Dr.Proxy

THE NATURE AND EXPERIENCE OF PAIN

Pain is a universal human experience and the most common reason people seek medical care. Pain tells us something is wrong in the structure or function of our body and that we need to do something about it. Because pain is such a strong motivator for action, it is considered one of the body's most important protective mechanisms.

Definitions of Pain

The International Association for the Study of Pain defined pain as "an unpleasant, subjective, sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage" (1979). Pain, however, is much more than a physical sensation caused by a single entity. It is subjective and highly individual, a complex mechanism with physical, emotional, and cognitive components.
Pain cannot be objectively measured in the same way as, for example, the chemical content of urine or the oxygen content level of blood. Only the person who is suffering knows how the experience feels. For these reasons, McCaffery defined pain as "whatever the experiencing person says it is and whenever he says it does" (1979). The American Pain Society goes further by stating that it is "not the responsibility of clients to prove they are in pain; it is the nurse's responsibility to accept the client's report of pain" (2005).
Pain alters the quality of life more than any other health-related problem. It interferes with sleep, mobility, nutrition, thought, sexual activity, emotional well-being, creativity, and self-actualization. Surprisingly, even though pain is such an important obstacle to comfort, it is one of the least understood, most undertreated, and oft-discounted problems of healthcare providers and their clients. For this reason, some nurses and therapists add comfort to Maslow's hierarchy of basic human needs (1968). The American Pain Society goes further, declaring the relief of pain a "basic human right" (2005).
Traditionally, pain was considered merely a physical symptom of illness or injury, a simple stimulus-response mechanism. Though the historic role of nurses and therapists has been to relieve pain and suffering, there has been little understanding of the complexity of pain and only limited ways to manage it. Recent research shows pain to be a distinct disorder, with physical, emotional, and cognitive components. This view of pain has broadened our understanding of pain and given us new ways to understand its characteristics.

Types of Pain

Pain is classified as acute and chronic. Acute pain has an identifiable cause and occurs soon after an injury to tissues in the body, such as bone, skin, or muscle. Acute pain is protective in that it motivates a person to take action. Its onset may be sudden or slow, and its intensity may vary from mild to severe. Acute pain is temporary and subsides as healing takes place. Severe acute pain activates the sympathetic nervous system, causing diaphoresis, increased respiratory and pulse rates, and elevated blood pressure.
Chronic pain lasts beyond an expected healing phase, is non-protective in that it serves no function, and may not have an identifiable cause (Patterson, 2007). When pain goes on more than 6 months, it moves from being a "symptom" to a "condition." Chronic pain afflicts more than 1 in 5 Americans and is one of the most pervasive and thorny medical conditions in the United States. Such pain is described as nonmalignant (noncancerous), malignant (cancerous), and intractable.

• Nonmalignant, noncancerous chronic pain typically accompanies such conditions as osteoarthritis and peripheral neuropathy. The lack of purpose and uncertainty of duration of such pain may lead to depression, fatigue, insomnia, anorexia, apathy, learned helplessness, and other psychosocial consequences. If it is severe, chronic pain—like prolonged stress—activates the parasympathetic nervous system, resulting in muscle tension, decreased heart rate and blood pressure, and failure of body defenses.
• Malignant, cancerous chronic pain may be due to tumor progression, invasive procedures, infection, toxicities of treatment, and physical limitations. Such pain may be felt at the tumor site or some distance from it. Since clients with cancer may experience both chronic and acute pain, caregivers need to investigate immediately any new pain in these clients.
• Intractable chronic pain is pain from any cause that is resistant to medical, surgical, and nursing measures. Persistent and ongoing, intractable chronic pain may be psychogenic in nature (Mosby's Dictionary, 2009).

Sources of Pain

Coronary artery disease is atherosclerosis of the coronary arteries that leads to a restriction of blood flow to the heart. Atherosclerosis is a chronic condition that narrows arteries by building fat-filled bulges in the arterial walls. These bulges are called atherosclerotic plaques, or simply, plaques. In some people, the plaques eventually break open, and the contents cause blood clots. If these clots are swept into the bloodstream, they can lodge in the smaller arteries downstream and completely block blood flow beyond that point.
Heart muscle is constantly active, and it requires a continuous blood supply. When a heart artery is blocked suddenly, the heart muscle it supplies stops working within a few minutes. If the blood supply remains blocked for a half-hour or more, the heart's muscle cells will begin to die.
Complete, sudden blockage of an artery is not the only problem. Even a reduced blood supply will reduce the oxygen supply to heart muscle, and oxygen-starved heart muscle responds with a characteristic feeling of pain or discomfort, called angina.
When its arteries are narrowed by atherosclerosis, a heart may still get enough oxygen to pump blood at rest. On the other hand, exercise increases the work of the heart, and narrowed arteries cannot always delivery the excess oxygen required by an exercising heart. Under these circumstances, a person with narrowed coronary arteries will get angina when exercising. One of the first symptoms of coronary artery disease is the appearance of angina when a person is working strenuously.
As atherosclerosis progresses, some of the plaques rupture and clots are formed. If a clot temporarily shuts down an artery, the patient will get sudden angina that lasts until the clot is broken or swept away. If the clot remains for an extended period of time, some heart muscle begins to die: this is a heart attack, or myocardial infarction.
In general, the sudden blockage of a coronary artery or one of its main branches is called an acute coronary syndrome, and myocardial infarctions are one form of acute coronary syndrome. Acute coronary syndrome is a medical emergency, and must be treated immediately in an emergency room.
Atherosclerosis, the cause of coronary artery disease, is a slow, long-term process. Typically, atherosclerosis begins in a person's teenage years or earlier, and the disease worsens quietly for decades. As people age, their atherosclerosis becomes more likely to involve the arteries of the heart and to become coronary artery disease.
The progression of atherosclerosis can be slowed or even stopped by a few preventive measures. These include stopping smoking, staying thin or losing weight, exercising regularly, and eating a low-fat balanced diet. To control atherosclerosis, it is also important to keep blood pressures low, to reduce high blood cholesterol levels, and to treat diabetes.
People who develop symptomatic coronary artery disease should begin or continue these anti-atherosclerotic programs. In addition, they should take aspirin daily, and they should probably take other medicines (typically, beta blockers) to reduce the workload of the heart. Nitroglycerin tablets can be used to alleviate occasional anginal pain, and surgical procedures are available to widen narrowed arteries.
Coronary artery disease is the number one killer in the developed world. In the United States, it is estimated that half of today's healthy 40-year-old men and a third of today's healthy 40-year-old women will eventually develop coronary artery disease.
The proportion of deaths in the United States that are due to coronary artery disease has been decreasing slowly but continuously over the past half-century. Nonetheless, coronary artery disease remains the single most common cause of death in the United States. One-fifth of all American deaths are attributed to coronary artery disease, and four-fifths of the deaths of people 65 years and older result from the disease.
Coronary artery disease is not just an American problem. Throughout the developed world, coronary artery disease causes more deaths and disabilities and is responsible for more economic costs than any other single illness. Moreover, it is predicted that, by the year 2020, coronary artery disease will have become the leading cause of death in the underdeveloped parts of the world.
The high death rates from coronary artery disease can be reduced by changing people's eating habits, by increasing their activity levels, and by convincing them of the dangers of cigarette smoking.

NORMAL CIRCULATION OF THE HEART

The heart is made up almost entirely of muscle. Cardiac muscle, which differs from the skeletal and smooth muscle of the rest of the body, is dependent on aerobic metabolism. This means that the heart cannot function without a constant supply of oxygen.