O50 – A Reappraisal of MRSA VAP in the Surgical ICU: Not Just a Late Infection Any More

Author(s):
Jacquelyn Glenn, Maria Rodil, Clay Burlew, Fredric Pieracci, Denver Health Medical Center

Background: Choice of empiric antibiotic(s) for early ventilator associated pneumonia (VAP) involves weighing the risks of potential infection with multidrug resistant (MDR) pathogens against those of over-exposure to broad-spectrum agents. Although early VAP is thought to be rarely caused by MDR pathogens, the overall incidence of all methicillin resistant Staphylococcus aureus (MRSA) infections is increasing. We questioned if MRSA VAP is becoming more common and if it these infections were occurring earlier in the patient’s hospital course.

Hypothesis: We hypothesized that 1) early (2-7 days from intubation) VAP caused by MRSA is relatively uncommon and 2) those patients with early VAP due to MRSA had risk factors associated with a MDR organism infection.

Methods: Methods: BALs from patients admitted to our SICU from 2010 – 2013 were reviewed. MRSA VAP was defined as growth of ≥105 cfu/mL from BAL. Risk factors included patient demographics or living conditions, prior recent hospitalization or transfer from long term care facility, and known prior colonization.

Results: Results: In the three year period, there were 438 cases of VAP. 47 specimens from 43 patients had quantitative microbiologic confirmation of early MRSA VAP for an overall prevalence of 10.7%. Of the 43 patients with MRSA VAP, 17 (39.5%) were early. Culture results were graphed according to ventilator days (Figure). The median days ventilated at the time of MRSA VAP were 11 days (range 2-81). None of the early MRSA VAP patients had identifiable risks for community or hospital acquired MRSA infection.

Conclusions: Conclusions: These data suggests that approximately 40% of cases of MRSA VAP occurred in the early window and without traditional or known risk factors. Since the rapid determination of the etiology of severe pneumonia is possible only in a limited number of cases, broad-spectrum antibiotic therapy that will treat infection with MRSA as well as other potential pathogens should be considered early in the course of treatment.