NCT04897841: OBLiBupi

Obstetric Liposomal Bupivacaine Via Surgical Transversus Abdominis Plane Block for Post Cesarean Pain Control

Completed Phase 4 Results posted Last updated 22 August 2025

What this trial tests

Phase 4 trial testing Liposomal bupivacaine in Cesarean Section Complications in 60 participants. Completed in 13 October 2022.

Timeline

11 October 2021

Primary endpoint
31 August 2022

13 October 2022

Quick facts

Lead sponsor	University of Wisconsin, Madison
Phase	Phase 4
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	single
Primary purpose	treatment
Enrollment	60
Start date	11 October 2021
Primary completion	31 August 2022
Estimated completion	13 October 2022
Sites	1 location across United States

Drugs / interventions tested

• Liposomal bupivacaine
• Bupivacaine Hydrochloride (Bupivacaine Hydrochloride) — full drug profile →
• saline

Conditions studied

• Cesarean Section Complications — all drugs for Cesarean Section Complications →
• Pain — all drugs for Pain →
• Opioid Use — all drugs for Opioid Use →

Sponsor

University of Wisconsin, Madison

Who can join

18 and older, female only, with Cesarean Section Complications or Pain. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Total Opioid Usage in Oral Morphine Equivalents Primary · up to 48 hours postpartum

Compared via Student's t-test or Mann-Whitney U test if the distribution is non-normally distributed

Group	Value	95% CI
Control Arm	8	0 – 40
Intervention: Liposomal Bupivacaine	2	0 – 24

Median Post-operative Pain Scores Measured on NRS Secondary · Collected per standard of care every 4-6 hours up to 24 hours postpartum

Numeric rating scale (NRS) which rates pain on a 0-10 scale where 10 is increased pain.

Group	Value	95% CI
Control Arm	3.75	2 – 5
Intervention: Liposomal Bupivacaine	3	2 – 4

Maximum Post-operative Pain Scores Measured on NRS Secondary · Collected per standard of care every 4-6 hours up to 24 hours postpartum

Numeric rating scale (NRS) which rates pain on a 0-10 scale where 10 is increased pain.

First 12 hours postpartum

Group	Value	95% CI
Control Arm	2.5	2 – 5
Intervention: Liposomal Bupivacaine	2	1 – 3.5

12-24 hours postpartum

Group	Value	95% CI
Control Arm	3.5	2 – 4.5
Intervention: Liposomal Bupivacaine	3	2 – 4.5

Minimum Post-operative Pain Scores Measured on NRS Secondary · Collected per standard of care every 4-6 hours up to 24 hours postpartum

Numeric rating scale (NRS) which rates pain on a 0-10 scale where 10 is increased pain.

First 12 hours postpartum

Group	Value	95% CI
Control Arm	2	1.5 – 3.5
Intervention: Liposomal Bupivacaine	2	1 – 2

12-24 hours postpartum

Group	Value	95% CI
Control Arm	3	2 – 4
Intervention: Liposomal Bupivacaine	3	2 – 3

Incidence of Opioid Side Effects Secondary · up to 7 days postpartum

Number of patients reporting opioid-related side effects, such as pruritis, constipation, nausea, and mental clouding.

Respiratory events

Group	Value	95% CI
Control Arm	0
Intervention: Liposomal Bupivacaine	0

Pruritis

Group	Value	95% CI
Control Arm	0
Intervention: Liposomal Bupivacaine	1

Constipation

Group	Value	95% CI
Control Arm	0
Intervention: Liposomal Bupivacaine	0

Nausea and/or vomiting

Group	Value	95% CI
Control Arm	2
Intervention: Liposomal Bupivacaine	2

Mental clouding

Group	Value	95% CI
Control Arm	1
Intervention: Liposomal Bupivacaine	1

Percentage of Participants With Adverse Events Secondary · up to 7 days postpartum

Percentage of complications of bupivacaine, such as local burning, nausea, dizziness, drowsiness, serious skin reactions such as blistering, confusion, blurred vision, ringing in the ears, arrhythmias, methemoglobinemia, and allergies and hypersensitivities

Group	Value	95% CI
Control Arm	10
Intervention: Liposomal Bupivacaine	6

Time to First Rescue Analgesic Medication Secondary · up to 7 days postpartum

Time to first rescue analgesic medication, measured in minutes from arrival in the post-anesthesia care unit (PACU) until the first as needed opioid dose is administered.

