Postoperative Analgesia Outcomes Of Pericapsular Nerve Group Block (PENG Block) Combined With Lateral Femoral Cutaneous Nerve Block After Hip Replacement Surgery: A Randomized Controlled Study

First, patients were explained about the study and asked to sign written informed consent if they agreed to participate in the study. Next, the patient was instructed to use the visual analogue scale (VAS) for pain score, as well as how to press the button to request pain relief. Then, a monitor was installed and operated to assess the clinical parameters (electrocardiogram, blood pressure, SpO2, arterial blood pressure, temperature). The patient was oxygenated 3-5 liters/minute and performed a peripheral intravenous line, with an 18G catheter, infused with 0.9% NaCl solution. Spinal anesthesia was administered with ropivacaine 0.5% and fentanyl.

During and after the surgery, a group of patients received intravenous morphine analgesia via PCA (concentration 1mg/ml, bolus dose of 1mg, lock time 10 minutes, maximum dose 10mg/4 hours). The remaining group of patients receive pain relief by PENG block and LFCN block. In this group, the ultrasound probe was placed horizontally from the anterior superior iliac spine, and was moved along the femoral arc defining the pubic spine. Then, the transducer was rotated 45 degrees, moved parallel to the femoral arch identifying the anterior inferior iliac spine (AIIS), iliopubic eminence (IPE) and inferior lumbosacral head. The ultrasound probe was moved lightly until the upper end of the femoral head was identified. Next, a 120 mm Tuohy 18G anesthetic needle was used under ultrasound guidance, which was moved lateral to medial in the plane between the ultrasound transducer and the superior tip of the femoral head. Then, 10 mL of ropivacaine 0.25% was injected through the anesthetic needle tip.

Data were collected at different times including: before surgery, before anesthesia, during surgery and after surgery. The information was recorded in the medical record.

Preoperative data: the collected information included the general characteristics of the study patients including age, gender, weight, height, history of smoking/motion sickness, diagnosis, health classification according to ASA, liver and kidney function tests. With pre-anesthesia data, information was collected including pulse, blood pressure, respiratory rate, SpO2.

Intraoperative data: the information collected includes information about anesthesia and surgical procedure.