Stomach as source of bacteria colonising respiratory tract during artificial ventilation

10 adults had intermittent positive-pressure ventilation for 3--34 days. All 10 had paralytic ileus. Microbial overgrowth in the stomach was found in 9 patients (bacterial in 7 and fungal in 2); gram-negative bacteria predominated. The trachea invariably became colonised by bacteria, mainly gram-negative organisms. In 3 instances the gram-negative bacteria were found in the stomach before they appeared in the tracheal aspirate, and in 1 case the pathogen originated in the faeces.