Is a 24-h cyclic closed enteral feeding system microbiologically safe in geriatric patients?

Background and aims: The microbiological quality of a 1-l closed enteral feeding system (CS) was prospectively monitored under clinical conditions simulating cyclic feeding over a 24-h period in geriatric patients. Method: The set was connected after diet sampling (T0). After 5-h feeding, the set was disconnected and a sample taken (T5). Diet was sampled after 12 h before (T12A) and after a 10 ml diet-flush of the set (T12B), after 24-h (T24) and in the pouch (P24). Concentrations of micro-organisms were considered significant when above 104 colony-forming units per millilitre. Results: Twenty-one CS were examined. T0 samples were all sterile; 10 out of 21 T5 were contaminated. The microbiological content of the diet was lower in T12B, compared to T12A (P=0.002). None of the P24 samples was contaminated; 19 were sterile and two contained low levels of micro-organisms that had been previously found in the sets. Conclusion: The CS was sterile before connecting to the patient. Retrograde contamination of the set was observed without contamination of the pouch after 24-h hanging time. Performing a diet-flush decreased the rate of diet contamination at the distal extremity of the set. Thus, cyclic enteral nutrition using the same pouch during a 24-h period seems to be safe in geriatric patients.