Remifentanil and Midazolam on Propofol for Loss of Consciousness

Yonsei University

Status: Completed

Conditions: Anesthesia

Treatments: Drug: Midazolam; Drug: Remifentanil; Drug: Propofol

Study type: Interventional

Funder types: Other

Identifiers

NCT02536690

2015-0183-004

Details and patient eligibility

About

Propofol in combination with remifentanil or midazolam can result in synergistic or additive effect.

The patients who are scheduled to undergo general anesthesia are enrolled in this study. 120 patients will be randomly allocated to 3 groups(P, PR, PMR). The patients in group P will receive general anesthesia only with propofol and group PR and PMR will receive 0.25 mcg/kg/min remifentanil infusion prior to propofol. The patients in group PMR will receive 0.03 mg/kg bolus dose of midazolam 1 min after start of the remifentanil infusion. 'Success' is defined as loss of both verbal response and eyelash reflex in 2 min after propofol administration. When 'success', the next patient will receive the same dose(in 18/19 probability) or 0.25 mg/kg lower dose(in 1/19 probability) of propofol. When 'failure', the next patient will receive 0.25 mg/kg higher dose of propofol at induction period.

Full description

Propofol is a well-known induction agent which can provide sound and quick hypnosis with anti-emetic effects. However, dose dependent hypotension or bradycardia have reported while using this agent. Propofol in combination with remifentanil or midazolam can result in synergistic or additive effect. There are not many studies which provide minimum dose of propofol to induce hypnosis in combination with these agents and advantage of the combination.

The patients who are scheduled to undergo general anesthesia are enrolled in this study. 120 patients will be randomly allocated to 3 groups(P, PR, PMR). Sample size have been decided due to the previous studies which have mentioned 40 participants as a adequate sample size for this biased coin design - up and down study.

After receiving informed consent, patients will be participated in this study. No premedication will be given to the patients before induction. The patients in group P will receive general anesthesia only with propofol and group PR and PMR will receive 0.25 mcg/kg/min remifentanil infusion for 5 min prior to propofol administration. The patients in group PMR will receive 0.03 mg/kg bolus dose of midazolam 1 min after the start of the remifentanil infusion. Initial propofol dose will be 1 mg/kg in each group and the dose will be changed by the result of prior study participant.

'Success' of this study will be defined as loss of both verbal response and eyelash reflex in 2 min after propofol administration. When 'success', the next patient will receive the same dose(in 18/19 probability) or 0.25 mg/kg lower dose(in 1/19 probability) of propofol. When 'failure', the next patient will receive 0.25 mg/kg higher dose of propofol at induction period.

Enrollment: 120 patients

Sex: Female

Ages: 20 to 50 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• The patients who are scheduled to undergo general anesthesia for a surgery.

Exclusion criteria

1. ASA class (American Society of Anesthesiologist physical status classification) II or higher
2. Patients with history of allergy or side effects on propofol, remifentanil, midazolam
3. BMI (body mass index) less than 20 or higher than 30
4. Pregnancy
5. Patients taking sedatives or hypnotic agents.

Trial design

120 participants in 3 patient groups

Group P

Active Comparator group

Description:

Induction with propofol bolus. Dose will be started at 1 mg/kg and will be adjusted as described in summary.

Treatment:

Drug: Propofol

Group PR

Active Comparator group

Description:

Induction with propofol and remifentanil. Remifentanil infusion 0.25 mcg/kg/min for 5 min followed by propofol bolus Propofol dose will be started at 1 mg/kg and will be adjusted as described in summary.

Treatment:

Drug: Propofol

Drug: Remifentanil

Group PMR

Active Comparator group

Description:

Induction with propofol, midazolam and remifentanil. Remifentanil infusion 0.25 mcg/kg/min for 5 min followed by midazolam 0.03 mg/kg bolus 1 min after remifentanil infusion start and propofol bolus administration. Propofol dose will be started at 1 mg/kg and will be adjusted as described in summary.

Treatment:

Drug: Propofol

Drug: Remifentanil

Drug: Midazolam