Pediatric Acute Pain Management Hon

Pediatric Acute Pain Management
Honorio T. Benzon, James P. Rathmell, Christopher L. Wu, Dennis C. Turk, Charles E. Argoff and Robert W. Hurley
Practical Management of Pain, 20, 304-311.e3

Recognition and treatment of acute pain in children have vastly improved the care of pediatric patients. 1 2 Data emphasizing the efficacy of adequate pain control and decreases in adverse neurohormonal changes have led to better treatment of infants and children. 3 4 5 Recent advances in pharmacologic therapy and regional anesthetic techniques have helped expand the scope of pediatric acute pain management. 6 In addition, the establishment of pediatric acute pain services has played an important role in ensuring timely and consistent care of children. 7 8 9 10 11 12


Developmental Neurobiology of Pain


The study of pain in neonates has been a major focus in the field of neuroscience. Nociceptive pathways are well developed even at birth. A study of brain perfusion in response to pain has demonstrated significant changes in perfusion with noxious stimuli versus non-noxious stimuli. 13 Newborn rats appear to have significant proliferation of A and C fibers at the site exposed to pain; a pattern of hyperalgesia appears to develop in these animals. 14 Human neonates exposed to repeated heel sticks may have cutaneous hyperalgesia, which can be reversed with topical local analgesia. 15 Studies in the area of pain in infants and children continue to be published, thus signifying interest in both pediatric pain management and its neurobiology. 16 17


Assessment of Pediatric Acute Pain


Essential to acute pain management in children is assessment of pain. 18 Unlike adults, pediatric patients may be too young, developmentally immature, or unwilling to provide adequate interpretation of their pain. 19 Measures of acute pain in such patients often rely on observer reports, whereas assessment in older children involves self-report measures 20 (see Table 20.1 ). 17 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Observational pain assessment tools use information about pain-related behavior, such as body movements, facial expression, and vocalizations; physiologic changes such as heart rate and oxygen saturation; and the child’s behavioral state. These measures have been designed to assess procedural pain (e.g., Premature Infant Pain Profile [PIPP], 17 Neonatal Facial Coding System [NFCS] 21 22 ) or postoperative pain (e.g., Children’s Hospital of Eastern Ontario Pain Scale [CHEOPS], 36 Toddler-Preschooler Postoperative Pain Scale [TPPPS] 28 ). The FLACC scale (faces, legs, activity, cry, consolability) 37 is another pain assessment tool that can be used for all ages, including mentally challenged children (see Table 20.2 ). These scales have been shown to have construct validity and internal and inter-rater reliability despite intrinsic limits in their specificity for pain, such as physiologic parameters, which can vary because of other conditions not associated with pain. 23 24 25 26 27 29 30 31 32 33 34 35

Table 20.1
Clinical Measurements of Pediatric Acute Pain
Age Group Measure Type of Measurement Type of Pain
Neonates and infants Premature Infant Pain Profile (PIPP) (preterm and full-term neonates) Neonatal Facial Coding System (NFCS) (preterm and full-term neonates, infants ≤18 mo) Behavioral, physiologic; gestational age Procedural
COMFORT scale (0-3 yr) Behavioral, physiologic Procedural, postoperative
Toddlers and preschoolers Faces scales Self-report Procedural, postoperative
Oucher (≥3 yr) Self-report Procedural
Poker chip tool (4-8 yr) Self-report Procedural
Toddler-Preschooler Postoperative Pain Scale (TPPPS) (1-5 yr) Behavioral Postoperative
Children’s Hospital of Eastern Ontario Pain Scale (CHEOPS) (1-7 yr) Behavioral Postoperative
Children’s and Infants’ Postoperative Pain Scale (CHIPPS) (0-4 yr) Behavioral, physiologic, alertness, calmness Postoperative
School-age children and adolescents Colored analog scale (CAS) (≥5 yr) Self-report Procedural, recurrent, chronic
Visual analog scale (VAS) (≥5 yr) Self-report Procedural, recurrent, chronic
Faces Pain Scale Self-report Procedural, recurrent, chronic
Non-communicating children, children with cognitive impairment Non-communicating Children’s Pain Checklist—Postoperative Version (NCCPC-PV), Non-Communicating Children’s Pain Checklist—R (NCCPC-R) Behavioral Procedural, postoperative injury, pain related to chronic medical condition
VAS Self-report Procedural
Table 20.2
FLACC Behavioral Pain Scale
Categories Scoring 0 Scoring 1 Scoring 2
Face No particular expression or smile Occasional grimace or frown, withdrawn, disinterested Frequent to constant frown, clenched jaw, quivering chin
Legs Normal position or relaxed Uneasy, restless, tense Kicking or legs drawn up
Activity Lying quietly, normal position, moves easily Squirming, shifting back and forth, tense Arched, rigid, or jerking
Cry No cry (awake or asleep) Moans or whimpers, occasional complaint Crying steadily, screams or sobs, frequent complaints
Consolability Content, relaxed Reassured by occasional touching, hugging, being talked to; distractible Difficult to console or comfort
Developmentally appropriate children 5 years and older can typically provide self-reports on one of several validated visual analog (e.g., coloured analogue scale [CAS] 31 38 ) or faces scales (e.g., Faces Pain Scale—Revised [FPS-R], 24 39 40 Oucher 26 ) ( Fig. 20.1 ). McGrath and Hillier 41 developed a separate Facial Affective Scale (FAS) designed to measure pain affect, as distinct from pain intensity. Interestingly, the faces scales anchored with a smiling face produce higher pain ratings than do those anchored with a neutral face. 42 The well-described discordance between an observer’s ratings of a child’s pain and the child’s self-report 43 44 45 46 allows the clinician to consider the child’s self-report as the “gold standard” whenever it can reliably be obtained. 47


