Effect of pre-treatment with intravenous atropine or glycopyrrolate on cardiac arrhythmias during halothane anaesthesia for adenoidectomy in children

We studied the effect of anticholinergics on the incidence of cardiac arrhythmias during paediatric anaesthesia. ASA I-II children (n = 77) undergoing adenoidectomy were randomly allocated to three groups. Intravenous atropine 0.02 mg kg-1 was given in group A (n = 25), glycopyrrolate 0.004 mg kg-1 in group G (n = 27) and physiological saline in group P (n = 25) 3 min before the induction of anaesthesia. The children breathed spontaneously under halothane anaesthesia with 66% nitrous oxide in oxygen after induction with thiopentone and succinylcholine. Perioperative monitoring of the ECG (Holter recordings) and oxygen saturation was carried out. Ventricular tachycardia occurred in 16.0%, 18.5% and 12.0% of the children in groups A, G and P respectively (ns). The incidence of ventricular arrhythmias (ventricular tachycardia, ventricular bigeminy, ventricular premature beats > 10) was 20.0% in group A, 44.4% in group G and 36.0% in group P (ns). Bradycardia (< 70 beats min-1) was observed in 0.0%, 14.8% and 24.0% of patients in groups A, G and P respectively (A vs P, P < 0.05). The use of anticholinergics did not influence the incidence of ventricular arrhythmias during halothane anaesthesia in children. Bradycardia was more common in the placebo group than in the atropine group.