Musculoskeletal (MSK) injuries, including limb injuries, are the most common cause for Emergency Department (ED) visits for children with pain. Broken arms and legs are known to cause moderate to severe pain in most children, yet previous research shows that children's pain in the emergency department is still under-treated. Further, children are less likely to receive appropriate pain medicine than adults with similar injuries.

The purpose of this research study is to compare the effectiveness and safety of 3 different possible medication combinations, for the pain management of children with acute MSK limb injuries. The pain medicines the investigators are studying are ibuprofen (Advil/Motrin), acetaminophen (Tylenol/Tempra), and hydromorphone (Dilaudid).

This study will consist of 2 trials that will be run simultaneously. Eligible caregiver/ child pairs presenting to the emergency department with acute MSK limb injury will decide in which trial they wish to participate: the Opioid trial or the Non-Opioid trial. If they select the Non-opioid trial, they will have an equal chance of receiving either (a) Ibuprofen OR (b) Ibuprofen and acetaminophen. If they select the Opioid trial, they will have an equal chance of receiving either (a) Ibuprofen OR (b) Ibuprofen and acetaminophen OR (c) Ibuprofen and hydromorphone. Regardless of which study they choose, their child will, at minimum, receive Ibuprofen (Advil/Motrin) for their pain. All study medicines will be given in oral liquid form.

This study will help the investigators figure out which pain medicine or combination of pain medicines works best for children with limb injuries. Promotion of adequate acute pain treatment of children presenting to the ED may help prevent the known short and long-term effects of inadequately treated pain in children, including unpleasant memories, stress and anxiety upon future visits to healthcare, and compromised functional outcomes such as missed school.

Rationale:

Multiple national and international organizations, including the American Academy of Pediatrics (AAP), have voiced concern over the emergency departments' (EDs) ability and willingness to provide appropriate analgesia for children's pain. Musculoskeletal (MSK) injury is a very common cause for ED visits for children with pain, with a child's risk of sustaining a fracture ranging from 27-42% by the age of 16 years. MSK injury is known to generate moderate to severe pain in most children and the ED serves as the critical entry point for these injured children. Despite three decades of pain research in this area, recent evidence confirms that ED pain management in children is still suboptimal. A retrospective cohort study of children presenting to the ED with an isolated long-bone fracture showed almost 1/3 received inadequate medication and 59% received no pain medications during the critical first hour of assessment. Previous studies have demonstrated that only 35% of children presenting to a Canadian pediatric ED with fractures or severe sprains received any analgesic. Further, a medical record review of two Canadian EDs showed unacceptably long delays in provision of initial analgesia, with children waiting a mean of 118 minutes to the provision of first analgesia.

The AAP's consensus statement on the assessment and management of pain in children recommends acetaminophen, ibuprofen, and opioids as the top three medication choices for the treatment of acute pain in children. These are also the top three most commonly used treatments in the ED for children with MSK injury pain. It stands to reason that clinicians (and certainly patients and their families) would prefer medication that has the best efficacy and safety profile. Although not based on robust evidence, there has recently been a concerted movement to limit opioid use in children. This is due, in part, to recent controversial publications and the Centre for Disease Control (CDC)'s position statement regarding opioid use in adults. Clinicians are increasingly less likely to prescribe oral opioids to younger children, and caregivers are increasingly less willing to accept or administer them.

Clinicians are currently seeking effective (and for many, non-opioid) oral analgesic options for their pediatric patients. Researchers have yet to identify the optimal acute pain management strategy for children with a suspected fracture, as very few studies of analgesic combination therapy for this injury exist, and monotherapy has been shown to be inadequate 50% of the time. This team's previous work has demonstrated that a combination of oral morphine with ibuprofen was no more effective and was less safe than oral ibuprofen, alone, for suspected fracture pain. Similarly, oxycodone was no more effective and was less safe than ibuprofen for post-discharge fracture pain. There is some emerging work from non-ED settings to suggest that oral hydromorphone may be an effective alternative to these two opioid medications. The investigators wish to study if acetaminophen or hydromorphone, when added to ibuprofen, offers more clinical pain relief than ibuprofen alone. They also wish to study if the combination of hydromorphone and ibuprofen is more clinically effective than the combination of acetaminophen with ibuprofen. This study, which will consist of two clinical trials, will inform health-care decisions by providing evidence for the effectiveness and safety of commonly prescribed analgesic combination therapies, and compare them to the most commonly used monotherapy, ibuprofen.

