Outcome of ventilator-associated pneumonia: Impact of antibiotic therapy and other factors

Abstract

Background: Ventilator-associated pneumonia (VAP) is the most frequent infection in patients intubated for longer than 48 hours. There is a great interest in determining the factors influencing the outcome of VAP, as it may help in reducing the associated morbidity and mortality. This study aimed to determine the impact of appropriate antibiotic therapy based on endotracheal aspirate cultures on the outcome of VAP. We have also studied the other factors that may influence the outcome of VAP.

Method: A cohort study was conducted in the intensive care units of a tertiary care hospital in South India over a period of 15 months. The outcome of VAP was assessed by prolongation of the duration of mechanical ventilation and/or death of the patient.

Results: The duration of mechanical ventilation was significantly prolonged in patients with VAP (16.61 ± 8.2 d vs. 8.21 ± 5.9 d, P < 0.0001). VAP patients receiving partially or totally inappropriate therapy (defined as lack of coverage of one or all the significant VAP pathogens) were at significantly high risk for death (Relative risk, 2.00; 95% confidence interval, 1.14 to 3.52; P 0.0008). A delay of > 2 days in administering the first dose of appropriate antibiotic therapy significantly prolonged the duration of ventilation (P < 0.0001). Infection by multi-drug resistant pathogens, polymicrobial infection and time of onset of VAP did not have significant impact on the outcome of VAP.

Conclusion: Early administration of appropriate antibiotic therapy, based on the antibiogram of the VAP pathogens identified by quantitative culture of endotracheal aspirate, could lead to an improved outcome of patients with ventilator-associated pneumonia.

Keywords: Ventilator-associated pneumonia; appropriate therapy; outcome; quantitative culture.