Concepts of Pain1

Editor's Notes

• #3: APS definition describes pain as a complex phenomenon with multiple components that impact a person's psychosocial and physical functioning. McCaffery’s definition of pain is the accepted clinical definition of pain. This is why all accepted guidelines consider the patient’s report to be the most reliable indicator is of pain.
• #4: Nociceptors detect a wide range of stimuli and respond to chemical, mechanical, and thermal stimulation. Myelinated Aδ receptor transmission is fast and conveys mechanical and thermal, sharp, localized pain. Unmyelin­ated polymodal C fiber transmission is slower and conveys diffuse burning and aching sensations.
• #5: Nociceptive pain refers to the normal functioning of physiologic systems that leads to the perception of noxious stimuli (tissue injury) as being painful. Simply stated, nociception means “normal” pain transmission. (with a known physiologic cause)Pain from surgery, trauma, burns, and tumor growth are examples of nociceptive pain. Patients often describe this type of pain as “aching,” “cramping,” or “throbbing.” Neuropathic ,pain non-nociceptive pain, results from the abnormal processing of sensory input by the nervous system as a result of damage to the brain, spinal cord, or peripheral nerves. Simply stated, neuropathic pain is pathologic. Examples of neuropathic pain include postherpetic neuralgia, diabetic neuropathy, phantom pain, and poststroke pain syndrome. Patients with neuropathic pain use very distinctive words to describe their pain, such as “burning,” “sharp,” and “shooting.” Some painful conditions and syndromes are not easily categorized and thought to be unique with multiple underlying and poorly understood mechanisms. These are referred to as mixed pain syndromes and include fibromyalgia and some low back and myofascial pain.
• #6: Examples of Acute pain: tissue damage as a result of surgery, trauma, or burns produces acute pain, which is expected to be relatively short-lived and to diminish with normal healing. Somatic pain arises from connective tissue, muscle, bone, and skin and is sharp and localized. Visceral pain is from the internal organs, is transmitted by sympathetic afferents, and is poorly localized. Referred pain usually arises from the viscera and terminates in an area of the spinal cord that is conjoined with fibers originating in the skin and other areas and thereby pro­duces the perception of pain at the referred site. Chronic pain may result from Chronic pain may result from underlying medical conditions, such as cancer pain from tumor growth or osteoarthritis pain from joint degeneration, and can persist throughout a person's lifespan. For example, some patients with cancer have continuous chronic pain and also experience acute exacerbations of pain periodically or are exposed to repetitive painful procedures related to cancer treatment. Chronic pain generally lasts at least 3 months and may be per­sistent—for example, low back pain or intermittent migraine headache pain, myofascial pain syndromes, chronic postop­erative pain, and chronic pain associated with cancer. Some patients have a combination of nociceptive and neuropathic pain. For example, a patient may have nociceptive pain as a result of tumor growth and if the tumor is pressing against a nerve plexus the patient may also report radiating sharp and shooting Sickle cell pain is usually a combination of both nociceptive pain from the clumping of sickled cells, and resulting perfusion deficits, and neuropathic pain from nerve ischemia.
