Tissue injury and the inflammatory response to pediatric cardiac surgery with cardiopulmonary bypass - A descriptive study

Background: There are few detailed descriptions of the inflammatory response to cardiac surgery with cardiopulmonary bypass (CPB) in children beyond 24 h postoperatively. This is especially true for the antiinflammatory cytokines and the extent of tissue injury. The aim of the current study was to describe the inflammatory and injury responses in uncomplicated pediatric cardiac surgery with CPB, where methylprednisolone and modified ultrafiltration (MUF) were used. Methods: Blood samples were collected up to 48 h postoperatively. Cytokines (tumor necrosis factor-alpha and interleukin-6, -1 beta -10, and -1ra), complement (C3d and C4d) and coagulation system (prothrombin activation fragments 1 and 2 and anti-thrombin III) activation, neutrophil elastase, and the resulting tissue injury (creatine kinase, lactate dehydrogenase, alanine transaminase, amylase, and gamma -glutamyl transferase) were measured. Results: The proinflammatory cytokine release varied widely, in contrast to a clear-cut antiinflammatory response. Cytokine concentrations did not decrease immediately after MUF, and no rebound increases later in the postoperative period were observed. The coagulation system, but not complement, was activated. There was a late release of C-reactive protein. Tissue injury could be quantified biochemically without evidence of hepatic or pancreatic dysfunction. Conclusion: In this group of uncomplicated subjects, the antiinflammatory cytokine and tissue injury responses were well defined, in contrast to a variable proinflammatory cytokine release. This was accompanied by activation of the coagulation system but not of complement. Concentrations of inflammatory mediators did not decrease immediately after MUF, and there was no evidence for rebound release later in the postoperative period.