Remifentanil and Midazolam on Propofol for Loss of Consciousness in Elderly Patients
Status:
Unknown status
Trial end date:
2016-10-01
Target enrollment:
Participant gender:
Summary
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 in elderly patients. 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 elderly patients (over 65 years old) 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 0.125
mcg/kg/min remifentanil infusion for 5 min prior to propofol administration. The patients in
group PMR will receive 0.015 mg/kg bolus dose of midazolam 1 min after the start of the
remifentanil infusion. Initial propofol dose will be 0.5 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
3 min after propofol administration. When 'success', the next patient will receive the same
dose(in 18/19 probability) or 0.125 mg/kg lower dose(in 1/19 probability) of propofol. When
'failure', the next patient will receive 0.125 mg/kg higher dose of propofol at induction
period.