Minimum Alveolar Concentration-Awake of Sevoflurane is Decreased in Patients with Parkinson’s Disease: An Up-and-Down Sequential Allocation Trial

Abstract

Background

An increasing number of patients with Parkinson’s disease (PD) will have surgery under general anesthesia. A previous study demonstrated that propofol requirement for inducing unconsciousness in PD patients was lower than that in non-PD (NPD) patients. However, the requirement of inhaled anesthetics in PD patients has not been clarified. The aim of this study was to investigate the minimum alveolar concentration-awake (MAC_awake) of sevoflurane in patients with PD compared to NPD patients.

Patients and Methods

The current study is an up-and-down sequential allocation trial. The initial end-tidal concentration of sevoflurane (CETsevo) was estimated by the response of the previous patient to verbal command using the Dixon’s up-and-down method. The first patient in each group received CETsevo at 1%, and the step size between patients was 0.2%.

Results

Forty-one patients including 20 PD patients and 21 NPD patients were enrolled. Patients’ characteristics and arterial blood gas parameters (except blood sodium) were comparable between two groups. The MAC_awake of sevoflurane estimated by the Dixon’s up-and-down method in PD patients (0.47% ± 0.08% [Mean ± S.D.]) was significantly lower than that in NDP patients (0.64% ± 0.10%) (P=0.003). The estimated difference in means was 0.17% (95% CI, 0.10–0.24%). Probit analysis showed that the MAC_awake of sevoflurane in PD and NPD patients was 0.49% (95% CI, 0.42–0.57%) and 0.67% (95% CI, 0.59–0.76%), respectively. The relative median potency was 0.73 (95% CI, 0.38–0.94).

Conclusion

Patients with PD exhibit a significantly lower MAC_awake of sevoflurane compared with NPD patients. Clinicians should avoid an overdose of sevoflurane in patients with PD.

Trial Registration

Registered at ChiCTR1900026956.

Keywords:

• Parkinson’s disease
• sevoflurane
• the minimum alveolar concentration-awake

Acknowledgment

The authors thank Yun Wu, M.D., from the Department of Anesthesiology, Second Affiliated Hospital of Anhui Medical University, for her helpful comments regarding the anesthesia induction.

Data Sharing Statement

The data supporting this study are available from the corresponding author for a reasonable request.

Ethics Approval

The current study was conducted in accordance with the Declaration of Helsinki and approved by the Medical Research Ethic Committee of Anhui Provincial Hospital (2019KY111).

Disclosure

The authors declare that they have no conflicts of interest.