MHR: Infective endocarditis
meduploader - 05-07-09 22:38

Strep. Viridians  most common overall cause (previously damage valve )
Staph. Aureus  IV drug abuse ( Normal / Previously damage valve ) Tricuspid Valve
Staph . Epidermidis  Prosthetic devices
Strep . bovis  ulcerative colitis / colorectal cancer patient  perform colonoscopy
Early cases of infective endocarditis may be difficult to diagnosis if there is a concomitant infection
elsewhere in the body.
Duke criteria for the diagnosis of IE:
Major:
1. Positive blood cultures
2. Positive echocardiogram for IE
Minor:
1. Predisposing factors such as IV drug abuse
2. Fever of >38C (greater than 100.4F)
3. Evidence of embolic phenomena jnewey lesions, septic pulmonary infarct, arterial emboli, mycoic aneurysm, conjuctival hemorrhage.
4. Evidence of immunologic phenomena such Osler's nodes, Roths spot, glomerulonephritis, etc.
5. Equivocal blood cultures ( + ive blood culture but doesn’t meet the major criteria)
6. Equivocal echo findings
Presence of 2 major or one major and 3 minor or 5 minor criteria is required for the diagnosis of IE.
Fever + new murmur or change in murmur  next step in management  perform blood culture first.
If bllod culture + ive  ECHO to look for vegetations (if TTE is negative than proceed to TEE)
RX:
1. In a patient with H/O IV drug abuse, the antibiotic choice should cover MRSA
(methicillin resistant staphylococcus aureus) and gram-negative organisms i.e. Vancomycin and
gentamicin.
2. Blood culture-negative native valve endocarditis is treated with ceftriaxone and gentamicin.
3. Blood culture-negative prosthetic valve endocarditis is treated with ceftriaxone ad gentamicin plus
vancomycin.
The indication for cardiac surgery in patients with infective endocarditis is not fully agreed upon.
However, some of the indications include, moderate to severe heart failure secondary to valvular
dysfunction or partially dehisced unstable prosthetic valve, prosthetic valve endocarditis with Staph
aureus or Staph epidermidis or relapse of the prosthetic valve after prosthetic valve endocarditis after
appropriate antimicrobial therapy, and large (greaer than 10 mm) hypermobile vegetations, which can potentially
cause septic embolism.
Antibiotic prophylaxis is recommended for prosthetic heart valves, patients with a history of infective endocarditis, those with cyanotic heart disease (unrepaired or within six months after repair), or heart transplant recipients with valvulopathy. (AHA 2007 guidelines no longer recommend it for hypertrophic cardiomyopathy, valvular disease, and mitral valve prolapse with a murmur or thickened leaflet.)
Procedures for which prophylaxis is recommended include dental extractions and periodontal procedures; incision or biopsy of respiratory mucosa (e.g., tonsillectomy, transbronchial biopsy); and procedures on infected skin or musculoskeletal structures (e.g., abscess drainage).
Following procedures don’t need prophylaxis
Dental filling, all flexible scopes, all OB/GYN procedures, all urinry procedures including cystoscope.
For dental procedures: PO amoxicillin, IV ampicillin or IV/PO clindamycin 30–60 minutes before the procedure.
For procedures on infected skin or musculoskeletal structures: PO cephalexin, IV nafcillin or cefazolin 30–60 minutes before the procedure.
For severe penicillin allergy or suspected MRSA, use clindamycin or vancomycin.
COMPLICATIONS
CHF: Caused by valvular destruction or myocarditis. The most common cause of death due to endocarditis.
Embolic phenomena: Mycotic aneurysms, infarcts, or abscesses in the CNS, kidney, coronary arteries, or spleen. Right-sided disease usually causes pulmonary emboli but may also cause systemic emboli with a patent foramen ovale ( bubble study on echocardiogram).
Arrhythmias and heart block.
Myocardial or perivalvular abscess (especially with S. aureus); may extend to cause pericarditis and tamponade.