotic therapy x 2 wk (after CVC removal)
II. Septic thrombophlebitis
A. Diagnostic features
l CVC infection
l High-grade/continuous bacteremia
l Pus from CVC site when CVC removed
l Palpable venous cord often present
l Temperatures usually 1028 F
l TTE/TEE negative (if no ABE)
B. Therapy
l Remove CVC
l Venotomy preferable
l Antibiotic therapy x 2 to 4 wk (if no ABE)III. MSSA/MRSA ABE
A. Diagnostic features
l Continuous prolonged/high-grade bacteremia (3/4, 4/4)
l Cardiac vegetation on TTE/TEE
l Cardiac murmur may (not be present early, later new/changing murmur)
l ESR:(*30–50 mm/h)
l TAA titers usually elevated (>1:4)
B. Therapy
l Antibiotic treatment directed against MSSA or MRSA when susceptibility to oxacillin/methicillin known
l Depending on oxacillin/methicillin sensitivity, treat MSSA or MRSA for 4 to 6 wk
l Verify cardiac vegetation regression/resolution of with serial TTEs, serial BCs,;ESR,;TAA titers
Abbreviations: BC, blood culture; ESR, erythrocyte sedimentation rate; MSSA, methicillin-sensitiveS. aureus;
MRSA, methicillin-resistantS. aureus; TAA, teichoic acid antibody; TTE, transthoracic echocardiography; TEE,
transesophageal echocardiography.Intravenous Central Line Infections in Critical Care 211