A quantitative neuromuscular monitoring device is desirable to titrate the depth of neuromuscular block (NMB) during a procedure, and to prevent residual effects after removal of the endotracheal tube. Unfortunately, the most widely used monitoring technique acceleromyography (AMG) typically implies a series of cumbersome installation and calibration procedures that frequently precludes correct use of these devices in clinical practice. Electromyography (EMG) has recently attracted a lot of attention as an alternative strategy to compensate for the deficiency of AMG-based neuromuscular monitors. Nowadays, a new technology that allows for the simultaneous acquisition of EMG and AMG signals is commercially available. Although its reliability has been rapidly accepted in Physical Medicine and Rehabilitation, the use of the technique in neuromuscular monitoring has never been reported. The aim of the present study is to assess the validity of the new device for estimating the neuromuscular block by comparing with TOF Watch®-SX, which is the most widely accepted AMG-based neuromuscular monitor that has been practiced in the clinical arena for decades.

Inclusion Criteria:

• Age less than 18 yr
• American Society of Anesthesiologists Physical Status I to III
• Elective surgery requiring muscle relaxation
• Patients participated voluntarily and signed informed consent

Exclusion Criteria:

• Patients with known neuromuscular disorder
• Stroke
• Patients with a history of allergic reaction toneuromuscular blocking agents
• Use of medications that might interfere with neuromuscular transmission
• Any previous injury to the examined arm that might influence nerve conduction parameters
• Pacemaker

Patients who need to be treated surgically under general anesthesia and are going to receive neuromuscular blocking agents.