Feature Article
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Challenges in End-of-Life Pain Management Challenges in End-of-Life Pain Management
Karl E. Miller, MD, and Marti Miller, RN, CRNH
Dr. Miller is Professor, Department of Family Medicine, Chattanooga Unit, University of Tennessee College of Medicine, and Medical Director, Adventa Hospice, Chattanooga. Ms. Miller is Administrator, Adventa Hospice. Address for correspondence: Karl E. Miller, MD, Associate Professor, Department of Family Medicine, Chattanooga Unit UTCOM, 1100 East Third St, Chattanooga, TN 37403. Email: millerkarle@hotmail.com.
Pain management at the end of life can be challenging but can provide significant relief when accomplished. To control pain, the first step is to perform a thorough assessment of the type and intensity. The next step is to utilize the World Health Organization’s stepladder approach to pain management. In addition, adjuvant medications need to be considered that are aimed at treating specific types of pain. This review discusses appropriate strategies regarding the management of difficult pain cases. (Annals of Long-Term Care: Clinical Care and Aging 2003;11[4]:26-32)
Of the complex issues that face healthcare workers who provide care at the end of life, pain management can be one of the most challenging. Symptoms can range from annoying to severe, which can require simple to complex interventions. Despite a renewed focus on pain management in these patients, many still suffer from being untreated or undertreated, which results in needless suffering at the end of life.1-3
Pain has also been identified by terminal patients as one of their major concerns when facing the end of their lives.4 Addington-Hall and colleagues3 found that in a majority of such patients, pain caused a significant amount of stress during the final phase of life. Pain can have a significant impact on both physical and psychological well being. In addition, family members can also suffer when pain is not well-controlled at the end of life. In order to provide better pain control during this time, healthcare providers need to establish aggressive pain management strategies.
BASIC PRINCIPLES
There are several basic principles in pain management at the end of life.5 The first principle is that good pain control can be achieved in the majority of patients. Multiple medications and delivery routes provide healthcare professionals with a variety of strategies. The second principle is that acute pain in terminal patients is a medical emergency and should be treated as such. If not treated aggressively, the pain can escalate and be more difficult to control. Addiction concern is the final principle. Despite the concern with addiction related to opioid use when pain is present, addiction to narcotics is rare.5 Addiction is less of an issue in patients with life-limiting diseases.
Maximizing pain management requires certain strategies.5 The first is to believe patients’ assessment of their pain and use them as a guide for management. The second strategy is to provide relief around the clock. Pain medications that are strictly used on an as-needed basis allow pain to develop and require more medication for control. The use of around-the-clock dosing suppresses the pain and will provide better comfort. Third, when possible, use the oral route for medications. There are currently a number of oral sustained (immediate-release) and intensol (concentrated liquid) preparations that can provide adequate pain control. Finally, titrate opioids to an appropriate level that provides adequate pain control. Most opioids have no ceiling, and large doses have not been shown to suppress respirations or decrease life expectancy when patients are in pain.6
Pain Assessment
The standards for assessing pain are the same regardless of whether the pain is related to an accident or end of life. The initial information gathered needs to include the location, quality, intensity, onset frequency, and duration of the pain. Factors that exacerbate or relieve the pain can provide insight into how to control the pain. When gathering this information, one method for organizing it is by utilizing a pain assessment form. Using multiple formats can help assess the intensity of the pain. One such format is the 0-to-10 pain scale, with 0 representing no pain and 10 representing the worst pain possible. This assessment can be performed with a visual analog or a pictorial assessment scale. Several other pain assessment tools can be utilized as well.7 When assessing pain, it is important to establish intensity of the current pain level; one should also assess the worst, least, and average pain intensity over the previous 24 hours. Patients that maintain a pain intensity log can document the relationship of intensity with the time of day. Persons may have more pain when awakening, so a higher nighttime dose of opioid would be helpful to facilitate better pain control.
