Dexmedetomidine Lowers Delirium After Hip Fracture Surgery
Key Takeaways
- In a multicenter randomized trial of adults aged 65 to 90 years undergoing hip fracture surgery under spinal anesthesia with fascia iliaca block in China, postoperative delirium within 72 hours occurred less often with dexmedetomidine sedation than with propofol sedation: 4.0% versus 7.8%.
- Higher-quality perioperative evidence from this study supports an association between dexmedetomidine sedation and a lower rate of early postoperative delirium within this specific protocol.
- Postoperative headache occurred in 1.7% of patients receiving dexmedetomidine and 3.4% receiving propofol.
- Pain scores, other postoperative complications, length of hospital stay, 30-day mortality, and sedation-related adverse events requiring intervention did not differ significantly between groups.
In a randomized trial of dexmedetomidine versus propofol sedation during hip fracture surgery, investigators conducted a multicenter, parallel-group study at 12 university-affiliated hospitals in China between September 2017 and July 2020. The trial included 834 adults aged 65 to 90 years with American Society of Anesthesiologists (ASA) physical status I to III who underwent hip fracture repair under spinal anesthesia. Of these patients, 422 were assigned to dexmedetomidine and 412 to propofol.
Patients and postoperative outcome assessors were blinded to treatment assignment, while anesthesia personnel administering the sedatives were aware of allocation. All patients received an ultrasound-guided fascia iliaca block before positioning, followed by spinal anesthesia and a standardized perioperative analgesic regimen.
The fascia iliaca block was performed with 20 mL of 0.375% ropivacaine approximately 30 minutes before positioning. Spinal anesthesia used 10 to 15 mg of isobaric ropivacaine. Dexmedetomidine was administered as 0.5 μg/kg over 15 minutes, followed by an infusion of 0.5 μg/kg/h. Propofol was administered by infusion. Sedation was titrated to a Bispectral Index of 70 to 80 and a Modified Observer's Assessment of Alertness/Sedation score of 4.
The primary outcome was postoperative delirium occurring within 72 hours after surgery. Patients underwent preoperative assessment and were evaluated twice daily on postoperative days 1 through 3. Assessors used the Richmond Agitation-Sedation Scale followed by the Confusion Assessment Method.
Postoperative delirium within 72 hours occurred in 17 of 422 patients receiving dexmedetomidine, or 4.0%, compared with 32 of 412 patients receiving propofol, or 7.8% (P = .021). Postoperative headache occurred in 7 of 422 patients receiving dexmedetomidine, or 1.7%, and 14 of 412 patients receiving propofol, or 3.4% (P = .04).
The investigators reported no significant between-group differences in pain scores, other postoperative complications, length of hospital stay, 30-day mortality, or sedation-related adverse events requiring intervention.
Several limitations affect interpretation. Delirium surveillance was limited to the first 72 postoperative hours, so episodes beginning later during hospitalization were not assessed. The trial also enrolled adults aged 65 to 90 years with ASA physical status I to III and excluded several higher-risk clinical groups, which limits generalizability to frailer or more medically complex patients.
The study was conducted within a specific perioperative protocol that included spinal anesthesia, fascia iliaca block, standardized postoperative analgesia, and targeted light sedation. The findings therefore apply most directly to patients managed within a similar clinical setting.
Overall, dexmedetomidine sedation was associated with a lower incidence of delirium during the first 72 hours after hip fracture surgery than propofol in this multicenter randomized trial. The study also reported fewer postoperative headaches with dexmedetomidine, while other measured postoperative and safety outcomes did not differ significantly between groups.
Clinician Questions
Which patients does the dexmedetomidine-versus-propofol delirium finding apply to after hip fracture surgery? The trial included adults aged 65 to 90 years with ASA physical status I to III undergoing hip fracture repair under spinal anesthesia at 12 university-affiliated hospitals in China. All patients were treated within a standardized regional anesthesia and analgesia protocol that included fascia iliaca block.
How was postoperative delirium measured after dexmedetomidine or propofol sedation? The primary outcome was delirium occurring within the first 72 hours after surgery. Patients were assessed preoperatively and twice daily on postoperative days 1 through 3 using the Richmond Agitation-Sedation Scale followed by the Confusion Assessment Method.
What perioperative protocol was used when dexmedetomidine was compared with propofol? Patients received an ultrasound-guided fascia iliaca block with 20 mL of 0.375% ropivacaine before positioning, followed by spinal anesthesia with 10 to 15 mg of isobaric ropivacaine and standardized postoperative analgesia. Sedation was targeted to a Bispectral Index of 70 to 80 and a Modified Observer's Assessment of Alertness/Sedation score of 4.
What were the main outcome differences between dexmedetomidine and propofol? Postoperative delirium within 72 hours occurred in 4.0% of patients receiving dexmedetomidine and 7.8% receiving propofol. Postoperative headache occurred in 1.7% and 3.4% of patients, respectively. Pain scores, other postoperative complications, length of hospital stay, 30-day mortality, and sedation-related adverse events requiring intervention did not differ significantly between groups.