Dexmedetomidine Supplemented Analgesia and Delirium After Hip Fracture Surgery

Impact of Dexmedetomidine Supplemented Analgesia on Delirium and Long-term Outcomes in Elderly After Hip Fracture Surgery: A Multicenter, Double-blinded, Randomized Controlled Trial

Delirium is common in the elderly after hip fracture surgery, and is associated with worse outcomes. The investigators hypothesize that, for elderly patients after hip fracture surgery, dexmedetomidine supplemented analgesia can reduce the incidence of delirium and improve the long-term outcomes.

Delirium is a common complication in patients after hip fracture surgery and is associated with worse outcomes, including prolonged hospital stay, poor functional recovery, decreased cognitive function, increased health care costs, and elevated mortality rate.

The etiology of delirium is multifactorial and include severe pain and sleep disturbances after surgery, as well as surgery-related inflammation. Dexmedetomidine is a selective alpha 2 receptor agonist. It exerts sedative effects by activating the endogenous sleep-promoting pathway and leads to a state like non-rapid eye movement sleep. It produces analgesic effects by activating the alpha2a adrenergic receptor subtype in the spinal cord. Perioperative dexmedetomidine also alleviates the degree of surgery-related inflammation.

Previous studies showed that, for elderly patients admitted to the intensive care unit after non-cardiac surgery, low-dose dexmedetomidine infusion improved subjective sleep quality and reduced delirium early after surgery; it also increased survival up to 2 years and improved life quality in 3-year survivors. The investigators hypothesize that dexmedetomidine supplemented patient-controlled analgesia can also reduce delirium and improve long-term outcomes in elderly patients after hip fracture surgery.

Inclusion Criteria:

• Age ≥ 65 years but < 90 years;
• Scheduled to undergo hip fracture surgery;
• Planned to use patient-controlled intravenous analgesia (PCIA) after surgery.

Exclusion Criteria:

• Refuse to participate in this study;
• Preoperative history of schizophrenia, epilepsy, Parkinsonism, or myasthenia gravis;
• Inability to communicate in the preoperative period because of coma, profound dementia or language barrier;
• Preoperative obstructive sleep apnea (diagnosed sleep apnea syndrome or a STOP-Bang score ≥3 combined with a serum bicarbonate ≥28 mmol/L);
• Sick sinus syndrome, severe sinus bradycardia (< 50 beats per minute), or second-degree or above atrioventricular block without pacemaker;
• Severe hepatic dysfunction (Child-Pugh class C);
• Severe renal dysfunction (requirement of renal replacement therapy before surgery);
• American Society of Anesthesiologists physical status >IV, or estimated survival ≤24 h.