This pilot randomised controlled trial compared sphenopalatine ganglion block (SPGB) using intranasal 2% lidocaine versus conservative management (bed rest and aggressive hydration) in patients who developed post-dural puncture headache (PDPH) following accidental dural puncture with 17G Tuohy needles during epidural procedures. The primary outcomes were feasibility metrics (recruitment, retention, and protocol adherence). Secondary outcomes included pain intensity measured by the Numerical Rating Scale (NRS 0-10) at 30 minutes, 12 hours, and 24 hours post-intervention; rescue analgesia requirements; mobilisation time; and adverse events.

Post-dural puncture headache is a significant complication of neuraxial anaesthesia, with substantially higher incidence and severity following accidental large-bore needle punctures. Conservative management (bed rest, hydration) lacks robust efficacy evidence, and epidural blood patch implementation is often delayed. The sphenopalatine ganglion block has emerged as a promising minimally invasive alternative, but high-quality randomised trial data are limited.

This single-centre, parallel-group pilot randomised controlled trial was conducted at Hospital Regional "General Ignacio Zaragoza," ISSSTE, Mexico City. Twenty-six patients (ASA I-II, age 18-55 years) who developed PDPH following accidental dural puncture with 17G Tuohy needles during epidural procedures were randomised using a computer-generated sequence to conservative management (n=13) or SPGB (n=13).

Conservative management comprised strict bed rest (supine then prone positioning), bathroom privileges at bedside only, and aggressive hydration (IV 0.9% saline 125 mL/hr plus a minimum of 3L oral fluids/24h). SPGB involved bilateral insertion of cotton-tipped applicators saturated with 2 mL of 2% lidocaine at 45° to the hard palate, advanced along the superior border of the middle turbinate to the posterior nasopharyngeal wall, remaining in place for 15-20 minutes. Interventions were initiated immediately post-randomisation. The outcome assessor was blinded to group allocation.

The trial was prospectively approved by the institutional ethics and research committee (Reference A2024-1014) and registered with the ISSSTE institutional research registry (RPI #408-2024) prior to enrolment of the first participant. Registration on ClinicalTrials.gov was not completed at the time of study initiation due to institutional policy restrictions in place at that time. This record documents the study retrospectively; the prospective institutional approval and registration are documented under the IRB approval number above.

Inclusion Criteria:

• Age 18-55 years
• ASA physical status I or II
• Developed post-dural puncture headache following accidental dural puncture with a 17G Tuohy needle during an epidural procedure
• Enrolled within 24 hours of dural puncture
• PDPH diagnosed clinically as headache with postural characteristics (worsening upright, relief supine), consistent with ICHD criteria
• Willing to provide written informed consent

Exclusion Criteria:

• History of migraine or chronic headache
• Received prior intervention for PDPH before enrolment
• Chronic use of anticonvulsants, gabapentinoids, or weak opioids

Elimination Criteria:

• Patient withdrawal of consent at any point during the study
• Development of side effects requiring further interventional management

De-identified individual participant data underlying the results reported in this article, along with the full analysis code, will be made available following article publication via the corresponding author's public GitHub repository (https://github.com/phabel-LD).

Beginning at the time of article publication, with no end date.

Data and code will be publicly available with no access restrictions via GitHub.

This was a single-blind trial. Blinding of patients and treating clinicians was not feasible given the nature of the interventions. The outcome assessor collecting NRS pain scores was instructed to remain blinded to group allocation and was not involved in treatment delivery.