Comparing Train-of-Four Recovery in the Adductor Pollicis Versus the Adductor Digiti Minimi in Elective Surgery Patients

Comparing Train-of-Four Recovery in the Adductor Pollicis Versus the Adductor Digiti Minimi in Elective Surgery Patients Using EMG

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.

Study Overview

• Status: Completed
• Conditions: Anesthesia; Neuromuscular Blockade
• Intervention / Treatment: Device: EMG Assessement of Recovery of Neuromuscular Function

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 57

Contacts and Locations

Study Locations

• United States
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • University of North Carolina at Chapel Hill

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

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

Description

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.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Adductor Pollicis EMG; The Train of Four Ratio will be recorded at 90% as a time and as a reference point	Device: EMG Assessement of Recovery of Neuromuscular Function; EMG Train of Four Assessment of Recovery of Neuromuscular Function
Adductor Digiti Minimi; The Train of Four Ratio will be recorded when the adductor pollicis ratio reads 90%	Device: EMG Assessement of Recovery of Neuromuscular Function; EMG Train of Four Assessment of Recovery of Neuromuscular Function

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in Measured Recovery of Train of Four at Adductor Pollicis and Adductor Digiti Minimi	The train of four ratio at the digiti minimi will be recorded when the adductor pollicis ratio reads 90 percent	All assessments are intraoperative and complete in one day

Collaborators and Investigators

• Sponsor: University of North Carolina, Chapel Hill
• Investigators: Principal Investigator: Stuart Grant, University of North Carolina, Chapel Hill

Study record dates

Study Major Dates

• Study Start (Actual): March 18, 2024
• Primary Completion (Actual): May 9, 2025
• Study Completion (Actual): June 1, 2025

Study Registration Dates

• First Submitted: June 14, 2024
• First Submitted That Met QC Criteria: June 14, 2024
• First Posted (Actual): June 21, 2024

Study Record Updates

• Last Update Posted (Actual): January 13, 2026
• Last Update Submitted That Met QC Criteria: January 9, 2026
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: 24-1013

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No