Changing heat and moisture exchangers every 48 hours does not increase theincidence of nosocomial pneumonia

This prospective study was conducted to evaluate the risk of nosocomial pne umonia when changing heat and moisture exchangers every 48 hours in 1996 in stead of every 24 hours in 1995 for patients needing continuous mechanical ventilation. Medical and surgical patients in the two periods did not diffe r in terms of demographic characteristics and markers of acute or underlyin g illnesses. The incidence density of nosocomial pneumonia was not differen t in the two groups. Extended heat and moisture exchanger use reduces circu it manipulation and cost.