Low-Dose Dexmedetomidine Attenuates the Dose Requirement of Propofol for Suppression of Body Movement in Patients Undergoing Operative Hysteroscopy.

BACKGROUND

Dexmedetomidine is a central α-2 adrenergic agonist characterized by its sedative, analgesic, and sympatholytic properties. We investigated the effect of low dose dexmedetomidine on the dose-response relationship of propofol for sedation in patients undergoing operative hysteroscopy.

METHODS

The patients were firstly randomly assigned to receive either propofol and fentanyl (P group, n = 100) or a combination of propofol, dexmedetomidine, and fentanyl (DP group, n = 100). Subsequently, participants were further randomized to receive propofol at doses of 1.0, 1.5, 2.0, and 2.5 mg/kg in P group, and 0.5, 1.0, 1.5, and 2.0 mg/kg in DP group. The primary outcome of this study was the incidence of patients achieving effective propofol dose, defined as the dosage at which a patient exhibited no body movement during cervical dilation and had a BIS value below60. The Probit method was used to calculate the ED50 and ED95 of propofol in the inhibition of body movement reaction to cervical dilation during hysteroscopic surgery.

RESULTS

The ED50 and ED95 values for propofol in the inhibition of body movement reaction to cervical dilation during hysteroscopic surgery were 1.781 (95% CI 1.507~2.118) and 4.670 (95% CI 3.555~7.506) mg/kg, respectively, in P group; while in the DP group, these values were found to be 0.983 (95% CI 0.800~1.173) and 2.578 (95% CI 2.013~3.895) mg/kg.

CONCLUSION

Low-dose dexmedetomidine (0.5μg/kg) could reduce the requirement of propofol for suppression of body movement in patients undergoing operative hysteroscopy.