The Influences of Clonidine Premedication on the Bispectral Index and Hemodynamics during the Induction of Anesthesia and Endotracheal Intubation with Propofol. |
Woo Jae Jeon, Myoung Soo Koh, Jae Hang Shim, Sang Yoon Cho, Jong Hoon Yeom, Woo Jong Shin, Kyoung Hun Kim |
Department of Anesthesiology, College of Medicine, Hanyang University, Seoul, Korea. goldnan@hanyang.ac.kr |
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Abstract |
BACKGROUND The bispectral index (BIS) has been used as an indicator of a sedative state. In this study, we investigated the influence of intravenous clonidine 2 or 3 microgram/kg on the bispectral index and cardiovascular response to anesthetic induction. METHODS The study design is prospective, randomized and double-blind. Ninety patients scheduled to undergo elective surgery under general anesthesia were divided into 3 groups.
Each group received no premedication (group 1, n = 30), clonidine 2 microgram/kg (group 2, n = 30) and clonidine 3 microgram/kg (group 3, n = 30). The sedation and responsiveness scores of the Modified Observer's Assessment of Alertness/Sedation Scale (MOAAS/S) were measured before induction and the BIS, blood pressure, and heart rate were measured at before induction, after propofol injection, and after intubation. RESULTS The BIS was significantly lower in groups 2 and 3 than in group 1 before anesthetic induction and intubation.
Mean blood pressure was significantly lower in groups 2 and 3 than in group 1 before anesthetic induction, after propofol infusion and after intubation. Heart rate was also significantly lower in groups 2 and 3 than in group 1 after intubation. The sedation score and MOAAS/S were significantly lower in groups 2 and 3 than in group 1. CONCLUSIONS Clonidine-premedicated patients appear to maintain stable hemodynamics during anesthetic induction and intubation. The bispectral index can be objectively used in clonidine-premedicated patients when evaluating the degree of sedation. |
Key Words:
alpha2-adrenoreceptor agonist; bispectral index; clonidine |
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