Early Labor Pre-Marking for Epidural Analgesia: Ultrasound vs Manual Palpation

NCT07669441 | Recruiting

• 1 other identifier: 104/GCN-HDDD
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn if finding and marking the best spot on the back early in labor helps doctors perform epidural pain relief more successfully in pregnant women. Usually, epidural pain relief is requested when labor pain is already severe, which makes it hard for women to hold still. This makes it difficult to find the right needle spot, leading to more needle attempts The main questions this study aims to answer are:

• Does using ultrasound to mark the back early in labor (before severe pain starts) help the doctor place the needle correctly on first try without adjusting it?
• Does this early marking method lower the number of needle attempts and the time it takes to finish the procedure? Researchers will compare marking the back using an ultrasound machine to the standard method of feeling the spine with hands. Both methods will be done early in the waiting room to avoid the challenges caused by severe pain. Importantly, neither the pregnant women nor the doctors performing the epidural will know which marking method was used. This design prevents personal beliefs or expectations from affecting the procedure, making the study results objective and trustworthy. Participants will, if consented and participated in the study:
• Have their lower back examined and marked by a doctor early in labor using either an ultrasound machine or the doctor's hands.
• Receive an epidural pain relief in the delivery room when they request it. This will be done by a different doctor who does not know how the back was marked.
• Answer short questions about their pain level and how happy they are with the procedure.

Conditions

Labor Pain; Epidural Analgesia for Labour and Delivery; Neuraxial Ultrasound

Keywords

Epidural Analgesia; Labor Pain; Neuraxial Ultrasound; Preprocedural Spinal Ultrasound; Anatomical Landmark Palpation; Obstetric Anesthesia; Regional Anesthesia; First-pass success

Outcome Measures

Primary Outcomes (1)

• First-pass success

  Yes/No variable. First-pass success is defined as the successful identification of the epidural space during the initial forward advancement of the needle, without any needle redirection or withdrawal

  Periprocedural

Secondary Outcomes (11)

• First-attempt success

  Periprocedural

• Number of needle redirections

  Periprocedural

• Number of needle attempts

  Periprocedural

• Procedure time

  Periprocedural

• Paresthesia

  Periprocedural

Study Arms (2)

Ultrasound group

EXPERIMENTAL

Participants in this arm will undergo preprocedural spinal ultrasound while on the left lateral decubitus position. The ultrasound is used to identify the L3-L4 interspace, the midline, and the optimal needle insertion point.

Procedure: Preprocedural Spinal Ultrasound

Landmark Group

ACTIVE COMPARATOR

Participants in this arm will undergo manual palpation of surface bony landmarks of L3-L4 interspace while on the left lateral decubitus position. This conventional approach determines the needle insertion point without relying on ultrasound guidance.

Procedure: Conventional Landmark Palpation

Interventions

Preprocedural Spinal Ultrasound PROCEDURE

A curvilinear probe is applied to the lower back in a transverse orientation. The vertebral midline is marked after identifying a symmetrical image in the transverse spinous process view. The probe is then oriented to obtain a paramedian sagittal laminar view. After locating the sacrum and lumbosacral junction, the probe is moved cephalad to identify and mark the L3 and L4 laminae. The probe is rotated back to a transverse view to systematically assess the lumbar interlaminar spaces, using the posterior complex (ligamentum flavum, epidural space, and posterior dura) and the anterior complex (anterior dura, posterior longitudinal ligament, and posterior vertebral body) as key landmarks. Markings are done with pen at four midpoints of the probe's edges in the L3-L4 space with the largest acoustic window. The intersection of horizontal and vertical lines drawn from these marks designates the needle insertion point.

Ultrasound group

Conventional Landmark Palpation PROCEDURE

The anesthesiologist manually palpates anatomical landmarks to identify L3-L4 interspace and marks the midline insertion site. An ultrasound probe is then placed over this marked site only to measure skin-to-epidural depth for data collection purposes. These measurements are recorded but are not used to adjust or alter the marked insertion point.