• #7: Although not all older adults experience pain, the incidence of pain increases with age, placing this population at higher risk for pain than younger individuals. Pain has been shown to be very common in the older adult in the inpatient acute care setting. And in the outpatient setting, such as in nursing homes. Older individuals may or may not have an increased pain threshold. In all age groups, women appear to be more sen­sitive to pain than are men. This is in large part because older adults suffer many of the conditions associated with pain, including musculoskeletal disorders, such as degenerative spine conditions and arthritis. reluctant or unable to report their pain because of illness or cognitive impairment. Pain in older adults is influenced by liver and renal func­tion, including alterations in the metabolism of drugs and metabolites. Research shows that clinicians fail to provide adequate analgesia based on the misconception that analgesics are not needed or fears that analgesics may cause adverse effects, such as confusion and respiratory depression. At the other end of the spectrum: Neonates and infants are at increased risks due to painful heel sticks, venipuncture, circumcision, etc. Other nonverbal individuals: toddlers, cognitively impaired, anesthetized, critically ill, comatose, and imminently dying patients
• #9: Pain triggers a number of physiologic stress responses in the human body. Unrelieved pain can prolong the stress response and produce a cascade of harmful effects in all body systems
• #11: Effective assessment of pain, pain medications and other non pharmacologic interventions. Incentive Spirometer to increase lung inspired volume, and open up alveoli, cough and deep breathing exercise…
• #13: Numeric Rating Scale (NRS): The NRS is most often presented as a horizontal 0 to 10 point scale, with word anchors of “no pain” at one end of the scale, “moderate pain” in the middle of the scale, and “worst possible pain” at the end of the scale. •Faces Pain Scale-Revised (FPS-R): The FPS-R has six faces to make it consistent with other scales using the 0 to 10 metric. The faces range from a neutral facial expression to one of intense pain and are numbered 0, 2, 4, 6, 8, and 10. Patients are asked to choose the face that best describes their pain. The FPS-R is valid and reliable for use in children and adults, including cognitively intact and impaired elders. Although young children may be able to select a face on a faces scale, they are unable to optimally quantify pain (identify a number) until approximately 8 years of age. •Wong-Baker FACES Pain Rating Scale: The FACES scale consists of six cartoon faces with word descriptors, ranging from a smiling face on the left for “no pain (or hurt)” to a frowning, tearful face on the right for “worst pain (or hurt).” The faces are most commonly numbered using a 0, 2, 4, 6, 8, 10 metric; however 0 to 5 can also be used. Patients are asked to choose the face that best describes their pain. The FACES scale is used in adults and children as young as 3 years old.
• #14: Quality: Ask the patient to describe how the pain feels. Descriptors such as “burning” or “shooting” may identify the presence of neuropathic pain. •Onset and duration: Ask when the pain started and whether it is constant or intermittent. •Alleviating and relieving factors: Ask the patient what makes the pain better and what makes it worse. The answers help to determine which pain medications and nonpharmacological interventions are effective and which are not. •Effect of pain on function and quality of life: Ask the patient to describe medication side effects (e.g., constipation, nausea, sedation) and difficulty sleeping or eating. Assess for comorbidities, such as anxiety and depression. It is particularly important to ask patients with chronic pain about how pain has affected their lives; what could they do before the pain began that they can no longer do, or what do they want to do but cannot do because of the pain? Comfort-function (pain) goal: Discuss the expectation of functional goal achievement. For example, tell surgical patients that they will need to deep breathe, cough, turn, and ambulate or participate in physical therapy after surgery. Patients with chronic pain can be asked to identify their unique functional or quality-of-life goals, such as being able to work, walk the dog, or garden. Ask the patient to identify (using a 0 to 10 scale) a level of pain that will allow accomplishment of the identified functional or quality-of-life goals with reasonable ease. A realistic goal for most patients is 2 or 3, and pain intensity ratings that are consistently above the goal warrant further evaluation and consideration of an intervention and possible adjustment of the treatment plan. Other information: The patient's culture, past pain experiences, and pertinent medical history such as comorbidities, laboratory tests, and diagnostic studies are considered when establishing a treatment plan.
• #15: Breakthrough pain (also called pain flare) is a transitory exacerbation of pain in a patient who has relatively stable and adequately controlled baseline pain. When breakthrough pain is brief and precipitated by a voluntary action, such as movement, it is referred to as incident pain. Another type of breakthrough pain called idiopathic pain is not associated with any known cause and often lasts longer than incident pain. Episodes of pain that occur before the next analgesic dose is due are called end-of-dose failure pain. Analgesic doses or the frequency of their administration is adjusted as needed to minimize the occurrence of breakthrough pain.
• #16: The frequency of reassessment depends on the stability of the patient's pain and is guided by institutional policy. For example, in the acute care hospital setting, reassessment may be necessary as often as every 10 minutes when pain is unstable during the titration phase (gradual increases in dose to establish analgesia) and every 8 hours in patients with stable pain.
