Fifty patients, age from 32 to 82 years, were submitted to extracorporeal circulation using a membrane oxygenator (D.M.G.) in which a venous arterial shunt was employed so that only one third to one half of the venous blood were gone through the oxygenator. The gas used in the oxygenator was pure oxygen. The patients were kept with temperature of 34 to 36°C, anestetized with phentanil and full curarization, to decrease to a minimum the O2 comsumption. The average arterial SO2 was ± 90% and the venous saturation ± 70%. There were no significant variations in PCO2 and PH. During perfusion the arterial and venous saturations were monitored with an oxymeter and also the volume of the shunt measured by an electromagnetic flowmeter (Biopump). There were two deaths in the post operative period (two weeks and three weeks after surgery) not related to the perfusion method. We conclude that the use of a venous arterial shunt and pure oxygen in membrane oxygenators can substitute the gas mixture routinely used in these devices and has as advantage to reduce in theory the inflamatory responses produced by the artificial oxygenators.
Arteriovenous shunt; Oxygenators; Perfusion; Hemodilution; Extracorporeal circulation
