Minimum Current for Train-of-four Monitoring

Ewha Womans University Mokdong Hospital36 enrolled

Overview

Neuromuscular monitoring during general anesthesia is important to make sure adequate muscle relaxation during operation and adequate recovery of muscle power and spontaneous breathing during emergence from general anesthesia. The neuromuscular monitoring is usually using electrical stimulants and the method called train-of-four (TOF) is representative. Because it uses electrical stimulants, the patients could be uncomfortable and feel pain during the monitoring when the patients are conscious. Lowering the current of the stimulants would be helpful in reducing the pain, but there is a concern that the TOF results performed in lower current would be underestimated or inaccurate. Therefore, the investigators want to find the minimal current for TOF monitoring that shows adequate TOF results.

Study Type

INTERVENTIONAL

Allocation

Purpose

SUPPORTIVE_CARE

Masking

NONE

Enrollment

Conditions

Anesthesia Anesthesia Recovery Period Neuromuscular Blockade

Train-of-four (TOF)DEVICE

Give 4 electrical stimulants on the ulnar nerve to see if the 4 responses (T1 \~ T4) of adductor pollicis fade or not. If there's no neuromuscular block, it shows no fade, or it fades. When an operation is over under general anesthesia, we use the ratio of the height of T4 to T1, and the ratio is over 90%, the neuromuscular block is recovered enough to extubation.

Eligibility

Sex: ALLMin age: 20 YearsMax age: 65 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age 20-65 * Scheduled for an elective surgery * ASA physical status 1 or 2 Exclusion Criteria: * BMI \> 25 kg/m2 * Neuromuscular disease * Decreased renal function * Neurologic disorder * Impossible to cooperate or communicate

Outcomes

Primary Outcomes

Minimal current for TOF

The minimal current among the four currents we use which is showing not significantly lower TOF ratio than TOF ratio of supramaximal stimulant.

Time frame: During the operation, from the height of T1 reaches back to the baseline, to the extubation of tracheal tube when the general anesthesia is over.