Safety of Wet-Primed Cardiopulmonary Bypass Circuits during prolonged standby

Umpaipan Thana, TANYONG PIPANMEKAPORN, THITIPONG TEPSUWAN, JARIN PHIROMPAKSAR, NIRAMOL BALCHON

CHIANG MAI UNIVERSITY, CHIANG MAI, Thailand

Date, time and location: 2018.05.26 15:30, Press Hall, 2F

Abstract

Background: The immediate establishment of cardiopulmonary bypass (CPB) is a critical step in emergency cardiac surgery. A pre-assembled CPB circuit is sometimes necessary in order to shorten the time. Only a few studies have tested the sterility of CPB circuits in a clinical environment. This lack of evidence means many cardiac surgeons are still reluctant to use them. The purpose of this study is to determine safety periods regarding sterility in wet-primed CPB circuits under normal conditions in an operating room environment.

Method: Experimental CPB circuits are assembled under routine clinical conditions and primed with 2000 ml of Acetate Ringer’s solution. The sterility of 9 pre-assembled CPB circuits were studied for 168 h. Three circuits were assembled and stored uncovered in one corner of the OR which was used for routine cardiac surgery.  Six circuits were assembled and stored in the perfusionist office. They were left unattended and were uncovered. The priming solution was continuously recirculated in the experimental CPB circuits. Fifty ml of circulating fluid were collected at the sampling port under aseptic conditions in order to test for microbial growth every 0, 24, 48, 72, 96, 120, 144 and 168 h. The membrane filter method was used to identify any microbial growth.

Result: Microbiology of all samples from both groups were negative at every time period apart from the occurrence of Bacillus species in two samples from the equipment held in the perfusionist office at 96 h. However they were considered as contamination as further samples (after  96 h) were negative

Conclusion: The sterility of wet-primed CPB circuits could be maintained for up to 168 h. The strategy to have primed circuits available could be beneficial in emergency situations without extra expense.