The Optimal Doses of Dexmedetomidine Combined with Propofol in Patients in Hysteroscopic Surgery: A Randomized...

Dexmedetomidine has been reported to be utilized in conjunction with propofol during hysteroscopic surgery. However, both dexmedetomidine and propofol have benefits and side-effects, and the optimal doses of dexmedetomidine when utilized in combination with propofol during hysteroscopic surgery remain unestablished.

One hundred and fifty patients undergoing hysteroscopic surgery at the affiliated hospital of North Sichuan Medical College were randomly divided into five groups and administered dexmedetomidine at a dose of 0.4 µg/kg, 0.6 µg/kg, 0.8 µg/kg, or 1.0 µg/kg, or saline, prior to anesthesia induction. Before the surgery, propofol was administered via target-controlled infusion using a pump with the Marsh model. The EC₅₀ of propofol was determined using an up-and-down sequential method with an adjacent concentration gradient of 1.2 to prevent purposeful movements. Hemodynamic parameters and adverse events related to anesthesia were also evaluated. The duration of the procedure and recovery, the amount of propofol required, and the postoperative recovery characteristics were documented.

The EC50 of propofol was significantly lower in the Dex 0.6, Dex 0.8, and Dex 1.0 groups compared to the S group (p<0.05). As the dose of dexmedetomidine increased, the demand for propofol gradually decreased (p<0.01), whereas the incidence of respiratory depression decreased (p<0.01). Nevertheless, the incidence of bradycardia slightly increased (p=0.02). No significant differences in the incidence of hypotension were observed among the five groups (p>0.05). The patients in the Dex1.0 groups had higher postoperative comfort scores than those in the S group. At both t1 and t2, Ramsay scores were higher in the Dex0.8 and Dex1.0 groups than in the S group (p<0.05). No significant differences were observed in the VAS scores among the five groups.

Dexmedetomidine 0.8 µg/kg offers an optimal balance between propofol-sparing effects, sedation quality, and manageable side effects for hysteroscopic surgery.

Date of registration: 24/05/2020, registration number: ChiCTR2000033220.