Nitrogen Gas: A Possible Contraindication In Bubble Oxygenators

An ultrasonic Doppler was used to monitor embolic activity in the arterial line of an extracorporeal circuit. No differences in embolic activity were observed when either 100% N2 or 95% Oz-5% C02 gases were swept through a bubble oxygenator. Information is presented suggesting that nitrogen or air micro emboli are more deleterious than oxygen or carbogen microemboli. Consequently, this article recommends that the use of compressed air or nitrogen should be contraindicated in bubble oxygenators. Since the cardiotomy suction is a major source of nitrogen microemboli, this article also emphasizes that the cardiotomy suction be minimized and that a pressurized cardiotomy return be prevented from directly entering the oxygenator.