Corticosteroid effect on down regulation in beta adrenergic receptors

Corticosteroid effect on early beta-adrenergic down-regulation during circulatory shock: hemodynamic study and beta-adrenergic receptor assay

OBJECTIVES

The steroid effect on critically ill patients remains controversial. The aim of this study is to characterize the effect of methylprednisolone on the heart in a beta-adrenergically down-regulated condition.

DESIGN

A prospective hemodynamic study and retrospective receptor assay.

SETTING

Multidisciplinary ICU in a university hospital.

SUBJECTS

42 patients who required pulmonary arterial catheters and an additional 4 corpses who were available for study within 3 h of their deaths.

INTERVENTION

Intravenous methylprednisolone (10 mg/kg).

MEASUREMENTS AND RESULTS

We pursued a hemodynamic study following a glucocorticoid administration. In patients who had undergone a long term (> 72 h) catecholamine treatment, the cardiac index increased. In patients who had undergone a short term (1-72 h) catecholamine treatment and in patients with no record of catecholamine administration, the cardiac index showed no remarkable change. Among the corpses, who died soon after their arrival, and the patients, who later died in the ward and were available for further study, we measured beta-adrenergic receptor density in the left ventricular myocardium. It was found that receptor density was decreased after long term catecholamine treatment. Methylprednisolone, on the other hand increased the receptor density.

CONCLUSION

Methylprednisolone improved the cardiac index, intriguingly, in patients with long term catecholamine treatment in circulatory shock. Myocardial beta-adrenergic receptor also increased in number after the administration of methylprednisolone. However, the hemodynamic improvement caused by methylprednisolone was not observed in patients without beta-adrenergic down-regulation.