Relationship Between Respiratory Distress and Cytokine Response after Cardiopulmonary Bypass

Abstract

The influence of cytokines on the inflammatory response in surgery has recently been the subject of investigations. We measured tumor necrotic factorga (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), and granulocyte elastase (GEL) in 26 patients undergoing elective cardiac operations using cardiopulmonary bypass (CPB), preoperatively, immediately after CPB, and on postoperative days (PODs) 1, 3, and 6. To evaluate the effect of these cytokines on pulmonary function, the patients were divided according to whether the oxygenation index (OI) on POD I was > 250 or < 250, into groups A and B, respectively. TNF-α and IL-1 β were undetectable and there were no significant differences in the preoperative IL-6, IL-8, and GEL levels. However, immediately following CPB, the mean IL-6, IL-8 and GEL levels in both groups were significantly higher than the preoperative levels (P < 0.01). Moreover, all these levels were significantly higher in group B than in group A, at 162 ± 150 pg/mlvs 64 ± 53 pg/ml (P < 0.05) for IL-6; 53 ± pg/mlvs 22 ± 20 pg/ml (P < 0.01) for IL-8; and 2477 ± 1642 mg/1vs 1397 ± 774 mg/l (P < 0.01) for GEL. The IL-6 levels returned to the preoperative values in both groups on POD 1; however, the GEL levels remained significantly higher in group B than in group A postoperatively, at 616 ± 326 mg/lvs 378 ± 70 mg/l on POD 1, and at 292 ± 70 mg/lvs 218 ± 62 mg/1 on POD 3 (P < 0.05). Thus high levels of cytokines such as IL-6, IL-8, and GEL may be detrimental to respiratory function.