Changing heat and moisture exchangers every 48 hours rather than 24 hours does not affect their efficacy and the incidence of nosocomial pneumonia

Am J Respir Crit Care Med. 1995 Nov;152(5 Pt 1):1562-9. doi: 10.1164/ajrccm.152.5.7582295.


Heat and moisture exchangers (HME) (Dar-Hygrobac II, Peters) can safely be used every 24 h for long-term mechanical ventilation and provide a cost-saving alternative to heated humidifiers. We have prospectively determined whether changing HMEs every 48 h only affects their clinical and bacteriological efficiency in a series of consecutive nonselected ICU patients requiring long-term mechanical ventilation. Two consecutive periods were compared. During period 1, HMEs were replaced every day; during period 2, they were changed every 48 h. Patients from the two periods were similar in terms of age and indication for and overall duration of MV (10 +/- 8.6 versus 10 +/- 9 d, p = 0.9). Minute ventilation and maximum values for peak airway pressure were identical during the two periods. These values were also identical after 1 and 2 d of HME use during period 2, indicating that HME resistance was not increased by prolonged use. Obstruction of the tracheal tube occurred only once in a period 1 patient. The results of quantitative cultures indicate that the maximum and mean levels of bacterial colonization during the two periods were similar for the pharynx, trachea, Y-connector, patient, and ventilator side of the HME. More importantly, the incidence of nosocomial pneumonia was similar during the two periods (6/61 versus 8/68, p = 0.7). Thus, prolonged HME use is safe and provides a substantial reduction in the cost of mechanical ventilation.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Cost-Benefit Analysis
  • Cross Infection / diagnosis
  • Cross Infection / epidemiology
  • Cross Infection / microbiology
  • Cross Infection / prevention & control*
  • Equipment Contamination / prevention & control
  • Equipment Contamination / statistics & numerical data
  • Evaluation Studies as Topic
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Pneumonia, Bacterial / diagnosis
  • Pneumonia, Bacterial / epidemiology
  • Pneumonia, Bacterial / microbiology
  • Pneumonia, Bacterial / prevention & control*
  • Prospective Studies
  • Respiration, Artificial / economics
  • Respiration, Artificial / instrumentation*
  • Respiration, Artificial / statistics & numerical data
  • Safety
  • Time Factors