Atropine with neostigmine impaired baroreflex sensitivity (7.12 vs 12.71 ms/mm Hg, P=0.022) and high-frequency heart rate variability (280.8 vs 569.2 ms2/Hz, P=0.015) at 2 hours compared to placebo.
RCT (n=30)
Double-blind
Do anticholinergic drugs with neostigmine (atropine or glycopyrrolate) impair parasympathetic control of heart rate compared to placebo in ASA I and II patients undergoing minor surgery?
Anticholinergic drugs with neostigmine (especially atropine) impair parasympathetic control of heart rate into the early postoperative period, suggesting glycopyrrolate may be preferable for patients at risk of cardiovascular complications.
Absolute Event Rate: 7.12% vs 12.71%
p-value: p=0.022
Impaired parasympathetic control of heart rate is associated with increased incidence of cardiac dysrhythmias and ischemia. Anticholinergic drugs suppress parasympathetic control and could be detrimental in the early postoperative period in high-risk patients. In this double-blind randomized trial, 30 ASA physical status I and II patients undergoing minor surgery received either atropine 20 micrograms/kg and neostigmine 50 micrograms/kg (Group A), glycopyrrolate 8 micrograms/kg and neostigmine 50 micrograms/kg (Group G), or placebo (Group P) for reversal of neuromuscular blockade. Two indices of parasympathetic modulation of heart rate, spontaneous baroreflex sensitivity, and high-frequency heart rate variability, were assessed. At 2 h after reversal, Group A showed persisting impairment of baroreflex sensitivity with respect to Group P (7.12 +/- 0.86 vs 12.71 +/- 1.38 ms/mm Hg, P = 0.022) as well as decreased high-frequency heart rate variability (280.8 +/- 30.1 vs 569.2 +/- 115.2 ms2/Hz, P = 0.015). Groups A and G showed a borderline decrease in normalized high-frequency variability at 2 h (P = 0.05 for Groups A and G versus Group P). Anticholinergic drugs with neostigmine cause impairment of parasympathetic control of heart rate which persists into the early postoperative period. The effects of glycopyrrolate appear to be of shorter duration; this drug may thus be preferable in patients at risk of cardiovascular complications.
Vlymen et al. (Wed,) conducted a rct in ASA physical status I and II patients undergoing minor surgery (n=30). Atropine and neostigmine OR glycopyrrolate and neostigmine vs. Placebo was evaluated on Spontaneous baroreflex sensitivity at 2 hours after reversal (p=0.022). Atropine with neostigmine impaired baroreflex sensitivity (7.12 vs 12.71 ms/mm Hg, P=0.022) and high-frequency heart rate variability (280.8 vs 569.2 ms2/Hz, P=0.015) at 2 hours compared to placebo.