Intravenous ketorolac versus morphine in children presenting with suspected appendicitis: a pilot single-centre non-inferiority randomised controlled trial

OBJECTIVES: Despite a lack of evidence demonstrating superiority to non-steroidal anti-inflammatory drugs, like ketorolac, that are associated with lower risk of harms, opioids remain the most prescribed analgesic for acute abdominal pain. In this pilot trial, we will assess the feasibility of a definitive trial comparing ketorolac with morphine in children with suspected appendicitis. We hypothesise that our study will be feasible based on a 40% consent rate. METHODS AND ANALYSIS: A single-centre, non-inferiority, blinded (participant, clinician, investigators and outcome assessors), double-dummy randomised controlled trial of children aged 6-17 years presenting to a paediatric emergency department with ≤5 days of moderate to severe abdominal pain (≥5 on a Verbal Numerical Rating Scale) and are investigated for appendicitis. We will use variable randomised blocks of 4-6 and allocate participants in 1:1 ratio to receive either intravenous (IV) ketorolac 0.5 mg/kg+IV morphine placebo or IV morphine 0.1 mg/kg+IV ketorolac placebo. Analgesic co-intervention will be limited to acetaminophen (commonly used as first-line therapy). Participants in both groups will be allowed rescue therapy (morphine 0.5 mg/kg) within 60 min of our intervention. Our primary feasibility outcome is the proportion of eligible patients approached who provide informed consent and are enrolled in our trial. Our threshold for feasibility will be to achieve a ≥40% consent rate, and we will enrol 100 participants into our pilot trial. ETHICS AND DISSEMINATION: Our study has received full approval by the Hamilton integrated Research Ethics Board. We will disseminate our study findings at national and international paediatric research conferences to garner interest and engage sites for a future multicentre definitive trial. TRIAL REGISTRATION: NCT04528563, Pre-results.