• #17: Attempt to obtain the patient's self-report, the single most reliable indicator of pain. Do not assume a patient cannot provide a report of pain; many cognitively impaired patients are able to use a self-report tool, such as the Faces Pain Scale-Revised (FPS-R) or Verbal Descriptor Scale (VDS). 2. Consider the patient's condition or exposure to a procedure that is thought to be painful. If appropriate, assume pain is present (APP) and document APP when approved by institution policy and procedure. 3. Observe behavioral signs (e.g., facial expressions, crying, restlessness, and changes in activity). There are many behavioral pain assessment tools available that will yield a pain behavior score and may help to determine if pain is present. However, it is important to remember that a behavioral score is not the same as a pain intensity score. Pain intensity is unknown if the patient is unable to provide it. A surrogate who knows the patient well (e.g., parent, spouse, or caregiver) may be able to provide information about underlying painful pathology or behaviors that may indicate pain. 4.Evaluate physiologic indicators with the understanding that they are the least sensitive indicators of pain and may signal the existence of conditions other than pain or a lack of it (e.g., hypovolemia, blood loss). Patients may have normal or below normal vital signs in the presence of severe pain. The absence of an elevated blood pressure or heart rate does not mean the absence of pain. Physiologic responses to acute pain include the following: increased heart rate, respiratory rate, and blood pressure; pallor or flush­ing; dilated pupils; and diaphoresis. The blood glucose level is elevated, gastric secretion and motility are decreased, and blood flow to the viscera and skin is decreased. 5.Conduct an analgesic trial to confirm the presence of pain and to establish a basis for developing a treatment plan if pain is thought to be present. An analgesic trial involves the administration of a low dose of nonopioid or opioid and observing patient response. The initial low dose may not be enough to illicit a change in behavior and should be increased if the previous dose was tolerated, or another analgesic may be added. If behaviors continue despite optimal analgesic doses, other possible causes should be investigated. In patients who are completely unresponsive, no change in behavior will be evident and the optimized analgesic dose should be continued.
• #19: A principle of pain management is to use the oral route of administration whenever feasible. All of the first-line analgesics used to manage pain are available in short-acting and long-acting formulations. For patients who have continuous pain, a long-acting analgesic, such as modified-release oral morphine, oxycodone, or hydromorphone, or transdermal fentanyl, is used to treat the persistent baseline pain. A fast-onset, short-acting analgesic (usually the same drug as the long-acting) is used to treat breakthrough pain if it occurs. When the oral route is not possible, such as in patients who cannot swallow or are NPO or nauseated, other routes of administration are used, including intravenous (IV), subcutaneous, transdermal, and rectal. Opioids are often given by IV patient-controlled analgesia (PCA), whereby patients manage their own pain by pressing a button attached to an infusion pump to deliver a preset bolus dose of pain medication. The concept of PCA recognizes that only the patient can feel the pain and only the patient knows how much analgesic will relieve it. Patients who use PCA must be able to understand the relationships between pain, pushing the PCA button, and pain relief. They must also be able to cognitively and physically use the PCA equipment.12 Some of the methods used to manage pain are accomplished via catheter techniques such as intraspinal analgesia and continuous peripheral nerve block infusions with or without PCA capability. Nurses play a key and extensive role in the successful management of these therapies, and the American Society for Pain Management Nursing (ASPMN.org) provides guidelines for care.
• #20: Life-threatening opioid-induced respiratory depression is the most serious of the opioid side effects; however, nurses can be key to preventing this complication by performing systematic assessments of their patients’ sedation levels Constipation, dry mouth, drowsiness, etc.
• #21: S. easy to arouse Acceptable; no action necessary; may increase opioid dose if needed no action necessary; may increase opioid dose if needed no action necessary; may increase opioid dose if needed monitor respiratory status and sedation level closely until sedation level is stable at less than 3 and respiratory status is satisfactory; decrease opioid dose 25% to 50% or notify primary or anesthesia provider for orders; consider administering a nonsedating, opioid-sparing non opioid, such as acetaminophen or a NSAID, if not contraindicated; ask patient to take deep breaths every 15 to 30 minutes. stop opioid; consider administering naloxone (Narcan) Call Rapid Response Team (Code Blue); stay with patient, stimulate, and support respiration as indicated by patient status; notify primary or anesthesia provider; monitor respiratory status and sedation level closely until sedation level is stable at less than 3 and respiratory status is satisfactory.
