Rescue designs in analgesic trials from 0 to 2 years of age: scoping review

Pediatric analgesic trials are challenging, especially in newborns and infants. Following an FDA-academic consensus meeting, we analyzed pragmatic rescue designs in postoperative trials of local anesthetics, acetaminophen, opioids, and NSAIDs involving children ages 0-2 years and assessed surgical volumes to provide trial design recommendations. Searches of PubMed, Embase, CINAHL, The Cochrane Library, and Web of Science were conducted. A scoping approach identified trends in analgesic trials with an emphasis on randomized controlled trials (RCTs) utilizing immediate rescue designs. Age-specific surgical volumes were estimated from French national databases. Of 3563 studies identified, 23 RCTs used study medication(s) of interest and immediate rescue paradigms in children ages 0-2 years. A total of 270 studies met at least one of these criteria. Add-on and head-to-head designs were common and often used sparing of non-opioid or opioid rescue medication as a primary outcome measure. According to French national data, inguinal and penile surgeries were most frequent in ages 1 month to 2 years; abdominal and thoracic surgeries comprise approximately 75% of newborn surgeries. Analgesic trials with rescue sparing paradigm are currently sparse among children ages 0-2 years. Future trials could consider age-specific surgical procedures and use of add-on or head-to-head designs. IMPACT: Clinical trials of analgesic medications have been challenging in pediatrics, especially in the group from newborns to 2 years of age. Following an FDA-academic workshop, we analyzed features of completed analgesic trials in this age group. Studies using immediate rescue in placebo control, add-on, and head-to-head trial designs are pragmatic approaches that can provide important information regarding clinical effectiveness, side effects, and safety. Using a French national dataset with a granular profile of inpatient, outpatient, and short-stay surgeries, we provide information to future investigators on relative frequencies of different operations in neonates and through the first 2 years of life.