Preoperative high dose methylprednisolone attenuates the cerebral response to deep hypothermic circulatory arrest

Objective: The aim of this study was to assess the effects of preoperative high dose methylprednisolone on cerebral recovery following a period of deep hypothermic circulatory arrest (DHCA). Methods: Sixteen 1-week-old piglets were randomized to placebo (n=8), or 30 mg/kg intramuscular methylprednisolone sodium succinate (MPRED) given at 8 and 2 h before induction of anaesthesia. All piglets underwent cardiopulmonary bypass, cooling to 18°C, 60 min of circulatory arrest followed by 60 min of reperfusion and rewarming. The radiolabelled microsphere method was used to determine the global and regional cerebral blood flow (CBF) and cerebral oxygen metabolism (CMRO₂) at baseline before DHCA and after 60 min of reperfusion. Results: In controls, mean global CBF (±1 standard error) before DHCA was 53.7±2.4 ml/100 g per min and fell to 23.8±1.2 ml/100 g per min following DHCA (P2 in controls fell from 3.9±0.2 ml/100 g per min before to 2.3±0.2 ml/100 g per min after DHCA (P=0.0001). This represents a post-DHCA recovery to 58.6±4.4% of the pre-DHCA value. In the MPRED group, however, recovery of global CMRO₂ post-DHCA was significantly higher at 77.9±7.1% of the pre-DHCA value (P=0.04). Conclusions: Treatment with high dose methylprednisolone at 8 and 2 h preoperatively attenuates the normal cerebral response to a period of deep hypothermic ischaemia. This technique may therefore offer a safe and inexpensive strategy for cerebral protection during repair of congenital heart defects with the use of DHCA. Copyright (C) 2000 Elsevier Science B.V.