Bacteremia

Etiologies

• 1" infxn due to direct inoculation of the blood, frequently assoc. w/ intravascular catheters

• 2° infxn due to infection in another site (eg. UTI. lung, skin) spreading to blood Microbiology

• 1° infxn/indwelling catheters (CU) 2004:39:309)

Coagulase-neg staphylococci (includes S. epidermidis and others) 31% Staphylococcus aureus 20% Enterococci 9% Candida species 9% E coli 6%

Klebsiella species 5%

• 2° infxn: dependent upon the source

Risk factors for true bacteremia (jama 1992:267.1962)

• Pt: fever, shaking chills. IVDA. major comorbidities

• Organism higher risk: S. aureus. P-hemolytic Strep, enterococci. GNR. S. pneumonia. Neisseria lower risk: coag-neg staph ( 10%). diptheroids & Propionibacterium ( 0%)

• Time to growth: 24 h — higher risk. >72 h — lower risk (except for slow-

growing organisms such as HACEK group)

• Confirmatory cultures

Treatment

• 1° infxn: antibiotics based upon culture results empiric initial vanco to cover coag-neg staph and MRSA while awaiting sensi. also Rx line tip w/ >15 colonies (in clinical setting suggestive of infxn; NEJM 198S. 3111142)

• S. aureus: d/c catheter, echo to r/o endocarditis; if echo . Rx x 2 wks from first BCx

• Coag-neg staph: may consider leaving catheter in place. Rx x 2 wks

Cleared 80% of time w/ line left in. unless tunnel infxn or clot (c/w 10% if S. aureus) If catheter left in place, re/ BCx > 1 wk after completion of abx regimen

• 2° infxn: assess for primary source of infection and treat underlying infection

• Persistently • BCx: d/c indwelling catheters, consider metastatic infxn, consider infected thrombosis

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