Figure 20.1
Faces Pain Scale.
The majority of pediatric pain assessment measures that have been developed focus on acute, procedure-related pain. 48 49 Alterations in the behavioral and sensory aspects of pain that can habituate when pain becomes chronic may not be captured by these measurement scales. 43 However, a systematic evaluation of chronic pain in children is beyond the scope of this chapter (see Chapter 33).


Nonmedical Management of Pediatric Acute Pain


Management of pain through nonmedical techniques (e.g., environmental and behavioral strategies) has proved effective in modulating pain, both independently and in conjunction with pharmacologic interventions in children. 50 51 52 53 54 Cognitive-behavioral therapy (e.g., relaxation, problem solving, cognitive coping skills) and distraction techniques such as deep breathing, cartoon videos, party blowers, and hypnosis have strong empirical support for their efficacy in easing procedure-related pain in children. 55 56 57 58 59 Distraction methods are hypothesized to work by engaging children and redirecting their attention away from the pain, thereby reducing perceived pain intensity and inhibiting the neural activity that underlies pain perception. 60 61 62 63 64 65 66 Complementary and alternative medicine techniques such as acupuncture have also been described as potential treatments of acute pain in children. 67 68


Pain Treatment Modalities


Acute pain in infants and children can be treated with various analgesics. 69 The use of multimodal analgesia is beneficial for the management of pediatric pain. 70 A pain treatment plan is best developed before the patient’s surgery, and an important goal is to provide a consistent approach to treating pain with minimal adverse effects. 12 71 72 73 74


Mild Analgesics



Sucrose


Administration of glucose and sucrose orally can provide mild analgesia since opioid peptides in the ventral striatum and cingulate gyrus may play a role in regulating positive responses to energy-rich food sources. 75 76 A Cochran database review suggested that sucrose may be effective in reducing procedural pain in neonates. 77 Doses in the range of 0.01 to 0.1 g can be used to reduce procedural pain in infants younger than 6 months. 78


Acetaminophen


Acetaminophen is commonly used in children to reduce or eliminate pain. It can be administered via the oral, rectal, and intravenous routes. The rectal and intravenous routes are preferable during the perioperative period. Rectal suppositories require higher dosing and may have variable absorption but can be an effective analgesic for postoperative pain in children. Specifically, an initial rectal dose of 30-40 mg/kg is recommended, followed by subsequent doses of 15-20 mg/kg at 4- to 6-hour intervals. This produces therapeutic plasma levels that may be adequate for managing pain. 79 80 Intravenous acetaminophen has recently been made available in the United States; it has more predictable bioavailability and achieves maximum concentration more rapidly than rectal dosing does. 81

Dosing in premature and term neonates can be affected by renal and hepatic immaturity. Hepatotoxicity is a potential risk with acetaminophen use and is dose dependent. Though a rare complication, the incidence of hepatic toxicity with higher doses of acetaminophen should be presented cautiously to parents so that injudicious use of the medication is avoided. 82


Nonsteroidal Anti-Inflammatory Drugs


Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in children in the perioperative and postoperative periods and can be administered via the oral, intravenous, or intramuscular routes. NSAIDs have been used effectively in children undergoing surgery to reduce postoperative pain and decrease requirements for supplemental pain medications. 83 84 85 Neonatal clearance of NSAIDs improves with age. Ibuprofen is metabolized by the 2C9 and 2C8 subgroups of cytochrome P-450 (CYP). 86 Ketorolac is commonly used in child