Evaluation of Quadrox-i® Adult Hollow Fiber Oxygenator with Integrated Arterial Filter

Gaseous microemboli (GME) remain a challenge for cardiopulmonary bypass procedures in adult as well as pediat- ric cardiac surgery patients. The present study tested the effec- tiveness of a new adult membrane oxygenator in models both with and without an integrated arterial filter to evaluate GME trapping capability and determine membrane pressure drops at various flow rates and temperatures. The experimental circuit included a RotaFlow centrifugal blood pump, Quadrox-i ® ( n = 8) or Quadrox ® ( n = 8) adult microporous membrane oxygen- ator, and Sorin adult tubing package. A Sorin Cardiovascular ® VVR ® 4000i venous reservoir served as pseudo-patient. The circuit was primed with 900 mL heparinized human red blood cells and 300 mL Lactated Ringer's solution. The final hema- tocrit was 36%. Tests were performed at different flow rates (4 L/min, 5 L/min, and 6 L/min) and temperatures (35° and 30°). Five mL of bolus air was injected into the venous line over 15 seconds using a syringe connected to a 3/8 × 1/2 luer con- nector. The Quadrox-i ® adult microporous membrane oxygen- ator with integrated arterial filter had a similar pressure drop at 4 L/min and 35°C compared with Quadrox ® membrane oxygen- ator whereas it had higher pressure drops at 5 L/min and 6 L/min ( p < .001). Quadrox-i ® adult microporous membrane oxygenator reduced the total emboli count and total emboli volume deliv- ered to the pseudo-patient at all flow rates ( p < .001). The emboli handling of Quadrox-i ® adult microporous membrane oxygen- ator was not affected by flow rate and temperature. Compared with the traditional Quadrox ® oxygenator, Quadrox-i ® adult microporous membrane oxygenator with integrated arterial fil- ter and Softline coating has improved GME handling capacity. Keywords: gaseous microemboli , membrane oxygenator , inte- grated arterial filter , cardiopulmonary bypass , neurological com- plication. JECT. 2010;42:134-138