Vascular pressures and passage of gas emboli through the pulmonary circulation.
Anesthetized dogs received venous air infusions at 0.35 ml.kg-1.min-1. In 60% of a group of 15 dogs, venous bubbles spilled over into the arterial circulation and were detected with the ultrasound Doppler technique. The pulmonary vascular pressure gradient (pulmonary artery pressure-pulmonary venous pressure or left atrial pressure) measured at the instant that spillover occurred was 34.7 +/- 4.7 mmHg. In a 2nd group of dogs we raised the pulmonary vascular pressure gradient before the venous air infusions to achieve spillover of bubbles 100% of the time. The resultant pressure gradient at the time of spillover of venous bubbles was 52.0 +/- 2.0 mmHg (P less than 0.05). It is concluded that venous bubbles can cross the lungs of anesthetized dogs when the driving pressures are sufficient to overcome the normal filtering function.
Butler
B D
BD
Department of Anesthesiology, University of Texas Medical School, Houston.
Katz
J
J
D000818:Animals; D001794:Blood Pressure; D004285:Dogs; D004618:Embolism, Air / Q000503:physiopathology*; D006439:Hemodynamics; D011652:Pulmonary Circulation; D014690:Venous Pressure