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

Tianjin First Central Hospital132 enrolled

Overview

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 Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

132

Conditions

Interventions

ropivacaine hydrochlorideDRUG

0.375% solution for transversus abdominis plane (TAP) local injection during surgery for postoperative analgesia.

Liposomal bupivacaine (LB)DRUG

266mg single dose for TAP block local injection for postoperative pain control after abdominal surgery.

Sufentanil citrateDRUG

Formulated into PCIA pump for continuous intravenous infusion for postoperative patient-controlled analgesia.

oxycodoneDRUG

Prepared in PCIA pump for intravenous patient-controlled analgesia after abdominal operation.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 80 Years

Medical Language ↔ Plain English

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).

Outcomes

Primary Outcomes

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.

Time frame: Postoperative Day 1 to Postoperative Day 7

Secondary Outcomes

Time-Weighted Average (TWA) of Rest & Movement NRS Pain Score within 72h Postoperatively

Postoperative 6h,12h,24h,48h,72h

Time frame: 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.

Time frame: 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.

Time frame: 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。

Time frame: 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.

Time frame: 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 frame: 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.

Time frame: 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.

Time frame: Postoperative Day 1 - Day7