The other aspect of pain assessment is to determine the type of pain syndrome. Pain is divided into the nociceptive and neuropathic types. Nociceptive pain is further divided into somatic and visceral pain. Somatic pain is described as aching, throbbing, stabbing, and/or pressure sensation; its source is skin, bone, or muscle. Words that describe visceral pain include gnawing, cramping, aching, sharp, or stabbing sensation; this pain originates in internal organs. Neuropathic pain has two distinct types. The first is continuous dysthesia, which is described as continuous, burning, electrical, or other abnormal sensations. The other is chronic lancinating or paroxysmal pain. This is described as sharp, stabbing, shooting, knifelike pain and often has a sudden onset. By determining the pain syndrome, treatment strategies developed specifically for those syndromes can provide better control.
Management
Management strategies for pain at the end of life include analgesic and adjuvant medications. In some patients, the only treatment necessary for pain control may be an over-the-counter preparation, while others may require high doses of opioids along with an adjuvant medication. The treatment strategy for pain control is based on a thorough assessment and the type of pain described by the patient.
Analgesic Treatment
The WHO guidelines divide pain into mild, moderate, and severe. Patients who rate their pain as 0 to 3 on a 10-point pain scale would be classified as mild, 4 to 6 as moderate, and 7 or above as severe.
Mild pain can be managed by using acetaminophen, nonsteroidal anti-inflammatory agents (NSAIDs), and COX-2 inhibitors (Table I).5 The COX-2 inhibitors should be reserved for patients who cannot tolerate the gastrointestinal side effects of NSAIDs, because they are more costly and do not provide any more analgesic effect.10
Moderate pain should be treated with weak opioids.5 (Table II) Combinations are available that include acetaminophen, aspirin, or NSAIDs with opioids. These should not be utilized for severe pain control because they limit the ability to titrate higher doses of the opioids.
Severe pain should be treated with strong opioids (Table II).5 It is important to initiate opioids at low doses and titrate to effectiveness. This means that patients need to have their pain assessed by a healthcare professional on a regular basis during the initiation phase so that adequate pain control can be achieved quickly.
Patients with moderate or severe pain should be treated with sustained-release preparations to provide a more steady-state control. In addition, a short-acting opioid should be available for breakthrough pain, because a substantial number of hospice patients report breakthrough pain despite being adequately managed.11 Using a breakthrough dose of an immediate-release opioid treats breakthrough pain, with the dose at 30-50% of the baseline sustained-release dose.
The total dose of breakthrough medication use in one day can be used to calculate the increase needed in the sustained-release opioid to provide better pain control. Patients who rate their pain as mild require an increase of their baseline opioid dose of 25% of the total breakthrough dose, while those in moderate pain require 50%, and those in severe pain need 100% of the breakthrough dose added to their baseline.12
Pain tends to escalate with disease progression at the end of life. In some cases, this escalation may be related to the patient developing a tolerance to the opioid being used for pain control. This can be managed by using an opioid rotation,13 which includes changing to a different opioid, maintaining the current opioid but changing the delivery route, or changing both the medication and delivery route.
Another type of pain that can cause unnecessary suffering if left untreated at the end of life is incident pain. This occurs with a specific activity such as walking for any length of time or sitting upright for prolonged periods. This pain should be anticipated, and approximately 30 minutes prior to the activity the patient should be treated with an immediate-release opioid.
A patient who develops acute or crescendo pain at the end of life presents an emergency in pain management. In this case, the pain has been under good control but, because of a new process or an escalation of an old process, the pain intensifies. The pain should be treated aggressively with the use of an immediate-release opioid. A health care provider who understands pain management can administer the opioid every 15 minutes until the patient becomes comfortable. Once the pain is under control, the baseline pain medication should be increased in an attempt to prevent a recurrence of the acute pain. Patients who do not respond to this management strategy may need parenteral pain medication.
