Determinants of prescription and choice of empirical therapy for hospital-acquired and ventilator-associated pneumonia

The objectives of this study were to assess the determinants of empirical antibiotic choice, prescription patterns and outcomes in patients with hospital-acquired pneumonia (HAP)/ ventilator-associated pneumonia (VAP) in Europe. We performed a prospective, observational cohort study in 27 intensive care units (ICUs) from nine European countries. 100 consecutive patients on mechanical ventilation for HAP, on mechanical ventilation >48 h or with VAP were enrolled per ICU. Admission category, sickness severity and Acinetobacter spp. prevalence >10% in pneumonia episodes determined antibiotic empirical choice. Trauma patients were more often prescribed non-anti- Pseudomonas cephalosporins (OR 2.68, 95% CI 1.50-4.78). Surgical patients received less aminoglycosides (OR 0.26, 95% CI 0.14-0.49). A significant correlation (p<0.01) was found between Simplified Acute Physiology Score II score and carbapenem prescription. Basal Acinetobacter spp. prevalence >10% dramatically increased the prescription of carbapenems (OR 3.5, 95% CI 2.0-6.1) and colistin (OR 115.7, 95% CI 6.9-1,930.9). Appropriate empirical antibiotics decreased ICU length of stay by 6 days (26.3 +/- 19.8 days versus 32.8 +/- 29.4 days; p=0.04). The antibiotics that were prescribed most were carbapenems, piperacillin/tazobactam and quinolones. Median (interquartile range) duration of antibiotic therapy was 9 (6-12) days. Anti-methicillin- resistant Staphylococcus aureus agents were prescribed in 38.4% of VAP episodes. Admission category, sickness severity and basal Acinetobacter prevalence >10% in pneumonia episodes were the major determinants of antibiotic choice at the bedside. Across Europe, carbapenems were the antibiotic most prescribed for HAP/VAP.