To explore the effects of bupivacaine liposomes in preemptive analgesia for iliofascial block on postoperative pain and postoperative delirium in elderly patients with hip fractures, to optimize perioperative analgesia strategies, to reduce the incidence of postoperative delirium, and to improve patient prognosis.

The incidence of hip fractures has risen significantly with population aging. In 2016, the incidence of hip fractures in China was 177 per 100,000 for women and 99 per 100,000 for men, and it is projected that the number of hip fracture surgeries worldwide will reach 6.3 million by 2050. Surgical treatment is preferred among elderly hip fracture patients, but postoperative delirium (POD) is a common complication, with an incidence rate of 4.0%-53.3%, which is much higher than that of elective surgery patients (3.6%-28.3%). POD is closely associated with increased morbidity, mortality and medical expenses, and its mechanism is complex, involving sleep disorders, acute traumatic stress and inflammatory responses.

Elderly people have underlying diseases such as decreased multi-system functions (for example, organ-specific or chronic diseases) and decreased sensory functions (for example, visual and hearing impairments), and hip fractures can cause pain and functional loss. Pain is A Class A risk factor for POD, and about 42 percent of elderly patients with hip fractures experience moderate to severe pain during the acute phase. Pain not only triggers the release of inflammatory factors but also reduces sleep quality, further increasing the risk of POD. Therefore, effective perioperative analgesia is crucial for reducing the incidence of POD.

Regional nerve block analgesia (such as iliofascial block, FIB) has been widely used in recent years because of its definite analgesic effect and few side effects. Bupivacaine liposomes, as a new type of long-acting local anesthetic, can achieve stable drug release within 72 hours after injection and provide long-acting analgesia, but its effect on POD is not yet clear. This study aims to explore the effect of bupivacaine liposomes on preemptive analgesia of iliofascial block on postoperative pain and POD in elderly patients with hip fractures.

Inclusion Criteria:

• Patients with hip fractures scheduled for surgical treatment (including femoral neck fractures, intertrochanteric fractures, and fractures more than 5 cm below the lesser trochanter of the femur).
• Age ≥65 years.
• American Society of Anesthesiologists (ASA) grade I - III.
• The patient or family member signed the informed consent form

Exclusion Criteria:

• Compound injuries (such as combined fractures of the head, chest, pelvis, or limbs).
• Have a clear history of mental illness or are taking psychotropic drugs.
• Preoperative delirium or the use of delirium-related medications (such as olanzapine).
• A history of acute cerebrovascular disease (cerebral infarction or cerebral hemorrhage) within 6 months.
• Patients requiring sedation or postoperative coma due to the condition.
• Allergy to amide local anesthetics.
• Severe arrhythmia or liver or kidney dysfunction