Acetaminophen dosing in the era of enhanced recovery after surgery

In an era of heightened awareness of the potential dangers and undesirable side effects of opioids, acetaminophen has become an important but potentially dangerous component of postoperative multimodal pain management strategies. Acetaminophen Pharmacokinetics in Severely Obese Adolescents and Young Adults addresses one of the less comfortable and typically ignored facts impacting our use of this drug. We know surprisingly little about acetaminophen dosing in many relevant populations, including overweight teenage girls. This gap in our knowledge is connected to an even larger missing piece. In an all too familiar pattern, nearly all of what we know about pediatric dosing and pharmacokinetic data of acetaminophen arises from analysis and extrapolation of adult data. Of course, this problem is not limited to acetaminophen. For example, in July of 2018, a Cochrane review of 13 studies found “no good evidence from studies to support or reject the suggestion that ketorolac is beneficial, or that it is associated with serious side effects in treating children's pain after surgery. ” This is a remarkable conclusion given that ketorolac is actually licensed by the US Food and Drug Administration (and other drug licensing authorities) for use in children more than 2 years old! Concerns about the danger of acetaminophen are associated with the potentially lethal hepatotoxic effects of its active metabolite. But when appropriately dosed, acetaminophen and other nonopioid analgesics reduce the need for even more dangerous opioids. Therefore, if we want to do the best job for our children, we need to provide them with optimal and safe doses of acetaminophen and other agents. Enhanced recovery after surgery (ERAS) projects and their attendant protocols and practices have been widely adopted because they improve clinical outcomes and reduce cost. ERAS protocols are well developed in a wide variety of adult surgeries. They all utilize a multidisciplinary approach to the surgical patient, emphasizing best practices and minimizing unnecessary variation. The ERAS Society is an international nonprofit organization that establishes guidelines for a wide variety of procedures and practices. Among its emphasized practices are early mobility and minimal use of opioid medications. Acetaminophen and other nonopioid analgesics play an obvious and important role in these goals. Noticeably absent from this body of information is nearly any recommendation related to the care of pediatric surgical patients. Evidence for the direct transfer of ERAS principles to the pediatric population is currently limited. It is easy to say, “Children are not just small adults. ” However, just like adults, children deserve the best available care and there is no reason to deny them the benefits of ERAS. We need guidelines for ERAS in children, and proper dosing of acetaminophen and other opioid‐sparing drugs and appropriate application of opioid‐sparing techniques are critical elements. Fortunately, the ERAS society is sponsoring a guideline development conference for pediatric surgery specialties in November 2018. We eagerly await the work product of this conference. In the meantime, studies that guide effective and safe dosing of analgesic medications in children cannot be overvalued.