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The reduction in minimum alveolar concentration for tracheal extubation after clonidine premedication in children
Yuichi Yaguchi1, Shinichi Inomata, Shin-ichi Kihara
1Department of Anesthesiology, Institute of Clinical Medicine, University of Tsukuba, Tsukuba City, Ibaraki, Japan.
Insights
Oral clonidine premedication reduced the minimum alveolar concentration for tracheal extubation (MAC-ex) in children receiving sevoflurane anesthesia. This study found that clonidine did not prolong emergence from anesthesia, suggesting a safe anesthetic approach.
Area of Science:
- Anesthesiology
- Pediatric Anesthesia
- Pharmacology
Background:
- The impact of clonidine on the minimum alveolar concentration for tracheal extubation (MAC-ex) is not well understood.
- Clonidine may potentially extend the duration of anesthesia emergence.
Purpose of the Study:
- To investigate the effect of oral clonidine premedication on MAC-ex.
- To evaluate the emergence characteristics from sevoflurane anesthesia in pediatric patients.
Main Methods:
- Sixty pediatric patients (2-9 years) received placebo, 2 microg/kg, or 4 microg/kg of oral clonidine 100 minutes before anesthesia.
- Anesthesia was induced and maintained with sevoflurane in oxygen and air.
- MAC-ex was determined using the modified Dixon's up-and-down method.
Main Results:
- MAC-ex for sevoflurane significantly decreased in a dose-dependent manner with clonidine.
- Mean MAC-ex values were 1.63% (Control), 1.04% (2 microg/kg), and 0.66% (4 microg/kg).
- No significant differences were found in eye-opening or awakening times between the control and 4 microg/kg clonidine groups.
Conclusions:
- Oral clonidine premedication effectively reduces the MAC-ex for sevoflurane in a dose-dependent manner.
- Clonidine premedication does not prolong emergence from sevoflurane anesthesia in pediatric patients.
Unlabelled:
The effects of clonidine on minimum alveolar concentration for tracheal extubation (MAC-ex) have not been elucidated. Clonidine may lead to prolonged emergence from anesthesia. We investigated the effects of oral clonidine premedication on MAC-ex and examined the emergence properties of sevoflurane in children. Sixty ASA physical status I pediatric patients, aged from 2 to 9 yr, were randomly divided into one of three groups and received placebo, clonidine 2 microg/kg, or clonidine 4 microg/kg (n = 20 each) orally, 100 min before the induction of anesthesia. The induction of anesthesia, tracheal intubation, and maintenance of anesthesia were performed with sevoflurane in air and oxygen. MAC-ex was defined according to the modification of Dixon's up-and-down method, with 0.25% as a step size. In addition, in the Control and 4 microg/kg groups, the time from tracheal extubation to spontaneous eye opening (eye-opening time) and the time from tracheal extubation to leaving the operating room (awakening time) were recorded. MAC-ex for sevoflurane (mean +/- SD) was 1.63% +/- 0.13%, 1.04% +/- 0.26%, and 0.66% +/- 0.09% respectively in the Control group, 2 microg/kg group, and 4 microg/kg group. Significant differences were observed among the three groups. The eye-opening times were 5.7 +/- 3.5 min in the Control group and 5.1 +/- 1.0 min in the 4 microg/kg group. The awakening times were 9.7 +/- 3.7 min in the Control group and 9.2 +/- 3.8 min in the 4 microg/kg group. No significant differences were observed among the groups.
Implications:
Oral clonidine premedication decreased MAC for tracheal extubation for sevoflurane dose dependency and did not prolong emergence from anesthesia.