For thousands of years, doctors have been helping to relieve their patients' pain with
a variety of medications and treatments. Like other areas of medicine, a new subset of
doctors have become specialists in treating pain. They are focused on managing all types
of pain - studying what causes it, how the body reacts to it, how different medications
dull or eliminate the pain, and how other treatments can be used to relieve many painful
Pain management encompasses pharmacological, nonpharmacological, and other approaches
to prevent, reduce, or stop pain sensations.
Purpose of pain management
Pain serves as an alert to potential or actual damage to the body. The definition for
damage is quite broad; pain can arise from injury as well as disease. After the message is
received and interpreted, further pain can be counter-productive. Pain can have a negative
impact on a person's quality of life and impede recovery from illness or injury.
Unrelieved pain can become a syndrome in its own right and cause a downward spiral in a
person's health and outlook. Managing pain properly facilitates recovery, prevents
additional health complications, and improves an individual's quality of life.
Description of pain management
What is pain?
Before considering pain management, a review of pain definitions and mechanisms may be
useful. Pain is the means by which the peripheral nervous system (PNS) warns the central
nervous system (CNS) of injury or potential injury to the body. The CNS comprises the
brain and spinal cord, and the PNS is composed of the nerves that stem from and lead into
the CNS. PNS includes all nerves throughout the body except the brain and spinal cord.
A pain message is transmitted to the CNS by special PNS nerve cells called nociceptors.
Nociceptors are distributed throughout the body and respond to different stimuli depending
on their location. For example, nociceptors that extend from the skin are stimulated by
sensations such as pressure, temperature, and chemical changes.
When a nociceptor is stimulated, neurotransmitters are released within the cell.
Neurotransmitters are chemicals found within the nervous system that facilitate nerve cell
communication. The nociceptor transmits its signal to nerve cells within the spinal cord,
which conveys the pain message to the thalamus, a specific region in the brain.
Once the brain has received and processed the pain message and coordinated an
appropriate response, pain has served its purpose. The body uses natural pain killers,
called endorphins, that are meant to derail further pain messages from the same source.
However, these natural pain killers may not adequately dampen a continuing pain message.
Also, depending on how the brain has processed the pain information, certain hormones,
such as prostaglandins, may be released. These hormones enhance the pain message and play
a role in immune system responses to injury, such as inflammation. Certain
neurotransmitters, especially substance P and calcitonin gene- related peptide, actively
enhance the pain message at the injury site and within the spinal cord.
Pain is generally divided into two categories: acute and chronic. Nociceptive pain, or
the pain that is transmitted by nociceptors, is typically called acute pain. This kind of
pain is associated with injury, headaches, disease, and many other conditions. It usually
resolves once the condition that precipitated it is resolved
Following some disorders, pain does not resolve. Even after healing or a cure has been
achieved, the brain continues to perceive pain. In this situation, the pain may be
considered chronic. The time limit used to define chronic pain typically ranges from three
to six months, although some healthcare professionals prefer a more flexible definition,
and consider chronic pain as pain that endures beyond a normal healing time. The pain
associated with cancer, persistent and degenerative conditions, and neuropathy, or nerve
damage, is included in the chronic category. Also, unremitting pain that lacks an
identifiable physical cause, such as the majority of cases of low back pain, may be
considered chronic. The underlying biochemistry of chronic pain appears to be different
from regular nociceptive pain.
It has been hypothesized that uninterrupted and unrelenting pain can induce changes in
the spinal cord. In the past, intractable pain has been treated by severing a nerve's
connection to the CNS. However, the lack of any sensory information being relayed by that
nerve can cause pain transmission in the spinal cord to go into overdrive, as evidenced by
the phantom limb pain experienced by amputees. Evidence is accumulating that unrelenting
pain or the complete lack of nerve signals increases the number of pain receptors in the
spinal cord. Nerve cells in the spinal cord may also begin secreting pain-amplifying
neurotransmitters independent of actual pain signals from the body. Immune chemicals,
primarily cytokines, may play a prominent role in such changes.
Considering the different causes and types of pain, as well as its nature and
intensity, management can require an interdisciplinary approach. The elements of this
approach include treating the underlying cause of pain, pharmacological and
nonpharmacological therapies, and some invasive (surgical) procedures.
