Comparison of Train of Four Measurements with Kinemyography NMT DATEX and Accelerography TOFscan

Abstract

Introduction: This study was designed to compare the Datex neuromuscular transmission (NMT) kinemyography (NMTK) device with the TOFscan (TS) accelerometer during the onset and recovery of neuromuscular blockade. Patients and methods: This prospective study included adult patients who were scheduled to undergo elective surgery with general anesthesia and orotracheal intubation. The TS accelerometer was randomly placed at the adductor pollicis on one hand, and the NMTK was placed on the opposite arm. Anesthesia was initiated with remifentanil target-controlled infusion (TCI) and 2.0–3.0 mg/kg of propofol. Thereafter, 0.5 mg/kg of atracurium or 0.6 mg/kg of rocuronium was injected. If needed, additional neuromuscular blocking agents were administered to facilitate surgery. First, we recorded the train of four (TOF) response at the onset of neuromuscular blockade to reach a TOF count of 0. Second, we recorded the TOF response at the recovery of neuromuscular blockade to obtain a T4/T1 90% by both TS and NMTK. Results: There were 32 patients, aged 38–83 years, with the American Society of Anesthesiologists (ASA) Physical Status Classification I–III included and analyzed. Surgery was abdominal, gynecologic, or head and neck. The Bland and Altman analysis for obtaining zero responses during the onset showed a bias (mean) of 2.7 s (delay) of TS in comparison to NMTK, with an upper/lower limit of agreement of [104; −109 s] and a bias of 36 s of TS in comparison to NMTK, with an upper/lower limit of agreement of [−21.8, −23.1 min] during recovery (T4/T1 > 90%). Conclusions: Under the conditions of the present study, the two devices are not interchangeable. Clinical decisions for deep neuromuscular blockade should be made cautiously, as both devices appear less accurate with significant variability.

Assessment of the New Acceleromyograph TOF 3D Compared with the Established TOF Watch SX: Bland-Altman Analysis of the Precision and Limits of Agreement between Both Devices—A Randomized Clinical Comparison

“…With regard to the onset of the block, limits of agreement were substantially higher reaching nearly 60%. However, this phenomenon has already been reported previously: while Claudius et al reported limits of agreement of 40%, Dubois et al and Motamed et al observed 48% and 49% assessing the onset of the block [ 10 , 15 ].…”

“…These observations correspond well with the results from other authors measuring the M. adductor pollicis: Dubois et al reported a bias of 3% together with limits of agreement of 10–20%, and Claudius et al observed a bias of 10% and limits of agreement of 20–30%, both comparing acceleromyography and mechanomyography [ 10 , 12 ]. Additionally, Motamed et al found a bias of 1% and limits of agreement of 20% in a study assessing kinemyography and acceleromyography [ 15 ].…”

Intraoperative Monitoring of Neuromuscular Blockade

“…Most of these monitors available commercially are in agreement with each other on values near 90% TOFR but are usually in important disagreement for the onset of neuromuscular blockade and shallow blocks [ 47 , 48 , 49 , 50 ].…”