Occipital Nerve Block Compared With Acetaminophen and Caffeine for Headache Treatment in Pregnancy

Abstract

OBJECTIVE: To evaluate the efficacy of occipital nerve block compared with standard care, defined as acetaminophen with caffeine, for treatment of acute headache in pregnancy. METHODS: We conducted a single-center, unblinded, parallel, randomized controlled trial of pregnant patients with headache and pain score higher than 3 on the visual rating scale. Patients with secondary headache, preeclampsia, or allergy or contraindication to study medications were excluded. Participants were randomized to occipital nerve block or standard care (oral 650 mg acetaminophen and 200 mg caffeine). Crossover treatment was given at 2 hours and second-line treatment at 4 hours to those with worsening visual rating scale score or visual rating scale score higher than 3. The primary outcome was headache improvement to a visual rating scale score of 3 or lower within 2 hours of initial therapy. Secondary outcomes included serial visual rating scale scores, receipt of crossover or second-line therapy, patient satisfaction, and perinatal outcomes. Outcomes were assessed in an intention-to-treat analysis. We estimated that a sample of 62 would provide 80% power to detect a difference from 85% to 50% between groups. RESULTS: From February 2020 to May 2022, 62 participants were randomized to occipital nerve block (n=31) or standard care (n=31). Groups were similar except payer status. The primary outcome, headache improvement to visual rating scale score of 3 or lower, was not significantly different between groups (64.5% vs 51.6%, P=.30). The occipital nerve block group experienced lower median [interquartile range] visual rating scale scores at 1 hour (2 [0–5] vs 6 [2–7], P=.014), and more patients in the occipital nerve block group had visual rating scale scores of 3 or lower at 1 hour. Among patients receiving crossover treatment at 2 hours, the standard care group had a significantly lower visual rating scale score 1 hour after crossover to occipital nerve block than the occipital nerve block group receiving crossover to standard care (P=.028). There were no significant differences in second-line treatment, refractory headache, satisfaction, or complications. Patients receiving occipital nerve block delivered earlier (36.6 weeks vs 37.8 weeks), but preterm birth did not differ between groups. CONCLUSION: Occipital nerve block is an effective and quick-acting treatment option for acute headache in pregnancy. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT03951649.