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

Ultrasound Evaluation Of Two Anatomic Landmarks In Spinal Anesthesia For Cesarean Section: The Posterior Superior Iliac Spine vs Iliac Crest

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT06711601
Acronym
USPSISICL
Enrollment
650
Registered
2024-12-02
Start date
2024-12-01
Completion date
2026-01-23
Last updated
2026-07-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

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

Keywords

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

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.

Detailed description

The investigators performed a two-stage study to evaluated the accuracy of Intercristal line and the PSIS line to identify the lumbar intervertebral space for spinal anesthesia using ultrasonography in pregnant woman. In phase 1, the distances between the PSIS line and each lumbar interspinous space is measured by ultrasound,and the mean and 95% confidence interval of distances in pregnant women with different height ranges were calculated to provide a reference for identifying specific lumbar spaces.In phase 2, a further 230 participants were received the PSIS, Intercristal line or both as palpation landmarks to define specific lumbar spaces.

Interventions

None listed

Sponsors

The Third Affiliated Hospital of Guangzhou Medical University
Lead SponsorOTHER

Study design

Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
FEMALE
Healthy volunteers
No

Inclusion criteria

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

Exclusion criteria

* 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.

Design outcomes

Primary

MeasureTime frameDescription
The distance between the PSIS line and each mid-interspinous spacethree daysPSIS 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.
The accuracy of the anatomic landmarks to determine the L3/4 interspinous spacethree daysThe 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.

Secondary

MeasureTime frameDescription
The distance between the palpated intercristal line and PSIS linethree dayspalpated intercristal line line was identified and marked by bilateral palpation of the iliac crest summits. Subsequently, two reference points were defined: "point PSIS" (intersection of the PSIS line with the spinal midline) and "point PI" (intersection of the PI line with the spinal midline). We then calculated the following three distances: the "L3/4 distance" (from the L3/4 interspinous space midpoint to point PSIS), the "PI distance" (from point PI to point PSIS) The experienced anesthesiologist for ultrasonographic examination assessed the actual interspinous space of the intercristal line.
baseline datathree daysThe age
Maternal heightthree daysMaternal height

Countries

China

Contacts

STUDY_DIRECTORSouping Wang, PhD

The Third Affiliated Hospital of Guangzhou Medical University

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 21, 2026