Evaluation of the Efficacy of Intra-nasal Sufentanil for Analgesia of Vaso-occlusive Crisis in Sickle-cell Adults.

Inclusion Criteria:

• Age 18 to 75 years old;

• Sickle-cell patient.

• Signs of a vaso-occlusive crisis (migratory bone pain, which may occur in the limbs,spine, thorax, pelvis, skull) or crisis known as such by the patient;

• Severe pain (NRS ≥ 6/10) on admission to the ED;

• Registered with the social security scheme or his beneficiaries (except AME)

• Signature of free and informed consen.

Exclusion Criteria:

• Strong opioids received in the previous 6 hours;

• Pregnancy or breastfeeding;

• Woman not menopausal nor sterile without effective contraception (HAS criteria)

• Oxygen saturation below 93%;

• Patients who cannot cooperate because of a State of agitation or a Cognitiveimpairment

• Unable to communicate;

• Unable to do self-assessment;

• Allergy or intolerance to opiates or nitrous oxide.

• Abuse or addiction to opioids

• Liver insufficiency

• Renal insufficiency

• Severe asthma or chronic obstructive bronchopulmonary disease

• Pulmonary disease necessitating oxygen

• Presence of seriousness signs:

• All respiratory seriousness signs

• all neurologic signs or consciousness impairment (coma Glasgow scale under 15)

• hyperthermia over than 39°C

• Signs of intolerance of acute anemia

• Signs of hemodynamic failure

• Known organ failure (renal insufficiency, pulmonary high blood pressure)

• A description by the patient of a non usual crisis.

• Current treatment with nasal vasoconstrictors is ongoing

• Head injury with suspicion of high intracranial pressure

• Severe thoracic trauma or decompensated respiratory insufficiency

• Contraindications of intranasal administration:

• Facial trauma

• Nose or sinusal surgery in the previous 6 months before inclusion

• Chronic nose and upper airway alteration (ex. facial malformation)

• Acute nose and upper airway alteration (ex. Epistaxis, acute respiratoryinfection, sinusitis).

• Contraindication to nitrous oxide

• Contraindication to morphine

• Patient's refusal to participate in the study.

• Previous inclusion in the study of less than 14 days.