Clinical importance of delays in the initiation of appropriate antibiotic treatment for ventilator-associated pneumonia

Study objectives: To determine the influence of initially delayed appropriate antibiotic treatment (IDAAT) on the outcomes of patients with ventilator-associated pneumonia (VAP). Setting: Medical ICU of Barnes-Jewish Hospital, St. Louis, a university-affiliated urban teaching hospital. Patients: One hundred seven consecutive patients receiving mechanical ventilation and antibiotic treatment for VAP. Interventions: Prospective patient surveillance and data collection. Measurements and results: All 107 patients eventually received treatment with an antibiotic regimen that was shown in vitro to be active against the bacterial pathogens isolated from their respiratory secretions. Thirty-three patients (30.8%) received antibiotic treatment that was delayed for ≥ 24 h after initially meeting diagnostic criteria for VAP. These patients were classified as receiving IDAAT. The most common reason for the administration of IDAAT was a delay in writing the antibiotic orders (n = 25; 75.8%). The mean time (± SD) interval from initially meeting the diagnostic criteria for VAP until the administration of antibiotic treatment was 28.6 ± 5.8 h among patients classified as receiving IDAAT, compared to 12.5 ± 4.2 h for all other patients (p < 0.001). Forty-four patients (41.1%) with VAP died during their hospitalization. Increasing APACHE (acute physiology and chronic health evaluation) II scores (adjusted odds ratio, 1.13; 95% confidence interval, 1.09 to 1.18; p < 0.001), presence of malignancy (adjusted odds ratio, 3.20; 95% confidence interval, 1.79 to 5.71; p = 0.044), and the administration of IDAAT (adjusted odds ratio, 7.68; 95% confidence interval, 4.50 to 13.09; p < 0.001) were identified as risk factors independently associated with hospital mortality by logistic regression analysis. Conclusion: These data suggest that patients classified as receiving IDAAT are at greater risk for hospital mortality. Clinicians should avoid delaying the administration of appropriate antibiotic treatment to patients with VAP in order to minimize their risk of mortality.