Ultrasound Versus Palpation for Determining Spinal Puncture Level in Cesarean Section

NCT07789756 | Not Yet Recruiting

• 1 other identifier: 2026/01
• Study Type: interventional
• Target: 66
• Locations: 1 country
• Sites: 2

Brief Summary

This study compares two methods of identifying the correct intervertebral level before performing spinal anesthesia in women undergoing elective cesarean delivery. In current practice, anesthesiologists locate the puncture site by feeling anatomical landmarks on the lower back (palpation of Tuffier's line). Ultrasound imaging offers an alternative in which the spine is scanned and the intended level is marked on the skin before the needle is inserted. It is not yet clear whether this additional step improves the success of the procedure or affects the mother's blood pressure and heart rate after the block. Sixty pregnant women scheduled for elective cesarean section will be randomly assigned to one of two groups. In one group, the puncture level will be determined by preprocedural ultrasound marking; in the other, by conventional landmark palpation. All other aspects of anesthetic care, including drug doses, will be identical in both groups. The main outcome is the proportion of patients in whom the subarachnoid space is entered successfully at the first attempt with a single skin puncture, producing a block adequate for surgery. Additional outcomes include the number of needle passes, procedure duration, changes in maternal blood pressure and heart rate, vasopressor requirement, sensory block level, and complications such as headache or back pain within 24 hours after surgery.

Conditions

Cesarean Section (MeSH: D002585); Anesthesia, Spinal (MeSH: D000775); Hypotension (MeSH: D007022)

Keywords

preprocedural ultrasound; neuraxial anesthesia; Tuffier's line; landmark palpation; obstetric anesthesia; first-attempt success

Outcome Measures

Primary Outcomes (1)

• First-attempt success rate

  Successful dural puncture (CSF flow) with a single skin puncture at the selected level, with adequate surgical block and no need for supplemental analgesia or GA.

  During spinal procedure (up to 30 minutes)

Secondary Outcomes (10)

• Number of skin punctures and needle redirections

  During the spinal procedure, up to 30 minutes

• Procedure duration

  During the spinal procedure, up to 30 minutes

• Incidence of hypotension

  From intrathecal injection to end of surgery, up to 90 minutes

• Total ephedrine dose

  From intrathecal injection to end of surgery, up to 90 minutes

• Sensory block level

  10 and 15 minutes after intrathecal injection

Study Arms (2)

Ultrasound Group

EXPERIMENTAL

Preprocedural ultrasound scanning of the lumbar spine in the sitting position with a low-frequency curvilinear probe. The sacrum is identified in the paramedian sagittal oblique plane, interspaces are counted cephalad, and the target interspace is marked on the skin. Spinal anesthesia is then performed at the marked level.

Procedure: Preprocedural ultrasound level identification

Palpation Group

ACTIVE COMPARATOR

Puncture level determined by palpation of Tuffier's line according to standard clinical practice, without ultrasound assistance. Spinal anesthesia is performed at the palpated level.

Procedure: Landmark palpation level identification

Interventions

Preprocedural ultrasound level identification PROCEDURE

Ultrasound-assisted identification and skin marking of the target intervertebral level before spinal needle insertion. Spinal anesthesia is performed with the patient seated, using a midline approach and a pencil-point spinal needle, with hyperbaric bupivacaine and fentanyl dosed according to the Harten table based on maternal height. A maximum of three puncture attempts is permitted.

Ultrasound Group

Landmark palpation level identification PROCEDURE

Identification of the target intervertebral level by palpation of Tuffier's line. Spinal anesthesia is performed with the patient seated, using a midline approach and a pencil-point spinal needle, with hyperbaric bupivacaine and fentanyl dosed according to the Harten table based on maternal height. A maximum of three puncture attempts is permitted.

Palpation Group

Eligibility Criteria

• Age: 18 Years - 45 Years
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Scheduled for elective cesarean section under spinal anesthesia
• Age 18 to 45 years
• ASA physical status II or III
• Singleton pregnancy
• No contraindication to spinal anesthesia
• Normotensive
• Provides written informed consent

You may not qualify if:

• Emergency cesarean section
• Morbid obesity (body mass index 40 kg/m² or higher)
• History of lumbar spine surgery
• Severe spinal deformity
• Local infection at the puncture site
• Coagulopathy or ongoing anticoagulant therapy
• Anatomical abnormality expected to require multiple puncture attempts

Sponsors & Collaborators

• Kahramanmaras Sutcu Imam University: lead

Study Sites (2)

Kahramanmaraş Sütçü İmam University Health Practice and Research Hospital

Kahramanmaraş, Onikişubat, 46040, Turkey (Türkiye)

Location

Kahramanmaraş Sütçü İmam University Health Practice and Research Hospital

Kahramanmaraş, Onikişubat, 46100, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Hypotension

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases

Study Officials

• Feyza Çalışır

  Kahramanmaras Sutcu Imam University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Feyza Çalışır, MD

CONTACT

+905056492875; fbolcal@hotmail.com

Betül Bağrıaçık, MD

CONTACT

fbolcal@hotmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor Dr

Model Details: Two-arm parallel-group design with 1:1 allocation. Participants are randomized to either preprocedural ultrasound-assisted level identification or conventional landmark palpation prior to spinal anesthesia. There is no crossover between arms; each participant receives only the allocated technique. All other aspects of anesthetic management, including drug selection and dosing, are identical across arms.

Study Record Dates

• First Submitted: July 24, 2026
• First Posted: August 27, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): September 1, 2027
• Last Updated: August 27, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

TU (2)