Dexmedetomidine Reduces Sevoflurane MAC-BAR During Pneumoperitoneum

Fujian Provincial Hospital

Status and phase: Enrolling; Phase 4

Conditions: Laparoscopic Cholecystectomy

Treatments: Drug: Dexmedetomidine high-dose; Drug: Dexmedetomidine low-dose; Drug: normal Saline

Study type: Interventional

Funder types: Other

Identifiers

NCT06575179

k2022-12-004

Details and patient eligibility

About

This clinical trial aims to learn the impact of dexmedetomidine on the minimum alveolar concentration blunting the adrenergic response (MAC-BAR) of sevoflurane to carbon dioxide pneumoperitoneum in patients undergoing laparoscopic cholecystectomy. It will also learn about the effect of dexmedetomidine on hemodynamic parameters. The main questions are:

• Does dexmedetomidine reduce the MAC-BAR of sevoflurane required to suppress the sympathetic response to carbon dioxide pneumoperitoneum?
• Would dexmedetomidine administration dose-dependently reduce the minimum alveolar concentration blunting the adrenergic response of sevoflurane required to suppress the sympathetic response to carbon dioxide pneumoperitoneum? Researchers will compare low-dose dexmedetomidine to high-dose dexmedetomidine to see if dexmedetomidine works to treat postoperative negative behavior change and emergence delirium.

Participants will:

• Take intravenous dexmedetomidine or 0.9% saline (a look-alike substance that contains no drug)
• Study drug infusions were initiated 15 minutes prior to anesthesia induction, allowing a minimum of 30 minutes to elapse before surgical incision to achieve steady-state plasma and brain concentrations.

Full description

Laparoscopic (minimally invasive) surgery has several advantages over open surgery, including less tissue damage, faster recovery, and fewer complications. This has led to widespread use of laparoscopic techniques. However, the inflated carbon dioxide gas used to create the surgical space during laparoscopic surgery causes significant changes in the body's normal blood pressure and heart function.

The anesthetic drug sevoflurane is commonly used during these procedures, but higher doses are needed to adequately block the body's stress response to the inflated gas. The minimum alveolar concentration blunting the adrenergic response (MAC-BAR) measures the minimum anesthetic depth required to suppress the sympathetic/stress response in 50% of patients. Doctors use MAC-BAR values to help determine the appropriate anesthetic dose to maintain hemodynamic stability. Unfortunately, using higher sevoflurane doses to reach the necessary MAC-BAR increases the risk of low blood pressure, reduced heart function, and confusion after surgery.

The drug dexmedetomidine has properties that can help manage the body's stress response during surgery. Researchers wanted to see if dexmedetomidine could allow the use of lower, more stable doses of sevoflurane during laparoscopic procedures by reducing the body's reaction to the inflated gas.

The goal of this study was to evaluate how dexmedetomidine affects the MAC-BAR of sevoflurane needed to block the sympathetic/stress response to the inflated gas used in laparoscopic surgery.

Enrollment: 90 estimated patients

Sex: All

Ages: 18 to 45 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• 1. Aged 18-45 years.
• 2. American Society of Anesthesiologists (ASA) grade I - II.
• 3. Patients undergoing elective laparoscopic cholecystectomy.

Exclusion criteria

• 1. Inability to provide informed consent;
• 2. History of chronic pain or substance abuse;
• 3. Pregnancy;
• 4. Body mass index (BMI) ≥ 30 kg/m2;
• 5. Known allergies to the study medications;
• 6. Intake of medications within the last 72 hours that potential interfere with the determination of the MAC-BAR;
• 7. Any other condition deemed exclusionary by the investigators.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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90 participants in 3 patient groups, including a placebo group

Control group

Placebo Comparator group

Description:

The control group received volume-matched 0.9% saline infusions at identical rates.

Treatment:

Drug: normal Saline

Low-dose dexmedetomidine group

Experimental group

Description:

The low-dose dexmedetomidine group received a 75 μg/h loading dose over 15 minutes, followed by 60 μg/h maintenance infusion intravenously.

Treatment:

Drug: Dexmedetomidine low-dose

High-dose dexmedetomidine group

Experimental group

Description:

The high-dose dexmedetomidine group received a 150 μg/h loading dose over 15 minutes, followed by 120 μg/h maintenance infusion intravenously.

Treatment:

Drug: Dexmedetomidine high-dose