Effect of Liposomal Bupivacaine TAPB Combined With Oxycodone PCIA on Postoperative Gastrointestinal Recovery in Patients Undergoing Major Abdominal Surgery

Effect of Liposomal Bupivacaine TAPB Combined With Oxycodone PCIA on Postoperative Gastrointestinal Function in Patients Undergoing Major Abdominal Surgery: A Randomized Controlled Trial

Rationale and Objective:

The purpose of this study is to evaluate the clinical efficacy and safety of a novel multimodal analgesia regimen, combining transversus abdominis plane block (TAPB) with patient-controlled intravenous analgesia (PCIA), in improving postoperative gastrointestinal function recovery in patients undergoing major abdominal surgery.

Study Design and Interventions:

This is a prospective, single-center, randomized, double-blind, parallel-controlled trial. A total of 132 eligible patients (aged 18-80 years, ASA I-III, scheduled for elective small bowel or colorectal surgery) will be randomly allocated to one of three groups (n = 44 per group) to receive distinct postoperative analgesia regimens:

Group R-S: 0.375% Ropivacaine TAPB + Sufentanil PCIA; Group LB-S: 266 mg Liposomal Bupivacaine TAPB + Sufentanil PCIA; Group LB-O: 266 mg Liposomal Bupivacaine TAPB + Oxycodone PCIA.

Primary Outcome:

The primary outcome is the area under the curve (AUC) of the I-FEED scoring system within the first 7 postoperative days, which comprehensively reflects the overall trajectory of gastrointestinal function recovery.

Hypothesis:

The investigators hypothesize that the combination of long-acting Liposomal Bupivacaine TAPB (for prolonged somatic pain relief) and Oxycodone PCIA (for precise visceral pain control via dual u and k receptor agonism) will synergistically attenuate the perioperative stress-inflammatory response. Consequently, this regimen is expected to significantly mitigate postoperative ileus (POI) and accelerate the recovery of gastrointestinal motility

Study Overview

• Status: Not yet recruiting
• Conditions: Postoperative Pain; Postoperative Ileus
• Intervention / Treatment: Drug: ropivacaine hydrochloride; Drug: Sufentanil citrate; Drug: Liposomal bupivacaine (LB); Drug: oxycodone

• Study Type: Interventional
• Enrollment (Estimated): 132
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Yu
• Study Contact Backup: Name: Ke yu Zhang; Phone Number: +86 19861121816; Email: m456365zky@163.com

Study Locations

• China
  • Tianjin Municipality
    • Tianjin, Tianjin Municipality, China, 300384
      • Tianjin First Central Hospital
      • Contact: Wenli Yu; Phone Number: +86 139 2009 8326; Email: yzxyuwenli@163.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Patients scheduled to undergo elective major abdominal surgery, specifically small bowel or colorectal resections.
• Aged between 18 and 80 years (inclusive).
• American Society of Anesthesiologists (ASA) physical status I, II, or III.
• Capable of understanding the study procedures, cooperating with postoperative pain/recovery assessments (e.g., VAS, QoR-15, I-FEED), and providing written informed consent prior to surgery.

Exclusion Criteria:

• History of significant neuropsychiatric disorders, including schizophrenia, epilepsy, Parkinson's disease, or myasthenia gravis, that may interfere with pain perception or cognitive evaluation.
• History of alcohol abuse or chronic opioid/analgesic dependence.
• Severe, uncontrolled hypertension (defined as systolic blood pressure ≥ 180 mmHg or diastolic blood pressure ≥ 110 mmHg).
• Severe cardiac, hepatic, renal, or pulmonary dysfunction that poses a high surgical/anesthetic risk or alters drug metabolism.
• Pregnant or lactating women.
• Known allergy, hypersensitivity, or contraindications to any of the study medications, including local anesthetics (ropivacaine, bupivacaine) or opioids (sufentanil, oxycodone).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Control Group（Ropivacaine + Sufentanil）; TAP block with 0.375% Ropivacaine + PCIA Sufentanil for postoperative analgesia after abdominal surgery	Drug: ropivacaine hydrochloride; 0.375% solution for transversus abdominis plane (TAP) local injection during surgery for postoperative analgesia.; Drug: Sufentanil citrate; Formulated into PCIA pump for continuous intravenous infusion for postoperative patient-controlled analgesia.
Experimental: Experimental Group 1（Liposomal Bupivacaine + Sufentanil）; TAP block with Liposomal Bupivacaine 266mg + PCIA Sufentanil for postoperative analgesia after abdominal surgery	Drug: Sufentanil citrate; Formulated into PCIA pump for continuous intravenous infusion for postoperative patient-controlled analgesia.; Drug: Liposomal bupivacaine (LB); 266mg single dose for TAP block local injection for postoperative pain control after abdominal surgery.
Experimental: Experimental Group 2（Liposomal Bupivacaine + Oxycodone）; TAP block with Liposomal Bupivacaine 266mg + PCIA Oxycodone for postoperative analgesia after abdominal surgery	Drug: Liposomal bupivacaine (LB); 266mg single dose for TAP block local injection for postoperative pain control after abdominal surgery.; Drug: oxycodone; Prepared in PCIA pump for intravenous patient-controlled analgesia after abdominal operation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Area Under Curve (AUC) of I-FEED Score within Postoperative 7 Days	The I-FEED score was recorded daily on days 1 through 7; the area under the curve (AUC) of the consecutive I-FEED scores within 7 days postoperatively was calculated to comprehensively assess the recovery of postoperative gastrointestinal function. A higher score indicates poorer recovery of gastrointestinal function. An I-FEED score > 6 indicates severe gastrointestinal dysfunction.	Postoperative Day 1 to Postoperative Day 7

