Median Versus Ulnar Nerve Quantitative Electromyography Neuromuscular Blockade Monitoring Comparison

Median Versus Ulnar Nerve Quantitative Electromyography Neuromuscular Blockade Monitoring Comparison

Medications used to relax the muscles are used during surgery. The amount of muscle relaxation can monitored with devices that stimulate a specific nerve and evaluate the muscle response. The response to, and recovery from, medications that relax the muscles are best described for a nerve in the arm called the ulnar nerve. The investigators believe that other nerves in the arm, such as the median nerve, could be used to monitor the amount of muscle relaxation. The purpose of this study is to compare the muscle response at two different nerve sites after giving medications to relax the muscles.

This study is going to measure the depth of muscle relaxation during surgery at two different sites. The muscle response to stimulation of the ulnar nerve (located in the arm) will be compared to the muscle response to stimulation of the median nerve (also located in the arm).

This is a single-center prospective, randomized controlled trial comparing ulnar versus median nerve electromyography transmission.

Neuromuscular blockade is used to provide muscle relaxation during surgery. The depth of neuromuscular blockade can be monitored with nerve stimulation or electromyography. The response to and recovery from non-depolarizing neuromuscular blockade is best described for the ulnar nerve. The investigators postulate that the median nerve may provide comparable information about the response non-depolarizing neuromuscular blockade. Electromyography electrodes will be positioned to stimulate the ulnar nerve in one arm and the median nerve in the other arm. The response to, and recovery from, non-depolarizing neuromuscular blockade will be compared between the ulnar and median nerve.

The location of median nerve monitoring will be randomized to the dominant or non-dominant hand.

The randomized arm will have electrodes positioned to stimulate the median nerve and the other arm will have electrodes positioned to stimulate the ulnar nerve (standard site for monitoring neuromuscular transmission during anesthesia).

The purpose of the study is to compare the response to, and recovery from, non-depolarizing neuromuscular blockade between the ulnar and median nerves.

Inclusion Criteria:

• Adults 18 - 75 years of age who are able to provide consent
• Scheduled for elective surgery requiring muscle relaxation, in a supine position under general anesthesia, with an anticipated duration of at least 1.5 hours

Exclusion Criteria:

• Contraindication to rocuronium use
• Comorbidities that may prolong the duration of neuromuscular blockade or alter pharmacodynamics and/or pharmacokinetics, such as:
• Neuromuscular disease
• Expected or known difficult airway
• Rocuronium allergy
• BMI < 18.5 or > 40
• History of adhesive allergy
• Upper extremity weakness, limb deformity, or absence of all or part of an upper limb
• Patients undergoing surgical procedures requiring cardiopulmonary bypass