Comparison of Kinemyography and Electromyography during Spontaneous Recovery from Non-Depolarising Neuromuscular Blockade

Abstract

This study compared two commercially available quantitative neuromuscular function monitoring techniques, kinemyography (KMG) and electromyography (EMG), to assess whether KMG could be used interchangeably with EMG to exclude residual neuromuscular blockade (RNMB). Train-of-four (TOF) ratios were recorded every 20 seconds using KMG at the adductor pollicis and EMG at the first dorsal interosseous of the same hand during spontaneous recovery from shallow neuromuscular blockade. TOF ratios were compared using Bland–Altman analysis for repeated measurements. The precision of each device was assessed by the repeatability coefficient. Agreement between devices was assessed by the bias and limits of agreement. Clinically acceptable agreement was defined as a bias <0.025 within limits of agreement ±0.05. We recorded 629 sets of TOF ratios from 23 patients. The repeatability coefficient for KMG was 0.05 (95% confidence interval [CI] 0.05 to 0.06) and for EMG 0.10 (95% CI 0.10 to 0.11). Overall, the bias of KMG TOF ratios against EMG TOF ratios was 0.11 (95% CI 0.10 to 0.12), with limits of agreement −0.11 to 0.32. In the 0.80 to 0.99 TOF range, the bias was 0.08 (95% CI 0.06 to 0.09) and the limits of agreement were-0.12 to 0.27. Overall, TOF ratios measured by KMG were on average 0.11 higher than EMG. In the 0.80 to 0.99 TOF range, KMG TOF ratios were 0.08 higher. EMG and KMG are not interchangeable because the bias is large and the limits of agreement are wide. Thus a maximum TOF ratio of 1.0 on KMG may not exclude RNMB.

Intraoperative Monitoring of Neuromuscular Blockade

“…Most of these monitors available commercially are in agreement with each other on values near 90% TOFR but are usually in important disagreement for the onset of neuromuscular blockade and shallow blocks [ 47 , 48 , 49 , 50 ].…”

Quantitative Neuromuscular Monitoring and Postoperative Outcomes: A Narrative Review

“…Although kinemyography has been used in clinical studies, its ability to accurately quantify the degree of neuromuscular blockade (correlation with mechanomyography) has been questioned. [35][36][37] Other limitations include the availability of only one sensor size for all adults, and one sensor size for all pediatric patients.…”