7-days Versus 14 Days of Antibiotics Therapy for Ventilator Associated Pneumonia

Ventilator-associated pneumonia (VAP) is one of the major causes of morbidity and mortality in the ICU, accounting for 25% of the total infections occurring in this setting and 50% of all antibiotic prescriptions in patients who are mechanically ventilated.1,2 The incidence of VAP depends not only on the type of the institution, the preventive measures and therapeutic approaches that are used, but also on the type of surveillance systems by which incidence is estimated. There are reports of incidence across different settings varying from 1.4 up to 42.8 episodes of VAP/1,000 ventilation-days.2 Patients with VAP have significantly longer ICU and hospital lengths of stay compared with similar patients without VAP.3,4 Consequently, the economic burden of VAP is considerable, leading to significant draining of resources. Even after adjusting for underlying severity of illness, the attributable cost of VAP amounts to several thousands of US dollars per patient.5 There is evidence that using shorter antibiotic regimens may help in decreasing antimicrobial resistance and reducing drug-related adverse events.6 Moreover, short-course treatments were found to be as effective as longer-course antibiotic treatment.7,8 In a pooled analysis of four randomized trials in VAP comparing shorter versus long duration of antibiotics in the management of VAP, no difference in the mortality was found.9 There was an increase in the antibiotic free days in the short course antibiotic arm. There was no difference in the number of relapses of VAP with either modality of treatment.9 In another analysis of six studies with 1088 subjects, there was a higher occurrence of relapses of VAP due to non-lactose fermenting gram negative organism.10 However, there was no difference in the mortality rates.10 The problem with both these meta-analyses was that they did not provide information regarding the outcomes of VAP due to Acinetobacter baumanii.9,10 Also, the short duration strategy included studies that randomized patients to seven to eight days and ten-to fifteen days in the long duration strategy. None of the previous studies has provided information about outcomes of VAP due to Acinetobacter baumanii. In our observation, most of the episodes of VAP in our ICU are due to drug resistant Acinetobacter baumanii. We hypothesize that the use of short course of antibiotics in the treatment of VAP due to drug resistant Acinetobacter baumanii (sensitive to carbapenems and/or colistin only) may result in a higher antibiotic-free days and drug related adverse events, in comparison to a longer duration of antibiotics. In this study, we propose to study a 7-day versus 14-day course of antibiotics in patients with drug-resistant Acinetobacter baumanii.