Comparison of Intermittent Bolus vs. Continuous Infusion PENG Block for Postoperative Pain in Hip Surgery (ICPENG)

Comparison of Intermittent Bolus and Continuous Infusion Pericapsular Nerve Group Block on Recovery Quality and Analgesic Consumption: A Retrospective Study

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.

Study Overview

• Status: Completed
• Conditions: Hip Surgery; Postoperative Pain Management; Regional Anesthesia; Pericapsular Nerve Group Block (PENG Block)
• Intervention / Treatment: Procedure: Intermittent Bolus PENG Block; Procedure: Continuous Infusion PENG Block

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 82

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Tekirdağ, Turkey (Türkiye), 59000
    • Tekirdağ Namık Kemal University Research Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

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.

Description

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.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Intermittent Bolus Group; Patients in this group received intermittent bolus administration of the Pericapsular Nerve Group (PENG) Block via a catheter placed under ultrasound guidance at the end of surgery. A researcher manually administered 20 mL of 0.25% bupivacaine every 4 hours over a 24-hour period.; Total bupivacaine volume: 120 mL of 0.25% bupivacaine over 24 hours; Additional analgesia: All patients received PCA with tramadol, IV paracetamol, and rescue NSAIDs as per protocol.	Procedure: Intermittent Bolus PENG Block; Patients received intermittent bolus administration of the Pericapsular Nerve Group (PENG) Block via a catheter. A researcher manually administered 20 mL of 0.25% bupivacaine every 4 hours over a 24-hour period.
Continuous Infusion Group; Patients in this group received continuous infusion of the Pericapsular Nerve Group (PENG) Block via a catheter placed under ultrasound guidance at the end of surgery. A pump delivered 5 mL/hour of 0.25% bupivacaine continuously over a 24-hour period.; Total bupivacaine volume: 120 mL of 0.25% bupivacaine over 24 hours; Additional analgesia: All patients received PCA with tramadol, IV paracetamol, and rescue NSAIDs as per protocol.	Procedure: Continuous Infusion PENG Block; Patients received continuous infusion of the Pericapsular Nerve Group (PENG) Block via a catheter. A pump delivered 5 mL/hour of 0.25% bupivacaine continuously over a 24-hour period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Pain Scores (VAS)	Postoperative pain levels will be assessed using the Visual Analog Scale (VAS, 0-10) where: 0 = No pain; 10 = Worst possible pain; Higher scores indicate worse pain levels.	From 0 hours (postoperatively) to 24 hours postoperatively, assessed at 0, 2, 6, 12, and 24 hours.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Postoperative Opioid Consumption	Total opioid consumption (including PCA tramadol) will be recorded and converted into morphine milligram equivalents (MME) for comparison between groups.	From 0 hours (postoperatively) to 24 hours postoperatively, assessed at 0, 2, 6, 12, and 24 hours.
Time to First Rescue Analgesia	The time from surgery completion to the first NSAID rescue analgesia administration (ketorolac or dexketoprofen) will be recorded.	From the end of surgery until the first administration of rescue analgesia, assessed up to 24 hours postoperatively.
Postoperative Nausea and Vomiting (PONV) Incidence	Incidence of postoperative nausea and vomiting (PONV) will be recorded based on medical chart reviews and antiemetic administration (ondansetron IV use).	From 0 hours (postoperatively) to 24 hours postoperatively.
Incidence of Complications	Any adverse events (hematoma, infection, nerve injury, hemodynamic instability, etc.) will be documented from patient records.	From 0 hours (postoperatively) to 24 hours postoperatively.
Quality of Recovery (QoR-15 Score)	The Quality of Recovery-15 (QoR-15) questionnaire will be used to assess the patient's postoperative recovery quality, including physical and emotional well-being. The QoR-15 is a validated tool that measures postoperative recovery across five domains: physical comfort, emotional state, psychological support, physical independence, and pain. Scale Range: 0 to 150 Interpretation: Higher scores indicate better recovery quality. Time Frame: Assessed at 24 hours postoperatively.	Assessed at 24 hours postoperatively.

Collaborators and Investigators

• Sponsor: Onur Baran
• Collaborators: Namik Kemal University School of Medicine, Tekirdag
• Investigators: Study Chair: Cavidan Arar, Prof. Dr., Medical Faculty of Tekirdağ Namık Kemal University

Publications and helpful links

General Publications

• Kukreja P, Uppal V, Kofskey AM, Feinstein J, Northern T, Davis C, Morgan CJ, Kalagara H. Quality of recovery after pericapsular nerve group (PENG) block for primary total hip arthroplasty under spinal anaesthesia: a randomised controlled observer-blinded trial. Br J Anaesth. 2023 Jun;130(6):773-779. doi: 10.1016/j.bja.2023.02.017. Epub 2023 Mar 22.
• Huda AU, Ghafoor H. The Use of Pericapsular Nerve Group (PENG) Block in Hip Surgeries Is Associated With a Reduction in Opioid Consumption, Less Motor Block, and Better Patient Satisfaction: A Meta-Analysis. Cureus. 2022 Sep 6;14(9):e28872. doi: 10.7759/cureus.28872. eCollection 2022 Sep.

Study record dates

Study Major Dates

• Study Start (Actual): November 15, 2023
• Primary Completion (Actual): November 15, 2024
• Study Completion (Actual): November 15, 2024

Study Registration Dates

• First Submitted: February 12, 2025
• First Submitted That Met QC Criteria: February 13, 2025
• First Posted (Actual): February 19, 2025

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 12, 2026
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: analgesia; postoperative pain; Hip surgery; pericapsular nerve group block
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Postoperative Complications; Pathologic Processes; Neurobehavioral Manifestations; Perceptual Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Agnosia
• Other Study ID Numbers: TNKU-PENG-Retro

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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."

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No