Ultrasonographic ONSD as a Predictor of PDPH in Spinal Anesthesia for Cesarean Delivery (NCT07360756) | Clinical Trial Compass
Not Yet RecruitingNot Applicable
Ultrasonographic ONSD as a Predictor of PDPH in Spinal Anesthesia for Cesarean Delivery
Egypt150 participantsStarted 2026-01-28
Plain-language 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.
Who can participate
Age range
18 Years – 45 Years
Sex
FEMALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* 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
Exclusion Criteria:
* 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
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Optimal Delta ONSD cut-off value for predicting PDPH