Influence of passive humidification on respiratory heat loss in tracheotomized patients.

Abstract

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. 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. 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. 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.