[Mechanical ventilation-associated pneumonia and the prevention of stress ulcer. A randomized clinical trial of antacids and ranitidine versus sucralfate]

Abstract

Background: To study two groups of patients intubated with different prophylaxis of stress gastric ulcer in a prospective randomized trial. The differential effect on gastric pH, gastric colonization and the incidence of pneumonia associated to mechanical ventilation (PMV) were analyzed.

Methods: A prospective randomized study was carried out in two groups of patients: 1) prophylaxis with antacids and H2 blockers (AA+H2) and 2) prophylaxis with sucralfate. Intubated patients without initial respiratory infection were included in the protocol. Periodically gastric aspirations were collected measuring gastric pH and performing semi-quantitative cultures. When pneumonia was suspected bronchial brushing was carried out with telescoped catheter (BBTC) and quantitative culture.

Results: Fifty-one patients were studied (n = 51), distributed into 25 in the AA+H2 group and 26 in the sucralfate group. In the first group mean pH was higher (5.3 +/- 1.7) than in the sucralfate group (3.2 +/- 2.1) (p = 0.006). Nosocomial pneumonia (NP) was suspected on 25 occasions: 20 patients were positive for NP, 11 in the AA+H2 group and nine in the sucralfate group with no significant differences being observed. S. aureus, S. pneumoniae and H. influenzae (n = 14) were the etiology of predominant PMV. The global mortality of the group was of 22%.

Conclusions: The prophylaxis of stress ulcers in intubated patients treated with antacids and ranitidine provoked higher gastric pH and an increase in gastric colonization in comparison to that observed with sucralfate. No significant differences were observed in the frequency of pneumonia by PMV diagnosed by BBTC.