title: Oxygen consumption and blood gas exchange during controlled and intermittent mandatory ventilation after cardiac surgery.
abstract: The purpose of this study was to determine the consequence of intermittent mandatory ventilation (IMV) on gas exchange, cardiac function, and blood oxygenation immediately after cardiopulmonary bypass grafting. The results showed a marked increase in oxygen uptake, cardiac index, and pulmonary artery pressure, and a decrease in mixed venous oxygen saturation of 20 adult patients recovering from surgery. These effects may have been associated with the presence of an endotracheal tube, because 2 h after removal of this tube there were significant decreases in elevated cardiac function and blood oxygenation variables, while mixed venous oxygen saturation increased from 64% to 75% (p less than .001). These results suggest that IMV can dramatically increase oxygen uptake, cardiac index, and pulmonary artery pressure in awake and intubated patients.
mesh_terms: D000328:Adult; D001784:Blood Gas Analysis; D001026:Coronary Artery Bypass; D003422:Critical Care; D006334:Heart Function Tests; D006801:Humans; D008875:Middle Aged; D010101:Oxygen Consumption; D011184:Postoperative Period; D012121:Respiration, Artificial