Most women with breast cancer are prone to postoperative sleep disturbances (POSD). Little is known about the differences between sevoflurane and propofol combined with dexmedetomidine on POSD in the same context. We investigated the effect of intra-operative sevoflurane or propofol combined with intravenous dexmedetomidine on the incidence of POSD and postoperative sleep structures.

A monocentric, randomized-controlled, double-blind trial. Female patients undergoing radical surgery for breast cancer were randomly assigned to receive sevoflurane and placebo, sevoflurane and dexmedetomidine, propofol and placebo, or propofol and dexmedetomidine. Dexmedetomidine was administered at 1.0 μg kg⁻¹ infusion 15 min before induction, then infused at 0.4 μg kg⁻¹ h⁻¹ until the surgical drain started to be placed. The primary outcome was the incidence of POSD within the postoperative first three days (defined as an Athens Insomnia Scale score ≥ 6 points on at least one day of postoperative first three days). The secondary outcome was the duration of sleep structures, collected from the Fitbit Charge 2® smart bracelet (Fitbit, Inc., San Francisco, CA, USA).

There were 188 women analyzed with the modified intention-to-treat method. The incidences of POSD in the dexmedetomidine and placebo groups were similar (p = 0.649). In the sevoflurane sedation strategy, dexmedetomidine decreased nocturnal wakefulness on postoperative first day (p = 0.001). In the propofol sedation strategy, dexmedetomidine increased nocturnal deep sleep on postoperative first (p < 0.001) and third (p < 0.001) days.

Intra-operative infusion of dexmedetomidine had no significant effect on POSD but decreased nocturnal wakefulness in the sevoflurane group and increased nocturnal deep sleep in the propofol group.

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