Ultrasonographic ONSD as a Predictor of PDPH in Spinal Anesthesia for Cesarean Delivery

NCT07360756 | Not Yet Recruiting

• 1 other identifier: RC. 1.12.2025
• Study Type: observational
• Target: 150
• Locations: 1 country
• Sites: 1

Brief Summary

The Optic Nerve Sheath Diameter (ONSD), measured non-invasively by bedside ultrasound, is a well-established surrogate for intracranial pressure (ICP), as the optic nerve sheath is continuous with the intracranial dura mater and its subarachnoid space is filled with cerebrospinal fluid (CSF). While ONSD is typically used to detect elevated ICP (with a cut-off often \> 5.0-5.7 mm for ICP \> 20 mmHg), studies investigating PDPH have paradoxically shown a reduction in ONSD post-spinal anesthesia, correlating with the state of intracranial hypotension. Previous research has demonstrated that a lower ONSD or a significant decrease in ONSD values 24 hours post-puncture is associated with PDPH development. A study determined that an ONSD at 24 hours of less than 0.40 cm was the best predictor for PDPH. Our study aims to specifically investigate the utility of the immediate change in ONSD to offer a bedside, real-time assessment of risk.

Conditions

Cesarean Section Complications

Keywords

Post-Dural Puncture Headache; Optic Nerve Sheath Diameter

Outcome Measures

Primary Outcomes (1)

• Optimal Delta ONSD cut-off value for predicting PDPH

  To determine the numerical value of the change in Optic Nerve Sheath Diameter (Delta ONSD = ONSD\<sub\>pre\</sub\> - ONSD\<sub\>post\</sub\>) that best predicts the development of PDPH.

  72 hours post-spinal.

Secondary Outcomes (2)

• Post-Dural Puncture Headache (PDPH)

  72h.

• The Need for Epidural Blood Patch (EBP)

  72 hour

Study Arms (1)

Study Cohort (Single Cohort)

This study comprises a single, prospectively enrolled cohort of 150 adult female patients (ASA physical status II-III) scheduled for elective cesarean section under standardized spinal anesthesia. All participants receive the same planned intervention (spinal anesthesia for surgery) and undergo the same standardized measurement protocol for Optic Nerve Sheath Diameter (ONSD). Within this cohort, participants are naturally divided by outcome during follow-up into two groups for analytical purposes: PDPH-Positive Subgroup: Patients who develop Post-Dural Puncture Headache (PDPH) within 72 hours, as diagnosed using the International Classification of Headache Disorders (ICHD-3) criteria. PDPH-Negative Subgroup: Patients who do not develop PDPH within the follow-up period.

Procedure: Study Cohort (Single Cohort)

Interventions

Study Cohort (Single Cohort) PROCEDURE

This study comprises a single, prospectively enrolled cohort of 150 adult female patients (ASA physical status II-III) scheduled for elective cesarean section under standardized spinal anesthesia. All participants receive the same planned intervention (spinal anesthesia for surgery) and undergo the same standardized measurement protocol for Optic Nerve Sheath Diameter (ONSD). Within this cohort, participants are naturally divided by outcome during follow-up into two groups for analytical purposes: PDPH-Positive Subgroup: Patients who develop Post-Dural Puncture Headache (PDPH) within 72 hours, as diagnosed using the International Classification of Headache Disorders (ICHD-3) criteria. PDPH-Negative Subgroup: Patients who do not develop PDPH within the follow-up period.

Study Cohort (Single Cohort)

Eligibility Criteria

• Age: 18 Years - 45 Years
• Gender Eligibility Details: Cesarean Section
• Healthy Volunteers: No
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Target Population: The target population consists of adult female parturients who are medically eligible for spinal anesthesia and are undergoing elective cesarean delivery in a hospital setting. Source Population: The source population is defined as all consecutive adult female patients (aged 18-45 years, ASA II-III) who are admitted to Benha University Hospitals for an elective cesarean section during the study enrollment period (December 2025 - June 2026) and who meet the eligibility criteria. Study Sample (Final Cohort): The study sample will comprise 150 consenting patients drawn consecutively from the source population, forming a single observational cohort. These participants will undergo standardized spinal anesthesia and serial Optic Nerve Sheath Diameter (ONSD) measurements, with follow-up for Post-Dural Puncture Headache development over 72 hours.

You may qualify if:

• Adult female patients, aged 18-45 years
• ASA(American Society of Anesthesiologists) physical status II or III
• Scheduled for elective cesarean section
• Undergoing surgery under standardized spinal anesthesia

You may not qualify if:

• Pre-existing headache disorders (e.g., migraine, chronic tension-type headache)
• Known ophthalmic conditions (e.g., optic neuropathy, glaucoma)
• Inability to cooperate with ONSD(Optic Nerve Sheath Diameter) ultrasound measurements or follow-up
• Allergy to local anesthetics
• Emergency cesarean section
• Contraindications to spinal anesthesia:
• Coagulopathy
• Infection at the puncture site
• Preexisting hypertension on medication
• Pre-eclampsia with severe features (suggested for separate study)
• Known cardiac disease with hemodynamic instability
• Allergy to study drugs
• Fetal distress or non-reassuring cardiotocography (CTG)
• Body Mass Index (BMI) \>40 kg/m²
• Refusal to sign informed consent

Sponsors & Collaborators

• Benha University: collaborator
• Al-Azhar University: lead

Study Sites (1)

Al-Azhar University

Cairo, Egypt, 11865, Egypt

Location

MeSH Terms

Conditions

Post-Dural Puncture Headache

Interventions

Cohort Studies

Condition Hierarchy (Ancestors)

Headache Disorders, Secondary; Headache Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases

Intervention Hierarchy (Ancestors)

Epidemiologic Studies; Epidemiologic Study Characteristics; Epidemiologic Methods; Investigative Techniques; Health Care Evaluation Mechanisms; Quality of Health Care; Health Care Quality, Access, and Evaluation; Public Health; Environment and Public Health

Central Study Contacts

Neveen A Kohaf, Ph.D

CONTACT

+201060383012; nevenabdo@azhar.edu.eg

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Lecturer of Clinical Pharmacy

Study Record Dates

• First Submitted: December 26, 2025
• First Posted: January 22, 2026
• Study Start: January 28, 2026
• Primary Completion (Estimated): November 30, 2026
• Study Completion (Estimated): December 30, 2026
• Last Updated: January 22, 2026

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP

Locations

EG (1)