Sphenopalatine Ganglion Block for Post-Dural Puncture Headache: A Pilot Randomized Controlled Trial

Background: Post-dural puncture headache (PDPH) affects up to 11.2% of patients after neuraxial anesthesia. The sphenopalatine ganglion block (SPGB) is a promising minimally invasive intervention, but high-quality randomized trial data are limited. We conducted a pilot randomized controlled trial to assess feasibility and inform a future definitive trial. Methods: Twenty-six patients with PDPH following accidental dural puncture with 17G Tuohy needles were randomized to conservative management (bed rest, hydration) or SPGB (bilateral intranasal 2% lidocaine). Primary outcomes were feasibility (recruitment, retention, protocol adherence). Secondary outcomes included pain intensity (Numeric Rating Scale, NRS 0-10) at 30 minutes, 12 hours, and 24 hours; rescue analgesia requirements; mobilization time; and adverse events. Results: Feasibility was confirmed: 100% recruitment of target sample, 100% retention, 100% protocol adherence. At 30 minutes, all SPGB patients reported complete pain resolution (NRS=0) versus median NRS 3 (IQR 2) in controls (p<0.001), though this finding is limited by lack of blinding and baseline assessment. No SPGB patients required rescue analgesia or experienced adverse events. Conservative group patients had prolonged hospitalization (46%). Sample size calculation for a definitive trial (90% power, =0.05) yields 120 participants (60/group). Conclusions: A definitive RCT comparing SPGB to conservative management for PDPH is feasible. Preliminary efficacy data suggest rapid analgesia with SPGB, but rigorous confirmation in a sham-controlled trial is required. Trial registration: ClinicalTrials.gov -NCT07494383 (retrospectively registered). Keywords: Post-dural puncture headache, sphenopalatine ganglion block, pilot study, feasibility, regional anesthesia, randomized controlled trial