Ventilator associated pneumonia (VAP), once diagnosed in critically ill patients, should be managed with prompt initiation of broad spectrum antibiotic coverage (this is based on extrapolation of data from septic patients which shows a direct correlation between mortality and time to initiation of appropriate antibiotic coverage (Ref. 1) followed by a reasonable attempt at making a microbiologic diagnosis (data do not support blind suctioning versus fiberoptic bronchoscopy for this purpose). Treatment duration should be eight days (based on a randomized, double-blind, multicenter French trial of 401 ICU patients with VAP, 8 days vs. 15, showing no difference in outcomes were no different (Ref. 2) although subgroup analysis from this landmark trial showed no an increased recurrence with pseudomonas, suggesting that this organism may require longer treatment duration.
The actual antibiotic regimen selected depends on patient and institutional factors. Patient factors include sickness and duration of hospitalization. Institutional factors include the most likely causative organisms and their suspected susceptibilities. No antibiotic regimen can cover 100% of possible pathogens, thus close coordination between the infectious disease service, pharmacology, and the critical care team is necessary. Institutional antibiograms are essential and obviate the use of generic tables found in textbooks. Particular attention should be paid to dosing in the critically ill patient population (many of whom have expanded volumes of distribution).
Assuming that clinical improvement occurs, if a clear microbiologic diagnosis is made (e.g. based on broncheoalveolar lavage), one may consider de-escalation of therapy.
Anand Kumar, Daniel Roberts, Kenneth E Wood, Bruce Light, Joseph E Parrillo, Satendra Sharma, Robert Suppes, Daniel Feinstein, Sergio Zanotti, Leo Taiberg, David Gurka, Aseem Kumar, Mary Cheang Duration of hypotension before initiation of effective antimicrobial therapy is the critical determinant of survival in human septic shock. Crit. Care Med.: 2006, 34(6);1589-96
Jean Chastre, Michel Wolff, Jean-Yves Fagon, Sylvie Chevret, Franck Thomas, Delphine Wermert, Eva Clementi, Jesus Gonzalez, Dominique Jusserand, Pierre Asfar, Dominique Perrin, Fabienne Fieux, Sylvie Aubas, PneumA Trial Group Comparison of 8 vs 15 days of antibiotic therapy for ventilator-associated pneumonia in adults: a randomized trial. JAMA: 2003, 290(19);2588-98