An in vitro study of the effectiveness of carbon dioxide flushing of arterial line filters

Abstract

Gaseous microemboli (GMEs) have been connected to neurologic impairment and other ischemic complications after surgery. The components of the extracorporeal circuit (ECC) have a large influence on GME production. This in vitro study investigates the use of carbon dioxide flushing of the 38-μm Medtronic Affinity CB351 and 38-μm Medtronic Affinity 351 arterial line filters (ALFs) to decrease GMEs and time for air to clear the ALF. An adult circuit was implemented with a silicone oxygenator for vacuum-assisted gas removal and to reduce air before ALF. The 48 filters were separated into four equal groups: flushed coated and non-coated and non-flushed coated and noncoated. Carbon dioxide flushing was performed at 6 L/min for 3 minutes. ALFs were retrograde primed at 200 mL/min. An Emboli Detection and Classification Quantifier (EDAC) was used to gather data. The average total emboli and time to clear (seconds) for flush coated were 20.25 ± 16.78 and 142.17 ± 174.80 seconds, respectively, flushed non-coated were 30.5 ± 34.65 and 124.17 ± 131.40 seconds, non-flushed coated were 162.08 ± 79.90 and 390.42 ± 84.36 seconds, and non-flushed non-coated were 163.67 ± 212.67 and 305.92 ± 179.36 seconds. Flushed filters had an average total emboli count of 25.375 ± 27.14 and an average time to clear of 133.167 ± 151.51 seconds. Non-flushed filters had an average total emboli count of 162.875 ± 157.11 and an average time to clear of 348.167 ± 143.70 seconds. Coated and non-coated filters for total emboli and time to clear had p values of.86 and.24, respectively. Flushed and non-flushed filters had total emboli and time to clear p values of