A single-centre, randomised comparison of the performance and safety of a novel mechanomyography sensor with...

Quantitative neuromuscular monitoring is crucial to ensure patient safety when using neuromuscular blocking agents. Although historically considered as the research standard for neuromuscular monitoring, currently, no certified mechanomyography device is available for routine clinical use. This study aimed to investigate noninferiority in precision of a newly developed mechanomyography (TOF^3D mechanosensor; MIPM, Mammendorf, Germany) compared with electromyography.

We conducted a prospective, interventional, single-centre agreement study comparing electromyography and mechanomyography in 33 anaesthetised adult patients. Devices were randomly installed on opposite arms. Train-of-four (TOF) ratios were measured beginning before administration of rocuronium 0.45 mg kg^-1 i.v. until spontaneous recovery and after additional administration of sugammadex 2 mg kg^-1 i.v. The primary endpoint was precision using the repeatability coefficient at baseline and full recovery. Precision of the TOF ratio measurement was assumed noninferior if the repeatability coefficient did not exceed a margin of 0.01.

Mechanomyography had higher repeatability coefficients than electromyography at all measured TOF intervals. Mechanomyography was partially noninferior to electromyography because the 95% confidence interval of the median difference between TOF ratios of both techniques (0.039 [0.007 to 0.042]) covered the acceptable margin during baseline, but not after recovery to TOF ratio >0.9 (0.052 [0.047 to 0.076]).

The TOF^3D mechanosensor was not less precise than electromyography during baseline. Better hand fixation must be achieved to improve precision mechanomyography.

EUDAMED (CIV-23-06-043334); ClinicalTrials.gov (NCT06230653).