Faculty Collaboration Database

Train-of-four ratio, counts and post tetanic counts with the Tetragraph electromyograph in comparison to mechanomyography. J Clin Monit Comput 2025 Feb;39(1):149-156

Date

10/19/2024

Pubmed ID

39424740

DOI

10.1007/s10877-024-01225-3

Scopus ID

2-s2.0-85207276056 (requires institutional sign-in at Scopus site)   2 Citations

Abstract

Automated EMG devices to detect compound muscle action potentials from the adductor pollicis muscle in response to ulnar nerve stimulation, regardless of hand and thumb position, may serve as a better reference ("gold standard") for clinical assessment of neuromuscular function than traditional mechanomyography (MMG) systems that need custom design and validation in lab settings. This evaluation compared the TetraGraph EMG system against a validated MMG device to investigate the accuracy and repeatability of this quantitative EMG monitor for detecting onset, offset and deep neuromuscular block. Simultaneous muscle action potential recordings from the EMG neuromuscular monitor and muscle contractions from an in-house developed MMG monitor in response to ulnar nerve stimulation were obtained from patients having elective surgery requiring neuromuscular block. Train-of-four (TOF) ratios, TOF counts, and post-tetanic counts (PTCs) were recorded simultaneously from the same hand muscle and compared. In total, 685 pairs of simultaneous TOF ratios were evaluated. The mean difference (bias) of TOF ratios between devices was small (- 2.1%). TOF counts from 285 data pairs were within a count of 2 or less 96% of the time. During deep block, PTC comparisons from 215 data pairs were within a count of 2 or less 95% of the time. These findings, along with prior EMG device evaluations, indicate that real-time EMG neuromuscular monitoring technology to detect muscle action potentials from the adductor pollicis in the clinical setting is closely aligned with the force of thumb contraction determined from MMG. The accuracy of quantitative EMG technology of the TetraGraph EMG system lends strong support for this monitor, along with other similarly validated EMG monitors, to become a clinical standard for all phases (onset, depth and reversal) of neuromuscular block in clinical practice.

Author List

Ebert TJ, Vogt JA, Kaur R, Iqbal Z, Peters DJ, Cummings CE, Stekiel TA

Author

Craig Elliott Cummings MD Assistant Professor in the Anesthesiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Action Potentials
Adult
Aged
Electric Stimulation
Electromyography
Female
Humans
Male
Middle Aged
Monitoring, Intraoperative
Muscle Contraction
Muscle, Skeletal
Myography
Neuromuscular Blockade
Neuromuscular Monitoring
Reproducibility of Results
Signal Processing, Computer-Assisted
Thumb
Ulnar Nerve