Dyspnea is the subjective experience of difficulty breathing and may be characterized by patients as tightness in the chest, shortness of breath, breathlessness, or a feeling of suffocation. Up to half of people at the end of life may experience severe dyspnea.
Treatment of dyspnea is usually first directed at the cause (see Chapter 9-20). At the end of life, dyspnea is often treated nonspecifically with opioids, which are the single best class of medications for dyspnea with demonstrated effectiveness in multiple randomized trials. Starting doses are typically lower than would be necessary for the relief of moderate pain. Immediate-release morphine given orally (2–4 mg every 4 hours) or intravenously (1–2 mg every 4 hours) treats dyspnea effectively. Sustained-release morphine given orally at 10 mg daily is safe and effective for most patients with ongoing dyspnea. Supplemental oxygen may be useful for the dyspneic patient who is hypoxic. However, a nasal cannula and face mask are sometimes not well tolerated, and fresh air from a window or fan may provide relief for patients who are not hypoxic. Judicious use of noninvasive ventilation as well as nonpharmacologic relaxation techniques, such as meditation and guided imagery, may be beneficial for some patients. Benzodiazepines may be useful adjuncts for treatment of dyspnea-related anxiety.
Nausea and vomiting are common and distressing symptoms. As with pain, the management of nausea may be optimized by regular dosing and often requires multiple medications targeting the four major inputs to the vomiting center (see Chapter 15-02).
Vomiting associated with opioids is discussed below. Nasogastric suction may provide rapid, short-term relief for vomiting associated with constipation (in addition to laxatives), gastroparesis, or gastric outlet or bowel obstruction. Prokinetic agents, such as metoclopramide (5–20 mg orally or intravenously four times a day) or domperidone (not available in the United States), can be helpful in the setting of partial gastric outlet obstruction. Transdermal scopolamine (1.5-mg patch every 3 days) can reduce peristalsis and cramping pain, and ranitidine (50 mg intravenously every 6 hours) can reduce gastric secretions. High-dose corticosteroids (eg, dexamethasone, 20 mg orally or intravenously daily in divided doses) can be used in refractory cases of nausea or vomiting or when it is due to bowel obstruction or increased intracranial pressure. Malignant bowel obstruction in people with advanced cancer is a poor prognostic sign and surgery is rarely helpful.
Vomiting due to disturbance of the vestibular apparatus may be treated with anticholinergic and antihistaminic agents (including diphenhydramine, 25 mg orally or intravenously every 8 hours, or scopolamine, 1.5-mg patch every 3 days).
Benzodiazepines (eg, lorazepam, 0.5–1.0 mg given orally every 6–8 hours) can be effective in preventing the anticipatory nausea associated with chemotherapy. For emetogenic chemotherapy, therapy includes combinations of 5-HT3-antagonists (eg, ondansetron, granisetron, dolasetron, or palonosetron), neurokinin-1 receptor antagonists (eg, aprepitant, fosaprepitant, ...