Transpulmonary polymorphonuclear leukocyte number after cardiopulmonary bypass

Polymorphonuclear leukocyte (PMN) numbers were determined in samples of central venous or pulmonary artery blood and in simultaneously drawn samples of systemic arterial blood 5 min before institution of cardiopulmonary bypass (CPB) and 5 min after the termination of CPB in 10 adult patients. In only 2 of 10 patients was the systemic arterial PMN number lower than that in central venous or pulmonary arterial blood in the post-CPB period. The results suggest that intrapulmonary PMN sequestration, reported to be a frequent consequence of complement activation during CPB, is a transient and self-limited phenomenon in most persons.