Methylprednisolone prior to cardiopulmonary bypass.

Patients undergoing cardiopulmonary bypass were randomly allocated to receive methylprednisolone 30 mg/kg in a single dose prior to bypass, or to a control group receiving saline. The effect of this treatment on 2,3-DPG and oxygen delivery to the tissues was determined. There was no difference between the groups in 2,3-DPG levels, P50 or oxygen availability, but the methylprednisolone group showed a highly significant difference in oxygen consumption immediately following cardiopulmonary bypass (p < 0.001) and a significant difference in serum phosphate levels in the immediate postoperative period (p < 0.05). Methylprednisolone levels were measured by radioimmunoassay, and these showed a rapid decline in the 4 hours following administration.