Correlation of Train Of Four with Frontal EMG measured by Patient State Index monitor in extubation phase of general anesthesia

Abstract

Aim: The routine use of processed electroencephalography (EEG) monitoring (like Patient State Index-PSI) and train of four (TOF) monitors is recommended for patients under general anesthesia. The aim of our study is to examine the correlation of the frontal electromyography (EMG) parameter, which can evaluate muscle strength in PSI monitoring, with the measured TOF value, so that both muscle strength and anesthetic depth can be evaluated with a single monitoring technique.
 Materials and methods: One hundred patients aged 18-65 years old, American Society of Anesthesiologists risk score (ASA) I-III who underwent general anesthesia that lasted more than 1 hour were included in our study. Following the end of the procedure, PSI and EMG values were recorded at TOF of 0%, 25%, 50%, 75% and 90% time points. When TOF was 90%, patients were extubated. Final measurements for TOF, PSI and EMG were recorded 5 minutes after extubation. 
 Results: A strong positive relationship was found both between TOF and PSI (r=0.74 p