A Comparative Study Between Ultrasound Guided Erector Spinae Plane Block and Combined Ultrasound Guided Pericapsular Nerve Group and Lateral Femoral Nerve Block Following Total Hip Arthroplasty

The patients will be randomized into 2 equal groups by a computer-generated random numbers table, named group A, B.

Group A: patients will receive PENG and LFCN blocks.

Group B: Patients will receive ESP block, which will be the control group.

After obtaining approval from Ain Shams hospital academic and ethical committee, written, informed and valid consent will be taken from all participants after proper explanation of the study procedure and the expected outcome in a clear language for patients of either sex, aging from 18 to 65 years old, ASA physical status (I, II) scheduled for total hip arthroplasty surgeries.

Patients with the following criteria will be excluded from the study: Patient refusal, ASA physical status III or more, known allergy to any of the study drugs, infection at the site of injection, history of cardiovascular, renal, hepatic or neuromuscular diseases, history of any psychiatric disorder, presence of any coagulopathy, chronic opioid, gabapentin or pregabalin use, BMI more than 35 kg/m2. Patients will be randomly assigned to either both PENG and LFCN blocks and ESP block with ultrasound guidance before spinal anesthesia.

After IV access insertion and oxygen nasal cannula application, ECG (Electrocardiography), pulse oximeter, noninvasive blood pressure monitoring will be applied for all patients, sedation in the form of midazolam 0.02mg/kg with or without fentanyl 0.5-1 mcg/kg will be administered to any of the patients who felt discomfort or could not tolerate the procedure.

For (Group A) PENG block will be done before spinal anesthesia ultrasound-guided using a curvilinear array ultrasound transducer (2-5 MHz) Sono site M-turbo ultrasonography. While the patient is in the supine position, the probe will be placed in parallel to the inguinal crease and will be rotated clockwise until visualizing femoral artery, iliopsoas muscle tendon, anterior inferior iliac spine (AIIS) and ilio-pubic eminence. 22G 80 mm needle will be inserted in plane from lateral side of probe until tip of needle touch iliopubic eminence, after negative aspiration 20 ml of bupivacaine 0.5% will be injected. Success of injection will be confirmed by fluid spreading between the iliopsoas tendon and periosteum of iliopubic eminence.

LFCN block will be performed using linear ultrasound probe (10-15 MHz). while the patient is in supine position the probe will be directed caudally to AIIS until visualizing LFCN between sartorius muscle and tensor fascia latae. 5 ml of bupivacaine will be injected after negative aspiration.

For (Group B), ESP block will be done before spinal anesthesia in the lateral decubitus position by curvilinear probe (2-5 MHz). Probe will be placed on the third lumber vertebra in the parasagittal line to identify the transverse process of L3. Needle will be directed in plane caudo-cephalic to the lateral edge of L3 transverse process. 30 ml of bupivacaine will be injected under visualization along the erector spinae plane. Correct placement will be defined by spread of local anesthetic cranially and caudally from injection point, dissecting the plane between the transverse processes and erector spinae muscles.

Spinal anesthesia will be chosen as the main anesthetic technique by injecting 3-3.5 ml of hyperbaric bupivacaine 0.5% by 24 G pencil-point needle at L2-L3 or L3-L4 space with 25 ug of fentanyl as adjuvant while patient is in setting position.

In postoperative period all patients will receive the same adjuvant multimodal analgesia which will be 1000 mg of paracetamol with or without 30 mg ketorolac depending on comorbidities and depending on the patients" needs.