Clinical study on opioid sensitivity index based on sympathetic response evoked threshold

JRCT ID: jRCTs062240075

Registered date:06/11/2024

Basic Information

• Recruitment status: Recruiting
• Health condition(s) or Problem(s) studied: Laparotomy under general anesthesia
• Date of first enrollment: 08/11/2024
• Target sample size: 20
• Study type: Interventional
• Intervention(s): The study is performed during the induction of general anesthesia in general. After induction with propofol, remifentanil is administered continuously to achieve an effect site concentration of 2 ng/ml using the blood concentration prediction formula (Minto). Propofol continuous doses are adjusted as needed to achieve an Entropy value of 40-60. Percutaneous standardized tetanus stimulation (50 Hz for 5 seconds in 8 steps of 10 mA to 80 mA at 10 mA increments) is performed on the forearm on the opposite side of the hand to which the intravenous arterial pressure catheter and pulse oximeter are attached to measure the vascular stiffness value (K) when the blood pressure change is within 5% of the last 5 minutes. Allow sufficient time between each stimulus to ensure that heart rate, blood pressure, pulse oximeter amplitude, and K have returned to pre-stimulus values. The MECK (Minimum Evoked Current of K) is calculated from the rate of change of K for this stimulus. (Specifically, MECK is defined as the minimum stimulus current value at which K changed by more than 5% before and after standardized tetanus stimulation.) Among the intervention group, those with a MECK of 10-30 mA were assigned to the low MECK group, those with a MECK of 40-60 mA to the medium MECK group, and those with a MECK of 70 mA or higher to the high MECK group, and for each group, the dose of remifentanil was adjusted so that the remifentanil effect site concentration at the time of surgical skin incision was 10 ng/ml, 6 ng/ml, and 2 ng/ml. In the external control group, the rate of change in blood pressure during surgical skin incision will be measured at 2 ng/ml of remifentanil, regardless of the MECK value.

Outcome(s)

• Primary Outcome: Difference between intervention group and external control group in the mean value of rate of change of blood pressure during surgical skin incision

Secondary Outcome

1. Evaluation of the equivalence of the high MECK group among the intervention group to the external control group
2. Blood pressure before surgical skin incision in the intervention group

Key inclusion & exclusion criteria

• Age minimum: >= 18age old
• Age maximum: Not applicable
• Gender: Both

Include criteria

A) Cases in which the patient is at least 18 years of age at the time consent is obtained and in which laparotomy is scheduled to be performed under general anesthesia.
B) Cases in which invasive radial arterial blood pressure monitering will be performed.
C) Cases in which the patient's written consent to participate in this study is obtained.

Exclude criteria

A) Cases with atrial fibrillation or irregular R-R interval.
B) Cases in which it is inappropriate to perform invasive radial arterial monitering.
C) Patients with significant hemodynamic or neurologic impairment in the upper extremities.
D) Patients with severe stenosis or occlusive lesions in cerebral vessels.
E) Cases in which the use of remifentanil, propofol, or rocuronium is contraindicated.
F) Cases in which the anesthesiologist in charge deems it inappropriate to conduct the study.

Related Information

• Primary Sponsor: Nakamura Ryuji
• Source(s) of Monetary Support: Japan Society for the Promotion of Science