Comparison of Neostigmine-Atropine Administration Methods for Hemodynamic Parameters in Patients Undergoing Elective Surgery: A Randomized Control Trial

Abstract

Objective: The aim of this study is to compare the hemodynamic effects of neostigmine-atropine in the reversal of muscle relaxants when administered either sequentially or simultaneously. Methods: Patients undergoing noncardiac surgery were recruited and randomly allocated to either a sequential or a simultaneous administration of neostigmine (0.04 mg kg^−1) and atropine (0.02 mg kg−1) at the end of surgery. Sequential group (SEQ group): Neostigmine and 1/3 dose of atropine were administered first minute, followed by another 2/3 dose of atropine 3 minutes later. Simultaneous group (SIM group): Neostigmine and atropine mixture was finished in 4 minutes. The primary outcome was the area under the curve (AUC) of the heart rate difference within 15 minutes of administration. The secondary outcome was the heart rate at each time point and the heart rate difference. Results: The AUC of heart rate difference within 15 minutes after administration in the SEQ group was 13.05±9.57 versus 43.56±10.54 in the SIM group (P<0.05). SIM group had a significantly lower heart rate when compared to SEQ group at 9, 10, 11, 12, 13, 14, and 15 minutes after administration (P<0.05). Heart rate difference was significantly smaller at 9, 10, 11, 12, 13, 14, and 15 minutes after administration in the SEQ group (P<0.05). Conclusion: Sequential administration, when atropine was administered later, induced smaller heart rate variability. Atropine and neostigmine should be administered in this order: neostigmine combined with small doses of atropine was administered first, followed by the remaining atropine.