Inflammatory reaction is the one of deteriorating causes of pulmonary function after cardiopulmonary bypass. And leukocytes play a major role in inflammatory reaction by producing cytotoxic oxygen free radicals, initiating complement cascade, and so on. We tested the hypothesis that reducing the circulating leukocyte by using leukocyte poor RBC(LPR) in priming solution, and low-dose aprotinin which reduces whole body inflammatory response can reduce inflammatory reaction and results in less release of cytokines and preserving better pulmonary function after cardiopulmonary bypass.

In a prospective, randomized study, 23 children undergoing open heart surgery were investigated. LPR was used in 8 patients(group 1), 8 patients received low-dose aprotinin(50,000 KIU per body weight in priming solution, group 2) and 7 patients were control group (group 3). Patients with complex heart diseases, body weight over 10kg, palliative surgery, and residual defect after surgery were excluded from this study. CBC, interleukin 6, and granulocyte elastase were analyzed after 60 minutes of cardiopulmonary bypass, and (A-a)DO₂(alveolar arterial oxygen difference) was measured postoperatively.

There was no statistically significant difference in interleukin 6 level, granulocyte elastase level, (A-a)DO₂, intubation period, mortality, pulmonary complication, and WBC count at postoperative 1st day.

Our results suggested that LPR in priming solution and low-dose aprotinin have little influence on the inflammatory reaction and pulmonary function deterioration caused by cardiopulmonary bypass. Although LPR in priming solution can reduce circulatory leukocyte, the leukocytes increase rapidly after initiation of cardiopulmonary bypass, so that reducing leukocytes by LPR use has little influence on the inflammatory reaction.