Background: Total hip arthroplasty (THA) is a common surgery that is associated with moderate to severe pain. Optimal pain relief is essential for functional recovery and outcome and reducing the immobility related complications after surgery.

Objective: to achieve of better postoperative analgesia in patients undergoing total hip arthroplasty using ultrasound Pericapsular Nerve Group block.

Patients and methods: This study included 64 patients undergoing total hip arthroplasty at Zagazig University Hospitals. Patients divided into 2 equal groups: patients received standard general anesthesia, and patients received GA then receive an ultrasound guided PENG block following anesthesia induction and before initiation of surgery. Anesthesia was induced with fentanyl 1 mcg/kg, propofol (2-3 mg/kg) and rocuronium (0.7 mg/kg) for intubation, cuffed endotracheal tube (ETT) was inserted and mechanical ventilation was adjusted using tidal volume (6-8 ml/kg) after induction of anesthesia.

Results: Post-operative pain at rest and movement was statistically significant increase in NRS in control group compared to PENG group. The time of 1st rescue analgesia was significantly longer in PENG group than control group. There was statistically significant decrease in nalbuphine consumption in PENG group in comparison with control group. According to duration of motor block, there was no statistically significance difference between the two studied groups.

Conclusion: Ultrasound guided PENG block is an effective method for postoperative analgesia in patients undergoing total hip arthroplasty as it prolongs time to first rescue analgesia, decreases postoperative pain scores, without significant effect on motor power or the incidence of complications.