Effects of diltiazem on renin-aldosterone and ACTH-adrenocortical function during upper abdominal surgery

Study Objective: To observe the effects of continuous intravenous infusion of diltiazem on the renin-aldosterone system and ACTH-adrenocortical axis responses during surgical stimulation.

Design: Randomized study of intravenous diltiazem.

Setting: Operating room at the Hyogo Medical College Hospital.

Patients: Twenty-three patients undergoing upper abdominal surgery were divided into two groups: the control group (n = 10) and the diltiazem group (n = 13). All the patients were without any complications and classified as ASA physical status I.

Interventions: Patients in the diltiazem group received an infusion of 10 μg/kg/ min for 90 to 120 minutes following skin incision.

Measurements and Main Results: Plasma adrenocorticotropic hormone, plasma aldosterone and cortisol concentrations, and plasma renin activity were determined with radioimmunoassay before the induction of anesthesia at 10, 30, 60, and 90 minutes after skin incision and at the end of anesthesia. Renin activity did not change significantly. Maximal increases in plasma adrenocorticotropic hormone, aldosterone, and cortisol observed 90 minutes after skin incision were 355 ± 95 pg/ml, 118 ± 30 pg/ml, and 14.2 ± 2.3 μg/dl in the control group versus 246 ± 41 pg/ml, 119 ± 25 pg/ml, and 15.0 ± 1.8 μg/dl in the diltiazem group, respectively, and there were no significant differences between these groups. Adrenocorticotropic hormone was significantly lower in the diltiazem group compared with that in the control group 60 minutes after the start of surgery (p < 0.05). There was marked natriuresis (40 ± 25 μEq/min vs 470 ± 147 μEq/min at the 90-minute mark) and diuresis (0.16 ± 0.13 ml/min vs. 2.53 ± 0.88 ml/min) in the diltiazen group.