Effective dose of dexmedetomidine to induce adequate sedation in elderly patients under spinal anesthesia.
10.4097/kjae.2015.68.6.575
- Author:
Ki Ho KO
1
;
In Jung JUN
;
Sangseok LEE
;
Yunhee LIM
;
Byunghoon YOO
;
Kye Min KIM
Author Information
1. Department of Medicine, Jodo Subcenter, Jindo Public Health Center, Jindo, Korea.
- Publication Type:Randomized Controlled Trial ; Original Article
- Keywords:
Aged;
Dexmedetomidine;
Sedation;
Spinal anesthesia
- MeSH:
Aged*;
Anesthesia, Spinal*;
Dexmedetomidine*;
Hemodynamics;
Humans;
Hypotension;
Logistic Models;
Oxygen;
Vital Signs
- From:Korean Journal of Anesthesiology
2015;68(6):575-580
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: During sedation with dexmedetomidine, a dose adjustment may be needed based on the invasiveness of the procedure, the patient's general condition, and their age. We aim here to determine the effective dose (ED) of dexmedetomidine to induce an adequate depth of sedation in elderly patients undergoing spinal anesthesia. METHODS: In this study, 47 patients aged 65 years or older, American Society of Anesthesiologists physical status I or II, undergoing spinal anesthesia were included. Patients were randomly allocated into group I, II, III, IV or V according to the dexmedetomidine loading dose of 0.1, 0.3, 0.5, 0.7 and 1.0 microg/kg, respectively. After spinal anesthesia, the assigned loading dose of dexmedetomidine was infused intravenously for 10 minutes, after which infusion was maintained at a rate of 0.3 microg/kg/h for the next 10 minutes in all groups. We assessed the depth of sedation with the Ramsay sedation scale every five minutes and measured vital signs and the oxygen saturation. The ED50 and ED95 of dexmedetomidine to obtain adequate sedation (Ramsay sedation score > or = 3) upon the completion of the loading dose were calculated with logistic regression. RESULTS: The ED50 and ED95 of dexmedetomidine for adequate sedation were 0.29 microg/kg (95% confidence intervals [CI] 0.14-0.44) and 0.86 microg/kg (95% CI 0.52-1.20), respectively. Hypotension was frequent in groups IV, V compared to groups I, II, III (31.6 vs. 3.6%, P = 0.013). CONCLUSIONS: ED95 of dexmedetomidine loading dose for adequate sedation is 0.86 microg/kg. However, dose higher than 0.5 microg/kg can lead to hemodynamic instability.
