Internal Medicine

0521779407-10 CUNY1086/Karliner 0 521 77940 7 June 7, 2007 18:40

832 Infective Endocarditis

■HACEK organisms treated with ceftriaxone for 4 weeks (6 weeks for

prosthetic valves); therapy in the allergic patient not established, but

trimethoprim-sulfamethoxazole, fluoroquinolones and aztreonam

have in vitro activity

follow-up

■Blood cultures usually negative in 3–5 days; fever may persist 10–

12 days; persistent fever should prompt evaluation for myocardial

abscess, infected or sterile systemic emboli with or without infarc-

tion, superinfection or drug reaction

■Most relapses occur within 1–2 months of completion of therapy;

careful clinical follow-up and blood cultures every other week to

detect early relapses

■Progressive valvular dysfunction after successful antibiotic therapy

may require valve replacement, especially in the first year.

complications and prognosis

■Major complications include valvular destruction with heart fail-

ure requiring valve replacement, myocardial abscess, systemic

embolization with infarction (kidney, spleen), mycotic aneurysms

that can rupture (great vessels or intracerebral vessels) and pul-

monary emboli resulting in infarcts or abscesses.

■Use of prophylactic antibiotics indicated in high-risk patients (pros-

thetic valves, previous endocarditis) or moderate-risk patients (con-

genital abnormalities other than atrial septal defects, rheumatic

heart disease with valvular dysfunction, mitral valve prolapse with

regurgitation) undergoing procedures likely to result in bacteremia

(dental procedures associated with significant bleeding, periodon-

tal procedures, implant placement; respiratory procedures that

breach the mucosa such as tonsillectomy; invasive gastrointestinal

procedures such as ERCP, sclerotherapy; invasive genitourinary pro-

cedures, prostatic surgery); for dental, respiratory or esophageal pro-

cedures, amoxicillin (clindamycin if penicillin allergic) 1 hour before;

for gastrointestinal procedures (other than esophageal) and geni-

tourinary procedures in high-risk patients ampicillin plus gentam-

icin parenterally 30 minutes before and either ampicillin g IV or IM

or amoxicillin orally, 6 hours after (vancomycin instead of ampicillin

in the penicillin-allergic patient); in moderate-risk patients amoxi-

cillin 1 hour before (vancomycin as above for the penicillin-allergic

patient)