Preoperative low-dose dexmedetomidine reduces postoperative delirium in elderly patients with hip fracture under spinal anesthesia: A randomized, double blind, controlled clinical study

Study objective

This study aims to evaluate the effects of preoperative low-dose dexmedetomidine administration for one night on the incidence of postoperative delirium in elderly patients with hip fracture.

Design

This was a randomized, double blind, placebo-controlled clinical trial.

Setting

Lu'an Hospital of Anhui Medical University, Anhui, China.

Patients

Patients aged ≥65 years with hip fracture (femoral neck, intertrochanteric, or subtrochanteric fracture) and scheduled for surgical repair(total hip arthroplasty, hemiarthroplasty, internal fixation with cannulated screw or intramedullary nail) under spinal anesthesia were eligible.

Intervention

Patients were randomized 1:1 to receive low-dose dexmedetomidine or placebo from 8:00 pm before surgery to 8:00 am the day of surgery.

Measurements

The primary outcome was the incidence of POD between postoperative days 1 and 7 or at hospital discharge. The secondary outcome measures included preoperative sleep quality, days of delirium, visual analog scale scores in quiet and active states on postoperative days 1–3, C-reactive protein level, number of analgesic pump presses, activities of daily living score at discharge and postoperative hospital stay. Perioperative adverse events were recorded.

Main results

Of the 248 patients randomized to the placebo (n = 124) or dexmedetomidine (n = 124) group, 233 participants (117 in the placebo group and 116 in the dexmedetomidine group) were included in the modified intention-to-treat analysis. The incidence of POD was lower in the dexmedetomidine group (10.3 %) than placebo group (22.2 %, P = 0.014). Compared to the placebo group, the dexmedetomidine group had higher preoperative Leeds Sleep Evaluation Questionnaire (LSEQ) scores (P < 0.001), lower preoperative Insomnia Severity Index (ISI) scores (P < 0.001), and lower postoperative C-reactive protein (CRP) levels (P < 0.001). No differences in other secondary outcomes and perioperative adverse events were observed between the two groups.

Conclusion

In patients aged ≥65 years undergoing elective hip fracture surgery under spinal anesthesia, continuous overnight administration of low-dose dexmedetomidine improved sleep quality on the night before surgery and reduced the incidence of POD.