Ultrasound Evaluation of Two Anatomic Landmarks in Spinal Anesthesia for Cesarean Section: the Posterior Superior Iliac Spine VS Iliac Crest

NCT06711601 | Recruiting

• 1 other identifier: [2024] No. 131
• Study Type: observational
• Target: 660
• Locations: 1 country
• Sites: 1

Brief Summary

Intercristal line as palpation landmarks to identifying the vertebral level is frequently inaccurate.To find more safe and reliable body surface markers and convenient methods to be solved in clinical work.The investigators performed a two-stage study to evaluated the accuracy of intercristal line and the The Posterior Superior Iliac Spine (PSIS) line to identify the lumbar interspinous spaces for spinal anesthesia using ultrasonography in pregnant woman which will provide a second option.

Conditions

Spinal Anesthesia; Ultrasonography; Intercristal Line; Posterior Superior Iliac Spine

Keywords

cesarean section; ultrasonography; spinal anesthesia; Posterior Superior Iliac Spine; intercristal line

Outcome Measures

Primary Outcomes (2)

• The distance between the PSIS line and each mid-interspinous space

  PSIS line was defined as an intercristal line drawn between the the final posterior superior iliac spine point.Use a ruler to measure the distance between the PSIS line and each midddle- interspinous space （L1/2 through L5/S1）and record. The mean of distances and 95% confidence interval are calculated.

  three days

• The accuracy of the anatomic landmarks to determine the L3/4 interspinous space

  The L3-L4 intervertebral space was detected using intercristal line and the PSIS line in a random order by 2 experienced anesthesiologists. After determining the L3-L4 intervertebral space using each method alternately, horizontal skin marks were created with an erasable pen. Then, another experienced anesthesiologist for ultrasonographic examination assessed the intervertebral spaces.After identifying the sacrum, the investigator moved the probe in a cephalad direction, counted the intervertebral spaces and assessed the actual intervertebral spaces of the 2 skin marks.

  three days

Secondary Outcomes (6)

• The distance between the palpated intercristal line and PSIS line

  three days

• baseline data

  three days

• baseline data

  three days

• Maternal height

  three days

• baseline data

  three days

Study Arms (3)

T group

The intercristal line-based palpation protocol followed the rule described by Kim et al\[19\], with minor modifications to accommodate the flexed lateral decubitus position: Select the interspinous space that is either intersected by the intercristal line or lies immediately below it.

P group

The PSIS line-based palpation protocol stipulated targeting the L3/4 interspinous space within the an interval using hierarchical rules: single spaces are labeled L3/4; for two spaces, L3/4 is the intercristal line-intersected one (or lower if neither); for rare three spaces, the lowest is L3/4

Group M

Based on an interim analysis of Phase 1 data, we established the following decision protocol for L3/4 interspinous space localization: 1. PI ≥9 cm: Select the interspace at or immediately below the PI line. 2. PI ≤7 cm: Select the interspace at or immediately above the PI line. 3. PI 7-9 cm: Apply a 6.5-10 cm target window from the PSIS point. * If one interspace lies within this window, select it. * If multiple interspaces are present, choose the most caudal one.

Eligibility Criteria

• Sex: female
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

We enrolled parturients aged 22-45 years at 37-42 weeks of gestation scheduled for epidural or combined spinal-epidural anesthesia (for labor or cesarean section)

You may qualify if:

• After obtaining written informed consents,pregnant women at 37-42 weeks of gestation

You may not qualify if:

• BMI ≥ 40 kg/m² (to minimize palpation variability), History of lumbar surgery/deformity (scoliosis, spondylolisthesis or osteoporotic vertebral collapse), Inability to maintain the flexed lateral decubitus position, Participant withdrawal, Unforeseen anatomical anomalies discovered during screening.

Sponsors & Collaborators

• The Third Affiliated Hospital of Guangzhou Medical University: lead

Study Sites (1)

The Third Affiliated Hospital of Guangzhou Medical University

Guangzhou, Guangdong, China

RECRUITING

Study Officials

• Souping Wang, PhD

  The Third Affiliated Hospital of Guangzhou Medical University

  STUDY DIRECTOR

Central Study Contacts

Wenhua Zhang, PhD

CONTACT

+86 13611453199; zhangcobra@126.com

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 18, 2024
• First Posted: December 2, 2024
• Study Start: October 10, 2024
• Primary Completion: December 30, 2025
• Study Completion: January 23, 2026
• Last Updated: February 3, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)