• #22: Body based modalities such as massage, acupuncture, and application of heat and cold, and the mind-body methods, such as guided imagery, relaxation breathing, and meditation. Biological based therapies that involve the use of herbs and vitamins, and energy therapies such as reiki and tai chi. The effectiveness of nonpharmacological methods can be unpredictable, and although not all have been shown to relieve pain, they offer many benefits to patients with pain. For example, research has shown that nonpharmacological methods can facilitate relaxation and reduce anxiety and stress. Many patients find the use of nonpharmacological methods helps them cope better with their pain and feel greater control over the pain experience.44 These effects may ultimately contribute to improvements in overall quality of life. •Proper body alignment achieved through proper positioning and regular repositioning can help prevent or relieve pain. Pillows can be used to maintain the position and support the patient's back and extremities. •Thermal measures such as the application of localized, superficial heat and cooling may relieve pain and provide comfort by decreasing sensitivity to pain and muscle spasms and alleviating joint and muscle aches. The two measures are often used interchangeably. •Mind-body therapies are designed to enhance the mind's capacity to affect bodily function and symptoms and include music therapy, distraction techniques, meditation, prayer, hypnosis, guided imagery, relaxation techniques, and pet therapy, among many others.
• #23: The two types of pain, nociceptive pain (from tissue damage) and neuropathic pain (from nerve damage), share common effects when left untreated or inadequately managed. The figure demonstrates that some of the most disturbing effects of unrelieved pain are seen in the musculoskeletal system with impaired muscle function (Mobility), Fatigue, and immobility. Inadequately managed pain in the postoperative setting limits the patient's ability to ambulate and participate in important physical therapy activities, prolongs recovery, and is associated with a higher incidence of complications including long-term disability. In the outpatient setting, individuals with poorly managed chronic pain report inability to complete even the simplest of activities of daily living (Functional ability), which can result in loss of independence and greater reliance on family, friends, and the health care system. The adverse effects of unrelieved pain on quality of life are numerous and can be particularly devastating because they affect both the person with pain and the person's family and friends. Patients with poorly managed chronic pain frequently report sleep disturbances, are more likely to rate their general health as poor, and describe having suicidal thoughts (Mood and affect). Research has even shown that severe chronic pain is associated with increased mortality, independent of sociodemographic factors, such as income, age, and gender.
• #24: Pain assessment in Jenny is a challenge because she is unable to report pain using customary assessment tools. According to the Hierarchy of Pain Measures, when self-report of pain cannot be obtained, clinicians should assume pain is present based on the existence of painful pathology. Behaviors, if present, may also be observed as possible indicators of pain. The nurse correctly suspected that Jenny's restlessness might be due to unrelieved pain and administered analgesia promptly. It is important to note that elevated vital signs, which often accompany restlessness, are not reliable measures of pain, but they are sometimes used to further support the assumption that acute pain may be present. When Jenny recovers enough to provide a report of pain, self-report tools such as the NRS or FPS-R will be introduced and used to assess her pain. The type of pain is used to determine the appropriate treatment approach. Jenny has experienced surgery as well as significant trauma-related tissue damage, both of which yield nociceptive pain. The first-line analgesics for moderate to severe nociceptive pain include opioids and nonopioids, such as acetaminophen and NSAIDs. Because Jenny is on a ventilator, the analgesics are administered by the IV route. Fortunately, there are several opioid and some nonopioid analgesics available in IV formulation. Administration of a loading dose (IV bolus in this case) before initiation of the maintenance analgesic (IV infusion) is recommended to establish rapid analgesia. When Jenny is able to take oral fluids, analgesics will be given orally.