[Effect of high-frequency oscillation on hypoxic pulmonary vasoconstriction].
We studied the effect of high-frequency oscillatory ventilation (HFO) on hypoxic pulmonary vasoconstriction (HPV) in mongrel dogs. Arterial blood gas as well as pulmonary and systemic hemodynamic variables were measured. Using a double-lumen endotracheal catheter, the right lung was ventilated by controlled mechanical ventilation (CMV) and the left lung was ventilated by CMV (controlled group, n = 5), HFO (HFO group, n = 6) and a combined use of CMV and HFO (combined group, n = 6). Under the same condition as in HFO group, chest was opened and the left pulmonary arterial flow was determined by electromagnetic method (opened thorax group, n = 4). Bilateral lungs were ventilated with pure oxygen during the control period. The right lung was ventilated with pure oxygen while the left lung was ventilated with pure nitrogen afterward during the study. There was no significant change in arterial oxygen partial pressure due to delayed HPV in HFO group or combined group between 30 and 120 minute values. Although there was an increase in mean pulmonary arterial pressure in combined group, in HFO group it was not observed. At the same time, the decrease in pulmonary flow was minimum in open thorax group. Authors conclude that HFO interferes with the effect of HPV to a certain extent.
Sugaya
K
K
Watanabe
S
S
Gao
W
W
D000818:Animals; D004285:Dogs; D006612:High-Frequency Ventilation; D000860:Hypoxia / Q000503:physiopathology*; D011651:Pulmonary Artery / Q000503:physiopathology*; D014661:Vasoconstriction / Q000502:physiology*