Articles

Pain Management

Introduction

When pain presents itself, one’s first instinct is to find relief from the pain. Pain is extremely subjective and very difficult to define, thus becoming whatever the patient perceives it to be. Pain disables millions of people to some extent, many receiving inappropriate analgesic regimens. Pain has a tremendous impact on society. Pain is the number one reason why people seek medical advice. (1)

The pathophysiology of pain perception is very complex and not well understood. Stimulation of receptors known as nociceptors is the first step leading to a pain sensation. Bradykinins, hydrogen ions, potassium ions, prostaglandins, histamine, leukotrienes and serotonin sensitize nociceptors. Once sensitized and activated, the receptor sends an action potential along A-delta or C afferent nerves to the spinal cord. A-delta fiber stimulation results in sharp localized pain whereas stimulation of C fibers results in a dull, diffuse, aching pain. These afferent, nociceptive nerve fibers synapse in the dorsal horn of the spinal cord. The pain transmission will eventually reach the brain via ascending pathways that allow the brain to distinguish sharp localized pain from dull aching pain. (2)

Acute pain is generally of sudden onset which serves as notification of tissue injury. This tissue injury can result from trauma, surgery, damaged to various parts of the body as a result of cancer, or numerous other stimuli. Acute pain is usually accompanied with physical indications of increased autonomic activity such as an elevation in heart rate and blood pressure. Once the pain stimuli is eliminated, the pain sensation is usually reduced.

Chronic pain can be chronic lower-back pain, chronic headaches, peripheral neuralgia, herpetic neuralgia, cancer pain, or phantom limb pain. Chronic pain is generally associated with a chronic disease and lacks a clear etiology. This is pain that exists past the normal expected healing time.

Pain can present itself as somatic, visceral, or neuropathic. Somatic pain can be mild to severe and is generally characterized as being a dull, sharp, or aching pain. Visceral is described as being diffuse or gnawing. Both of these types of pain respond well to opioids. Neuropathic pain is a result of a peripheral nerve injury and can be burning, shooting, tingling, or numbing. Neuropathic pain usually requires more nontraditional analgesics.

Statistic

The National Institute of Neurological Disorders and Stroke of The National Institutes of Health, 1999.

    15 to 20 percent of hypnotizable patients with moderate to severe pain can achieve total relief with hypnosis. 35 percent in any experiment using placebos are able to tap into their brains' endorphin systems.

The American Association of Neurological Surgeons / Congress of Neurological Surgeons, 1998.

    More than 75 million Americans suffer chronic, handicapping pain. Chronic low back pain affects nearly 31 million Americans.

National Institute of Health, 1998.

    Pain costs the U.S. more than $100 billion annually in health care and lost productivity. 40 million visits to health care providers and prolong hospital stays are due to pain.

Signs and Symptoms

[span class=alert]The following list does not insure the presence of this health condition. Please see the text and your healthcare professional for more information.[/span]

Pain is itself an important symptom. It may signal the presence of disease, trauma, or other conditions, and is the most common symptom for which patients seek medical evaluation. Since the word “pain” can encompass a myriad of complaints, this section will be devoted to the description, or characteristics of different types of pain. Pain can be defined by its temporal characteristics.

Acute pain is usually accompanied by a clear description of location, character, and timing. It is generally associated with ANS hyperactivity (tachycardia, hypertension, diaphoresis), and is commonly self-limiting as in post-op pain or traumatic pain. The category of acute pain generally encompasses sub-acute pain, which is pain that may develop over several days or episodic pain, which occurs at regular intervals for specific lengths of time.

Chronic pain is defined as pain, which persists for three months or longer. Acute signs of autonomic nervous system hyperactivity disappear as the patient adapts to pain, however, due to its persistence, this type of pain may lead to significant changes in personality, lifestyle, functional ability, and quality of life. Chronic pain may be further subclassified by etiology. These classifications include chronic pain associated with structural disease such as metastatic disease, sickle cell disease and rheumatoid arthritis. It is characterized by prolonged episodes of pain alternating with pain-free intervals or constant pain that waxes and wanes. Psychophysiologic disorder is another etiologic category and includes pain that results where structural disease was once present but initial problem has been healed. However, psychological factors have caused a physiologic alteration, which produces pain (e.g. muscle spasms). Patients suffering from this type of pain are generally physically inactive, preoccupied with their pain and are often more impaired by “chronic illness behavior” than by a pathologic reason. These patients typically respond poorly to analgesic therapy alone. Pain with no structural or physiologic basis is the third etiologic classification. In this type of pain, the patient’s explanation of the history of pain is generally vague and bizarre, with the distribution of pain showing no anatomic pattern. These patients generally have severe psychiatric disorders.