Treating the cause of pain underpins the idea of managing it. Injuries are repaired,
diseases are diagnosed, and certain encounters with pain can be anticipated and treated
prophylactically (by prevention). However, there are no guarantees of immediate relief
from pain. Recovery can be impeded by pain and quality of life can be damaged. Therefore,
pharmacological and other therapies have developed over time to address these aspects of
disease and injury.
Pain-relieving drugs, otherwise called analgesics, include nonsteroidal
anti-inflammatory drugs (NSAIDs), acetaminophen, narcotics, antidepressants,
anticonvulsants, and others. NSAIDs and acetaminophen are available as over-the-counter
and prescription medications, and are frequently the initial pharmacological treatment for
pain. These drugs can also be used as adjuncts to the other drug therapies, which might
require a doctor's prescription.
NSAIDs include aspirin, ibuprofen (Motrin, Advil, Nuprin), naproxen sodium (Aleve), and
ketoprofen (Orudis KT). These drugs are used to treat pain from inflammation and work by
blocking production of pain-enhancing neurotransmitters, such as prostaglandins.
Acetaminophen is also effective against pain, but its ability to reduce inflammation is
NSAIDs and acetaminophen are effective for most forms of acute (sharp, but of a short
course) pain, but moderate and severe pain may require stronger medication. Narcotics
handle intense pain effectively, and are used for cancer pain and acute pain that does not
respond to NSAIDs and acetaminophen. Narcotics are classified as either opiates or
opioids, and are available only with a doctor's prescription. Opiates include morphine and
codeine, which are derived from opium, a substance naturally found in some poppy species.
Opioids are synthetic drugs based on the structure of opium. This drug class includes
drugs such as oxycodon, methadone, and meperidine (Demerol).
Narcotics may be ineffective against some forms of chronic pain, especially since
changes in the spinal cord may alter the usual pain signaling pathways. Furthermore,
narcotics are usually not recommended for long-term use because the body develops a
tolerance to narcotics, reducing their effectiveness over time. In such situations, pain
can be managed with antidepressants and anticonvulsants, which are also only available
with a doctor's prescription.
Although antidepressant drugs were developed to treat depression, it has been
discovered that they are also effective in combating chronic headaches, cancer pain, and
pain associated with nerve damage. Antidepressants that have been shown to have analgesic
(pain reducing) properties include amitriptyline (Elavil), trazodone (Desyrel), and
imipramine (Tofranil). Anticonvulsant drugs share a similar background with
antidepressants. Developed to treat epilepsy, anticonvulsants were found to relieve pain
as well. Drugs such as phenytoin (Dilantin) and carbamazepine (Tegretol) are prescribed to
treat the pain associated with nerve damage.
Other prescription drugs are used to treat specific types of pain or specific pain
syndromes. For example, corticosteroids are very effective against pain caused by
inflammation and swelling, and sumatriptan (Imitrex) was developed to treat migraine
Drug administration depends on the drug type and the required dose. Some drugs are not
absorbed very well from the stomach and must be injected or administered intravenously.
Injections and intravenous administration may also be used when high doses are needed or
if an individual is nauseous. Following surgery and other medical procedures, patients may
have the option of controlling the pain medication themselves. By pressing a button, they
can release a set dose of medication into an intravenous solution. This procedure has also
been employed in other situations requiring pain management. Another mode of
administration involves implanted catheters that deliver pain medication directly to the
spinal cord. Delivering drugs in this way can reduce side effects and increase the
effectiveness of the drug.
Nonpharmacological options for pain management
Pain treatment options that do not use drugs are often used as adjuncts to, rather than
replacements for, drug therapy. One of the benefits of non-drug therapies is that an
individual can take a more active stance against pain. Relaxation techniques, such as yoga
and meditation, are used to decrease muscle tension and reduce stress. Tension and stress
can also be reduced through biofeedback, in which an individual consciously attempts to
modify skin temperature, muscle tension, blood pressure, and heart rate.
Participating in normal activities and exercising can also help control pain levels.
Through physical therapy, an individual learns beneficial exercises for reducing stress,
strengthening muscles, and staying fit. Regular exercise has been linked to production of
endorphins, the body's natural pain killers.
