Pain is one of the most common reasons for children to attend emergency departments, particularly following traumatic injuries such as fractures, sprains, or contusions. Despite advances in medical care, severe acute pain in children is still sometimes inadequately treated. One important reason is that intravenous pain medication can be technically difficult, stressful, or delayed in paediatric patients.

Intranasal drug administration, which involves spraying medication into the nose, offers a rapid and needle-free way to relieve pain and is increasingly used in paediatric emergency care. Two medications can be administered through this route: ketamine and sufentanil. Intranasal ketamine is already widely used in children for pain management. Sufentanil is a potent opioid analgesic commonly used in adults and in anaesthesia but has been much less studied in children when administered intranasally.

The aim of this study is to compare the effectiveness and safety of intranasal sufentanil and intranasal ketamine in children aged 6 to 17 years who present to the emergency department with severe traumatic limb pain. Both medications will be given in addition to standard care, including the routine use of an oxygen-nitrous oxide gas mixture (MEOPA), which is commonly used to reduce pain and anxiety in children.

Children who take part in the study will be randomly assigned to receive either intranasal sufentanil or intranasal ketamine. Pain levels will be assessed at regular time points after medication administration using age-appropriate pain scales. Sedation level and possible side effects will also be closely monitored for a short period following treatment.

The hypothesis of this study is that intranasal sufentanil will provide greater pain relief than intranasal ketamine 30 minutes after administration, without increasing the risk of adverse effects, when both are used alongside standard emergency care.

The results of this study are expected to improve knowledge about fast, effective, and non-invasive pain relief strategies for children in emergency settings and may help optimise future pain management protocols in paediatric emergency care.

Inclusion Criteria:

• Children aged 6 to 17 years inclusive, under 18 years old, weighing more than 10kg, and requiring analgesia for the management of acute pain
• Presenting with pain assessed as severe using a validated pain scale (VAS > 6/10)
• Acute traumatic lime injury
• Pain caused by trauma, excluding thoracic trauma with dyspnea and abdominal pain
• Obtaining written and signe informed consent from one of the two parents or legal guardians
• Affiliation with a social security system
• Hemodynamically stable
• For post-menarche girls: negative urine pregnancy test and effective contraception, in accordance with national regulations

Exclusion Criteria:

• Patient in a state of immediate life-threatening distress
• Parents who don't understand and/or don't speak French
• Known hypersensitivity to opiods
• Allergy to one of the study treatments
• History of epilepsy or known psychiatric illness
• History of respiratory, cardiac or renal insufficiency
• Use of serotonergic antidepressants
• Any child with an ongoing respiratory condition (asthma, laryngitis)
• Thoracic trauma
• Use of opioids within the 4 hours prior to arrival in the ermergency department
• Any child with an ongoing respiratory condition (asthma, laryngitis)
• Thoracic trauma
• Use of opioids within the 4 hours prior to arrival in the ermergency department
• History of head, abdominal, or spinal trauma
• Confirmed pregnancy
• History of toxic substance use
• Facial or nasal trauma
• Whithdrawal of informed consent from the parents or legal guardian