35RC17_8826_NEPHROPAIN Phase APRES : Interest of the Equimolar Oxygen Nitride Mixture (MEOPA) in the Treatment of Pain in Patients Presenting to the Emergency Department for Suspected Renal Colic: a Study BEFORE AFTER

Inclusion Criteria : * Age greater than or equal to 18, * Presenting a suspicion of renal colic, that is to say a pain at the level of a lumbar fossa radiating towards the external genital organs, of rapidly progressive, non-febrile appearance, * Having given free, informed and written consent, * Affiliated to the social security system. Exclusion Criteria : * Patient in shock of all types, defined here as an acute cardio-circulatory failure with mean arterial pressure less than 65 mm Hg. * Oxygen saturation below 93% in ambient air, * With suspicion of pneumothorax, * Having a history of emphysema and / or COPD (chronic obstructive pulmonary disease), * Contraindications to the administration of MEOPA: Patients requiring ventilation in pure oxygen; Intracranial hypertension (headache associated with jet vomiting); Any alteration of the state of consciousness, preventing the cooperation of the patient (Glasgow score less than 15); Head trauma; Pneumothorax; Emphysema bubbles; Gas embolism; Diving accident; Abdominal gas distension; Patient who has recently received an ophthalmic gas (SF6, C3F8, C2F6) used in ocular surgery as long as a gas bubble persists inside the eye and at least for a period of 3 months; Known and unsubstituted deficiency of vitamin B12 or folic acid; Neurological abnormalities of recent appearance and unexplained) * Contraindication to NSAIDs, * Patient treated in the long course by analgesic stage 3, * Pregnant or lactating woman, * Concomitant participation in another research involving the interventional or minimal risk and minimal human person, * Major persons subject to legal protection (legal safeguards, guardianship, tutorship) and persons deprived of their liberty.