Landmark Group

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Parturients aged 18 years and older, with gestational age at 37 weeks or older.
• Actively requesting epidural analgesia for labor pain management without any contraindication to the procedure.

You may not qualify if:

• Parturients with spinal abnormalities or a history of spinal surgery.
• Inability to visualize epidural landmarks under ultrasound imaging.
• Parturients experiencing severe pain requiring immediate, emergent labor analgesia.

Sponsors & Collaborators

• University Medical Center Ho Chi Minh City (UMC): lead

Study Sites (1)

University Medical Center Ho Chi Minh City

Ho Chi Minh City, Ho Chi Minh, 700000, Vietnam

RECRUITING

Related Publications (13)

• Li M, Ni X, Xu Z, Shen F, Song Y, Li Q, Liu Z. Ultrasound-Assisted Technology Versus the Conventional Landmark Location Method in Spinal Anesthesia for Cesarean Delivery in Obese Parturients: A Randomized Controlled Trial. Anesth Analg. 2019 Jul;129(1):155-161. doi: 10.1213/ANE.0000000000003795.

  PMID: 30234528 BACKGROUND

• Tubinis MD, Lester SA, Schlitz CN, Morgan CJ, Sakawi Y, Powell MF. Utility of ultrasonography in identification of midline and epidural placement in severely obese parturients. Minerva Anestesiol. 2019 Oct;85(10):1089-1096. doi: 10.23736/S0375-9393.19.13617-6. Epub 2019 Jun 17.

  PMID: 31213044 BACKGROUND

• Ni X, Li MZ, Zhou SQ, Xu ZD, Zhang YQ, Yu YB, Su J, Zhang LM, Liu ZQ. Accuro ultrasound-based system with computer-aided image interpretation compared to traditional palpation technique for neuraxial anesthesia placement in obese parturients undergoing cesarean delivery: a randomized controlled trial. J Anesth. 2021 Aug;35(4):475-482. doi: 10.1007/s00540-021-02922-y. Epub 2021 May 29.

  PMID: 34050798 BACKGROUND

• de Carvalho CC, Porto Genuino W, Vieira Morais MC, de Paiva Oliveira H, Rodrigues AI, El-Boghdadly K. Efficacy and safety of ultrasound-guided versus landmark-guided neuraxial puncture: a systematic review, network meta-analysis and trial sequential analysis of randomized clinical trials. Reg Anesth Pain Med. 2025 Sep 4;50(9):737-746. doi: 10.1136/rapm-2024-105547.

  PMID: 38876801 BACKGROUND

• Perna P, Gioia A, Ragazzi R, Volta CA, Innamorato M. Can pre-procedure neuroaxial ultrasound improve the identification of the potential epidural space when compared with anatomical landmarks? A prospective randomized study. Minerva Anestesiol. 2017 Jan;83(1):41-49. doi: 10.23736/S0375-9393.16.11399-9. Epub 2016 Oct 4.

  PMID: 27701372 BACKGROUND

• Ekinci M, Alici HA, Ahiskalioglu A, Ince I, Aksoy M, Celik EC, Dostbil A, Celik M, Baysal PK, Golboyu BE, Yeksan AN. The use of ultrasound in planned cesarean delivery under spinal anesthesia for patients having nonprominent anatomic landmarks. J Clin Anesth. 2017 Feb;37:82-85. doi: 10.1016/j.jclinane.2016.10.014. Epub 2017 Jan 4.

  PMID: 28235536 BACKGROUND

• Bae J, Kim Y, Yoo S, Kim JT, Park SK. Handheld ultrasound-assisted versus palpation-guided combined spinal-epidural for labor analgesia: a randomized controlled trial. Sci Rep. 2023 Dec 27;13(1):23009. doi: 10.1038/s41598-023-50407-7.