Physiologic characteristics are used to describe the type of pain present. Somatic pain is typically localized and describable. It may be a sharp pain, or dull, and results form the activation of peripheral receptors and somatic sensory efferent nerves without injury to the central nervous system (CNS) or peripheral nerve. Visceral pain may be described as deep, aching, cramping pain and is often referred to cutaneous sites. Visceral nociceptive receptors and visceral nerves are activated. Neuropathic pain results from direct injury to peripheral receptors, nerves, or the CNS. It is described as burning, sharp, knifelike or stabbing, and tends to be constant.

Pain may also be described using Quantitative characteristics. This includes the use of pain scales, such as one frequently employed describing pain on a scale of 0 to 10, with 0 representing no pain, and 10 representing the worst pain imaginable. Patients may also be asked to describe their pain in terms such as mild, moderate, severe, or excruciating. The use of such descriptions in determining the intensity of pain is a major factor for choosing pharmacologic therapy.

Treatment Options

Conventional

Acute/Chronic Pain

    Acetaminophen Aspirin/NSAIDs Opioids Anesthetics (lidocaine, bupivicaine)
Chronic (muscle)
    Muscle relaxants
Chronic Neuropathic
    Antidepressants TCA/SSRI Anticonvulsants Capsaicin Clonidine Mexelitine
Routes
    Po Iv/im Epidural transdermal

Nutritional Supplementation


Phenylalanine

D-Phenylalanine is an amino acid that inhibits carboxypeptidase A, an enzyme that regulates the degradation of enkephalins and other endogenous analgesic-producing compounds in the body. Preventing the enzymatic degradation of these substances means that more pain-relieving compounds will be present in the body for longer periods of time. A study in Japan reported that D-phenylalanine effectively increased the level of analgesia when combined with acupuncture in patients being treated two conditions, low back pain and tooth extractions. (3)

Other studies have also documented that D-phenylalanine potentiates acupuncture analgesia in mice and humans and note that it has been used successfully to treat a variety of human chronic pain conditions. (4)

One study evaluated the ability of D-phenylalanine to alleviate intractable pain in cancer patients. Frequently, chronic pain treatments used for the management of terminally ill cancer patients do not prevent acute or intermittent pain from occurring. D-phenylalanine was investigated for 20 months with nine patients who were between forty-nine and seventy-eight years old. All were all experiencing painful conditions related to complications of their disease. They were administered D-phenylalanine, 250 mg three times a day on a rotating schedule of 15 days on and 10 days off. Seven patients out of nine were alleviated and never needed more or other analgesics until they died. Four of them achieved a state of mental calmness and tranquility without depression during the same time. No side effect was reported. These results indicate that D-phenylalanine is useful in preventing acute or incident pain episodes that occur in advanced cases of cancer. (5)


Methyl Sulfonyl Methane (MSM)

MSM (methyl sulfonyl methane) is a derivative of DMSO, also known as dimethylsulfoxide. The two compounds reportedly share many of the same therapeutic benefits. Although a number of clinical trials have been conducted with DMSO, very few studies have been conducted with MSM because it is a natural product that cannot be patented. However, the world’s leading authority on MSM, Stanley Jacob, M.D, has written a book about the benefits of MSM. In that book, Dr. Jacob reports on MSM’s remarkable pain-relieving properties in a wide range of conditions based on his clinical observations with patients over a period of twenty years. The conditions in which MSM has reportedly had some level of success in pain reduction includes muscle soreness, fibromyalgia, back pain from herniated discs, tendonitis, bursitis, rheumatoid and osteoarthritis. (6)

In one published study, patients with arthritis reported a 60 percent pain reduction in 4 weeks, and the average reduction in pain at 6 weeks was 82 percent. (7)


Glucosamine

Glucosamine has been highlighted in many studies for its ability to relieve pain in patients with osteoarthritis. (8) , (9) However, its onset is gradual over a period of several weeks, so it is not effective for acute pain. Also, its use is primarily limited to reducing the pain associated with osteoarthritis. The usual dose is 1,500 mg/day.


