title: Pulmonary shunting during alveolar hypoventilation in the dog.
abstract: Pulmonary shunting (Qs/Qt) was measured in 16 anesthetized and paralyzed healthy beagle puppies during a control period when the end-expired CO2 concentration was 5 per cent and during alveolar hypoventilation, when the PaCO2 increased to 100 plus or minus 13 torr (mean plus or minus SE) and the ;Ha vecame 7.04 plus or minus 0.04. A constant tidal volume was maintained throughout each study, and hypoventilation was achieved by slowing only the respiratory rate. During the control period Qs/Qt was 2.9 plus or minus 0.3 per cent; during hypoventilation Qs/Qt was 3.2 plus or minus 0.3 per cent (an insignificant difference). The puppies, therefore, responded to anesthesia and alveolar hypoventilation without development of increased pulmonary shunts.
mesh_terms: D000771:Anesthesia, Intravenous; D000818:Animals; D001769:Blood; D002245:Carbon Dioxide / Q000097:blood; D004285:Dogs; D006863:Hydrogen-Ion Concentration; D007040:Hypoventilation / Q000097:blood / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D010313:Partial Pressure; D010424:Pentobarbital; D011312:Pressure; D011650:Pulmonary Alveoli / Q000098:blood supply*; D011652:Pulmonary Circulation; D013147:Spirometry; D013997:Time Factors; D014065:Tonometry, Ocular
chemical_list: D002245:Carbon Dioxide; D010424:Pentobarbital; D010100:Oxygen