Trial Outcomes & Findings for Optimal Bupivacaine Dose for Initiation of Labor Epidural Techniques (NCT NCT04814537)

NCT ID: NCT04814537

Last Updated: 2026-08-04

Results Overview

The dose of bupivacaine with which 90% of participants achieve adequate analgesia (NRS\<3 at 30min)

Recruitment status

COMPLETED

Study phase

PHASE4

Target enrollment

100 participants

Primary outcome timeframe

30 minutes

Results posted on

2026-08-04

Participant Flow

Participant milestones

Participant milestones
Measure
Dural Puncture Epidural Technique
Laboring women receiving the Dural Puncture Epidural (DPE) Technique with dose of Bupivacaine 0.25% diluted to 20 mL with isotonic sterile 0.9% saline. The first subject in the DPE group will receive an initial dose of bupivacaine 25 mg, with an endpoint being the achievement of an NRS \< 3 at 30 min. Subsequent patients are administered bupivacaine doses determined by the response of the previous subject, as per the biased coin method. The subsequent up and down interval doses are bupivacaine 2.5 mg (1 mL) increments, with an anticipated dose range from 20 mg to 40 mg. Bupivacaine Hydrochloride: Local Anesthetic Agent
Epidural Technique
Laboring women receiving the Conventional Epidural Technique (EPL) with dose of Bupivacaine 0.25% diluted to 20 mL with isotonic sterile 0.9% saline. The first subject in the EPL group will receive an initial dose of bupivacaine 25 mg, with an endpoint being the achievement of an NRS \< 3 at 30 min. Subsequent patients are administered bupivacaine doses determined by the response of the previous subject, as per the biased coin method. The subsequent up and down interval doses are bupivacaine 2.5 mg (1 mL) increments, with an anticipated dose range from 20 mg to 40 mg. Bupivacaine Hydrochloride: Local Anesthetic Agent
Overall Study
STARTED
50
50
Overall Study
COMPLETED
45
50
Overall Study
NOT COMPLETED
5
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

5 participants were removed from analysis due to technical failure.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Dural Puncture Epidural
n=50 Participants
Participants were randomized 1:1 to the DPE or EPL techniques based on a computer-generated (SAS Institute) schedule consisting of permuted blocks of random sizes 4, 6, or 8. The sequence was generated by a statistician with no clinical involvement in the trial. Upon request for labor analgesia, an attending or fellow anesthesiologist opened a sealed envelope containing the randomized DPE or EPL technique assignment with a specific dose allocation (dosing protocol and dose allocation).
Epidural
n=50 Participants
Participants were randomized 1:1 to the DPE or EPL techniques based on a computer-generated (SAS Institute) schedule consisting of permuted blocks of random sizes 4, 6, or 8. The sequence was generated by a statistician with no clinical involvement in the trial. Upon request for labor analgesia, an attending or fellow anesthesiologist opened a sealed envelope containing the randomized DPE or EPL technique assignment with a specific dose allocation (dosing protocol and dose allocation).
Total
n=100 Participants
Total of all reporting groups
Age, Categorical
<=18 years
0 Participants
n=50 Participants
0 Participants
n=50 Participants
0 Participants
n=100 Participants
Age, Categorical
Between 18 and 65 years
50 Participants
n=50 Participants
50 Participants
n=50 Participants
100 Participants
n=100 Participants
Age, Categorical
>=65 years
0 Participants
n=50 Participants
0 Participants
n=50 Participants
0 Participants
n=100 Participants
Age, Continuous
32.8 years
STANDARD_DEVIATION 3.5 • n=50 Participants
33.4 years
STANDARD_DEVIATION 3.4 • n=50 Participants
33.1 years
STANDARD_DEVIATION 3.45 • n=100 Participants
Sex/Gender, Customized
Female
50 Participants
n=50 Participants
50 Participants
n=50 Participants
100 Participants
n=100 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=45 Participants • 5 participants were removed from analysis due to technical failure.
0 Participants
n=50 Participants • 5 participants were removed from analysis due to technical failure.
0 Participants
n=95 Participants • 5 participants were removed from analysis due to technical failure.
Race (NIH/OMB)
Asian
5 Participants
n=45 Participants • 5 participants were removed from analysis due to technical failure.
2 Participants
n=50 Participants • 5 participants were removed from analysis due to technical failure.
7 Participants
n=95 Participants • 5 participants were removed from analysis due to technical failure.
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=45 Participants • 5 participants were removed from analysis due to technical failure.
0 Participants
n=50 Participants • 5 participants were removed from analysis due to technical failure.
0 Participants
n=95 Participants • 5 participants were removed from analysis due to technical failure.
Race (NIH/OMB)
Black or African American
0 Participants
n=45 Participants • 5 participants were removed from analysis due to technical failure.
4 Participants
n=50 Participants • 5 participants were removed from analysis due to technical failure.
4 Participants
n=95 Participants • 5 participants were removed from analysis due to technical failure.
Race (NIH/OMB)
White
35 Participants
n=45 Participants • 5 participants were removed from analysis due to technical failure.
44 Participants
n=50 Participants • 5 participants were removed from analysis due to technical failure.
79 Participants
n=95 Participants • 5 participants were removed from analysis due to technical failure.
Race (NIH/OMB)
More than one race
5 Participants
n=45 Participants • 5 participants were removed from analysis due to technical failure.
0 Participants
n=50 Participants • 5 participants were removed from analysis due to technical failure.
5 Participants
n=95 Participants • 5 participants were removed from analysis due to technical failure.
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=45 Participants • 5 participants were removed from analysis due to technical failure.
0 Participants
n=50 Participants • 5 participants were removed from analysis due to technical failure.
0 Participants
n=95 Participants • 5 participants were removed from analysis due to technical failure.
Region of Enrollment
United States
50 participants
n=50 Participants
50 participants
n=50 Participants
100 participants
n=100 Participants

PRIMARY outcome

Timeframe: 30 minutes

The dose of bupivacaine with which 90% of participants achieve adequate analgesia (NRS\<3 at 30min)

Outcome measures

Outcome measures
Measure
Dural Puncture Epidural Technique
n=45 Participants
Participants were randomized 1:1 to the DPE or EPL techniques based on a computer-generated (SAS Institute) schedule consisting of permuted blocks of random sizes 4, 6, or 8. The sequence was generated by a statistician with no clinical involvement in the trial. Upon request for EPL labor analgesia, an attending or fellow anesthesiologist opened a sealed envelope containing the randomized DPE or EPL technique assignment with a specific dose allocation (dosing protocol and dose allocation).
Epidural Technique
n=50 Participants
Participants were randomized 1:1 to the DPE or EPL techniques based on a computer-generated (SAS Institute) schedule consisting of permuted blocks of random sizes 4, 6, or 8. The sequence was generated by a statistician with no clinical involvement in the trial. Upon request for EPL labor analgesia, an attending or fellow anesthesiologist opened a sealed envelope containing the randomized DPE or EPL technique assignment with a specific dose allocation (dosing protocol and dose allocation).
ED90
29.30 mg
45.25 mg

Adverse Events

Dural Puncture Epidural Technique

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Epidural Technique

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Ayumi Maeda, MD, PhD

Brigham and Women's Hospital

Phone: 617-732-5500

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place