[Pathogenic flora in the gastric juice and bronchial secretion of long-term ventilated intensive-care patients]

Abstract

Nosocomial pneumonia is a major risk for long term ventilated ICU patients. The infection route may be hematogenic or via inhalation or aspiration of microorganisms. The source of aspiration is the oropharynx. This prospective study intended to study the role of the stomach as a reservoir of bacteria in ICU patients treated with cimetidine. Gastric juice and bronchial secretion from 34 patients ventilated for more than 4 days were examined bacteriologically. 72,8% of the gastric (G) and 79,1% of the bronchial aspirates (B) revealed significant bacterial growth (more than 10(4) microorganism/ml). Pseudomonas, Klebsiella, and Candida spp. were found in 56,7% (B) and 51,8% (G) of the positive cultures as an effect of selection caused by antibiotics. Organisms of intestinal origin were found in 17,8% (B) und 15,5% (G), respectively. In 32,5%, identical organisms or patterns of organisms were found in the gastric and bronchial aspirates. 7 of the 34 patients (20,6%) developed pneumonia; in 6 of these 7 cases, the same organisms could be identified at the same and/or at the last examination before developing pneumonia in gastric content and bronchial secretion. The pH-value of the sterile aspirates was lower than of the colonized aspirates (5,39 vs 5,99). During enteral nutrition, 31,4% of the aspirates were sterile, whereas during parenteral nutrition only 24,3% of the gastric aspirates were sterile. Therefore, enteral nutrition should be started as soon as possible, the pH-value should be checked frequently and should not exceed 4 in order to reduce bacterial overgrowth in the stomach. A further consequence is to use as few antibiotics as possible.