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Recognizing and Managing Breakthrough Pain in Complex Regional
Pain Syndrome
By Howard L. Rosner, MD
Pain is a painful subject for most people; both for patients
as well as the physicians and nurses who take care of them.
All of us share a common cultural conviction that people who
complain about pain are exaggerating their discomfort to gain
attention, elicit sympathy, or to gain access to narcotic
drugs. People in pain know better; they know that it hurts,
but they also don't want to be known as "complainers"
or "whiners" to their family, friends and health
care providers. Our culture teaches us to "keep a stiff
upper lip" and "grin and bear it", keeping
our distress quiet and private. Ultimately, this leads to
increased disability and depression, promoting dysfunction
instead of a reasonably normal life. For those who suffer
from CRPS, pain is a daily reality that must be recognized
and addressed before a semblance of normalcy can return to
life. Because pain cannot be assessed by purely objective
criteria, the patient's subjective assessment is essential
to accurate diagnosis and effective management.
Social and cultural factors play major roles in the self-assessment
of pain, and behavioral patterning, set down in early childhood,
can influence the patient's pain experience. While sensation
threshold does not differ from culture to culture or among
members of different communities, the translation of sensation
into pain (or suffering) does differ widely from patient to
patient.
Complex regional pain syndrome, or CRPS, is a chronic and
progressive neurologic condition which can affect a single
extremity or the entire body. It is called a syndrome because
it presents as a myriad of symptoms, only some of which are
needed for diagnosis, and can involve the skin, muscles, joints,
and bones. First described in 1868, CRPS has been known by
many names, including Reflex Sympathetic Dystrophy (RSD) and
Causalgia. The syndrome usually develops in an injured extremity,
and can be due to fractures, sprains, or even simple bumps.
The extent of the injury is not a predisposing factor to develop
the syndrome. Often it is triggered by a major injury, but
in many cases, can be triggered by something innocuous or
inconsequential. In some cases, no precipitating event at
all can be identified. The primary symptom is pain, which
may begin in one area or limb and then spread to other limbs.
CRPS is characterized by various degrees of burning pain,
excessive sweating, swelling and sensitivity to touch. Symptoms
of RSD/CRPS may recede for years and then reappear with a
new injury.
Two sub-types of CRPS have been described:
- Type 1 (formerly called RSD) - without major nerve injury
- Type 2 (formerly called causalgia) - with major nerve
injury
Both types express the same signs and symptoms; primary
among them is pain.
Although pain is part of almost all diseases, it is the common
condition of many people who have CRPS, and although some
pain is to be expected, it doesn't have to be overwhelming.
Pain in all its forms, sharp or dull, throbbing or steady,
constant or intermittent, can be controlled. For that to happen,
patients must tell their physician that they are in pain.
To get fast, lasting relief from that pain, patients must
also have to be able to describe that pain: quality, quantity,
duration, factors that improve or worsen the problem, accompanying
factors, and special characteristics.
Breakthrough Pain
Many people with CRPS experience intermittent flares of
pain that occur even though they are taking pain killers on
a fixed shedule. The term for this is "breakthrough pain"
because the pain "breaks through" the regular pain
medication cycle. Almost all people experiencing chronic pain
and who are being treated medically should receive adequate
medications for around-the-clock pain control at rest as well
as medication specifically indicated for managing breakthrough
cycles of pain. More medication than is needed to relieve
rest pain may cause overmedication; hence, trying to control
episodic or breakthrough pain with an increased dose of the
around-the-clock medication can lead to excess sedation and
other side effects at rest. On the other hand, a breakthrough
occurring just before the next dose of medication is an indication
of "end-of-dose" breakthrough. This should be managed
by adjusting either the dose or schedule of the medication.
The characteristics of breakthrough pain vary from person
to person and episode to episode, including its duration and
possible exacerbating factors. Generally, breakthrough pain
happens suddenly, often as a result of physical activity,
and may last anywhere from seconds to hours. Most people who
experience breakthrough pain can have several cycles per day.
Regardless of cause, the objective of pain treatment is three-fold:
to reduce discomfort, decrease anxiety, and return the patient
to previous levels of function. There are no easy formulas
for achieving these objectives. The treatment of pain must
always be individualized, because people exhibit a remarkably
wide range of pain tolerance and responsiveness to drug therapy.
Opiate analgesics are rarely used for mild pain, but they
are frequently prescribed for moderate-to-severe pain.
Many people with CRPS suffer chronic pain and it is entirely
appropriate to use sustained-release opiate analgesics to
reduce this pain. The specific agent chosen is less important
than the principle that maintaining a near-constant level
of opiate in the blood stream is desirable when patients have
deep and enduring pain.
