The train-of-four (TOF) ratio is a quantitative measure used in anesthesia to assess the degree of neuromuscular blockade induced by neuromuscular blocking agents during surgical procedures. Current American Society of Anesthesiologists guidelines recommend monitoring the TOF ratio to guide the administration and reversal of NMBAs, with a target ratio of 0.9 or higher at adductor pollicis muscle indicating adequate reversal and restoration of neuromuscular function.

This proposed study aims to observe and compare the TOF ratio between two different muscles of the hand: adductor pollicis and adductor digiti minim using anesthesia monitors on both of their arms during recovery of neuromuscular function. Surgery and anesthesia will occur per standard of care.

The study population will enroll adult patients (>18) who will receive non-depolarizing neuromuscular blocking drugs as part of a routine general anesthetic and who will have monitoring of their recovery from neuromuscular block performed using the Tetragraph (Senzime Sweden). Patients with upper limb weakness, neurological deficits, and inability to use the other arm to record the second EMG recording will be excluded.

Procedures (methods):

Adult patients undergoing general anesthesia with the use of muscle relaxants will have anesthesia monitors on both of their arms. On one arm, the study sticky pad will be placed on the forearm and over the base of the little finger. On the other arm, the standard monitor is placed on the forearm and over the base of the thumb.

To identify pre-operative patients, an EPIC report will be utilized to screen for eligible participants. Patients will be contacted via phone by a research team member the day before their procedure and enrolled. Informed consent will be formally obtained on the day of the procedure.

Inclusion Criteria:

• Surgery and general anesthesia with administration of non depolarizing neuromuscular blocking drug

Exclusion Criteria:

• neuromuscular disease or weakness of one of upper limbs.
• Inability to use one of subjects arms to record neuromuscular monitor.
• Contraindication to administration or allergy to non depolarizing neuromuscular blocking drug.

Consented patients undergoing general anesthesia with an endotracheal tube and non depolarizing muscle relaxants and objective monitoring of train of four.