Ventilatory and pulmonary vascular responses to acute hypoxia are nonuniform in healthy man.
The present study was undertaken to examine the pulmonary vascular and ventilatory responses to acute hypoxia in healthy individuals. Pulmonary hemodynamics and minute ventilation (VE) were serially measured during inhalation of 13% O2 for 15 min. There was a wide variability in the pulmonary vascular response to acute hypoxia, and a significant negative correlation between the initial increase in VE after the start of hypoxia (delta VE) and the percent increase in mean pulmonary arterial pressure (r = -0.646; p < 0.01). The fall in arterial oxygen tension significantly decreased in response to an increase in delta VE. These results support the view that a blunted ventilatory response to acute hypoxic stimulation enhances alveolar hypoxia, thereby favoring the constriction of pulmonary vasculature. Thus, our results suggest that the ventilatory response to acute hypoxia plays a significant role in the pulmonary vascular response to acute hypoxia.
Naito
T
T
Second Department of Internal Medicine, Nagasaki University School of Medicine, Japan.
Miyahara
Y
Y
Ikeda
S
S
D000208:Acute Disease; D001794:Blood Pressure; D005260:Female; D006439:Hemodynamics; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000503:physiopathology; D011652:Pulmonary Circulation; D012016:Reference Values; D012119:Respiration; D014655:Vascular Resistance