Tomoki Nishiyama.
Effects of nicardipine versus diltiazem on catecholamine secretion and reninangiotensin-aldosterone system during isoflurane anesthesia.
Anesth Pain Intens Care Jan ;18(4):332-7.

Background: Nicardipine and diltiazem might have different actions on hemodynamics, catecholamine secretion and hormonal response during anesthesia. However, there have been no studies to compare these effects between nicardipine and diltiazem during general anesthesia. The present study was performed to compare the effects on hemodynamics, catecholamine secretion and hormonal response between nicardipine and diltiazem in isoflurane anesthesia. Methodology: Twenty patients who received resection of brain tumor were divided into two groups Anesthesia was induced with thiopental and fentanyl. Anesthesia was maintained with isoflurane 0.5 to 1.5% and 67% nitrous oxide in oxygen. After microsurgical procedure started and when hemodynamics were stable, nicardipine 1 mg or diltiazem 10 mg were administered in one minute. Blood pressure, heart rate, and plasma concentrations of epinephrine, norepinephrine, angiotensin I and II, aldosterone, and renin activity were measured for 30 min. During the study period, isoflurane concentration was kept constant. Results: Blood pressure decreased significantly in one minutes in both groups, and the decrease continued for 10 min in the nicardipine group and for 30 min (study periods) in the diltiazem group. Heart rate significantly increased at 1 to 10 min in the nicardipine group and decreased at 5 to 30 min in the diltiazem group. Blood pressure and heart rate were significantly lower in the diltiazem group at 5 to 30 min. Plasma epinephrine and norepinephrine concentrations increased significantly in the nicardipine group but did not change in the diltiazem group, and significantly lower at 10 to 30 min in the diltiazem group. Plasma renin activity and concentrations of angiotensin I and II, and aldosterone did not change and had no differences between the groups. Conclusion: To decrease blood pressure in isoflurane anesthesia, nicardipine should be used when sympathetic activation is favorable, while diltiazem should be used to decrease heart rate without increase of sympathetic activity.

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