Opiate analgesics are regarded as a mainstay of pain control
in CRPS; however, drugs are not the only means of alleviating
pain. Patients may also want to consider a number of other
approaches to pain management, including hypnosis, biofeedback,
electrical nerve stimulation, physical therapy, nerve blocks,
and acupuncture. These are often labeled "alternative"
therapy, as if one had to choose this treatment or that. The
more recent and informed description of these treatment choices
is "complementary" medicine, and should be used
side-by-side with more conventional therapies.
Cognitive techniques, including relaxation training, hypnosis,
guided imagery, and distraction techniques may also help relieve
breakthrough pain for many people. Many patients benefit from
neuromodulation: modifying pain conduction through the use
of electric currents or medications directly administered
to the central nervous system.
Many practitioners use the WHO (World Health Organization)
pain ladder for guidance in selecting an appropriate medication
to treat pain. Unfortunately, this ladder does not take into
account neuropathic pain, the primary diagnosis of CRPS-related
pain. Neuropathic pain may not completely respond to narcotic
analgesics, so providers need to treat this form of pain with
what are often termed "adjuvant" medications, which
include tricyclic antidepressants, anti-seizure medications,
and membrane stabilizers. Most patients, however, will be
managed by some combination of adjuvant medications and opiates.
Practitioners should allow adequate time for gastrointestinal
absorption of these drugs, a process that can take up to 90
minutes. In the case of many longer-acting opiates, there
can be a four-hour lag from ingestion to activity. Therefore,
follow-up doses of the scheduled medication should be taken
well before drug levels in the blood drop to sub-therapeutic
levels. The therapeutic goal of any pain-relief regimen is
to achieve an adequate level of drug in the blood stream,
a level high enough to assure relief of "background"
pain when you are resting. If the patient experiences pain
during activity, additional medications should be available
to blunt this breakthrough pain. To manage both forms of pain,
two forms of medication are needed: a long-acting drug, taken
on a fixed schedule to eliminate background pain and a rapid-onset
medication, used on an as needed basis for the breakthrough
pain.
The ideal treatment for breakthrough pain should be easily
administered, work rapidly, be non-toxic, and have a short,
controlled duration of action. Traditionally, most treatments
for breakthrough pain are opioids (potent painkillers). Getting
a sufficient blood level for activity is very important; the
route of administration of the medication and its chemical
properties directly affects the speed of onset. Medications
for breakthrough pain can be administered in many ways: by
mouth (PO), by injection in the vein (IV), muscle (IM) or
under the skin (SC), under the tongue (SL), by rectal suppository
(PR), or absorbed across the mucous membranes of the mouth
but not swallowed (oral transmucosal). Most people prefer
oral medications, but these are not always the fastest in
onset of action. Some patients may not be able to take an
oral drug due to difficulty in swallowing, nausea, or other
gastrointestinal problems. The newest delivery system in our
armamentarium is the oral transmucosal lozenge. This delivery
system provides extremely fast onset of action, and the dose
delivered can be controlled both by the amount of medication
in the lozenge and by the length of time the lozenge remains
in the mouth. For breakthrough pain, rapid onset is highly
desired. The speed of onset of the oral transmucosal lozenge
is, in many cases, comparable to injectable breakthrough medications.
Unlike antibiotics, anti-inflammatories, and other medications,
there is no specific dose of an opiate analgesic that should
be given to treat pain. The ideal way to use opiates is to
titrate them to the desired level of efficacy, on a case-by-case
basis. With the important exceptions of meperidine, propoxyphene,
and pentazocine, there are no peak doses for opiates. The
major limiting factor in increasing opiate doses is the escalation
of undesirable side effects (such as constipation, sedation,
respiratory suppression, and confusion). When opiates are
used for the treatment of pain, it is unlikely that addiction
will become a major factor. Controversy exists among health
care providers at all levels of expertise (including the pain
management community) about maximum doses above which further
dosing is inadvisable. For many practitioners, the opiate
dose should be pushed to whatever level it takes to make the
patient comfortable. For others, the concern over long-term
damage to central nervous system receptors and other organ
damage will limit the extent to which a dose will be escalated.
Modern medicine is capable of delivering a high degree of
pain control to most patients without sacrificing their sense
of self and their ability to think and function. In some patients,
more invasive techniques may be needed, including spinal stimulators
and infusion pumps. However, in the vast majority of cases,
carefully considered titration of medications can result in
a satisfactory outcome for both patient and doctor. The combination
of carefully selected, properly dosed around-the-clock long-acting
medication for baseline comfort at rest is ideally paired
with an as-needed rapid onset medication for incident or breakthrough
pain. This combination suits people's lifestyles; we are neither
wholly sedentary nor active 24-hours per day. Pairing these
two types of painkillers gives patients the opportunity to
live more normal lives, blunting pain while maintaining dignity
and comfort.
Howard L. Rosner, MD is Medical Director of The Pain Center
at Cedars-Sinai Medical Center in Los Angeles, California.
Updated July 19, 2005 |
