Mechanomyography (MMG) is considered the gold-standard for neuromuscular blockade (NMB) monitoring. However, it is quite bulky and difficult to use on a routine basis. Therefore, alternative methods like Acceleromyography (AMG), Electromyography (EMG) and the TOF-CUFF method have been developed. The aim of this study was to compare the TOF-Cuff monitor and Electromyography (EMG-NMT module with the CARESCAPE B450 monitor) data following rocuronium-induced neuromuscular blockade and its reversal.

Neuromuscular relaxation of the patient during surgery is necessary for multiple reasons, such as facilitating intubation or improving the effectiveness of some surgical procedures. Premature extubation of the patient without having achieved a complete recovery of the NMB can have deleterious consequences, increasing postoperative complications, especially those related to the respiratory system. Given this, current guidelines of good clinical practice recommend the monitoring of pharmacologically induced NMB during general anesthesia. In addition, monitoring allows confirmation of optimum relaxation before intubation, and allows for control over re-dose administration and recovery of NMB upon awakening from general anesthesia.

There are different methods of quantitative monitoring of NMB. The TOF-CUFF monitor uses a method based on a traditional pressure cuff that incorporates stimulation electrodes. The placement of the cuff which aligns the stimulation electrodes on the path of the brachial plexus at the humeral level allows to evaluate the muscular response evoked from the changes in the cuff pressure, generated by the muscular contraction after the electrical stimulus. Its main advantage is that monitoring of the NMB is included within the pressure cuff itself, which is always used in any anesthetic act. Then, when the pressure cuff is placed, monitoring of the NMB is easily established. This specific design facilitates the task of anesthesiologists because they do not have to perform any additional preparation for the monitoring of NMB.

The TOF-CUFF monitor has been validated regarding the mechanomyography, which is considered the gold-standard for the monitoring of NMB. The main objective of the study is to compare the values of NMB measured with the TOF-CUFF monitor with NMB values measured with the CARESCAPE B450 monitor during the pharmacologically induced NMB and evaluate the degree of equivalence in different situations. Secondary objective is to verify that the design for joint monitoring of the NMB and NIBP in the TOF-CUFF monitor does not affect the independent measure of the two variables.

Prospective, single-center, open and controlled observational clinical study. The study is aimed to be conducted with 40 patients aged between 18 and 65 years.

Inclusion Criteria:

• ASA I-II
• Patients who give their written informed consent
• Elective surgery under general anesthesia that according to the anesthetic plan muscle relaxants will be administered

Exclusion Criteria:

• Patients who refuse to give their informed consent
• Patients who present any of the contraindications for the devices used in the study
• Patients who are participating or have participated in a clinical trial during the 4 weeks prior to inclusion
• Women of childbearing age who do not use effective contraceptive methods, pregnant women, with suspicion of pregnancy or breast-feeding
• Patients with the following criteria: upper limb peripheral vascular pathologies, a difficult airway, myasthenia gravis and other neuromuscular diseases, use of medication that may alter NMT

Patients American Society of Anesthesiologist (ASA) I-II, between 18-65 years and scheduled for elective surgery under general anesthesia.