Comparison of Ketorolac at Three Doses In Children With Acute Pain: A Randomized Controlled Trial (KETODOSE TRIAL)
Background: Despite the ongoing opioid crisis, opioids remain a commonly prescribed analgesic for patients with acute pain. Ketorolac is the leading parenteral non-steroidal anti-inflammatory drug (NSAID) in Canada commonly used in the Emergency Department (ED) and inpatient settings for acute abdominal pain and migraine headaches. Though it has safer adverse event profile than opioids, its use in children is off label as there are virtually no pediatric trials to inform this practice. Currently the recommended dosing for children is 0.5 mg/kg to a maximum dose of 30 mg. Recent trials with adults have shown no added analgesic benefit to higher doses of ketorolac, when comparing 10 mg to 15 mg or 30 mg, intravenous (IV). A lower dose will be desirable if it achieves similar reduction of pain, as it allows for safer cumulative daily dosing and lower rates of adverse events. This has led many physicians to change their adult practice to a maximum dose of 10 mg IV; however, despite their smaller size, most children continue to be exposed to doses of 30 mg IV, due to a lack of similar available evidence.
Research Question: In children aged 6 - 17 years, with moderate to severe pain (measured using the 11-point verbal numerical rating scale (VNRS)), who are prescribed IV Ketorolac by their treating physician, is low-dose IV Ketorolac (0.25 mg/kg/dose up to 10 mg OR 0.5 mg/kg/dose up to 10 mg) non-inferior (NI) to standard treatment (0.5 mg/kg/dose up to 30 mg) in reducing mean pain scores within a NI margin of 1?
Study Design: Our trial is a single-center, block randomized, double-dummy, double-blind, three-arm, controlled trial with parallel groups. Participants will include: (i) ≥6 years; (ii) with moderate-severe pain (defined as VNRS \> 4; (iii) seen in the ED or inpatient setting; and (iv) who have an IV access planned/available. These individuals will be randomized to an arm with active ketorolac and a 'placebo' ketorolac of a differing dose, to maintain blinding through the double-dummy design: (1) standard-dose ketorolac (0.5 mg/kg IV up to 30 mg IV) + low-dose ketorolac placebo; (2) low-dose ketorolac (0.25 mg/kg up IV up to 10 mg IV) + standard-dose ketorolac placebo; or (3) low-dose ketorolac (0.5 mg/kg IV up to 10 mg) + standard-dose ketorolac placebo.
Participants will be allowed any other non-NSAID rescue therapy at any point after our trial drugs are administered, based on clinical team discretion. Based on available adult literature, a chosen NI margin of 1 point (50% of the established MID), an expected mean difference of 0.2 on the VNRS, and standard deviation of 1.5 points, 57 participants will be needed in each group to achieve a 5% alpha at 80% power.
Primary Outcomes: Between each low-dose ketorolac group and standard group mean differences in pain as measured on VNRS at 60 minutes.
Summary: Acute pain requiring parenteral analgesia is very common amongst Canadian children.Despite data in adults and children supporting preferential NSAID use for acute pain, significant gaps in knowledge regarding safe and effective Ketorolac dosing in children still exists. The drug's superior adverse effect profile and lack of dependence and abuse potential, makes this an appropriate than opioids, and is not known to be a substance of misuse.
