Porth's Essentials of Pathophysiology, 4e

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Nervous System

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numeric scales (i.e., 1 to 10) and word graphic scales (i.e., “none,” “a little,” “most I have ever experienced”) can be used. Another supplementary strategy for assess- ing a child’s pain is to use a body outline and ask the child to indicate “where it hurts.” Pain Management The management of children’s pain basically falls into two categories: pharmacologic and nonpharmacologic. In terms of pharmacologic interventions, many of the analgesics used in adults can be used safely and effec- tively in children and adolescents. However, it is criti- cal when using specific medications to determine that the medication has been approved for use with chil- dren and that it is dosed appropriately according to the child’s weight and level of physiologic development. Age-related differences in physiologic functioning, nota- bly in neonates, will affect drug action. Neonates have decreased fat and muscle and increased water, which increases the duration of action for some water-soluble drugs; neonates also have decreased concentration of plasma proteins (albumin and α 1 -glycoprotein), which increases the unbound concentration of protein-bound drugs. 58 Neonates and infants also have decreased levels of the hepatic enzymes needed for metabolism of many analgesics. The levels of these hepatic enzymes quickly increase to adult levels in the first few months of life. Drug clearance in the 2- to 6-year-old age group is actu- ally higher than adult levels because of the larger hepatic mass relative to body weight. 58,60 The renal excretion of drugs depends on renal blood flow, glomerular filtration rate, and tubular secretion, all of which are decreased in neonates, particularly premature neonates. Renal func- tion reaches adult levels by 1 year of age. 58,60 The overriding principle in all pediatric pain manage- ment is to treat each child’s pain on an individual basis and to match the analgesic agent with the cause and intensity of pain. 60 A second principle involves main- taining the balance between the level of side effects and pain relief such that pain relief is obtained with as little opioid and sedation as possible. One strategy toward this end is to time the administration of analgesia so that a steady blood level is achieved and, as much as possible, pain is prevented. This requires that the child receive analgesia on a regular dosing schedule, not “as needed.” Also, most drugs are packaged primarily for adult use, and dose calculations and serial dilutions may predispose to medication errors. Common errors include milligram–microgram errors, decimal point errors, confusion between daily dose and fractional dose (e.g., 100 mg/kg/d divided by 6 hours versus 100 mg/kg per dose every 6 hours), and dilution errors. 60 Nonpharmacologic strategies can be very effective in reducing the overall amount of pain and amount of analgesia used. In addition, some nonpharmacologic strategies can reduce anxiety and increase the child’s level of self-control during pain. Pacifiers and sucrose are being used in the NICU. The effects of sucrose (sweet taste) are believed to be opioid mediated because its effects are reversed by naloxone (an opioid antagonist). 59

Distraction helps children of any age divert their atten- tion away from pain and onto other activities. Common attention diverters include bubbles, music, television, conversation, and games. Relaxation techniques and massage therapy are particularly useful in children with chronic pain. Other nonpharmacologic techniques can be taught to the child to provide psychological prepara- tion for a painful procedure or surgery. These include positive self-talk, imagery, play therapy, modeling, and rehearsal. The nonpharmacologic interventions must be developmentally appropriate and, if possible, the child and parent should be taught these techniques when the child is not in pain (e.g., before surgery or a painful pro- cedure) so that it is easier to practice the technique.  Pain in Older Adults Among adults, the prevalence of pain in the general population increases with age. Prevalence reports for persistent pain in older adults ranges from 25% to 80%, depending on whether the older adults are com- munity dwelling or reside in a nursing home. 61 Among the common causes of pain in older adults are musculo- skeletal disorders such as osteoarthritis and chronic low back pain; rheumatologic diseases such as rheumatoid arthritis and polymyalgia rheumatica; and neurologic conditions such as diabetic neuropathy, postherpetic neuralgia, and central post-stroke pain. Unrelieved pain can have significant functional, cog- nitive, emotional, and societal effects in the elderly. 61,62 Decreased activity because of pain can lead to myofas- cial deconditioning and gait disturbances, which in turn can result in injuries from falls. Pain in the elderly has been associated with impaired appetite, increased sleep disturbances, and in some cases a decrease in cognitive function. These consequences can lead to less than opti- mal participation in rehabilitation efforts and decreased quality of life. Increased costs because of health care use have also been attributed to unrelieved pain in the elderly. Pain Assessment The assessment of pain in the elderly can range from relatively simple in a well-informed, alert, cognitively intact individual with pain from a single source and no comorbidities to extraordinarily difficult in a frail individual with severe dementia and many concurrent health problems. 61,63,64 When possible, a patient’s report of pain is the gold standard, but behavioral signs of pain should be considered as well. Accurately diagnosing pain when the individual has many health problems or some decline in cognitive function can be particularly challenging. In recent years, there has been increased awareness of the need to address issues of pain in indi- viduals with dementia. The Assessment for Discomfort in Dementia Protocol is one example of the efforts to improve assessment and pain management in these indi- viduals. It includes behavioral criteria for assessing pain and recommended interventions for pain. Its use has been shown to improve pain management. 65