Some inflammation-related parameters in patients following normo- and hypothermic Cardio-Pulmonary Bypass

Aims: One of the complications of Cardio-Pulmonary Bypass is the Systemic I nflammatory Response Syndrome. Cardio-Pulmonary Bypass can be performed und er either normothermic or hypothermic conditions. The aim of this study was to compare some inflammation-related parameters of patients following norm othermic and hypothermic bypass. Moreover, attempts were undertaken to dete ct endotoxin, an inflammatory agent that has been implicated in the Systemi c Inflammatory Response Syndrome, in the serum of patients. Levels of serum anti-endotoxin antibodies were estimated since they have been reported to negate the effect of endotoxin in the inflammatory syndrome. Methods and Re sults: Seventeen normothermic and 20 hypothermic cases were studied. Blood specimens were collected pre-, off- and post-bypass. Pertinent clinical and surgical data were collected. Hematological parameters (leukocyte, neutrop hil and platelet counts) and liver function tests were determined by standa rd procedures. Endotoxin was determined by the Limulus Lysate Assay and ant i-endotoxin antibodies by an enzyme immunoassay. Complement (C3 and C4) lev els were determined by radial immunodiffusion. There were increases in leuk ocyte and neutrophil, and a decline in platelet numbers in both groups of p atients. There was a decline in C3 and C4 levels in both groups of patients . Endotoxin was not detected in sera, and anti-endotoxin antibody levels we re similar, in both groups of patients. Conclusion: There were no significa nt differences in most of the altered inflammation-related parameters betwe en the two groups of patients. Some of the findings might be partly due to hemo-dilution. The hydrophobic nature of endotoxin among other factors, mig ht have hindered its detection in serum.