Group	Value	95% CI
Control Arm	21.8	5.1 – 29.2
Intervention: Liposomal Bupivacaine	18.2	3.2 – 29.5

Total Dose of Opioids in Oral Morphine Equivalents Secondary · at 12, 24, 72 hours postpartum and entire hospital stay

12 hours postpartum

Group	Value	95% CI
Control Arm	0	0 – 0
Intervention: Liposomal Bupivacaine	0	0 – 6

24 hours postpartum

Group	Value	95% CI
Control Arm	0	0 – 8
Intervention: Liposomal Bupivacaine	0	0 – 8

72 hours postpartum

Group	Value	95% CI
Control Arm	24	0 – 40
Intervention: Liposomal Bupivacaine	6	0 – 32

entire hospital stay

Group	Value	95% CI
Control Arm	24	0 – 40
Intervention: Liposomal Bupivacaine	6	0 – 46

Length of Postpartum Hospital Stay Secondary · up to 7 days postpartum

Group	Value	95% CI
Control Arm	2.97	2.76 – 3.81
Intervention: Liposomal Bupivacaine	2.82	2.09 – 3.13

Incidence of Supplemental Oxygen Use During Hospitalization Secondary · up to 7 days postpartum

Number of participants requiring supplemental oxygen use

Group	Value	95% CI
Control Arm	0
Intervention: Liposomal Bupivacaine	0

Number of Participants Breastfeeding at Hospital Discharge Secondary · up to 7 days postpartum

Breastfeeding rates, both exclusive and breastfeeding with supplementation at the time of discharge

Group	Value	95% CI
Control Arm	26
Intervention: Liposomal Bupivacaine	29
Control Arm	3
Intervention: Liposomal Bupivacaine	2

Amount of Opioid Prescribed at Discharge Secondary · up to 7 days postpartum

Group	Value	95% CI
Control Arm	10	0 – 15
Intervention: Liposomal Bupivacaine	0	0 – 10

Adverse events — posted to ClinicalTrials.gov

Time frame: 6 weeks post-partum. Reporting threshold: 0%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Control Arm

Serious: 1/29 (3%)

Deaths: 0/29

Intervention: Liposomal Bupivacaine

Serious: 1/31 (3%)

Deaths: 0/31

Serious adverse events (2 terms)

Reaction	System	Control Arm	Intervention: Liposomal Bu…
Post-partum hemorrhage	Reproductive system and breast disorders	—	—
Nystagmus	Eye disorders	—	—

Other adverse events (9 terms — click to expand)

Reaction	System	Control Arm	Intervention: Liposomal Bu…
Local burning or blistering	Skin and subcutaneous tissue disorders	—	—
Dizziness	General disorders	—	—
Any potential or definitive local anesthetic systemic toxicity or symptoms (LAST)	Investigations	—	—
Nausea and vomiting	Gastrointestinal disorders	—	—
Edema, erythema, pruritis, or irritation at site of injection	Skin and subcutaneous tissue disorders	—	—
Arrythmias	Cardiac disorders	—	—
Confusion or tremors	Nervous system disorders	—	—
Pruritis	Skin and subcutaneous tissue disorders	—	—
Mental clouding	General disorders	—	—

Most-reported serious reactions: Post-partum hemorrhage, Nystagmus.

Data from ClinicalTrials.gov NCT04897841 adverse events section.

Sponsor's own description

This study seeks to identify whether the addition of liposomal bupivacaine to regular bupivacaine and saline administered via surgical transversus abdominis plane (TAP) block will reduce the cumulative opioid dose in the first 48 hours after cesarean. 60 women scheduled for cesarean at Unity-Point Health Meriter Hospital in Madison, Wisconsin will be enrolled and can be expect to be on study for up to 6 weeks post-partum.

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

1. Surgical transversus abdominis plane block with liposomal bupivacaine at cesarean: a pilot randomized trial.
   Antony KM, McDonald RC, Gaston L, Hetzel S, et al · · 2024 · cited 3× · PMID 38154599 · DOI 10.1016/j.ajogmf.2023.101273
2. Extracellular Vesicles in Calcific Aortic Valve Disease: From Biomarkers to Drug Delivery Applications.
   Cook-Calvete A, Delgado-Marin M, Fernandez-Rodriguez B, Zaragoza C, et al · · 2025 · PMID 41301466 · DOI 10.3390/biom15111548