ABSTRACT
Objective:
To calculate the effective dose (ED) of dexmedetomidine for caesarean section under spinal anaesthesia.
Methods:
Consecutive parturients scheduled for caesarean section under spinal anaesthesia were included. The loading dose of dexmedetomidine was evaluated using the up-and-down method, starting at 1.0 µg kg−1 and a step size of 0.1 µg kg−1. The loading dexmedetomidine was administrated by the venous route for 10 min, and afterwards a maintenance dose began at a rate of 0.3 µg kg−1 h−1 in all parturients. Adequate sedation was defined as a Ramsay sedation score ≥3. The ED50 and ED95 of loading dexmedetomidine were calculated using probit regression.
Results:
The ED50 and ED95 of loading dexmedetomidine for adequate sedation were 0.82 µg kg−1 (95% confidence intervals [CI] 0.73–0.89 µg kg−1) and 0.96 µg kg−1 (95% CI 0.90–1.39 µg kg−1), respectively.
Conclusion:
The ED50 and ED95 of loading dexmedetomidine to achieve adequate sedation were 0.82 µg kg−1 and 0.96 µg kg−1 for caesarean section under spinal anaesthesia.