A randomized controlled trial of the effect of preoperative dexmedetomidine on the half maximal effective concentration of propofol for successful i-gel insertion without muscle relaxants.
J Anesth
; 29(3): 338-345, 2015 Jun.
Article
en En
| MEDLINE
| ID: mdl-25394762
ABSTRACT
BACKGROUND:
Dexmedetomidine is a useful anesthetic adjuvant for general anesthesia. We determined whether preoperative dexmedetomidine administration could reduce the half maximal effective concentration (EC50) of propofol for successful i-gel insertion without muscle relaxants.METHODS:
Thirty-seven patients were randomly allocated to one of two groups. In the dexmedetomidine group (n = 19), dexmedetomidine (1 µg/kg) was loaded for 10 min preoperatively. In the control group (n = 20), the same volume of 0.9% normal saline was administered in the same manner. The EC50 of propofol for successful i-gel insertion was determined using Dixon's up-and-down method. The EC50 of propofol was calculated as the midpoint concentration after at least six crossover points had been obtained. For successful i-gel insertion, all of the following four factors were required(1) no major movement of the body within 1 min of insertion, (2) no significant resistance to mouth opening, (3) cough ≤2, and (4) visible square wave capnogram without air leakage at a peak airway pressure of <10 cmH2O. Mean blood pressure (MBP) and heart rate (HR) were monitored during the peri-insertion period of i-gel.RESULTS:
The EC50 of propofol for successful i-gel insertion was 3.18 µg/mL in the dexmedetomidine group and 6.75 µg/mL in the control group (p < 0.001). The incidence of hypotension (MBP <80% of the baseline) during the peri-insertion period of i-gel was higher in the control group (p = 0.001), whereas the incidence of bradycardia (HR <80% of the baseline) was higher in the dexmedetomidine group (p = 0.001).CONCLUSIONS:
Preoperative dexmedetomidine reduced the EC50 of propofol for successful i-gel insertion without muscle relaxants.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Propofol
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Dexmedetomidina
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Anestesia General
Tipo de estudio:
Clinical_trials
Límite:
Adult
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
J Anesth
Asunto de la revista:
ANESTESIOLOGIA
Año:
2015
Tipo del documento:
Article
País de afiliación:
Corea del Sur