The effect of beta2adrenergic blockade on serum potassium and glucose levels during open heart surger

Abstract

Changes in serum potassium and glucose levels during cardiopuimonary bypass were studied in 20 ± patients undergoing coronary artery bypass surgery. Ten had previously been treated with propranolol and 10 with metoprolol using mean daily dosages of 244 and 215 mg respectively. In the propranolol group there was a mean rise in serum potassium of l.13 mmol7/l (P= <0.01) whereas there was no significant. change in the metoprolol group. In both groups there was an initial rise in blood glucose which remained elevated in the propranolol group but fell towards normal in the metoprolol group. Metabolic changes due to beta1 adrenergic blockade are not generally recognized but may have profound clinical significance in some patients.