A Comparison Between TOF Watch® SX and Tetragraph®

Study Overview
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Brief Summary
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This observational study was designed to assess the agreement between the recently marketed electromyographic neuromuscular blockade monitor Tetragraph® (Senzime, Uppsala, Sweden) and the TOF Watch® SX (Organon Teknika B.V., Boxtel, Holland), an accelerometric neuromuscular blockade monitor frequently used in clinical practice

Detailed Description
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Before the induction of general anesthesia both monitors will be placed in the same arm. After induction of general anesthesia and before neuromuscular blocking agent administration both devices will be consecutively calibrated and a baseline measurement will be obtained. During the surgical procedure the investigators will monitor neuromuscular function with one of the two devices. Then the investigators will switch the device used as a guide between subsequent patients. The protocol will start as soon as the leading device will register a train-of-four ratio (TOFr) ≥ 0.2. During the protocol a comparison between the two devices will be conducted as soon as the device used as a guide will display a TOFr ≥ 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1. For each of the TOFr reported, we will deliver two subsequent TOF stimulations with the guiding device followed by two TOF stimulations with the other monitor. Both the stimulations delivered by each device and the two consecutive stimulations delivered by different monitors will be conducted 20 sec from one another. Stimulations with the same device will be used to assess intraobserver variability for each methodology, while the second and the third measurements (consecutive stimulations with different devices) will be used to assess agreement between them. The protocol will end when the leading device will show a TOFr ≥ 1.0, or if, at the end of the surgical procedure, acceleromyographic TOFr will be > 0.9.

Official Title
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A Comparison of Accelerometric Monitoring by TOF Watch® SX and Electromyographic Monitoring by Tetragraph® for Recovery From Neuromuscular Blockade

Conditions
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Neuromuscular Blockade, Neuromuscular Monitoring

Intervention / Treatment
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* Device: Tetragraph® (Senzime, Uppsala, Sweden)
* Device: TOF Watch® SX (Organon Teknika B.V., Boxtel, Holland)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age > 18 years Rocuronium bromide use is anticipated for neuromuscular blockade during surgical procedure Upper arms will be freely available during the surgical procedure Exclusion Criteria: Known neuromuscular disease Known allergy to Rocuronium bromide end-stage liver disease chronic kidney disease

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| All subjects<br>Adult patients >18 years of age, who are scheduled to undergo any elective procedure under general anesthesia at our Institution in which the administration of rocuronium for neuromuscular blockade is anticipated. All participants will be monitored with both TOF Watch and Tetragraph neuromuscular monitors. | Device: Tetragraph® (Senzime, Uppsala, Sweden)<br>* The Tetragraph® is a recently marketed electromyographic neuromuscular monitor that uses a disposable electrode array (TetraSens) that combines stimulating and recording electrodes<br>* Other names: Electromyographic neuromuscular monitor;Device: TOF Watch® SX (Organon Teknika B.V., Boxtel, Holland)<br>* The TOF Watch® SX is a common used neuromuscular monitor<br>* Other names: Acceleromyographic neuromuscular monitor;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Agreement between TOF Watch® SX and Tetragraph® train-of-four ratios | Bias and Limits of Agreement between the two methodologies using Bland-Altman analysis | Recovery from neuromuscular blockade at the end of the surgical procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Agreement between normalized TOF Watch® SX and Tetragraph® train-of-four ratios | Normalized TOF Watch® SX train of four ratios will be calculated as the ratio between actual train-of-four ratio and baseline. Bias and Limits of Agreement will be derived using Bland-Altman analysis | Recovery from neuromuscular blockade at the end of the surgical procedure | 
| Agreement between TOF Watch® SX and Tetragraph® train-of-four ratios for TOF ratios < 0.8 | Normalized TOF Watch® SX train of four ratios will be calculated as the ratio between actual train-of-four ratio and baseline. Bias and Limits of Agreement will be derived using Bland-Altman analysis | Recovery from neuromuscular blockade at the end of the surgical procedure | 
| Agreement between TOF Watch® SX and Tetragraph® train-of-four ratios for TOF ratios ≥ 0.8 | Normalized TOF Watch® SX train of four ratios will be calculated as the ratio between actual train-of-four ratio and baseline. Bias and Limits of Agreement will be derived using Bland-Altman analysis | Recovery from neuromuscular blockade at the end of the surgical procedure | 
| Absolute and relative intraobserver variability for TOF Watch® SX and Tetragraph® | Absolute intraobserver variability will be calculated as the absolute difference between pairs of consecutive measurements by the same device. Relative intraobserver variability will be calculated as the ratio between the absolute difference and mean of the measurements. | Recovery from neuromuscular blockade at the end of the surgical procedure |