4.4 INFECTIVE ENDOCARDITIS Flashcards
Pathophysiology
(1) Endocarditis is a bacterial or fungal infection of the valvular or endocardial surface of the heart.
(2) Underlying valvular disease disrupts blood flow and provides a nidus of
attachment. It is present in 50% of cases.
(3) Initiating event is the colonization of the valve by bacteria/yeast that can
gain access to the blood stream by dental/surgical procedures or respiratory, urologic, and lower GI infections
(4) Native valve endocarditis is usually caused by Staph Aureus or Streptococci
(5) In IV Drug users Staph Aureus infection accounts for 60% of cases
(6) IV drug users typically present with right sided endocarditis vs other causes usually affect left sided valves
Symptoms/Physical Findings
(1) Duration: days to weeks to get symptoms
(2) Fever
(3) Non-specific symptoms (cough, dyspnea, arthralgias, abdominal, back,
or flank pain)
(4) Characteristic peripheral lesions caused by emboli:
(a) Petechia on palate, conjunctiva, or beneath finger nails
(b) Splinter hemorrhages: red, linear streaks under nail plate and within nail
bed
(c) Janeway lesions: painless (micro-abscesses), erythematous lesions on
palms and soles
(d) Osler’s nodes: painful (immune-complex depositions)
(e) Roth spots: exudative lesions in the retina; occurs in 25% of patients
(5) New onset heart murmur (ANY new heart murmur with a fever is Endocarditis until proven otherwise)
(6) Strokes and major systemic events in 25% of patients, occurring before
or within the first week of antibiotic therapy.
Differential Diagnosis
(1) Skin and soft tissue infection
(2) Osteomyelitis
(3) Meningitis
(4) Pneumonia
(5) Sepsis
(6) Myocarditis
(7) Pericarditis
(8) Cardiomyopathy
Labs/Studies/EKG
(1) Blood cultures
(2) CBC with differential
(3) Chemistry to evaluate of kidney damage
(4) EKG: non-diagnostic, new conduction abnormalities suggest myocardial
abscess formation
(5) Echocardiogram: gold standard to evaluate for valvular vegetations
Treatment
(1) Since blood cultures are positive in 90% of patients it is acceptable to await blood culture results before initiating antibiotics
(2) Empiric therapy if patient is septic would be Ertapenem 1 gram IV q24
hours or Vancomycin 1 gram IV q12 hours plus Ceftriaxone 2 grams IV daily
(3) If in heart failure then management should focus on that as well
Initial Care
(1) IV, O2 if saturation < 94%, Monitor
(2) 3 sets of blood cultures
(3) Transfer to higher level of care
Complications
1) Heart failure
(2) Perivalvular abscess
(3) Pericarditis
(4) Pericardial Tamponade
(5) Septic embolization to brain, extremities, eye, spleen, kidneys, PE, or
AMI
