A comparison of the effect of atropine 0.75 mg and glycopyrrolate 0.5 mg combined with neostigmine 2.5 mg on heart rate after reversal of non-depolarized muscle relaxant

Abstract

Background : Neostigmine  was recommended to reverse effect of non-depolarized muscle relaxant at the end of general anesthesia. To reduce muscarinic effect from neostigmine, atropine 1.2 mg is preferred in most case, however high dose atropine may caused seriouse tachyarrhythmia. Gyclopyrrolate was recently  introduced to Thailand to minimize tachyarrhythmia and muscarinic effect from neostigmine. Anyway glyclopyrrolate was not available in most hospital in Thailand and it’s expensive.

Objectives : Primary objective is to compare different heart after reversal non-depolarized muscle relaxant with atropine 0.75 mg and glycopyrrolate 0.5 mg mixed with neostigmine and secondary objective are to compare amount of secretion, incidence of bradyarrhythmia and blood pressure in both groups.

Method : Prospective randomized double blind control trial was conducted in 60 patients at age of 18 to 64 years old who underwent elective surgery and received balanced general anesthesia technique with endotracheal tube. Patients were randomly divided into 2 groups to receive atropine 0.75 mg or glycopyrrolate 0.5 mg mixed with neostigmine 2.5 mg for reversal muscle relaxant at the end of surgery.

Heart rate  and blood pressure were recorded before reversal then every 1 minute for 10 minute  and every 5 minute until 60 minute of observation

Result : Difference mean heart rate in atropine 0.75 mg group were less than glycopyrrolate 0.5 mg  group at 2^nd, 3^rd, 5^th, 6^th, 7^th, 8^th , 9^th, 10^th, 15^th, 20^th, 25^th, 30^th and 40^thminute significantly (p<0.05). Maximum increment of heart rate of 5.21% and 20.67% from baseline in atropine 0.75 mg and glycopyorrolate 0.5 mg group,  respectively. Three cases in atropine  and two cases in glycopyorrolate  group got bradycardia (heart rate < 50 bpm).  Secretion score and blood pressure both groups were not significantly different.(p > 0.05)

Conclusion :  Atropine 0.75 mg mixed with neostigmine 2.5 mg is as safe as glycopyrrolate  for reversal non-depolarized muscle relaxant. It can be used as alterative choice in case of high risk  cardiovascular patients and glycopyrrolate is not available.

Keywords : atropine 0.75 mg, glycopyrrolate, reversal, non-depolarized muscle relaxant, heart rate