This retrospective study evaluates the effects of two different administration methods of the Pericapsular Nerve Group (PENG) Block on postoperative pain control, opioid consumption, and recovery in patients undergoing hip surgery.

All patients in the study received:

• PENG block via a catheter
• Patient-Controlled Analgesia (PCA) with tramadol
• Multimodal analgesia, including IV paracetamol and nonsteroidal anti inflammatory drugs (NSAIDs) as rescue analgesia

The study compares two groups:

1. Intermittent Bolus Group: A researcher administered 20 mL of 0.25% bupivacaine every 4 hours.
2. Continuous Infusion Group: A pump delivered 5 mL/hour of 0.25% bupivacaine continuously.

Both groups received the same total volume of local anesthetic over 24 hours. All PENG blocks were performed under ultrasound guidance at the end of surgery. This study aims to determine whether intermittent bolus or continuous infusion PENG block administration leads to better pain control, lower opioid consumption, and improved recovery outcomes.

Postoperative pain management after hip surgery remains a critical factor in recovery quality, opioid consumption, and overall patient outcomes. Among regional anesthesia techniques, the PENG Block is increasingly utilized for pain control due to its ability to provide effective analgesia while minimizing systemic opioid use. However, the optimal administration method of PENG block remains unclear.

This retrospective cohort study evaluates the effectiveness of two different PENG block administration techniques in patients undergoing hip surgery:

1. Intermittent Bolus Group: A researcher manually administered 20 mL of 0.25% bupivacaine every 4 hours via a catheter placed under ultrasound guidance at the end of surgery.
2. Continuous Infusion Group: A pump delivered 5 mL/hour of 0.25% bupivacaine continuously via a catheter placed under ultrasound guidance at the end of surgery.

Total local anesthetic volume over 24 hours was equal in both groups.

Study Objectives:

The primary objective is to compare intermittent bolus vs. continuous infusion PENG block administration in terms of:

• Postoperative pain control (Visual Analog Scale) (VAS scores)
• Total opioid consumption (morphine equivalent)
• Time to first rescue analgesia
• Quality of recovery (QoR-15 at 24 hours postoperative)

Secondary outcomes include:

• Postoperative nausea and vomiting (PONV)
• Incidence of complications (hematoma, infection, nerve injury)

This study aims to provide evidence on whether intermittent bolus or continuous infusion leads to better pain relief, reduced opioid consumption, and improved recovery in hip surgery patients.

Inclusion Criteria

Participants must meet all of the following criteria to be included in the study:

1. Patients who underwent hip surgery between November 15, 2023 - November 15, 2024.
2. Patients who received Pericapsular Nerve Group (PENG) Block via a catheter for postoperative analgesia.
3. Patients who received Patient-Controlled Analgesia (PCA) with tramadol.
4. Patients aged 18 to 65 years.
5. ASA I - III classification.
6. BMI ≤ 35 kg/m². Exclusion Criteria

Participants who meet any of the following criteria will be excluded from the study:

1. Patients who received analgesia with techniques other than PENG block.
2. Patients with incomplete or missing medical records.
3. Patients with a psychiatric illness diagnosis that may interfere with pain perception or reporting.
4. Patients with coagulation disorders (e.g., INR >1.5, thrombocytopenia).
5. Patients with hepatic or renal failure (Creatinine clearance <30 mL/min or AST/ALT >3x normal).
6. Patients with chronic opioid use before surgery.

This study includes adult patients (ages 18-65) who underwent hip surgery at Tekirdağ Namık Kemal University Hospital between November 15, 2023, and November 15, 2024. All patients received Pericapsular Nerve Group (PENG) Block via a catheter for postoperative pain management, along with multimodal analgesia including tramadol PCA, IV paracetamol, and rescue NSAIDs. The study compares two PENG block administration techniques: intermittent bolus versus continuous infusion.

Individual participant data (IPD) will not be shared due to ethical considerations and institutional privacy regulations. Only de-identified, aggregated results will be published in scientific journals and conferences."