Optic Nerve Sheath Diameter for Predicting Post-Dural Puncture Headache in Cesarean Section Patients

Post-dural puncture headache (PDPH) is a common complication after spinal anesthesia, particularly in patients undergoing cesarean section. It is thought to occur due to cerebrospinal fluid leakage and decreased intracranial pressure.

Optic nerve sheath diameter (ONSD) measured by ocular ultrasound reflects changes in intracranial pressure and may help identify patients at risk for PDPH. This prospective observational study aims to evaluate the predictive value of serial ONSD measurements for the development of PDPH in patients undergoing cesarean section under spinal anesthesia.

Non-invasive bedside ultrasound measurements of ONSD will be performed at predefined perioperative time points. Participants will be followed postoperatively to assess the occurrence of headache.

The results of this study may help improve early identification of patients at risk for PDPH and enhance postoperative management.

• Optic Nerve Sheath Diameter Measurement (Other): Participants will undergo non-invasive ocular ultrasound measurement of optic nerve sheath diameter at five predefined time points: preoperatively, 10 minutes after spinal anesthesia, at the end of surgery, at postoperative 24 hours, and at postoperative 48 hours.

Primary outcomes

• Association Between Optic Nerve Sheath Diameter Measurements and Post-Dural Puncture Headache [Within 48 hours after spinal anesthesia]: Assessment of the association between optic nerve sheath diameter measurements and the development of post-dural puncture headache.

Sex: Female, ages: 18 Years to 45 Years

Inclusion Criteria:

* Women aged 18 to 45 years
* Singleton pregnancy
* Planned cesarean section (elective or emergency due to fetal indications)
* Spinal anesthesia planned for the procedure
* American Society of Anesthesiologists (ASA) physical status II-III
* Normal coagulation parameters (INR less than 1.5, platelet count greater than 100,000/mm³)
* Ability to provide written informed consent and cooperate with study procedures

Exclusion Criteria:

* Known ophthalmologic diseases affecting the optic nerve or retina (e.g., glaucoma, optic atrophy)
* Active eye infection or recent ocular surgery
* Known intracranial pathology affecting cerebrospinal fluid dynamics (e.g., intracranial mass, hydrocephalus, idiopathic intracranial hypertension)
* History of stroke or subarachnoid hemorrhage
* Hypertensive disorders of pregnancy such as preeclampsia or eclampsia
* Contraindications to spinal anesthesia (e.g., coagulopathy, anticoagulant therapy, infection at puncture site)
* Allergy to local anesthetics
* Conversion to general anesthesia due to failed or inadequate spinal block
* Presence of moderate or severe preoperative headache or active primary headache disorders such as migraine

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• Tulay Sahin, MD, Principal investigator, Department of Anesthesiology and Reanimation Kocaeli University Faculty of Medicine Kocaeli, Turkey