Objective of this study was to determine incidence, risk factors, etiological micro-organisms and their antimicrobial susceptibility pattern and outcome of VAP; and to study effect of ranitidine vs. sucralfate, used for stress ulcer prophylaxis, on gastric colonization and on occurrence of VAP.

Methods: Design: Prospective randomized study. Setting: ICUs of Medicine Department and Anesthesiology Department, Maulana Azad Medical College and Lok Nayak Hospital, University of Delhi, New Delhi. Patients: 50 patients of age more than 12 years, who had been on ventilator for more than 48 hrs. Intervention: Endotracheal Aspirate and blood sample of all patients were cultured to determine micro-organisms causing VAP and their antimicrobial susceptibility pattern. Patients were divided into 2 groups on random basis. The first group was given ranitidine for stress ulcer prophylaxis while the second was given sucralfate. Thereafter, difference in gastric colonization (on basis of quantitative culture of nasogastric aspirate) and on occurrence of VAP in both the groups was compared.

Study Hypothesis: Study was designed to create data about Ventilator associated pneumonia in developing countries like India. This data is crucial for providing information for deciding future guidelines for treatment of and prevention of Ventilator associated pneumonia. Further to test the hypothesis that H2 blockers, by virtue of raising gastric Ph, increase gastric colonization by pathogenic organism and increase incidence of Ventilator associated pneumonia; patients were divided into two groups on random basis, as described above.