Does steroid pretreatment increase endotoxin release during clinical cardiopulmonary bypass?

Objective: The mechanism involved in the endotoxemia frequently recognized during cardiopulmonary bypass remains unclear. It has also been suggested that endotoxin levels were higher in steroid-pretreated patients undergoing cardiopulmonary bypass. Methods: Twenty patients undergoing cardiopulmonary bypass were randomly pretreated with steroids (methylprednisolone, 30 mg/kg or placebo. Blood samples for endotoxin measurement were drawn simultaneously from the superior and inferior venae cavae before heparin administration, 5 and 50 minutes after the onset of bypass, 5 minutes after aortic declamping, at the end of I,a pass, and 1, 2, and 20 hours after the end of cardiopulmonary bypass. Results: The perioperative variables in the tyro groups were similar. Blood endotoxin levels were higher in the inferior vena cava than in the superior vena cava immediately after the onset of bypass. Endotoxin levels in inferior vena cava blood were significantly lower in steroid-pretreated patients than those in patients not receiving steroids. Conclusions: Endotoxin is released during cardiopulmonary bypass from the region drained by the inferior vena cava, Steroid pretreatment mag actually reduce endotoxin release during bypass.