Labor PainNCT04946032
Optimum Length of Catheter in the Epidural Space for Labor Analgesia in Non-obese Women: a Randomised Controlled Trial of 4 cm Versus 5 cm
A study testing Epidural catheter in people with Labor Pain, run by Samuel Lunenfeld Research Institute, Mount Sinai Hospital at 1 site in Canada.
Trial summary
Epidural analgesia was introduced to the world of obstetrics in 1909 by Walter Stoeckel. Over the following 100 years it has developed to become the gold-standard for delivery of intra-partum analgesia, with between 60 and 75% of North American parturients receiving an epidural during their labor. Read more about this study
- Who is it for?
- Ages 18 to 50 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Labor Pain
- What is being tested?
- Epidural catheter
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 200 participants
- Where
- 1 siteCanada
- Study dates
- 23 Nov 2021to 27 Jul 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- All women aged 18 years and above.
- In established second stage of labor.
- 3-7 cm dilation at time of insertion.
- Women with BMI < 40 kg/m2
Who cannot join
- Known contraindication to epidural insertion.
- Inability or unwillingness to provide written consent.
- Previous difficult epidural insertion.
- Previous failed epidural.
- Imminent instrumental or operative delivery.
- Dural puncture.
- Combined spinal epidural analgesia.
- High BMI > 40 kg/m2
Trial locations and contacts
1 site in 1 country.
About this study
Epidural analgesia was introduced to the world of obstetrics in 1909 by Walter Stoeckel. Over the following 100 years it has developed to become the gold-standard for delivery of intra-partum analgesia, with between 60 and 75% of North American parturients receiving an epidural during their labor. Effective labor analgesia has been shown to improve maternal and fetal outcomes. One aspect of catheter insertion that has not been fully evaluated, and with very little recent work undertaken, is the optimal length of epidural catheter to be left in the epidural space. Dislodgement or displacement of epidural catheter remains a significant cause for failure with analgesia. Novel methods of fixation may further reduce the risk of catheter migration. Another factor is the direction of travel within the epidural space, only 13% of lumbar catheters remain uncoiled after insertion of more than 4 cm into the epidural space.
Hypothesis: The investigators hypothesize that catheters inserted to 4 cm will have a lower rate of failure when compared to those inserted to 5 cm.
Read more
Objective: This study aims to evaluate the difference in quality of labor analgesia delivered by epidural catheters inserted to either 4 or 5 cm into the epidural space.
This study will be conducted as an interventional double-blinded randomised control trial to establish best practice.
Read the detailed description
Effective labor analgesia has been shown to improve maternal and fetal outcomes. It is of paramount importance to the obstetric anesthesiologist to optimize the quality of labor analgesia and identify any factors leading to ineffective epidural analgesia. One aspect of catheter insertion that has not been fully evaluated, and with very little recent work undertaken, is the optimal length of epidural catheter to be left in the epidural space.
Previous studies have advocated, for varying reasons, different lengths of catheter to be left in the space; these range from 2cm to 8cm. Longer epidural lengths in the space can be associated with foraminal escape, leading to unilateral block, and intravascular insertion, prompting additional manipulation. Shorter lengths have previously been associated with more frequent dislodgement. The directionality of the epidural catheter once in the space has been demonstrated to correlate with misdirection.
The aim of the study would be to standardize practice in how much epidural catheter is threaded into the epidural space.
- Conditions
- Labor Pain
- Being tested
- Epidural catheter
- Keywords
- epidural catheter, epidural analgesia, labor epidural
- Medical subject headings
- Labor Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Epidural catheterOther
Also called epidural
The epidural catheter length will vary, either 4 cm or 5 cm into the epidural space.
| Study group | Role | What they receive |
|---|---|---|
| 4 cm epidural catheter | Active comparator | The epidural catheter will be thread into the epidural space at a length of 4 cm. Receives: Other: Epidural catheter |
| 5 cm epidural catheter | Active comparator | The epidural catheter will be thread into the epidural space at a length of 5 cm. Receives: Other: Epidural catheter |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sensory block level < T10
Sensory block level to ice will be measured 1 hour after the loading dose is administered.
Yes: inadequate block No: adequate block
Measured: 1 hour
Block height discrepancy
Unilateral block or block height discrepancy of >3 dermatomal levels at any time prior to delivery.
