Iliopsoas Plane Block vs PENG Block for Hip Arthroplasty

Comparison of the Effect of Ultrasound-guided Iliopsoas Plane Block and PENG Block on Postoperative Analgesia Management in Patients Undergoing Hip Arthroplasty: A Randomized, Prospective Study

Hip arthroplasty is one of the most common orthopedic procedures especially in elderly patients due to deformation of joints. Patients may complain of severe pain due to surgical trauma and prosthesis. Regional anesthesia methods may be performed to reduce opioid consumption and opioid-related side effects. The hip joint consists of the femoral head and the acetabulum. Sensory innervation of the hip joint is provided by the femoral nerve, obturator nerve, articular branches of the sciatic nerve, and superior gluteal nerve. Because of the increasing use of ultrasound (US) in anesthesia practice, US-guided nerve blocks are widely used. Pericapsular nerve group block (PENG block) is a novel fascial block defined by Arango et al. This block aims to block the femoral nerve and the accessory obturator nerve by injecting local anesthetic between the pubic ramus and the psoas tendon. The iliopsoas plane block (IPB) is a new block defined by Nielsen et al. It does not cause a motor block, but selectively blocks the sensory branches of the hip joint originating from the accessory obturator nerve and the femoral nerve. This prospective study compares the efficacy of PENG block and IPB for postoperative analgesia management in patients undergoing hip arthroplasty with a prosthesis.

Hip arthroplasty is one of the most common orthopedic procedures especially in elderly patients due to deformation of joints. Patients may complain of severe pain due to surgical trauma and the prosthesis. Opioid agents are commonly used for analgesia management. However, opioids have adverse effects such as nausea, vomiting, sedation, and respiratory depression. Regional anesthesia methods may be performed to reduce opioid consumption and opioid-related side effects. The hip joint consists of the femoral head and the acetabulum. Sensory innervation of the hip joint is provided by the femoral nerve, obturator nerve, articular branches of the sciatic nerve, and superior gluteal nerve. Skin innervation of the lateral femur is supplied by the lateral cutaneous femoral nerve. The upper anterior part of the thigh is innervated by the genitofemoral and ilioinguinal nerves. These nerves originate from the lumbar and sacral plexus. The innervation of the hip joint is complex, and the selection of the blocking technique is essential after these operations. Pericapsular nerve group block (PENG block) is a novel fascial block defined by Arango et al. In this block, it is aimed blocking the femoral nerve and the accessory obturator nerve by injecting local anesthetic between the pubic ramus and the psoas tendon. By blocking these nerves, anterior hip analgesia is provided. It is a safe and effective method as it is applied superficially and under ultrasound guidance. In radiological and cadaver studies, it has been reported that total hip analgesia can be provided by blocking the lateral femoral cutaneous, genitofemoral, obturator, and femoral nerves when high volume is applied. Studies evaluating PENG block efficacy are limited in the literature. The iliopsoas plane block (IPB) is a new block defined by Nielsen et al. It does not cause a motor block, but selectively blocks the sensory branches of the hip joint originating from the accessory obturator nerve and the femoral nerve. There is a study showing that it does not cause a motor block in healthy volunteers. Although there are case series in the literature reporting that it provides hip joint analgesia, there is no clinical study yet. This prospective, randomized study aims to compare the efficacy of PENG block and IPB for postoperative analgesia management in patients undergoing hip arthroplasty with a prosthesis. Our primary aim is to compare postoperative opioid consumption, secondary aim is to evaluate pain scores (Numerical Rating Scale-NRS), quadriceps motor block (paresis or paralysis in knee extension), and side effects (allergic reaction, nausea, vomiting, etc.) associated with opioid use.

The patient and the outcomes assessor who performs postoperative pain evaluation will not know the group.

While the patient is in the supine position, the probe will be placed in the transversal plane distal to the anterior superior iliac spine. Then, the probe will be rotated approximately 30° counterclockwise and slid along the inguinal ligament until the femoral head enters the edge of the acetabulum. The block needle will be passed through the sartorius and iliopsoas muscles and the iliopsoas plane between the iliopsoas muscle and the iliofemoral ligament will be reached. After the block site is confirmed with 5 ml of saline, 10 ml of local anesthetic solution containing 0.25% bupivacaine will be injected.

The probe will be placed on the anterior inferior iliac crest in the transverse plane. Then, the pubic ramus will be visualized by rotating 45 degrees. The femoral artery, iliopubic process, and psoas muscle will be visualized. The needle will be punctured with the in-plane method to reach between the pubic ramus and the psoas tendon. After the block site is confirmed with 5 ml of saline, 20 ml of local anesthetic solution containing 0.25% bupivacaine will be injected.

Intravenous 0.5 mg/kg tramodol and 400 mg ibuprofen will be administered to all patients 30 minutes before the end of the surgical procedure. In the postoperative period, patients will be administered ibuprofen iv 400 mg 3x1. Postoperative patient evaluation will be performed by another pain nurse who is unaware of the procedure. Patients in all groups will be attached to IV PCA containing 10 mcg/ml fentanyl, 10 mcg bolus without infusion dose, 10 min lock time protocol. If the NRS score is ≥ 4, 0.5 mg kg-1 iv meperidine will be administered as a rescue analgesic.

Postoperative pain assessment will be performed using the NRS score (0 = no pain, 10 = the most severe pain felt)

Quadriceps muscle strength (knee extension and hip adduction) will be evaluated according to the Oxford muscle strength rating

Inclusion Criteria: Patients with ASA classification I-III, Aged 20-80 years Who will be scheduled for hip arthroplasty under general anesthesia. Exclusion Criteria: Patients who have a history of bleeding diathesis, Take anticoagulant therapy, History of chronic pain before surgery, Multiple trauma, Who cannot assess their pain (dementia), Who have been operated under spinal or epidural anesthesia, Who have an infection in the area and do not accept the procedure

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