Evaluation of the Tof Cuff for Perioperative Neuromuscular Transmission

Leiden University Medical Center250 enrolled

Overview

Acceleromyography (AMG) is the most wide spread used method to assess neuromuscular block during anesthesia. However AMG is known to be inaccurate when compared to the gold standard in neuromuscular transmission monitoring, electromyography (EMG). Furthermore when the patients arms require to be positioned next to the body and beneath surgical drapes, AMG measurements are often hindered and inaccurate. The TOF cuff is a new device which measures neuromuscular blockade at the upper arm with a blood pressure cuff. It overcomes the previously mentioned disadvantages of AMG. However, it validity compared to EMG and AMG has not yet fully been investigated. This study aims to compare the bias, limits of agreement and precision of the Train-of-Four cuff relative to AMG and EMG during recovery of moderate and deep neuromuscular block in patients with normal body mass index and morbidly obese patients.

Study Type

OBSERVATIONAL

Enrollment

250

Conditions

Neuromuscular Blockade

Interventions

Measurements of the level of neuromuscular blockadeDIAGNOSTIC_TEST

Study participant were not prospectively exposed to an intervention. Administration of a moderate or deep neuromuscular blockade is at the discretion of the attending anesthesiologist. Study participants only received diagnostic non-invasive monitoring. In routine clinical care the neuromuscular blockade is monitored non-invasively by either acceleromyography, electromyography or by the TOF-Cuff. In this study participants were monitored by the monitors and were not exposed to any additional risk and no effect of an intervention was assessed in this study.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * American society of Anesthesiologist Physical Status class I-III * \>18 years of age * Ability to give oral and written informed consent Exclusion Criteria: * Known or suspected neuromuscular disorders impairing neuromuscular function; * Allergies to muscle relaxants, anesthetics or narcotics; * A (family) history of malignant hyperthermia; * Women who are or may be pregnant or are currently breast feeding; * Renal insufficiency, as defined by a glomerular filtration rate \< 30 ml/min * Scheduled for anesthesia without the use of muscle relaxants.

Outcomes

Primary Outcomes

Depth of Neuromuscular Block During Moderate Neuromuscular Blockade (Outcome Measure/Row Title Train of Four Ratio) and During Deep Neuromuscular Blockade (Outcome Measure/ Row Title Post Tetanic Count)

Depth of as neuromuscular block will be compared between the Tof-Cuff and electromography at five minute intervals during moderate neuromuscular blockade. Bland-Altman analysis modified for repeated measurements (http://sec.lumc.nl/method\_agreement\_analysis). This Bland-Altman analysis corrects for between subject variability of repeated paired measurements in individual subjects. Bland-Altman analysis estimates bias and limits of agreement (95% differences between compared devices) between Tof-Cuff and electromography and evaluates instrumental imprecision by calculating the repeatability coefficient, which is equal to the standard deviation of the within-subject variability of each device. For interpretation of the Bland-Altman bias during offset of neuromuscular blockade one can assume that a bias above zero indicates that TOF-Cuff overestimates neuromuscular blockade recovery whilst a bias below zero indicates that Tof-Cuff underestimates neuromuscular blockade recovery.

Time frame: at 5 minute intervals during the length of the entire procedure [which lasted between 20 to 372 minutes]; a mean of the differences between the TOF-Cuff and electromyography of all measurements is calculated and reported below