Chondroitin Sulfate

Chondroitin sulfate is also known for its ability to gradually relieve pain in patients with osteoarthritis. (10) , (11) The usual dose is 1,200 mg/day.

Herbal Supplementation


Ginger

The volatile oils in ginger are thought to act as peripheral vasodilators or circulatory stimulants. (12) Gingerol stimulates gastric secretions and peristalsis. (13) Whether or not ginger works on the CNS or locally in the gut is debated. Ginger’s structural phenols are similar to aspirin and may have an effect on prostaglandins, PGE2 and PGF2, aiding in decreasing inflammation and pain as well as decreasing thromboxane, leading to its use as an anticoagulant. (14)


Turmeric

In Ayurvedic medicine (traditional Indian medicine), turmeric rhizome has been used for centuries internally as a tonic for the stomach and liver and as a blood purifier, and externally in the treatment and prevention of skin diseases and in arthritic complaints. (15) The laboratory and clinical research indicates that turmeric and its phenolics have unique antioxidant and anti-inflammatory properties. (16) The anti-inflammatory strength of turmeric is comparable to steroidal drugs such as indomethacin. (17) Turmeric has been reported to be anti-rheumatic, anti-inflammatory, and antioxidant. (18) Curcuminoids reportedly inhibit enzymes which participate in the synthesis of inflammatory substances (leukotrienes and prostaglandins) derived from arachidonic acid, and it is claimed they are comparable in activity to the NSAID. (19) In a double-blind study of individuals with rheumatoid arthritis, curcumin produced significant improvement in all subjects. (20) Turmeric is also claimed to inhibit platelet aggregation. (21)

Curcumin reportedly has a similar action to that of aspirin and aspirin-like anti-inflammatory agents. (22) However, an advantage of curcumin over aspirin is claimed, since curcumin, unlike aspirin, is reported to selectively inhibit synthesis of inflammatory prostaglandins but does not affect the synthesis of prostacyclin. (23) Curcumin may be preferable for individuals who are prone to vascular thrombosis and require anti-inflammatory and/or anti-arthritic therapy.


Feverfew

Feverfew has gained immense popularity because of its effectiveness in relieving migraine headaches and in other inflammatory conditions. (24) , (25) Feverfew reportedly inhibits the manufacture of inflammatory mediators such as leukotrienes, prostaglandins, and thromboxanes. (26) , (27) Several clinical studies have reported the efficacy of feverfew in the prevention of migraine headaches. (28) , (29) Feverfew exhibits several pharmacological actions that may be implicated in migraine prophylaxis, including inhibition of histamine secretion, (30) inhibition of granular secretion, platelet aggregation, and arachidonate mediated responses, (31) , (32) and inhibition of vascular smooth muscle contractility. (33) Also, excess serotonin (5HT) release from platelets has been implicated as one of the primary mechanisms in the pathogenesis of migraines, which may explain some of feverfew’s prophylactic activity in migraine headaches. (34)


Willow

The bark of the white willow tree has been used as a medicinal agent since the ancient Greeks, fist reported by Dioscorides in his herbal De Materia Medica written in the first century B.C. (35) During the Middle Ages, willow bark was used therapeutically to reduce fevers and relieve pain, attributed to the salicylates found in the bark. Researchers have discovered over the years that the salicylates have anti-inflammatory and antipyretic activities, and they have been actually synthesized from another plant as a precursor of acetylsalicylic acid, commonly known as aspirin. (36) The general mechanism of action includes inhibition of prostaglandin synthesis, causing sensitization of peripheral pain receptors. A proprietary product containing white willow bark has been used in Europe for the over-the-counter treatment of arthritis. In one double-blind clinical study, the product containing willow bark was compared to placebo in 82 patients with chronic arthritic pain. (37) There was a small but statistically significant improvement in pain symptoms, less so in sufferers from osteoarthritis. There were no other significant changes in any other measures nor in the use of other self-prescribed analgesics. There were few side-effects noted. It is concluded that Reumalex has a mild analgesic effect in chronic arthritis at a level appropriate to self-medication.

Clinical Lab Assessment

Some of the following laboratory testing can provide information necessary for diagnosis and treatment. In addition, the tests listed may also give insight to functional metabolism and functional nutrient status in the body.

References

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