Key points

Introduction

Pain management in the pediatric population can be a daunting task for treating physicians. Although this is an important responsibility, it has been reported that a large percentage of children’s pain goes undertreated. This untreated pain can be a significant cause of morbidity and mortality, especially in the postoperative period. Acute pain, from injury, illness, or medical and surgical procedures, is the most common type of pain experienced by the pediatric population.

Over the last 2 decades, pediatric pain management has progressed greatly. In the 1970s, pediatric procedural and postoperative pain was almost completely disregarded. It soon became evident that inadequate pain control had negative short-term and long-term effects on these patients. New pediatric pain assessment tools have been developed and validated. In the past, proper treatment of pediatric pain was lacking compared with adult pain, mainly because of a deficiency of clinical knowledge, inadequate research in the realm of pediatric pain, and a fear of using opioid analgesia. However, most major children’s hospitals in the United States have a dedicated department focusing on the evaluation and treatment of pediatric pain. A multimodal approach using pharmacologic measures, opioid and nonopioid analgesics, local and regional anesthesia, as well as nonpharmacologic measures is being used to adequately treat pain.

Assessment of pain

The accurate assessment of pain is vital when managing pain in any population, but may be especially difficult in the pediatric population. In general, pediatric patients experience more fear and anxiety surrounding painful situations, including postoperative pain. Young children and infants pose a challenge in the assessment of pain, especially if they are nonverbal or minimally communicative because of age or developmental disabilities. Self-reporting of pain has been considered the gold standard for accurate pain assessment ( Table 1 ). However, this is only practical in older children that have the capabilities to rate their pain on a scale.

Observing behavioral changes in the pediatric population may be useful to help quantify pain. A behavioral checklist can be performed, and, based on the behaviors present, a numerical score can be given. An estimate can then be made of the level of pain of the patient. These pain checklists may be a reliable resource to aid in the assessment of pain in noncommunicative or developmentally disabled children.

Modalities of pain control

It is imperative to provide both the patient as well as the family with education on the various pharmacologic and nonpharmacologic analgesia options. This education should include effectiveness of the treatment plan as well as the potential side effects and adverse reactions associated with the various medications.

The ideal method of providing perioperative analgesia to the pediatric population is through a multimodal approach. For example, preoperative regional anesthesia, postoperative local anesthetic use, and a variety of intravenous and oral analgesics postoperatively can be used to create a synergistic or additive effect that allows appropriate analgesia in the perioperative setting. Analgesics can work at the peripheral level. These analgesics include modalities such as local anesthesia, regional nerve block, and nonopioid and opioid pain medications. Analgesia can also be achieved at the level of the brain, and include such modalities as local anesthetics, opioids, and alpha-2 agonists.

Nonpharmacologic

As discussed previously, the pediatric population is unique in that generally there is increased fear and anxiety associated with painful situations and procedures. The unique neurodevelopmental stages of newborns, infants, and children dictate the way this population perceives and copes with pain. Interventions should be individualized to patients based on the age and developmental stage of the patient.

In instances of traumatic situations, first aid maneuvers should be used. Immobilization through splints can stabilize fractures and dislocations, which can reduce pain. Cryotherapy decreases swelling and may provide localized topical pain relief in the setting of a traumatic injury.

The role of child life specialists has been shown in the acute setting to reduce children’s pain and anxiety. The presence of the children’s parents may also play a beneficial role, with the caveat that parental anxiety can increase pain. For this reason, physicians should counsel parents before any procedures and instruct them on different coping strategies specific to the child’s current neurodevelopmental stage.

Distraction techniques may be a useful adjunct to treat pain in preschool and school-aged children. Toddlers showed improved pain tolerance when distraction techniques, such as playing peek-a-boo, blowing bubbles, and looking at books, were used. In older children, distraction via video games, cartoons, or other forms of TV entertainment were effective in lessening self-reported anxiety.

In the neonatal and infant population, oral stimulation and physical touch has shown effectiveness in both anxiety reduction as well as pain control. Skin-to-skin care occurs when the infant is placed directly on the parent’s chest for 30 minutes before and during the procedure. A sucrose solution has been recommended in neonates less than 30 days old for certain painful procedures. It is easy to administer, accessible, cost-effective, and has a very low risk of adverse events.

Acupuncture has also been proposed as a modality to treat pain in pediatric patients. Up to 30% of the pediatric pain centers reported acupuncture services. One study reported on 243 children treated with acupuncture for 6 weeks for various pain complaints. The visual analogue scale score decreased significantly from 8.3 at the beginning of the study to 3.3 after the final treatment. The safety of acupuncture has been shown in several studies, but it is recommended that only experienced and qualified individuals perform these services.

Nonopioid analgesics

Medications such as acetaminophen, aspirin, nonsteroidal antiinflammatory drugs (NSAIDs), and selective cyclooxygenase (COX) 2 inhibitors make up the broad category of nonopioid analgesics. COX enzymes are implicated in the pain and inflammation pathway by converting arachidonic acid to prostanoid products. There are different subtypes of COX enzymes that are differentially found in the peripheral tissues and vary in function. COX-1 is found in platelets. Both NSAIDs and aspirin inhibit the action of COX-1, but aspirin ingestion results in an irreversible inhibition. Of note, aspirin and NSAIDs inhibit a broad spectrum of COX enzymes. COX-2 is found primarily in leukocytes and other inflammatory cells. COX-2 inhibitors such as celecoxib are designed specifically to inhibit this subtype of COX enzyme. COX-3 is found in the central nervous system and is inhibited by acetaminophen.

