Safety of wet-primed cardiopulmonary bypass circuits during extended standby

Abstract

Objectives To determine the period of sterility safety in wet-primed cardiopulmonary bypass (CPB) circuits under normal conditions during prolonged standby.

Methods Experimental CPB circuits were assembled under routine clinical conditions. The sterility of 9 pre-assembled CPB circuits was studied for a period of 168 hours. Three circuits were assembled and stored uncovered in the operating room and six circuits were assembled and stored in the perfusionist room. Priming solution was added and continuously recirculated in the experimental CPB circuits. Fifty milliliters of circulating fluid was collected at the sampling port under aseptic conditions to test for microbial growth after 0, 24, 48, 72, 96, 120, 144 and 168 hours.

Results The microbiology of all samples from both groups was negative throughout the study period with the exception of the occurrence of Bacillus species in two samples from the equipment in the perfusion room at 96 hours.  However, that was considered to be contamination because further samples after 96 hours were all negative.

Conclusions The sterility of wet-primed CPB circuits can be maintained for up to 168 hours. The strategy of having primed circuits available could be a benefit in emergency situations without extra expense.