Effects of sevoflurane on QT dispersion and heart rate variability

Effects of Neostigmine and Sugammadex for Reversal of Neuromuscular Blockade on QT Dispersion Under Propofol Anesthesia: A Randomized Controlled Trial

Introduction

Reversal of non-depolarizing neuromuscular blocking agent neostigmine is associated with QT prolongation under general anesthesia. To clarify the effects of neostigmine and sugammadex on hemodynamic status, the QT interval and QT dispersion after reversal of neuromuscular blockade were evaluated with a 12-lead electrocardiogram. To exclude QT prolongation due to sevoflurane, the present study was performed under propofol anesthesia.

Methods

After receiving approval from the ethics committee of Dokkyo Medical University Hospital, 40 patients with American Society of Anesthesiologists physical status I or II were randomly allocated to group N (n = 20) or group S (n = 20). Group N was administered neostigmine (40 μg/kg) and atropine (20 μg/kg), while Group S was administered sugammadex (4 mg/kg) for reversal of neuromuscular blockade after surgery. The changes in RR interval, QT interval (QT), corrected QT interval (QTc), QT dispersion (QTD), and corrected QT dispersion (QTcD) before and after administration of reversal agents were recorded using computerized measurements. Statistical analysis was performed using two-way analysis of variance.

Results

The RR interval significantly decreased after reversal of the neuromuscular blockade in group N, compared with group S (p < 0.05). Compared with group S, the QT decreased, whereas QTc and QTcD increased, in group N (p < 0.05). Sugammadex was not found to alter QT, QTc, QTD, or QTcD throughout the study.

Conclusion

In the present study, a mixture of neostigmine and atropine, but not sugammadex, increased QTc and QTcD under propofol anesthesia. Thus, neostigmine may cause electrocardiogram abnormalities that could precede the development of fatal arrhythmias.

Anesthesia induction with sevoflurane and propofol: evaluation of P-wave dispersion, QT and corrected QT intervals

The present study compared the effects of anesthesia induction with sevoflurane and propofol on hemodynamics, P-wave dispersion (Pwd), QT interval and corrected QT (QTc) interval. A total of 72 adult patients were included in this prospective study. All patients had control electrocardiograms (ECGs) before anesthesia induction. Anesthesia was induced with sevoflurane inhalation or intravenous propofol. Electrocardiography for all patients was performed during the 1(st) and 3(rd) minutes of induction, 3 minutes after administration of muscle relaxant, and at 5 minutes and 10 minutes after intubation. Pwd and QT intervals were measured on all ECGs. QTc intervals were determined using the Bazett formula. There was no significant difference in Pwd and QT and QTc intervals on control ECGs. In the sevoflurane group, except for control ECGs, Pwd and QTc interval on all ECGs were significantly longer than those in the propofol group (p < 0.05). We conclude that propofol should be used for anesthesia induction in patients with a predisposition to preoperative arrhythmias, and in those whose Pwd and QTc durations are prolonged on preoperative ECGs.