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time-Weighted Average (TWA) of Rest & Movement NRS Pain Score within 72h Postoperatively	Postoperative 6h,12h,24h,48h,72h	Resting pain and activity-induced pain were assessed using a numerical rating scale (NRS, 0-10; higher scores indicate more severe pain) at predetermined time points, and the time-weighted average score was calculated for the 72-hour postoperative period
TWA of Short-form McGill Pain Questionnaire 2 (SF-MPQ-2) Score within Postoperative 72h	The Short-form McGill Pain Questionnaire 2 (SF-MPQ-2) Score (consisting of 22 items, each scored on a scale of 0-10, with higher scores indicating more severe pain) was used to distinguish between somatic pain and visceral pain; the weighted average (TWA) of the visceral pain subscale scores was calculated.	Postoperative 24h,48h,72h
Total opioid dose (morphine equivalent) within 72 hours postoperatively	The cumulative doses of sufentanil or oxycodone administered via the PCIA pump within 72 hours postoperatively, as well as the doses of opioid rescue analgesics, were converted to morphine equivalents to facilitate intergroup comparisons.	0-72 hours after surgery
Incidence of Prolonged Postoperative Ileus (PPOI)	PPOI defined as patients without mechanical bowel obstruction who meet ≥2 of 5 criteria after postoperative 72h: persistent PONV, intolerance to solid diet, no flatus/stool, obvious abdominal distension, daily I-FEED>6 points。	Within postoperative 7 days
First Flatus & First Defecation Time	Record interval from operation completion to the first spontaneous flatus and first spontaneous defecation separately, marker of gastrointestinal peristalsis recovery.	The time from the end of surgery to the first flatus and the first defecation was recorded. The maximum follow-up duration was 7 days postoperatively.
First Ambulation Time & Length of Hospital Stay(LOS)	Record time of first independent ambulation after surgery and total postoperative hospital days.	Time from the end of surgery to first ambulation and time to hospital discharge after surgery were recorded, with follow-up capped at 2 weeks postoperatively.
QoR-15 Recovery Score	The QoR-15 questionnaire was administered on days 1, 2, and 3 postoperatively to assess overall postoperative recovery quality, with preoperative baseline scores used as covariates in the statistical analysis. The questionnaire consists of 15 items, each scored on a scale of 0 to 10, for a total score of 150. A higher score indicates better recovery quality.	Postoperative day 1，Postoperative day 2 ，Postoperative day 3
Incidence of Postoperative Adverse Events	Calculate the incidence of postoperative nausea and vomiting (PONV), constipation, dizziness, and respiratory depression (SpO₂ < 95% or respiratory rate < 10 breaths per minute) within 7 days postoperatively.	Postoperative Day 1 - Day7

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Serum IL-6 and Cortisol Concentrations	Serum levels of interleukin-6 and cortisol were measured at three time points to assess perioperative inflammatory and surgical stress response.	End of surgery, Postoperative Day1, Postoperative Day2
Serum Motilin and Gastrin Concentrations	Detect serum motilin and gastrin to explore the effect of analgesic regimens on gastrointestinal endocrine function.	End of surgery, Postoperative Day1, Postoperative Day2
Plasma β-Endorphin Concentration	Determine plasma β-endorphin level to explore central pain modulation mechanism of multimodal analgesia.	End of surgery, Postoperative Day1, Postoperative Day2

Collaborators and Investigators

• Sponsor: Tianjin First Central Hospital
• Investigators: Study Director: Wenli Yu, Tianjin First Central Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: June 5, 2026
• First Submitted That Met QC Criteria: June 10, 2026
• First Posted (Actual): June 16, 2026

Study Record Updates

• Last Update Posted (Actual): June 16, 2026
• Last Update Submitted That Met QC Criteria: June 10, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heterocyclic Compounds, Fused-Ring; Alkaloids; Polycyclic Aromatic Hydrocarbons; Polycyclic Compounds; Anilides; Amides; Aniline Compounds; Amines; Piperidines; Heterocyclic Compounds, 4 or More Rings; Morphinans; Opiate Alkaloids; Heterocyclic Compounds, Bridged-Ring; Phenanthrenes; Morphine Derivatives; Codeine; Fentanyl; Ropivacaine; Oxycodone; Sufentanil
• Other Study ID Numbers: TJH-2026-99

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Individual participant data (IPD) will be made available upon reasonable request to the corresponding author, beginning 12 months after the publication of the primary results manuscript.

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