Comparison of the TOFscan and the TOF-Watch SX during pediatric neuromuscular function recovery: a prospective observational study

Perioper Med (Lond). 2021 Dec 10;10(1):45. doi: 10.1186/s13741-021-00215-2.


Background: TOFscan is a three-dimensional acceleromyography neuromuscular monitoring device that does not require initial calibration before muscle relaxant injection. This study aimed to compare TOFscan with TOF-Watch SX, the currently widely accepted uni-dimensional acceleromyography, for use among the pediatric population. We aimed to assess the agreement between TOFscan with TOF-Watch SX in the pediatric population's neuromuscular recovery.

Methods: A total of 35 children aged 6-12 years were enrolled. Prior to any muscle relaxant injection, TOFscan and TOF-Watch SX were applied at each opposite arm and monitoring began concurrently throughout neuromuscular recovery. Calibration was performed for TOF-Watch SX, and train-of-four values were recorded every 15 s. Agreement between the two devices was evaluated with Modified Bland-Altman analysis.

Results: The bias between TOF-Watch SX and TOFscan were all within the 95% limits of agreement. The bias and standard deviation were smaller and the limit of agreement was narrower in the normalized group than in the non-normalized group [normalized bias -0.002 (95% CI, -0.013 to 0.010), standard deviation (SD) 0.111 vs non-normalized bias 0.010 (95% CI, -0.003 to 0.0236), SD 0.127].

Conclusions: TOFscan reliably demonstrated lack of bias and good concordance with TOF-Watch SX throughout the neuromuscular recovery, especially when normalized. Despite technical limitations, the two devices were unbiased along the path of spontaneous and pharmacological reversal in pediatric patients.

Trial registration: NCT03775603. Registered on 13 March 2018.

Keywords: Acceleromyography; Pediatric; TOF-Watch SX; TOFscan.

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