Yes: inadequate block No: adequate block
Measured: 24 hours
Re-siting of the epidural
Re-siting of the epidural at any time during labour will indicate an inadequate block, for any of the following reasons:
- Inadequate analgesia
- Persistent unilateral block
- Persistent intravascular placement
- Extensive motor block
- Hypotension
- High block
Measured: 24 hours
Adjustment of catheter length
Adjustment of catheter length at any time during labour would also indicate an inadequate block.
Measured: 24 hours
Abandonment of epidural or substitute for alternative method of analgesia after initial failure: questionnaire
The epidural analgesia will also be considered inadequate if the procedure is abandoned or another method of analgesia is used. This will be recorded by the anesthesiologist.
Measured: 24 hours
Secondary outcomes (10)
Pain score >3 at any time during labour: questionnaire
A verbal numerical rating score (VNRS) greater than 3, where 0=no pain and 10=worst pain ever.
Measured: 24 hours
Number of epidural top-ups administered by the nursing team
The number of times the labour and delivery nurse has to administer a top-up of the epidural.
Measured: 24 hours
Number of epidural top-ups administered by the anesthesiologist
The number of times the anesthesiologist has to administer a top-up of the epidural.
Measured: 24 hours
Pain scores recorded throughout labour: questionnaire
A verbal numerical rating score (VNRS), where 0=no pain and 10=worst pain ever. A verbal numerical rating score (VNRS) greater than 3, where 0=no pain and 10=worst pain ever.
Measured: 24 hours
Hourly sensory block height assessment
Hourly sensory block height assessment, using sensation to ice. This is recorded hourly as standard practice.
Measured: 24 hours
Incidence of intravascular epidural placement
Any incidence of intravascular epidural placement during labour will be recorded.
Measured: 24 hours
Incidence of catheter dislodgement
Any incidence of catheter dislodgement during labour will be recorded.
Measured: 24 hours
Motor block using Bromage scale
Bromage scale will be recorded hourly as standard practice.
- 3: Unable to move feet or knees
- 2: Able to move feet only
- 1: Able to just move knees
- 0: Full flexion of knees and feet
Measured: 24 hours
Presence of paresthesia on insertion.
Any presence of paresthesia on insertion will be recorded.
Measured: 1 hour
Adequacy of conversion to surgical block if required for cesarean delivery: questionnaire
Adequacy of conversion to surgical block in cases requiring cesarean deliveries for failed labor or fetal issues. This will be recorded by the anesthesiologist.
Measured: 24 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jun 2021
- Study start23 Nov 2021
- Primary completion26 Jul 2024
- Study completion27 Jul 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Labor PainStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 200 participants (actual)
Sponsor and investigators
- Lead sponsor
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Mrinalini Balki, MD, Principal investigator, MOUNT SINAI HOSPITAL
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04946032
- Sponsor's protocol ID
- 21-06
- Status last verified
- Mar 2025
- First submitted
- 25 Jun 2021
- Last updated
- 6 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Optimum Length of Catheter in the Epidural Space for Labor Analgesia in Non-obese Women: a Randomised Controlled Trial of 4 cm Versus 5 cm
- ClinicalTrials.gov ID
- NCT04946032
- Acronym / sponsor ID
- 21-06
- Conditions
- Labor Pain
- Keywords
- epidural catheter, epidural analgesia, labor epidural
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 200 participants (actual)
- Lead sponsor
- Samuel Lunenfeld Research Institute, Mount Sinai HospitalUniversity, hospital or other
- Study start
- 23 Nov 2021 (actual)
- Primary completion
- 26 Jul 2024 (actual)
- Study completion
- 27 Jul 2024 (actual)
- First posted
- 30 Jun 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Epidural analgesia was introduced to the world of obstetrics in 1909 by Walter Stoeckel. Over the following 100 years it has developed to become the gold-standard for delivery of intra-partum analgesia, with between 60 and 75% of North American parturients receiving an epidural during their labor. Effective labor analgesia has been shown to improve maternal and fetal outcomes. One aspect of catheter insertion that has not been fully evaluated, and with very little recent work undertaken, is the optimal length of epidural catheter to be left in the epidural space. Dislodgement or displacement of epidural catheter remains a significant cause for failure with analgesia. Novel methods of fixation may further reduce the risk of catheter migration. Another factor is the direction of travel within the epidural space, only 13% of lumbar catheters remain uncoiled after insertion of more than 4 cm into the epidural space.
