[Effect of superimposed high frequency oscillation on pulmonary edema induced by intrapulmonary injection of hydrochloric acid in dogs].
Effect of superimposed high frequency oscillatory ventilation on pulmonary gas exchange was investigated in seven anesthetized and paralyzed dogs with pulmonary edema induced by intrapulmonary injection of hydrochloric acid. Efficacy of the ventilatory modes (HFO:6 Hz and 12 Hz) was evaluated observing changes in ventilation-perfusion mismatch, which was demonstrated by using six inert gas elimination method. The ventilation with 6 Hz HFO had no significant effect on PaO2, true shunt, and perfusion distribution. With 12 Hz HFO, PaO2 showed a tendency to increase from 57 +/- 18 mmHg at IPPV to 144 +/- 117 mmHg (0.05 less than P less than .01), and the true shunt decreased from 42.2 +/- 29.0% at IPPV to 16.6 +/- 25.8% (P less than 0.05). However, no change appeared in the perfusion distribution. During the ventilation with 12 Hz HFO increased mean airway pressure produces a PEEP-like effect, which may improve the pulmonary gas exchange by opening small airways, namely a decrease in the true shunt rather than an improvement in the ventilation-perfusion maldistribution.
Yoshida
H
H
Department of Anesthesiology, Kawasaki Medical School, Kurashiki.
Sakai
T
T
Takaori
M
M
D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D006612:High-Frequency Ventilation / Q000379:methods; D006851:Hydrochloric Acid / Q000008:administration & dosage; D011654:Pulmonary Edema / Q000209:etiology / Q000628:therapy*
D006851:Hydrochloric Acid