Duration of Antibiotic Therapy for Ventilator-Associated Pneumonia in Burn Patients

Abstract

Shorter compared with longer courses of antibiotic therapy for ventilator-associated pneumonia (VAP) in mixed medical-surgical intensive care units (ICUs) have been reported to produce equivalent outcomes. There have been few studies on the duration of antibiotic therapy for VAP in the burn population. We hypothesized that a shorter duration of antibiotic therapy for VAP would produce similar outcomes in our burn ICU. All burn patients from July 2001 to December 2006 admitted to the burn ICU requiring mechanical ventilation were studied. VAP was diagnosed prospectively by our Infection Control Liaison using bronchoalveolar lavage for cultures. Patients were cohorted into two groups: before July 1, 2004, antibiotic therapy duration was directed by the discretion of the attending physician (preprotocol), and after, the goal was 8 days of appropriate therapy or longer based on physician discretion (postprotocol). There were 98 patients treated for VAP with similar rates of inhalation injury, %TBSA burn size, age, and need for mechanical ventilation between the groups. The incidence of recurrent VAP was the same: 17% for the preprotocol and 15% for the postprotocol periods. The overall duration of antibiotic therapy did not change from 11 +/- 4 to 12 +/- 6 days. For patients treated longer than the target of 8 days, 66% had positive respiratory cultures at 4 days after initiation of antibiotic therapy. For the majority of patients with aspiration-type organisms or nonvirulent strains, there were fewer antibiotic days overall at 10 +/- 5 days (P < .05), with no episodes of recurrent VAP with the same bacteria. Despite a focused effort to decrease antibiotic usage for VAP in burn patients, the overall duration of therapy did not change. The majority of patients with virulent organisms such as methicillin-resistant Staphylococcus aureus or nonfermenting Gram-negative rods still had clinical signs of pneumonia and positive cultures, leading clinicians to continue antibiotics. In patients without virulent pathogens, a shorter antibiotic course was well-tolerated without recurrences.