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 t hat 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/k g or placebo. Blood samples for endotoxin measurement were drawn simultaneo usly from the superior and inferior venae cavae before heparin administrati on, 5 and 50 minutes after the onset of bypass, 5 minutes after aortic decl amping, at the end of I,a pass, and 1, 2, and 20 hours after the end of car diopulmonary bypass. Results: The perioperative variables in the tyro group s were similar. Blood endotoxin levels were higher in the inferior vena cav a than in the superior vena cava immediately after the onset of bypass. End otoxin levels in inferior vena cava blood were significantly lower in stero id-pretreated patients than those in patients not receiving steroids. Concl usions: Endotoxin is released during cardiopulmonary bypass from the region drained by the inferior vena cava, Steroid pretreatment mag actually reduc e endotoxin release during bypass.