Acupuncture involves the inserting of small needles into the skin at key points.
accupressure uses these same key points, but involves applying pressure rather than
inserting needles. Both of these methods may work by prompting the body to release
endorphins. Applying heat or being massaged are very relaxing and help reduce stress.
Transcutaneous electrical nerve stimulation (TENS) applies a small electric current to
certain parts of nerves, potentially interrupting pain signals and inducing release of
endorphins. To be effective, use of TENS should be medically supervised.
Invasive procedures for pain management
There are three types of invasive procedures that may be used to manage or treat pain:
anatomic, augmentative, and ablative. These procedures involve surgery, and certain
guidelines should be followed before carrying out a procedure with permanent effects.
First, the cause of the pain must be clearly identified. Next, surgery should be done only
if noninvasive procedures are ineffective. Third, any psychological issues should be
addressed. Finally, there should be a reasonable expectation of success.
Anatomic procedures involve correcting the injury or removing the cause of pain.
Relatively common anatomic procedures are decompression surgeries, such as repairing a
herniated disk in the lower back or relieving the nerve compression related to carpal
tunnel syndrome. Another anatomic procedure is neurolysis, also called a nerve block,
which involves destroying a portion of a peripheral nerve.
Augmentative procedures include electrical stimulation or direct application of drugs
to the nerves that are transmitting the pain signals. Electrical stimulation works on the
same principle as TENS. In this procedure, instead of applying the current across the
skin, electrodes are implanted to stimulate peripheral nerves or nerves in the spinal
cord. Augmentative procedures also include implanted drug-delivery systems. In these
systems, catheters are implanted in the spine to allow direct delivery of drugs to the
Ablative procedures are characterized by severing a nerve and disconnecting it from the
CNS. However, this method may not address potential alterations within the spinal cord.
These changes perpetuate pain messages and do not cease even when the connection between
the sensory nerve and the CNS is severed. With growing understanding of neuropathic pain
and development of less invasive procedures, ablative procedures are used less frequently.
However, they do have applications in select cases of peripheral neuropathy, cancer pain,
and other disorders.
Preparation for pain management
Prior to beginning management, pain is thoroughly evaluated. Pain scales or
questionnaires are used to attach an objective measure to a subjective experience.
Objective measurements allow healthcare workers a better understanding of the pain being
suffered by the patient. Evaluation also includes physical examinations and diagnostic
tests to determine underlying causes. Some evaluations require assessments from several
viewpoints, including neurology, psychiatry and psychology, and physical therapy. If pain
is due to a medical procedure, management consists of anticipating the type and intensity
of associated pain and managing it preemptively.
Risks of Pain Management
Owing to toxicity over the long term, some drugs can only be used for acute pain or as
adjuncts in chronic pain management. NSAIDs have the well-known side effect of causing
gastrointestinal bleeding, and long-term use of acetaminophen has been linked to kidney
and liver damage. Other drugs, especially narcotics, have serious side effects, such as
constipation, drowsiness, and nausea. Serious side effects can also accompany
pharmacological therapies; mood swings, confusion, bone thinning, cataract formation,
increased blood pressure, and other problems may discourage or prevent use of some
Nonpharmacological therapies carry little or no risks. However, it is advised that
individuals recovering from serious illness or injury consult with their healthcare
providers or physical therapists before making use of adjunct therapies. Invasive
procedures carry risks similar to other surgical procedures, such as infection, reaction
to anesthesia, iatrogenic (injury as a result of treatment) injury, and failure.
A traditional concern about narcotics use has been the risk of promoting addiction. As
narcotic use continues over time, the body becomes accustomed to the drug and adjusts
normal functions to accommodate to its presence. Therefore, to elicit the same level of
action, it is necessary to increase dosage over time. As dosage increases, an individual
may become physically dependent on narcotic drugs.
However, physical dependence is different from psychological addiction. Physical
dependence is characterized by discomfort if drug administration suddenly stops, while
psychological addiction is characterized by an overpowering craving for the drug for
reasons other than pain relief. Psychological addiction is a very real and necessary
concern in some instances, but it should not interfere with a genuine need for narcotic
pain relief. However, caution must be taken with people with a history of addictive