Inclusion Criteria:  18 years old or more Affiliated to a french public health insurance ED admission for migraine evocative headache, regarding ICHD3 criterions written informed consent  Exclusion Criteria:  COPD or other chronic respiratory failure conditions Pregnant or breastfeeding women or women of childbearing potential not using any means of contraception. A pregnancy test will be performed for women of childbearing age. The results will be communicated to the patient by a doctor of her choice. Under legal protection Patients who have received treatment with triptan in the past 2 weeks Patients who have consumed NSAIDs in the hour before the doctor's examination State of migraine headache (crippling attack for more than 72 hours)