The capability of trapping gaseous microemboli of two pediatric arterial filters with pulsatile and nonpulsatile flow in a simulated infant CPB model.

The study objective was to test the capability of Medtronic Affinity and Terumo Capiox pediatric arterial filters to trap gaseous microemboli in a simulated infant cardiopulmonary bypass (CPB) model. The filters were used in parallel pattern. The circuit was primed with lactated ringer's solution (700 ml) and postfilter pressure was maintained at 100 mm Hg using a Hoffman clamp. Trials were conducted at flow rates ranging from 500 to 1,250 ml/min. After introducing 20 ml air into the venous line via an 18-G needle, 2-minute segments of data were recorded. This entire process was repeated 6 times for each unique combination of arterial filter, flow rate and perfusion mode, yielding a total of 96 experiments. More than 80% of gaseous microemboli were trapped by the two pediatric arterial filters. With increased flow rates and pulsatile mode, more gaseous microemboli passed through the arterial filters. There were no differences in terms of the percentage of gaseous microemboli trapped and pressure drops between Medtronic Affinity and Terumo Capiox pediatric arterial filters. Results demonstrated that Medtronic Affinity and Terumo Capiox pediatric arterial filters could trap the majority of gaseous microemboli in this particular setting of an open arterial filter purge line in a simulated infant CPB circuit with pulsatile and nonpulsatile flow.