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Management of Pain in Special Populations of Cancer Patients

Management of Pain in Special Populations of Cancer Patients

Children, the elderly, AIDS patients, and former narcotic drug
abusers pose special problems in pain management that may lead to
undermedication even more frequently than occurs in the general
population of cancer patients with pain. A multidisciplinary panel of
six pain experts with clinical experience in caring for these special
groups met in Santa Fe, New Mexico, to discuss assessment methods and
pharmacologic approaches to the treatment of pain in these patients.
A summary of the roundtable discussion follows.

C. Stratton Hill, MD: The literature continues to contain
reports indicating that pain from advanced cancer is undermedicated.
There also is ample evidence that, in some cases, pain may be
difficult to manage. This roundtable discussion will explore some of
the barriers to effective pain management and will outline practical
approaches to difficult management issues that arise in special
populations of cancer patients, such as children, the elderly, AIDS
patients, and former narcotic drug abusers.

Some of the barriers to pain management are intrinsic to
clinician-patient relationships, and others are extrinsic. In
addition, there are many societal and cultural barriers to the
adequate and appropriate use of opioids. These barriers are
demonstrated by the fact that pain management does not become an
issue until the intensity and diffuseness of pain require the use of
systemic opioids. Alternatively, nonopioid methods of pain relief may
be effective for a while but may be insufficient to manage severe pain.

In terms of cultural and societal barriers to adequate and
appropriate use of opioids, much prejudice and misinformation exist
among health-care professionals, patients, pharmacists, and friends
and relatives of patients. Much of this bias comes from confusion
about the legitimate and illegitimate uses of opioids.

Unfortunately, illegitimate images of opioid drugs often dominate our
thinking. Physicians, who ultimately make prescribing decisions,
often focus on customary and societally accepted uses of these drugs,
rather than on their pharmacodynamic and pharmacokinetic properties.
Some physicians are reluctant to prescribe opioid drugs for adequate
periods of time because they generally prescribe these agents for the
treatment of acute—not chronic—pain. They fail to recognize
that, in instances of acute pain, opioid use is usually self-limited,
whereas in chronic pain, it is necessary to use opioid drugs over a
longer time period.

In addition, there is some reluctance on the part of clinicians to
use stronger opioids, and the practice of polypharmacy to avoid their
use is common.

The final barrier to adequate use of opioid drugs is fear of
regulatory agencies. Drugs that are used for the treatment of pain
are also drugs of abuse and are classified as controlled substances.
Often, regulatory issues are so restrictive that clinicians may be
reluctant to prescribe these drugs for legitimate medical purposes.

These issues should be kept in mind during our discussion of
considerations for pain relief in special populations of cancer
patients. Children will be the first such population to be discussed.

Pediatric Patients

Ada G. Rogers, RN: For many years, conventional thinking held
that children did not feel any pain because their nervous systems
were not as developed as those of adults. This has been shown to be
untrue, however.

Another major problem in pediatrics is the assessment of pain. In a
younger child, pediatric nurses and physicians often rely on behavior
as a means of assessing pain. Unfortunately, many clinicians assume
that if children are engaged in “normal activities,” such
as watching television, they are not in pain. In one study, however,
I found that when asked about their pain, 50% of hospitalized
children who were watching television, listening to music, or playing
reported feeling severe pain. Thus, many children are undermedicated
because behavior is used exclusively as the pain assessment tool.

For children over 3 year old, several more objective assessment tools
available (Figure 1). In 1980, I developed a tool called
“happy/sad faces,” which consists of a series of five faces
with different expressions. It has proved to be useful in diagnosing
pain in children from 2½ years old to approximately 8 years old.
In children over age 8, one can use verbal rating scales (which ask
the child to rate pain as slight, moderate, or severe) or visual
analog scales. Children respond well to these assessment instruments.

With regard to selecting an analgesic for children, one problem is
that very few good studies have been conducted in this population.
The lack of clinical data is due to our reluctance to treat children
with experimental drugs, as well to parental objections to the use of
a placebo. Thus, we do not have a good understanding of what pain
medications can and cannot do in children. Our current knowledge is
based on clinical experience rather than research. It is only
recently that some studies have been conducted in children, primarily
using acetaminophen and ibuprofen.

Opioid analgesics are very well tolerated by children with cancer
pain. The two most common concerns relate to the potential of the
these drugs to produce respiratory depression and addiction. Both of
these concerns are unfounded, as no data show that either of these
side effects occurs in children with cancer pain.

Children can safely take morphine, hydromorphone, levorphanol
(Levo-Dromoran), or methadone, among other opioids. However, I do not
use meperidine chronically in pediatric patients. In children, as in
adults, the accumulation of the toxic meperidine metabolite
normeperidine can cause central nervous system excitation, ranging
from irritability to grand mal seizures. Also, since children tend to
develop itching more often than do adults, I generally use drugs that
do not release histamine, such as oxy-codone, oxymorphone
(Numorphan), and fentanyl (Tables 1
and 2).

Ronald Kanner, MD: Are the pediatric doses of opioids based on weight?

Ms. Rogers: Body weight is appropriate as a starting point,
but once a child has been medicated, the clinician must observe the
patient’s response and titrate the dose accordingly. If a child
received analgesics in the past, previous dosing should be used as a
starting point.

Dr. R. F. Kaiko at Memorial Sloan-Kettering Cancer Center studied
almost 1,000 adult patients taking 8 or 16 mg of morphine. He found
that age was a better parameter than weight for determining the
starting dose. This guideline also applies to children. I have had
young children taking very high doses of opioid analgesics who had no
problems with breathing or sedation.

Christine Miaskowski, PhD, RN: What about the role of the
parent or caregiver in managing pain? Are parents facilitory or
obstructive? What are their fears?

Ms. Rogers: Concerns vary with from parent to parent. One of
the biggest worries is drug abuse. Parents fear that the
child—especially if an adolescent—will become addicted to
pain medication.

Other parental fears stem from misinformation about what pain
medications do in the body. Parents may think that these drugs will
interfere with chemotherapy or deteriorate their child’s liver
and lungs. Some nurses may perpetuate these misconceptions. For
example, one nurse told a child that levorphanol would eat away his
lungs if he kept taking it.

As to whether parents are facilitory or obstructive, I have found
that once you win the confidence of a family member or caregiver, he
or she may provide important information by monitoring and assessing
the child’s pain.

Dr. Hill: Can children be trusted to administer intravenous
patient-controlled analgesia (PCA)?

Ms. Rogers: Studies have shown that children 7 years and older
can be taught to use a PCA system. However, PCA is not appropriate
for every child. For example, a 14-year-old boy told me that he did
not like pushing the button. He preferred to have his mother give him
the injection of rescue medication. The main point that I wish to
make about PCA is that it should not take the place of good pain
assessment and management.

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