Background: The aim of this study was to evaluate changes in total respiratory heat loss during use of a heat and moisture exchanger (HME) in tracheotomized patients.
Methods: Tracheal humidity and temperature were measured before the application and during use of the HME (plastic foam impregnated with CaCl2), and total respiratory heat loss was calculated.
Results: No significant difference was found between the convective heat exchange before and after use of the HME for a 10-minute period. When the HME was placed on the tracheal opening, the evaporative heat exchange and the total respiratory heat loss decreased significantly.
Conclusions: The results indicate that passive airway humidification is effective in tracheotomized patients even after a 10-minute period. However, the positive effect on the energy balance of the tracheal mucosa after prolonged use of the HME remains to be proven.
Copyright 2006 Wiley Periodicals, Inc.