Intranasal hydromorphone has been shown to be effective in reducing acute pain in adults. It has not been previously studied in children, but may be a viable option for effectively and safely reducing pain in children by administering an analgesic by the intranasal route.

This study will be a prospective, open-label pilot study of intranasal hydromorphone in children with moderate to severe acute pain presenting to the pediatric emergency department. The investigators aim to describe the amount of pain reduction associated with intranasal hydromorphone, and to determine the optimal dose of intranasal hydromorphone associated with a clinically meaningful improvement in acute pain.

Primary Aim: Determine the change in pain intensity in children with moderate to severe pain who receive intranasal hydromorphone one hour after administration.

Secondary Aim(s): Describe the incidence of minor and major adverse events associated with intranasal hydromorphone in children with acute pain.

The investigators will assess the patient's pain at baseline (prior to study drug administration), then after study drug administration: 5 minutes, 15 minutes, 30 minutes, 45 minutes, 60 minutes, and then every 30 minutes thereafter until 6 hours; administration of non-protocolized rescue medication administration (i.e. administered after first two rescue doses of IN hydromorphone); or discharge from emergency department (whichever comes first). The pain score at 60 minutes will be the primary outcome.

The investigators will evaluate qualitative improvement in pain intensity at 15- and 30-minutes after study drug administration. If there is no improvement, or worsening of pain intensity, at each assessment, an additional rescue dose rescue dose of intranasal hydromorphone will be administered. After 60 minutes, the treating physician may administer any additional rescue medications at their discretion to treat the child's pain.

The patient will be assessed for minor and major adverse events for the duration of the study.

Inclusion Criteria:

• Age 4 to 17 years old, inclusive
• Moderate to severe pain (i.e. FPS-R or vNRS score of 4 or more)
• Requires parenteral opioid analgesic to treat their pain, as decided by treating physician

Exclusion Criteria:

• Allergy or known contraindication to receiving opioids
• Receipt of any opioid or benzodiazepine within preceding 6 hours
• Presence of intranasal obstruction that cannot be cleared readily
• Cannot speak English or Spanish
• Patient unlikely to be able to complete self-report measures of pain or questionnaires
• Known liver or kidney problems
• Currently critically ill
• Chronic pain condition (e.g. sickle cell disease, fibromyalgia)

6 hours