Evaluation of the Tof Cuff for Perioperative Neuromuscular Transmission

Completed

Interventions: Diagnostic Test: Measurements of the level of neuromuscular blockade

Brief Summary: 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.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Arm && Interventions

Group	Intervention	Description
deep neuromuscular block, high body mass index	Measurements of the level of neuromuscular blockade	Patients with high BMI (\> 30) who will receive a deep neuromuscular block (post tetanic count of 1-2 twitches)
moderate neuromuscular block, normal body mass index	Measurements of the level of neuromuscular blockade	Patients with normal BMI (\< 30) who will receive a moderate neuromuscular block (train of four 1-3 twitches)
deep neuromuscular block, normal body mass index	Measurements of the level of neuromuscular blockade	Patients with normal BMI (\< 30) who will receive a deep neuromuscular block (post tetanic count of 1-2 twitches)
moderate neuromuscular block, high body mass index	Measurements of the level of neuromuscular blockade	Patients with high BMI (\> 30) who will receive a moderate neuromuscular block (train of four 1-3 twitches)

Primary Outcome Measures

Name	Time	Method
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)	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	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.

Secondary Outcome Measures

Name	Time	Method

Locations (2): Medisch Centrum Haaglanden / Nederlandse Obesitas Kliniek
🇳🇱
The Hague, Zuid Holland, Netherlands
Leiden University Medical Center
🇳🇱
Leiden, Zuid-Holland, Netherlands