Analgesic Efficacy of Ultrasound-Guided Deep Iliacus Plane Block in Patients Undergoing Hip Fracture Surgery

This study is designed as a prospective, randomized, double-blind, sham-controlled clinical trial involving adult patients undergoing hip fracture surgery under spinal anesthesia.

Eligible participants will receive standard monitoring in accordance with the American Society of Anesthesiologists recommendations, including electrocardiography, noninvasive blood pressure measurement, and pulse oximetry. Spinal anesthesia will be performed under sterile conditions at the L3-L4 intervertebral level using 15 mg of isobaric bupivacaine.

Following completion of surgery, while the sensory effects of spinal anesthesia are still present, participants will be randomly allocated to one of two parallel study groups. Randomization will be performed using a computer-generated allocation sequence, and group assignments will be concealed using sequentially prepared sealed envelopes.

Participants assigned to the intervention group will receive an ultrasound-guided deep iliacus plane block on the surgical side. A low-frequency curvilinear ultrasound transducer will be positioned over the anterior hip region to identify the anterior inferior iliac spine, iliopubic eminence, iliopsoas muscle, psoas tendon, femoral nerve, and adjacent vascular structures. After identification of the target plane between the iliopsoas muscle and the anterior inferior iliac spine, a peripheral nerve block needle will be advanced using an in-plane approach. Following confirmation of appropriate needle-tip position, 30 mL of 0.25% bupivacaine will be administered.

Participants assigned to the control group will undergo an identical ultrasound-guided procedure and will receive 30 mL of normal saline as a sham block. Participants and postoperative outcome assessors will remain blinded to group allocation. The anesthesiologist performing the study intervention will not participate in postoperative outcome assessment.

All participants will receive a standardized multimodal postoperative analgesic regimen. Intravenous patient-controlled analgesia will contain tramadol at a concentration of 4 mg/mL, without a background infusion. The device will deliver 20 mg tramadol per patient-initiated bolus, with a 20-minute lockout interval and a maximum dose of 200 mg over four hours. Intravenous paracetamol 1 g will be administered routinely at the sixth postoperative hour. Intravenous dexketoprofen 50 mg will be provided as rescue analgesia when clinically required.

The primary outcome will be cumulative tramadol consumption during the first 24 postoperative hours. Pain intensity will be evaluated using the 0-10 Numerical Rating Scale, where 0 represents no pain and 10 represents the worst imaginable pain. Pain scores at rest and during movement will be recorded at predefined postoperative time points.

The sensory distribution of the block will be assessed approximately two hours after surgery, after resolution of the residual sensory effects of spinal anesthesia. Cold sensation will be evaluated using an alcohol-based swab over relevant lower-extremity and abdominal dermatomes. Participants will be asked to report any reduction, alteration, or loss of cold sensation compared with unaffected areas.

Additional outcomes will include rescue analgesic requirements, time to first rescue analgesia, patient-controlled analgesia demand frequency, presence and severity of motor block, postoperative nausea and vomiting, antiemetic requirements, block performance time, block-related complications, patient satisfaction, quality of recovery assessed using the Quality of Recovery-15 questionnaire at 24 hours, and duration of hospital stay.

The study aims to determine whether adding the deep iliacus plane block to standardized multimodal analgesia provides superior postoperative analgesia and reduces opioid requirements compared with standardized multimodal analgesia combined with a sham block.