Comparison of Bispectral Index and Patient State Index values according to recovery from moderate neuromuscular block under steady-state total intravenous anesthesia

Doyeon Kim,Gunyoung Heo,Ji Seon Jeong,Jin Hee Ahn

doi:10.1038/s41598-021-85419-8

Abstract

There were insufficient researches of the comparison between Bispectral Index (BIS) and Patient State Index (PSI) values during the recovery of moderate NMB. We investigated the response of these indices during neuromuscular blockade (NMB) reversal by sugammadex under steady-state total intravenous anesthesia (TIVA) using propofol/remifentanil. In this prospective, observational study, patients undergoing laparoscopic cholecystectomy were enrolled. At the end of surgery, after confirming that train-of-four (TOF) count as 1 or 2, we maintained a steady state (BIS value of 40–50). After administration of 2 mg kg−1 sugammadex, BIS, PSI, and electromyography (EMG) signal values were recorded at one-minute intervals for 10 min. The primary outcome was the difference between the changes in BIS and PSI from baseline to a TOF ratio (TOFR) of 90 after sugammadex administration in steady-state TIVA. A total of 48 patients completed this trial. There was no significant difference between the changes in BIS and PSI values from baseline to TOFR 90 (− 0.333 ± 4.955 vs. − 0.188 ± 4.616; 95% confidence interval [CI] − 2.095 to 1.803; p = 0.882). Both BIS-EMG and PSI-EMG values at baseline and TOFR 90 were not statistically different (95% CI − 0.550 to 1.092; p = 0.510, 95% CI − 1.569 to 0.527; p = 0.322, respectively). No patient experienced any complications. Changes in BIS and PSI values after NMB reversal during steady-state TIVA were not significantly different. Both BIS and PSI provide trustworthy values for monitoring anesthetic depth during NMB reversal under TIVA.Trial Registration: This study was registered in the Clinical Trial Registry of Korea (https://cris.nih.go.kr: KCT 0003805).

Highlights

Electroencephalogram (EEG)-based monitoring is currently conducted to determine the depth of anesthesia
Our results demonstrated that there was no difference between changes in Bispectral Index (BIS) and Patient State Index (PSI) values, and the recovery of moderate neuromuscular blockade (NMB) by sugammadex did not affect the BIS and PSI values
Considering that BIS and PSI values, which were concurrently collected alongside EEG recordings from each device, may be affected by EMG, the administration of NMB reversal agents has the potential to cause false changes in BIS or PSI values regardless of the anesthetic depth

Summary

Introduction

Electroencephalogram (EEG)-based monitoring is currently conducted to determine the depth of anesthesia. PSI assists in monitoring the depth of anesthesia derived from EEG power, frequency, and phase information[3]. Both BIS and PSI values detect a burst suppression and analyze the spectrum of EEG. According to the manufacturer’s instructions, the RD SedLine EEG sensor (Masimo Corp, Irvine, CA, USA) that provides PSI values is less disturbed by EMG relative to conventional EEG monitoring equipment. This is because this system extracts EEG signals through channels separate from EMG for calculating the PSI. The aim of the current study was to compare BIS and PSI values during recovery of moderate NMB under steady-state total intravenous anesthesia (TIVA)

Objectives

Methods

Results

Conclusion