Department of Medicine, University of Alabama at Birmingham 35294, USA.
BACKGROUND: The purpose of this research was to determine whether changing tubing circuits for mechanical ventilation less often than every 48 hours would allow maintenance of acceptably low rates for ventilator-associated pneumonia. METHODS: A computer search of the MEDLINE database from 1986 through 1996 was performed, and abstracts for 1992 through 1996 from the annual meetings of the Association for Professionals in Infection Control and Epidemiology and the Society for Healthcare Epidemiology of America were examined. RESULTS: Eight studies indicate that the interval between ventilator tubing circuit changes can be extended to 7 days without increasing the rate of ventilator-associated pneumonia. Furthermore, the rate can be maintained at or below 10 pneumonias per 1000 ventilator-days, the approximate median of the National Nosocomial Infections Surveillance System. There is very little evidence to suggest that these circuits can safely be changed at longer intervals. CONCLUSIONS: The weight of the evidence indicates that breathing circuits should be changed every 7 days. This practice of routine changes should be abandoned only if additional studies demonstrate that prolonged use of the same breathing circuit is associated with low rates of ventilator-associated pneumonia.