An observational study comparing the performance of TOF-Cuff with TOF-Scan monitoring during anaesthetic induction in clinical routine

• Published in: Anaesthesiology intensive therapy : official publication of the Polish Society of Anaesthesiology and Intensive Therapy 2020-01, Vol.52 (3), p.181-186
• Main Authors: Markle, Andrew, Horn, Katja, Welter, JoEllen, Dullenkopf, Alexander
• Format: Article
• Language: English
• Subjects: Accelerometry - methods; Adult; Aged; Anesthesia, General - methods; Atracurium; Blood pressure; Blood Pressure Determination; Body Mass Index; Electric Stimulation; Electrodes; Female; general anaesthesia; General anesthesia; Humans; Intraoperative Neurophysiological Monitoring - methods; Intubation; Male; Middle Aged; Neuromuscular Blocking Agents; neuromuscular monitoring; Neuromuscular Monitoring - methods; Neuromuscular Nondepolarizing Agents; Obesity - physiopathology; Observational studies; Original and Clinical; patient safety; Patients; Premedication; Prospective Studies; Sensors
• ISSN: 1642-5758; 1731-2531
• DOI: 10.5114/ait.2020.98124

Neuromuscular monitoring by acceleromyography assesses the effects of non-depolarising neuromuscular blocking agents used during anaesthesia induction to optimise intubation conditions. A new type of neuromuscular monitor, TOF-Cuff, integrates electrode stimulation into a blood pressure monitoring cuff. Comparisons of this device with TOF-Scan, considered a clinical standard acceleromyography device, have not been published. This prospective, observational study was approved by the Ethics Committee East Switzerland (BASEC-nr. 2016-02044), and patients' consent was obtained before inclusion. The study's aim was to compare TOF-Cuff with TOF-Scan by measuring the duration from the administration of a neuromuscular blocking agent to a train-of-four (TOF) ratio of 0%. After anaesthesia induction, atracurium was administered (0.5 mg kg-1) and TOF ratios were recorded every 15 seconds using the two devices simultaneously. Patients were grouped according to body mass index (< or ≥ 30 kg m-2). Twenty-five non-obese and twenty-five obese patients were included. In non-obese patients, bias was -3 s (± 21.2; limits of agreement -44.7 to 38.4; P = 0.702). In obese patients, bias was -20 s (± 35.0; limits of agreement -88.6 to 48.6; P = 0.0139). Large intra-individual differences of up to 60 seconds were detected even in non-obese patients. A significant systematic difference in the time to reach a TOF ratio of 0% was found when using the two devices in obese patients. In non-obese and obese patients, there were large intra-individual and clinically relevant differences. The two devices cannot be used interchangeably.