Behavioral signs of acute pain may include restlessness (especially among older adults), an inability to concentrate, apprehension, and overall distress.

Acute pain is usually temporary, has a sudden onset, and is easily localized. The pain is typically confined to the injured area and may subside with or without treatment. As the injured area heals, the pain sensation changes. Although possibly severe, acute pain is limited over time and generally can be managed successfully. Both the caregiver and the patient can see an end to the pain, which makes coping somewhat easier.

Pain that accompanies surgery is one of the most common examples of acute pain, but it is not always well managed. Usually, poorly managed postoperative pain is a result of inadequate drug therapy.

The severity of postoperative pain may be a predictor of long-term pain. The use of preemptive analgesia is a technique designed to decrease pain in the postoperative period, decrease the requirements for a postoperative analgesic, prevent morbidity, and decrease hospital stay. Preemptive analgesia includes administering local anesthetics, opioids, and other drugs in the preoperative, intraoperative, and/or postoperative period. This intervention may inhibit changes in the spinal cord—changes that can lead to a central sensitization that results in chronic pain.

In general, intrathoracic and upper intra-abdominal surgical approaches are associated with more severe, steady wound pain and with pain on movement after surgery. Many patients who undergo superficial surgery of the head and neck, chest wall, or limbs report minimal postoperative pain. Muscle-splitting procedures, like thoracotomy, are generally far more painful than muscle-stretching procedures, such as open hysterectomy. Patients who have joint replacements for severe arthritic pain often report less pain after surgery than before surgery because the damaged joint cartilage has been removed.

Chronic Pain

Chronic pain or persistent pain is often defined as pain that lasts or recurs for indefinite periods, usually for more than 3 months. The onset is gradual, and the character and quality of the pain change over time. Because chronic pain often involves deep body structures, it is usually poorly localized (hard to pinpoint) and often difficult to describe. If the underlying cause cannot be treated, controlling the long-term effects of chronic pain may be a difficult clinical challenge.

Because chronic pain persists for extended periods, it can interfere with personal relationships and ADLs. It can also result in emotional and financial burdens. Some patients feel depressed and hopeless because of uncontrolled chronic pain and its consequences. Although many characteristics of chronic pain are similar in different patients, be aware that each patient is unique and requires a highly specialized plan of care.

Pain Transmission

Painful stimuli often originate in the periphery (extremities) of the body. To be perceived, the stimuli must be transmitted first to the spinal cord and then to the central areas of the brain. If the pain impulse is not transmitted to the brain, the person feels no pain. In the periphery, two specific fibers can transmit stimuli: (1) A delta fibers, which are found primarily in the skin and muscle; and (2) C fibers, which are distributed in muscle, periosteum, and viscera. Both of these nerve fibers are capable of accepting nociceptive stimuli.

A delta fibers are myelinated fibers that carry rapid, sharp, pricking, or piercing sensations. A person feeling these sensations can generally localize them readily to a fairly well-defined area. Because these fibers respond mainly to mechanical rather than chemical or thermal stimuli, they are called mechanical nociceptors.

C fibers are unmyelinated or poorly myelinated fibers that conduct thermal, chemical, and strong mechanical impulses. Pain conduction from C fibers is slow, more diffuse (widespread) and dull, burning, or achy—quite different from the sensations of A delta fibers. In contrast to the intermittent nature of A delta sensations, C fibers usually produce persistent pain.

Morphine-like substances called endorphins are released when the large-diameter nerve fibers are stimulated. These fibers close the gate and decrease pain transmission. This helps explain why many noninvasive pain management techniques work to relieve pain. Endorphins are thought to be a gene product, and producing them requires a stimulus to the brain.

Similar gating mechanisms exist in the nerve fibers descending from the thalamus and cerebral cortex. These areas of the brain regulate thoughts and emotions, including beliefs and values. When pain occurs, a person’s thoughts and emotions can modify one’s perceptions as they reach the level of conscious awareness.

Attitudes and Practices Related to Pain

The attitudes of health care professionals toward pain influence the way they perceive and interact with patients in pain. Without adequate assessment skills or knowledge of pain and analgesic therapy, they may not be able to understand their patients’ pain.

Nurses who have little personal experience with pain may not appreciate the scope of painful conditions associated with diseases and medical or surgical interventions. They may expect patients with chronic pain to react similarly to those with acute pain. Nurses may assume that reactions to pain fall within a certain norm based on their own cultural values. The more that a patient’s response varies from these expected norms, the more likely that a nurse’s attitude toward the patient will be positively or negatively biased.

Not only do health care professionals need continued education about pain management, but the public needs education as well. Nurses can help patients and their families achieve and maintain successful pain management through education.

Many patients are reluctant to report pain. When they do, they may underreport its severity. Patients may not share their existence of pain because they want to be “good” patients or do not want to bother or distract their caregivers from other issues in their care. In patients with a history of cancer, pain can be an unwanted reminder of the disease and its progression.

Some patients are also reluctant to take pain medications, especially opioid analgesics, because they fear becoming addicted to or used to the drug, especially older adults. Educate patients and reassure them that these drugs are not likely to cause addiction in those having pain.

Certain painful conditions are more common in either men or women. Most chronic pain sufferers are women. Women have more migraine headaches, tension headaches, rheumatoid arthritis and osteoarthritis, fibromyalgia, and multiple sclerosis. Men have more cluster headaches, back pain, gout, peripheral vascular disease, and postherpetic neuralgia.

History

Remember that the patient’s personal preferences and values affect how he or she reports the pain history. When culturally appropriate, be sure to include families and significant others in this information-gathering process to be family-centered.

Patients may report pain in the absence of any observable or documented physiologic changes. To be patient-centered, respect the patient’s verbal and nonverbal expressions of pain without making judgments or inferences about the reality of the pain. If patients perceive that health care professionals doubt the existence of their pain, mistrust and other negative feelings can arise and interfere with a therapeutic nurse-patient relationship.

Assess the length of time the patient has experienced pain. Patients may welcome an opportunity to discuss acute pain with the nurse because it is a relatively short-term experience and is easily described. However, those with chronic pain can become frustrated when they are unable to adequately describe their often vague and diffuse pain experience. Structured interviews using assessment aids (e.g., pain scales, descriptors) often help patients express their pain.

Physical Assessment/Clinical Manifestations

People with acute pain may have physiologic changes, such as tachycardia and blood pressure changes. Blood pressure is usually increased initially and then decreased. However, not all patients with acute pain have these signs, so his or her statement of pain is the only reliable indicator.

A person with chronic pain usually adapts to these physiologic changes as the body attempts to compensate for and adapt to noxious stimuli. The pain no longer serves as a necessary warning. Patients with chronic pain, then, often develop coping skills and may appear to look quite well.

Certain motor or body movements may be associated with either acute or chronic pain. Some may be more exaggerated or obvious than others. Patients in pain may support or shield (“splint”), holding painful body parts while moving, or they may lie listlessly because they are afraid to move. Assess the functional status and degree of impairment in the patient with pain.