Hypothesis: The investigators hypothesize that catheters inserted to 4 cm will have a lower rate of failure when compared to those inserted to 5 cm.
Objective: This study aims to evaluate the difference in quality of labor analgesia delivered by epidural catheters inserted to either 4 or 5 cm into the epidural space.
This study will be conducted as an interventional double-blinded randomised control trial to establish best practice.
Detailed description
Effective labor analgesia has been shown to improve maternal and fetal outcomes. It is of paramount importance to the obstetric anesthesiologist to optimize the quality of labor analgesia and identify any factors leading to ineffective epidural analgesia. One aspect of catheter insertion that has not been fully evaluated, and with very little recent work undertaken, is the optimal length of epidural catheter to be left in the epidural space.
Previous studies have advocated, for varying reasons, different lengths of catheter to be left in the space; these range from 2cm to 8cm. Longer epidural lengths in the space can be associated with foraminal escape, leading to unilateral block, and intravascular insertion, prompting additional manipulation. Shorter lengths have previously been associated with more frequent dislodgement. The directionality of the epidural catheter once in the space has been demonstrated to correlate with misdirection.
The aim of the study would be to standardize practice in how much epidural catheter is threaded into the epidural space.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 4 cm epidural catheter | Active comparator | Other: Epidural catheterThe epidural catheter will be thread into the epidural space at a length of 4 cm. |
| 5 cm epidural catheter | Active comparator | Other: Epidural catheterThe epidural catheter will be thread into the epidural space at a length of 5 cm. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- All women aged 18 years and above.
- In established second stage of labor.
- 3-7 cm dilation at time of insertion.
- Women with BMI < 40 kg/m2
Key exclusion criteria (8 listed)
- Known contraindication to epidural insertion.
- Inability or unwillingness to provide written consent.
- Previous difficult epidural insertion.
- Previous failed epidural.
- Imminent instrumental or operative delivery.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Epidural catheterAlso: epiduralThe epidural catheter length will vary, either 4 cm or 5 cm into the epidural space. | Other | 4 cm epidural catheter, 5 cm epidural catheter |
Primary outcome
Sensory block level < T10
Time frame: 1 hour
Sensory block level to ice will be measured 1 hour after the loading dose is administered. Yes: inadequate block No: adequate block
Block height discrepancy
Time frame: 24 hours
Unilateral block or block height discrepancy of >3 dermatomal levels at any time prior to delivery. Yes: inadequate block No: adequate block
Re-siting of the epidural
Time frame: 24 hours
Re-siting of the epidural at any time during labour will indicate an inadequate block, for any of the following reasons: * Inadequate analgesia * Persistent unilateral block * Persistent intravascular placement * Extensive motor block * Hypotension * High block
Adjustment of catheter length
Time frame: 24 hours
Adjustment of catheter length at any time during labour would also indicate an inadequate block.
Abandonment of epidural or substitute for alternative method of analgesia after initial failure: questionnaire
Time frame: 24 hours
The epidural analgesia will also be considered inadequate if the procedure is abandoned or another method of analgesia is used. This will be recorded by the anesthesiologist.
10 secondary outcomes
Pain score >3 at any time during labour: questionnaire
Time frame: 24 hours
Number of epidural top-ups administered by the nursing team
Time frame: 24 hours
Number of epidural top-ups administered by the anesthesiologist
Time frame: 24 hours
Pain scores recorded throughout labour: questionnaire
Time frame: 24 hours
Hourly sensory block height assessment
Time frame: 24 hours
Incidence of intravascular epidural placement
Time frame: 24 hours
Incidence of catheter dislodgement
Time frame: 24 hours
Motor block using Bromage scale
Time frame: 24 hours
Presence of paresthesia on insertion.
Time frame: 1 hour
Adequacy of conversion to surgical block if required for cesarean delivery: questionnaire
Time frame: 24 hours
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Apr 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mrinalini Balki, MD principal investigator
MOUNT SINAI HOSPITAL
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Epidural catheter in people with Labor Pain, run by Samuel Lunenfeld Research Institute, Mount Sinai Hospital at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 6 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sensory block level < T10 (time frame: 1 hour). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Apr 2026.