Methods:

This study will be comprised of two Phase 2, six-centre, randomized, double blind, placebo-controlled trials that will be run simultaneously. These two 'sister trials will be run simultaneously within this novel preference-informed complementary trial design. Caregiver/child pairs presenting to the ED with acute MSK limb injury will decide in which trial they wish to participate: the Opioid trial or the Non-Opioid trial.

Those willing to consider an Opioid will be randomized to receive either single-dose: (a) oral ibuprofen (10mg/kg, max 600mg) plus 2 placebos (both oral hydromorphone and acetaminophen), OR (b) oral ibuprofen (10mg/kg, max 600mg) + oral acetaminophen (15 mg/kg, max 1000mg) plus hydromorphone placebo OR (c) oral ibuprofen (10mg/kg) + oral hydromorphone (0.05 mg/kg, max 5 mg) plus acetaminophen placebo. Those not willing to consider an opioid will be enrolled in the Non-Opioid trial and will be randomized to receive a single dose of (a) oral ibuprofen (10mg/kg, max 600mg) + oral acetaminophen (15 mg/kg, max 1000mg) OR (b) oral ibuprofen (10mg/kg, max 600mg) + oral acetaminophen placebo. Those without a preference for either trial will be assigned to the Opioid trial, as this one includes all three options of possible medication combinations. The investigators will measure pain scores, assess safety, and acquire other study measures, at designated study time points.

Inclusion Criteria:

1. Child aged 6-17 years
2. Presenting to the emergency department with an acute limb injury (<24 hours old) that is neither obviously deformed nor having neuro-vascular compromise (as assessed by the triage nurse)
3. Self-reported pain score > 5 on the 0 to 10 verbal Numerical Rating Scale at triage

Exclusion Criteria:

1. Deemed to require immediate intravenous (IV) or intranasal (IN) pain medications by the clinical team
2. Previously known hypersensitivity to study medications
3. Acetaminophen or NSAID use within 3 hours prior to recruitment
4. Opioid use within 1 hour prior to recruitment
5. Caregiver and/or child cognitive impairment precluding the ability to self-report pain or respond to study questions
6. Injury suspected to be due to non-accidental trauma/ child abuse (as assessed by the triage nurse or reported by the family)
7. Suspected multi-limb fracture
8. Chronic pain that necessitates daily analgesic use
9. Hepatic or renal disease/dysfunction
10. Bleeding disorder
11. Known pregnancy
12. Vomiting that precludes the ability to take oral medications (as determined by the family)
13. Caregiver and/or child inability to communicate fluently in English or French in the absence of a native language interpreter
14. Caregiver unavailable for follow-up
15. Previous enrolment in the NO OUCH study

This study will comply with the CIHR Open Access Policy. The trials will be registered at ClinicalTrials.gov, and results information from this study will be submitted to ClinicalTrials.gov. Also, every attempt will be made to publish results in peer-reviewed journals. Data from this study may be requested from other researchers 2 years after the completion of the primary endpoint by contacting the Women and Children&#39;s Health Research Institute (WCHRI) Data Coordinating Center (DCC). Conduct, reporting, editing, and publication of resultant scholarly work will be guided by the International Committee of Journal Medical Editors (ICJME)'s published recommendations.

The identity of participants will not be revealed in any published data or in presentation of the information obtained as a result of this study.

Data from this study may be requested from other researchers 2 years after the completion of the primary endpoint

Researchers will need to contact the WCHRI DCC for access to the data

Research staff, emergency department staff, and participants will be masked with respect to the allocated treatment. The data analyst will also be masked using codes that will not identify treatment groups until analysis is complete.