[Measurement of flow-resistive work of heat and moisture exchangers during simulated active breathing].
The performance of seven commercially available heat and moisture exchangers (HME) was evaluated in the dynamic flow state. A piston pump was used as a simulator with operative conditions with stroke volume of 500 ml and with respiratory rates of 20 and 40 cycles.min-1. A pressure-volume loop was produced for each HME and the flow-resistive work calculated. Each HME was studied under both dry and wet conditions. It was found that the flow-resistive work of the Humid-Vent 2 was the smallest and that of the Breathaid the largest under both conditions. The results suggest that application of HME causes a significant increase in resistance and demands a greater breathing effort from patients. Its use should thus be avoided in marginal patients.
Nishimura
M
M
Department of Anesthesia, Osaka Med. Ctr. & Research Inst. for Maternal and Child Health, Izumi.
Takezawa
J
J
Imanaka
H
H
Taenaka
N
N
Yoshiya
I
I
D000776:Anesthesiology / Q000295:instrumentation*; D005069:Evaluation Studies as Topic; D006801:Humans; D008954:Models, Biological; D012121:Respiration, Artificial / Q000295:instrumentation*