CARDIOPULMONARY RESPONSES TO INTRAVENOUS-INFUSION OF SOLUBLE AND RELATIVELY INSOLUBLE GASES

Background: Carbon dioxide is the current gas of choice for pneumoperi toneum, but hemodynamic and acid-base effects secondary to its systemi c absorption have been reported. Various studies have suggested inert gases as alternatives. Methods: We studied the cardiopulmonary respons es to intravenous infusion of carbon dioxide, nitrous oxide, argon, he lium, and nitrogen in anesthetized swine. The gas was infused into the femoral vein at a rate of 0.1 ml . kg(-1). min(-1) for 30 min. The ch anges in end-tidal CO2, mean arterial pressure, hemodynamics, and arte rial blood gases were compared to baseline values. Results: No animals died during infusion of the soluble gases (CO2 and N2O). Three of the five pigs infused with nitrogen died suddenly at 20 and 30 min of inf usion. The animals in the insoluble gas groups (Ar, He, N-2) experienc ed clinical pulmonary gas embolism and severe acidemia, hypercapnea an d tachycardia. Conclusions: Venous gas embolism is poorly tolerated wh en the gas is relatively insoluble. Insoluble gases should not be used for pneumoperitoneum when there is any risk of venous gas embolism.