Precision of neuromuscular monitoring in paediatric patients: a randomised prospective agreement study of kinemyography and electromyography.

BACKGROUND

Quantitative neuromuscular monitoring in children remains challenging, particularly in weight and age categories without equipment certification. The study compared the precision of kinemyography and electromyography in children <5 yr of age.

METHODS

Sixty-four children were stratified into neonates (≤44 weeks postmenstrual age), infants (44-58 weeks postmenstrual age), toddlers (>58 weeks postmenstrual age to ≤2 yr), and children (2-5 yr). Kinemyography and electromyography were applied to contralateral arms. Primary endpoints were precision of train-of-four ratios before rocuronium administration and after assumed complete recovery (i.e. after sugammadex administration). Precision was quantified using the repeatability coefficient, indicating the range within which a repeated train-of-four ratio is with 95% probability. A low repeatability coefficient indicates high precision.

RESULTS

Median repeatability coefficients were 0.06 [IQR 0.03-0.10] for kinemyography and 0.06 [0.05-0.09] for electromyography (median difference 0.00 [95% confidence interval, CI -0.01 to 0.01]) at baseline and 0.04 [0.02-0.07] and 0.04 [0.03-0.06] after recovery (median difference 0.00 [-0.01 to 0.01]). Kinemyography precision was worse in non-certified use (<5 kg: 0.08 [0.05-0.11], ≥5 kg: 0.04 [0.02-0.06]; median difference 0.04 [0.02-0.05]), whereas electromyography performed similarly regardless of its certification (neonates 0.05 [0.03-0.11], others 0.06 [0.03-0.09]; median difference -0.01 [-0.04 to 0.05]). Train-of-four ratios <0.9 were more frequent in kinemyography than in electromyography (33% vs 16%, P<0.05).

CONCLUSIONS

Neither kinemyography nor electromyography was inferior to the other in terms of precision. Unlike kinemyography, electromyography remained precise even when applied below recommended age or weight limits. The importance of baseline values before rocuronium is underlined by the frequently measured train-of-four ratios of <0.9.

CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; NCT06062290 (registered August 15th, 2023).