  PMID: 38155223 BACKGROUND

• Grau T, Leipold RW, Conradi R, Martin E, Motsch J. Efficacy of ultrasound imaging in obstetric epidural anesthesia. J Clin Anesth. 2002 May;14(3):169-75. doi: 10.1016/s0952-8180(01)00378-6.

  PMID: 12031746 BACKGROUND

• Arzola C, Mikhael R, Margarido C, Carvalho JC. Spinal ultrasound versus palpation for epidural catheter insertion in labour: A randomised controlled trial. Eur J Anaesthesiol. 2015 Jul;32(7):499-505. doi: 10.1097/EJA.0000000000000119.

  PMID: 25036283 BACKGROUND

• Grau T, Leipold RW, Conradi R, Martin E, Motsch J. Ultrasound imaging facilitates localization of the epidural space during combined spinal and epidural anesthesia. Reg Anesth Pain Med. 2001 Jan-Feb;26(1):64-7. doi: 10.1053/rapm.2001.19633. No abstract available.

  PMID: 11172514 BACKGROUND

• Chin A, Crooke B, Heywood L, Brijball R, Pelecanos AM, Abeypala W. A randomised controlled trial comparing needle movements during combined spinal-epidural anaesthesia with and without ultrasound assistance. Anaesthesia. 2018 Apr;73(4):466-473. doi: 10.1111/anae.14206. Epub 2018 Jan 10.

  PMID: 29322504 BACKGROUND

• Tawfik MM, Atallah MM, Elkharboutly WS, Allakkany NS, Abdelkhalek M. Does Preprocedural Ultrasound Increase the First-Pass Success Rate of Epidural Catheterization Before Cesarean Delivery? A Randomized Controlled Trial. Anesth Analg. 2017 Mar;124(3):851-856. doi: 10.1213/ANE.0000000000001325.

  PMID: 27183373 BACKGROUND

• Young B, Onwochei D, Desai N. Conventional landmark palpation vs. preprocedural ultrasound for neuraxial analgesia and anaesthesia in obstetrics - a systematic review and meta-analysis with trial sequential analyses. Anaesthesia. 2021 Jun;76(6):818-831. doi: 10.1111/anae.15255. Epub 2020 Sep 27.

  PMID: 32981051 BACKGROUND

Related Links

• Related Info

MeSH Terms

Conditions

Labor Pain

Condition Hierarchy (Ancestors)

Pain; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• An Vu Nguyen, MD, MSc

  University Medical Center Ho Chi Minh City

  PRINCIPAL INVESTIGATOR

Central Study Contacts

An Vu Nguyen, MD, MSc

CONTACT

+84826027842; an.nv1@umc.edu.vn

Phong Quang Le, MD, MSc

CONTACT

+84972789631; phong.lq@umc.edu.vn

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: * Participant: Following informed consent, a research assistant (not involved in the randomization process) opens a sealed envelope to determine the participant's group assignment. In the waiting room, an initial physician anesthesiologist performs both a spinal ultrasound and manual palpation for all participants. The insertion site is then marked based either on ultrasound findings (Ultrasound group) or anatomical palpation (Landmark group). * Investigator: A second physician anesthesiologist, blinded to group assignment, performs the epidural analgesia at the pre-marked site in the delivery room, which is separated from the waiting. * Outcomes Assessor: An independent nurse anesthetist accompanies each physician in each group to observe and document all data on a separate form; they do not participate in direct patient care or communicate group assignments.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Division Chief, Division of Obstetric & Gynecologic Anesthesiology, Department of Anesthesiology

Model Details: Parallel Assignment

Study Record Dates

• First Submitted: June 21, 2026
• First Posted: June 25, 2026
• Study Start: June 1, 2026
• Primary Completion (Estimated): August 30, 2026
• Study Completion (Estimated): August 30, 2026
• Last Updated: June 29, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

VN (1)