Predictive value of skin testing, neutrophil migration and C-reactive protein for postoperative infections in cardiopulmonary bypass patients.

Despite antibiotic cover for cardiac surgery the development of postoperative infection remains a feared complication. The present prospective study was designed to evaluate whether it is possible to identify preoperatively those individuals in whom the risk of a postoperative infection is significantly greater. Skin test response, chemotaxis and random migration of neutrophils, and serum levels of C-reactive protein (CRP) were chosen as indicators of host resistance. Pre-operatively and at defined postoperative time intervals, 80 patients undergoing open-heart surgery with the aid of cardiopulmonary bypass were examined. Of all the immunological variables measured in this study, the state of anergy proved the most reliable predictor of postoperative infection. Six of the nine pre-operatively anergic patients developed infections (P = 0.00026) representing one half of the postoperatively infected patients. No predictive role of CRP level or neutrophil chemotaxis can be derived from our data. The pre-operatively decreased random migration of polymorphonuclear leukocytes (PMN) from postoperatively infected patients, however, along with the significant defects in chemotactic and random PMN motility seen after cardiac surgery may partly explain the predisposition to bacterial infection in these patients. In conclusion, a pre-operative skin test makes a valuable contribution to the assessment of the patient's postoperative infectious risk.