Equianalgesia
One of the more common errors in managing pain at the end of life occurs when attempting to change from one opioid to another or when changing to a different route of delivery. In order to change opioids yet maintain the same analgesic effect, equianalgesic charts have been developed to assist in this endeavor.14 These charts are based on studies that compare different opioids and routes to 10 mg of parenteral morphine. Utilizing these charts can reduce the chance of under- or overmedicating patients. The equianalgesic chart can also be used to change both the medication and the route. Another pain treatment option in patients whose disease has progressed to the point where they are unable to tolerate oral medications is the fentanyl patch, which delivers analgesia at a consistent rate. It can be applied to the trunk and changed every 72 hours. The fentanyl patch has been shown to be as effective as subcutaneous morphine, has similar side effects to morphine, and has been shown to have excellent patient compliance.15,16 The recommended conversion rate from morphine to fentanyl is 2 mg of oral morphine daily for every 1 microgram per hour of fentanyl.14 The conversion provides a starting point for the patch, but its effectiveness does vary from patient to patient. Because of this, the fentanyl patch is difficult to titrate. The effectiveness of the patch takes approximately 12 hours after application and may take 3 to 4 days to reach a steady state. Patients with minimal subcutaneous fat may not be candidates for this treatment strategy, because they may not adequately absorb the medication.
Cognitively Impaired Patients
Because patients with cognitive impairment tend to lose their ability to communicate, their pain tends not to be adequately controlled.17-19 Agitation in these individuals may be related to pain and not their disease process.19 There are several different methods for assessing pain in such patients. Those with significant cognitive impairment were able to communicate pain intensity using a 0-to-5 scale, which was anchored by words in one study.20 In another study, a 6-item pain intensity scale questionnaire was able to determine the existence of pain and establish its intensity.21 This population needs to be given sufficient time to complete any pain assessment so they can process the information and respond. Because persons with severe impairment may not be able to communicate the presence of pain, nonverbal cues can be used to assess them. These include furrowed brow, agitation, grimacing, grinding teeth, and moaning. Elevation of pulse or blood pressure may also be related to the presence of pain.
Adjuvant Medications
When providing pain control at the end of life, using opioids may not provide good pain control in certain pain syndromes. The use of adjuvant medications is based on the type of pain syndrome identified by listening to and assessing the patient.
Neuropathic Pain
There are two distinct types of neuropathic pain, which are continuous dysesthesia and chronic lancinating (paroxysmal) pain. The distinction between the types is important; the best adjuvant medications used to treat them are different.
The first-line treatment for continuous dysesthesia pain is the use of tricyclic antidepressants (TCAs; Table III).22 The TCAs with the best analgesic properties include amitriptyline, doxepin, and imipramine, but these have a higher incidence of side effects than desipramine, clomipramine, and nortriptyline.23 Patients with a history of cardiovascular disease are not candidates for TCA treatment. If patients are not candidates for TCA treatment or have significant side effects to this class, systemic local anesthesia medications are the next option.22 If patients are refractory to first- or second-line treatment, oral or transdermal clonidine can be used.22
The anticonvulsants are the first-line treatment option for lancinating or paroxysmal neuropathic pain.22 The anticonvulsant with the highest safety profile and least drug–drug interactions is gabapentin.24 Some of the more common side effects of gabapentin include sedation and fatigue. The dose needs to be reduced in elderly patients and those with renal failure. Other treatment options include baclofen, systemic local anesthetics, TCAs, clonidine, and topical capsaicin.22
Nociceptive Pain
Nociceptive pain includes somatic and visceral pain and usually results from actual or potential tissue damage. The source of somatic pain is skin, muscle, or bone; intestinal organs are the source for visceral pain. Because treatment with certain opioids can worsen some of these pain types, it is vital to establish which pain type is occurring and to treat appropriately.
The first-line treatment for skin or musculoskeletal pain are the NSAIDs (Table I). Alternative medications that are available for patients who cannot tolerate NSAIDs secondary to gastrointestinal (GI) side effects include choline magnesium trisalicylate or the new cyclo-oxygenase-2 (COX-2) inhibitors (celecoxib and rofecoxib). The COX-2 inhibitors do cause less GI side effects than NSAIDs but provide no advantage with regard to analgesic effect and are expensive.10
Narcotics such as morphine are less likely to control somatic bone pain than any other type of pain.25 Patients with bone pain need to be treated with adjuvant medications in order to provide the best control. The first-line therapy for bone pain is the use of NSAIDs Annals of Long-Term Care - ISSN: 1524-7929 - Volume 11 - Issue 04 - April 2003 |