Palliative Care and Pain Management at the End of Life ___________________________________________
Etiology Opioids are the primary factor in constipation in the palliative care setting, and many other prescribed drugs can contribute to constipation, including tricyclic antidepressants, antacids, anti- epileptic drugs, anticholinergic agents, and antihypertensives [319]. Additional factors that may contribute to constipation are diverticuli, inflammatory bowel disease, metabolic condi- tions (hypercalcemia, hypokalemia, hypothyroidism, uremia), cerebral tumors, dehydration, and radiation fibrosis [319]. For patients with cancer, constipation may be directly due to tumor involvement that causes intestinal obstruction. A diet low in fiber and decreased physical activity also increase the likelihood of constipation. Prevention Prevention of constipation is key, as prophylaxis is more effec- tive than treatment after constipation has been identified. As such, all treatment guidelines strongly recommend that a prophylactic bowel regimen be initiated when treatment with opioids (or other constipation-causing drugs) begins [310; 319; 320; 321]. The recommended prophylaxis is an osmotic and/ or a stimulant laxative [310; 319; 320]. Many nonpharmaco- logic approaches are recommended, and patients should be encouraged to plan a diet with adequate fiber, to increase fluid intake, and to engage in physical activity, as appropriate [310; 319; 320; 321]. Family members should be asked to help the patient comply with these measures. Ensuring that the patient has sufficient privacy and comfort with toileting is also recom- mended [319; 320; 321]. Assessment Issues of personal privacy often lead to a reluctance of patients to discuss constipation, so clinicians and other healthcare professionals must initiate the discussion and talk honestly about what to expect and measures to prevent and manage the symptom. The assessment tools used most often are the Bristol Stool Form Scale and the Constipation Assessment Scale [319; 320]. Assessment should include a review of the list of medi- cations, a history of bowel habits, and abdominal and rectal examination. In addition to checking the list of prescribed medications to determine if constipation is a side effect, the physician should ask the patient about over-the-counter drugs and herbal remedies, as constipation can be a consequence of aluminum-containing antacids, ibuprofen, iron supplements, antidiarrhea drugs, antihistamines, mulberry, and flax. A detailed history of bowel habits helps to establish what is considered normal for the individual patient. The patient should be asked about frequency of stool, the appearance and consistency of stools, use of bowel medications, and previous occurrence of constipation. In general, physical examination of the abdomen for tenderness, distention, and bowel sounds can rule out intestinal obstruction as the cause of constipation. A rectal examination can identify the presence of stool, fecal impaction, or tumor. Imaging of the abdomen (by plain x-ray or computerized tomography) may be appropriate to confirm the presence of obstruction. Consideration of the patient’s
commonly prescribed opioid, but other opioids, such as dia- morphine, dihydrocodeine, fentanyl, hydromorphone, and oxycodone, may be used [213]. The dose should be selected and titrated according to such factors as renal, hepatic, and pulmonary function and past use of opioids [213]. An oral dose of morphine of 2.5–10 mg every four hours as needed (1–5 mg intravenously) has been recommended for opioid- naïve patients [122]. Although respiratory depression is a side effect associated with opioids, especially morphine, this effect has not been found with doses used to relieve dyspnea [122; 316]. Evidence-based recommendations for palliative care for people with heart failure note that diuretics represent the cornerstone of treatment of dyspnea [108]. Nitrates may also provide relief, and inotropes may be appropriate in select patients [108]. The recommendations also include the use of low-dose opioids [108]. Anxiolytics are often a recommended option for relief of breathlessness because of the association between anxiety and dyspnea. The NCCN guidelines suggest considering benzodi- azepines when opioids and other nonpharmacologic measures have failed to control dyspnea [310]. However, there is little evidence that anxiolytic agents are effective for managing dyspnea associated with end-stage disease. A systematic review published in 2010 (seven studies, 200 subjects) showed that benzodiazepines had no beneficial effect on breathlessness in people with advanced cancer or COPD [317]. An update of the review included one additional study, but it did not alter the authors’ original conclusion that benzodiazepines have no beneficial effect on breathlessness in these patient populations [318]. Bronchodilators and systemic corticosteroids may be helpful in relieving dyspnea in people with lung cancer and underlying obstructive airway disease [314]. Reducing excessive secretions with nonpharmacologic interventions and anti- secretory agents is often beneficial [310]. In addition, analgesics may help relieve dyspnea associated with pain. CONSTIPATION Constipation can be defined as a reduced frequency of bowel movements and an increased stool consistency. In defining constipation in people with life-limiting disease, measurable symptoms, as well as the person’s perception of constipation and the level of discomfort, are factors [319; 320]. The condi- tion may be accompanied by cramps and abdominal bloating, as well as by discomfort caused by straining and rectal pres- sure. The patient who complains of “constipation” should be encouraged to elaborate so that the full nature and extent of the difficulty, including associated symptoms, can be defined for that individual [319]. Prevalence The prevalence of constipation among adults with life-limiting disease ranges from 8% to 70%, and constipation occurs in almost all patients taking opioids [211; 227; 307]. The preva- lence of constipation in palliative care settings is even higher, at 30% to 90% [321].
38
MDCA1525
Powered by FlippingBook