Comparative effects of intravenous and intra-arterial methylprednisolone in cardiogenic shock

This study was undertaken to determine if a portion of intravenously administered methylprednisolone sodium succinate (MPSS) might be metabolized by the lung during cardiogenic shock. With plastic microsphere coronary artery embolization, myocardial infarction and shock were produced in mongrel dogs. Animals were assigned to control, intra-arterial MPSS, and intravenous MPSS groups, with the treated dogs receiving 30 mg/kg of MPSS 15 minutes after infarction. Compared to control animals, the group receiving intra-arterial MPSS had significantly higher mean blood pressure, cardiac index, and blood glucose levels and a lower peripheral resistance during shock. Compared with the intravenous MPSS group, dogs treated with intra-arterial MPSS had significantly lower peripheral resistance and a nearly significantly higher cardiac index. Permanent survival rates were 26% in the control group, 60% in the intravenous MPSS group, and 50% in the intra-arterial MPSS group. Although treatment with intra-arterial MPSS was associated with a better hemodynamic profile than that following intravenous MPSS (suggesting the possibility of corticosteroid metabolism by the lung), survival was not enhanced. It was concluded that functionally insignificant amounts of corticosteroids given intravenously might be inactivated by the lung. Hence, intravenous MPSS injection is a practical and adequate means of administering this valuable agent in cardiogenic shock.