Objective To evaluate the effect of preoperative application of dexmedetomidine nasal spray on postoperative sleep circadian rhythm and cognitive function in breast cancer surgery patients with anxiety.

Methods Patients with preoperative anxiety were screened using self-rating anxiety scale, and a total of 80 breast cancer patients scheduled for surgery with self-rating anxiety scale score more than 50 points were enrolled. The patients were divided into the dexmedetomidine hydrochloride group (DEX group, n = 40) and the control group (n = 40) using a random number table method. The DEX group was given 100 μg (0.2 mL) of dexmedetomidine via nasal spray 40 minutes before surgery, while the control group was given 0.2 mL of 0.9% sodium chloride solution via nasal spray at the same time point. The Richards-Campbell sleep questionnaire (RCSQ) scores, dynamic sleep data, Mini-Mental State Examination (MMSE) scores, visual analog scale (VAS) scores, usage of analgesia pump, and incidence of adverse reactions of patients were compared between the two groups.

Results On postoperative day 1, day 2, and day 4, the total RCSQ scores, MMSE scores, and total sleep duration of patients in the DEX group were higher than those in the control group (P ＜ 0.05 to P ＜ 0.01); among the scores in each dimension of RCSQ, the sleep depth, re-sleeping ability, and overall sleep quality scores of patients in the DEX group were better than those in the control group (P ＜ 0.05 to P ＜ 0.01), and the frequency of nocturnal awakenings and sleep latency scores in the DEX group were higher than those in the control group (P ＜ 0.05 to P ＜ 0.01); the sleep latency in the DEX group was shorter than that in the control group (P ＜ 0.05 to P ＜ 0.01); the proportion of deep sleep in the DEX group was higher than that in the control group, and the number of fragmented sleep episodes was reduced compared to the control group (P ＜ 0.05 to P ＜ 0.01). At 6 hours after surgery, the VAS scores in the DEX group were significantly lower than those in the control group (P ＜ 0.01). There were no statistically significant differences in the number of postoperative analgesia pump attempts or rescue analgesia rate between the two groups (P ＞ 0.05). The overall incidence of postoperative cognitive dysfunction and adverse reactions in the DEX group was lower than that in the control group (P ＜ 0.05).

Conclusions Preoperative application of dexmedetomidine hydrochloride nasal spray can effectively improve the postoperative sleep structure and sleep quality of breast cancer surgery patients with anxiety, and help reduce the incidence of postoperative cognitive dysfunction.