Pongrácz, Adrienn

Background/Objectives: The aim of this observational study was to collect hand measurements and anthropometric data in children aged 1–15 years of age to help the design of a pediatric skin electrode for electromyography-based neuromuscular monitoring. Methods: Data collection was performed at the Pediatric Department of the University of Debrecen Medical Centre between 1 December 2019 and 31 January 2021. After gaining written informed consent from the parents or legal representatives and verbal acceptance from age-appropriate (12–35 months) patients, a total of 153 children were enrolled. The following parameters were recorded: demographics (age, sex, weight, height, and hand dominance) and hand size parameters, defined as the distance between the following reference points: the ulnar groove and the midpoint of the hypothenar eminence (A); the midpoint of the hypothenar eminence and the first interphalangeal joint of the 5th finger (B); the ulnar groove and the midpoint of the thenar eminence (C); the midpoint of the thenar eminence and the interphalangeal joint of the thumb (D); the midpoint of the wrist crease and the tip of the third finger; wrist circumference (E); and forearm length. All measurements were made in centimeters (cm). Results: The children were divided into 4 groups (12–23 months, 2–5 years, 6–11 years and 12+ years). The number of children in the groups ranged between 6 and 16. The hand size parameters increased according to the children’s age (A: 4.3 ± 0.4, 5.0 ± 0.7, 6.3 ± 0.6, and 6.9 ± 1.0 cm; B: 3.2 ± 0.4, 4.1 ± 0.7, 5.0 ± 0.6, and 5.9 ± 0.6 cm; C: 3.0 ± 0.3, 3.6 ± 0.7, 4.1 ± 0.6, and 4.9 ± 0.6 cm; D: 4.1 ± 0.4, 4.8 ± 0.8, 6.2 ± 0.8, and 7.2 ± 0.9 cm; E: 10.1 ± 0.6, 12.0 ± 1.1, 15.3 ± 1.3, and 17.7 ± 1.7 cm, respectively, in the four groups, [mean ± SD]). The height of the children showed a closer correlation with hand size parameters (Pearson’s correlation coefficients: 0.702–0.961) than with age (0.665–0.904) or weight (0.675–0.863). The correlation was weaker when data were examined in prespecified age groups. Conclusions: The current pediatric hand size database provides previously unavailable information that was used in one manufacturer’s design, which may help with the future design of pediatric electrodes of electromyography-based neuromuscular monitors; this information may facilitate adoption of quantitative neuromuscular monitoring in routine pediatric anesthesia practice.

Background: Tracheal intubation and mechanical ventilation are facilitated by neuromuscular blocking agents. We investigated the effectiveness of subjective clinical evaluation of neuromuscular function on retroglossal area size, since it determines spontaneous ventilation adequacy following tracheal extubation. Secondarily, we correlated changes in retroglossal area and depth of neuromuscular block assessed during both respiratory phases using quantitative neuromuscular monitoring. Methods: Once mechanical ventilation was no longer needed, antagonists were used to reverse the neuromuscular block in 21 consenting patients; adequacy of reversal was assessed subjectively by delivering a sequence of four rapid (2 Hz) electrical stimuli (train-of-four, TOF) to a peripheral nerve and assessing attainment of four equal muscle contractions (TOF ratio = 1.0), signifying normal neuromuscular function. Retroglossal area during both inhalation and exhalation were measured pharyngoscopically at various phases of neuromuscular recovery, including at baseline after anesthesia induction but before neuromuscular block onset and at recovery before tracheal extubation; area changes were correlated with depth of quantitatively measured neuromuscular block. Results: Clinicians’ subjective evaluation of readiness for tracheal extubation failed to identify significant residual block in most patients who required rescue antagonism. Markedly decreased retroglossal areas (inhalation: 39.5% of baseline; exhalation: 20.1% of baseline) were present at extubation, and 11 out of 21 (52.4%) patients needed rescue antagonism. In contrast, in patients with neuromuscular recovery to the currently recommended threshold determined quantitatively (TOF ratio > 0.90), retroglossal areas were only 80% recovered but returned to near baseline values when the TOF ratio ≥ 0.95. Conclusions: Quantitative monitoring should guide the timing of tracheal extubation. Current definitions of the minimal threshold for adequate neuromuscular recovery (TOF ratio > 0.90) after mechanical ventilation in postoperative patients should be re-evaluated. A TOF ratio > 0.95 better correlates with return to normal (baseline) retroglossal area during both inhalation and exhalation.