Original Article

An In Vitro Comparison of Gas Transfer and Pressure Drop of the Bentley Duraflo Coated Spiral Gold and the Medtronic Carmeda Coated Maxima Hollow Fiber Membrane Oxygenators

Division of Cardiothoracic Surgery, Department of Surgery, University of Washington, Seattle, Washington

^* Address correspondence to: Craig Vocelka, BA, CCP, Chief Perfusionist, Division of Cardiothoracic Surgery, University of Washington, AA115, Box 356310, Seattle, WA 98195-6310

Abstract

Two models of heparin coated, hollow fiber membrane oxygenators were tested in vitro to compare gas transfer and transoxygenator pressure drop using an established protocol. Oxygen and carbon dioxide transfer rates were measured at blood flows of 2.5 and 5.0 liters per minute with gas flow : blood flow ratios of 1:1 and 2:1 at both blood flows. All testing was performed under normothermic conditions. The data shows that oxygen transfer increases as blood flow is increased in both oxygenators. Similarly, carbon dioxide transfer is increased by both increased blood and gas flows. Finally, the pressure drop was dependent on blood flow rate alone. This study demonstrated these two oxygenators to be comparable in both oxygen and carbon dioxide transfer and also in transoxygenator pressure drop.