LONDON, Ontario-For a child with cancer, the pain related to the disease, its therapy, and required procedures is quite often the worst pain that the child has ever encountered, said Patricia A. McGrath, PhD, in her presentation at the World Health Organization workshop session on cancer pain.
LONDON, Ontario-For a child with cancer, the pain related to thedisease, its therapy, and required procedures is quite often theworst pain that the child has ever encountered, said PatriciaA. McGrath, PhD, in her presentation at the World Health Organizationworkshop session on cancer pain.
Children may be terrified of cancer-related procedures and evenstruggle to get away, she said, but clinicians can take advantageof a fact that underlies the WHO's new guidelines for the managementof pediatric cancer pain: The child's pain system is plastic,and may be intensified by situation-specific factors that oftencan be modified.
"A finger prick, for example, creates a sequence of activityin nerves that respond to tissue damage, but
the final pain that the child experiences is related to the situationand context in which that finger prick is delivered," saidDr. McGrath, director, Child Health Research Institute, Universityof Western Ontario, London.
She contrasted a distressed 7-year-old cancer patient, whose painrating of this procedure was high, with a calm child with thesame kind of cancer who performed the procedure herself (see Figure1).
The child had learned that if she vigorously rubbed her fingerjust before pricking it, the pain intensity would not be as strongor last as long. "She was intently absorbed in doing theprocedure and reported almost no pain from the exact same kindof tissue damage that produced a great deal of pain in the distressedchild," Dr. McGrath said.
Health care professionals can help children decrease their anxietyor fear of procedures, and thus decrease their pain, in a numberof ways.
These include providing age-appropriate information about whatis going to happen; giving the child some level of control, suchas letting the child choose which finger will be pricked, whetherhe or she will watch the procedure or turn away, whether the childwill squeeze his mother's hand or hold a toy; and using variousother methods to distract the child's attention away from theprocedure.
Education to help relieve anxiety can include play activity, forexample, using puppets to demonstrate what happens in an IV insertion(see Figure 2, ).
In one case, a young girl who was undergoing an amputation forcancer helped her clinicians learn more about the quality andintensity of phantom limb pain by filling out a daily pain questionnaire.
She discovered that an intense itching in her missing knee couldbe relieved by scratching the intact knee, "exactly whatshe should have done, but no one had thought to tell her thatahead of time," Dr. McGrath said.
The WHO guidelines (Cancer Pain Relief and Palliative Care inChildren, in press) outline a simple therapeutic strategy forrelieving pain in children with cancer as follows:
Assess the child for pain as part of the physical examination.Determine primary and secondary causes of the pain. Develop atreatment plan that targets all causes. Implement the plan; thenassess the child regularly and revise the plan as necessary.
Dr. McGrath noted that a number of simple scales for measuringpain intensity are available for use in children, including thermometeror facial scales. "But you don't need anything more thanasking a child, How much pain do you have?" she said.
Dr. McGrath stressed that analgesic drugs are the mainstay oftherapy and should be administered "by the ladder, by theclock, by the mouth, and by the child."
By the ladder refers to the WHO three-step approach of using progressivelystronger agents as needed. Although morphine is generally thefirst choice for severe cancer pain, the latest revision of theladder has added other strong opiates to the list, including hydromorphone(Dilaudid), oxycodone (Roxicodone), and fentanyl (Sublimaze).
By the clock refers to the need to administer drugs on a regularschedule (plus rescue doses) rather than on an as-needed basis.
By the mouth refers to the preference for oral opioid dosing,with painful or invasive routes of administration avoided wheneverpossible. By the child refers to the need to base opioid dosingon each child's individual circumstances.
Nondrug therapies are also essential in managing a child's cancerpain. "Even children receiving the most sophisticated paincontrol protocols often do not receive optimal pain control becausethis side of the formula is missing," Dr. McGrath said.
Such therapies include supportive efforts involving the child'sfamily, and therapies labeled physical, behavioral, or cognitive,depending on whether they primarily modify the child's sensorysystems, change his or her behavior, or influence the child'sthoughts.