Heat and moisture exchangers in artificial ventilation. An experimental study of the effect of gas leakage

The effect of gas leakage around an uncuffed tracheal tube on the performance of Heat and Moisture Exchangers (HME) was examined experimentally. Such leaks were shown to cause measurable decreases in the humidity output and efficiency of HME. The magnitude of the decrease in humidity output was shown to be dependent upon the proportion of expired volume which was leaked, and on the inspired volume. Other factors are discussed.