Acetaminophen is probably the most widely used analgesic in the pediatric population. Unlike the other nonopioid analgesics, it has minimal effect in the periphery. It also acts as an antipyretic, which further increases its popularity among the pediatric population. Acetaminophen is primarily metabolized by the liver. Toxicity caused by acute and chronic overdose can result in hepatic injury. To avoid hepatic toxicity, the daily dose should not exceed 4 g/d. Acetaminophen is available in both oral and rectal formulations in the United States.

NSAIDs reversibly inhibit the COX enzyme, resulting in peripheral antiinflammatory and analgesic effects. They are commonly used for mild to moderate pain and are often used in conjunction with opioids to serve as an adjuvant. Unlike opioids, NSAIDs are not associated with respiratory depression, sedation, tolerance, or urinary retention. However, NSAIDs are associated with unique risks. These risks include, but are not limited to, nephropathy, gastropathy, and bleeding caused by reversible inhibition of platelets.

One area of controversy surrounding NSAID use revolves around bone healing in children with fractures or in pediatric patients who have undergone certain types of procedures that require bone formation, such as a posterior spinal instrumented fusion for scoliosis. Prostanoids play a key role in osteoblast activation and new bone formation. Animal models have raised theoretic concerns of potential nonunion complications with NSAID use. Some researchers have suggested that judicious use of NSAIDs is likely to have minimal to no effect on fracture healing or fusion formation.

Ketorolac is the most popular intravenous NSAID used in the United States, with an analgesic efficacy similar to most opioids. It may be particularly useful in patients that cannot tolerate opioids for any reason or in procedures that have a high affinity to cause nausea or vomiting. At present, oral ketorolac is not available for pediatric use. ^,

A 2014 randomized trial in Canada studied the use of morphine versus ibuprofen in acute postfracture pain in the pediatric population. Children that presented to the emergency department with a nonoperative fracture within the previous 24 hours were blindly randomized to either a morphine group or ibuprofen group. No statistically significant difference was found in analgesic efficacy between the two groups. However, morphine was associated with significantly more adverse effects.

COX-2 inhibitors provide similar analgesia and antiinflammatory effects to other NSAIDs, with the theoretic benefit of lower incidence of gastric issues. However, there does not seem to be a difference in renal toxicity compared with traditional NSAIDs. In the adult population, there have been reports of cardiovascular complications seen in patients with limited use. It is still unknown whether this risk is conferred to the pediatric population.

Ketamine is used as an adjuvant analgesic in perioperative pain management. It has recently been more widely used for procedural sedation and analgesia in a variety of settings, including the emergency department. It is widely recommended to administer ketamine along with an anticholinergic agent and benzodiazepine to reduce sialorrhea and hallucinations, respectively. When used, it is vital to have appropriate monitoring and resuscitation equipment available in the event of respiratory distress.

Opioid analgesics

The fear of patient opioid use, opiophobia, is present in all patient populations but is especially present in the pediatric population. An initial concern for addiction was diminished when a New England Journal of Medicine article cited that only 4 of 11,000 patients with a legitimate medical condition that are prescribed oral opioids for pain control develop addiction. To address the long-standing history of undertreatment of pediatric pain, opioid prescriptions doubled between 1990 and 2010. However, with this increase in opioid prescriptions, new areas of concerns began to appear: accidental opioid overdose in young children and illegal and/or recreational use by teenagers. A 2009 report by a poison control center cited more than 9000 accidental exposures to opioids in children younger than 6 years. These 9000 exposures resulted in multiple hospitalizations and 8 recorded deaths. Despite these considerations and valid concerns, opioids can play a key role in relief of acute pain and remain underused in the pediatric population.

Recent literature has been directed toward the use of opioid analgesics, tramadol and codeine, in the pediatric population. Both of these analgesics are metabolized via the cytochrome P450 2D6 enzyme into active compounds. There have been several case reports of children being rapid metabolizers of these specific opioid analgesics because of an overactive cytochrome P450 2D6 enzyme. This condition could lead to oversedation, respiratory distress, and potentially death. As of 2017, the US Food and Drug Administration updated the warnings regarding codeine and tramadol use in pediatric patients. It is now contraindicated in patients 12 years of age and younger.

Intravenous patient-controlled and nurse-controlled analgesia

Patient-controlled analgesia (PCA) institutes a delivery system with small doses of opioid that are preset before administration. A button can be pressed by the patient or the nursing staff to deliver the opioid intravenously. PCA usage seems to be more effective in children older than 7 years of age because of greater understanding of the cause-and-effect concept of pushing and button and receiving medication and pain relief.

Nurse-controlled analgesia is used in the younger pediatric population. This population is more likely to be physically or cognitively unable to control the PCA appropriately. Evidence supports that nurse-controlled analgesia is a safe way to titrate opioids in the younger patient population.

Summary

Adequate pain management in the pediatric population is a difficult undertaking for treating physicians. Pain management in the pediatric population has evolved greatly in the last 2 decades. Proper assessment of a child’s pain is the first step to adequately controlling pain. There are different modalities that can be used to treat pain in this population, including both pharmacologic and nonpharmacologic methods. Common pharmacologic methods include, but are not limited to, nonopioid medications such as nonsteroidal antiinflammatories, opioids, and ketamine. Regional anesthesia is also becoming increasingly popular. Nonpharmacologic methods include cryotherapy, distraction techniques, and, in some cases, acupuncture. A child life specialist can be a great asset with these nonpharmacologic pain control modalities.