Dyspnea encompasses complex interactions between peripheral and central sensory receptors and cognition, while the underlying causation remains unknown. Physiological, psychological, behavioral, social, and environmental factors play a role in the pathogenesis and perception of dyspnea (Rao & Gray, 2003). Although the underlying medical condition may not be treatable in the palliative care patient, dyspnea almost always responds to intervention or treatment.

Patients who complain of being breathless will often seek some relief through position changes, pursed lip breathing, use of accessory muscles, and/or use of environmental aids such as a fan or sitting near an open window or refraining from being exposed to humidity. Breathlessness can be easily observed (objective evaluation) in the patient who is struggling to breathe—but is often considered a subjective experience. For the clinician, a simple approach used to assess and evaluate the patient’s dyspnea would be to ask the patient to quantify his or her difficulty in breathing from a numerical scale that is rated from 0 (no breathlessness) to 10 (severe breathlessness). A numerical value provides the clinician with an understanding of the patient’s expression of his or her dyspnea intensity. The Edmonton Symptom Assessment System (ESAS) is an example of a numerical rating scale to evaluate the patient’s intensity associated with multiple symptoms including dyspnea (Bruera, Kuehn, Miller et al.,1991).

There are several psychometrically valid and reliable dyspnea assessment tools that are used in clinical and research settings to assess and evaluate the symptom of dyspnea. The traditional approach to providing care for patients with chronic respiratory disease has primarily relied on pulmonary function tests (PFTs) to quantify the severity of the patient’s disease and/or their response to therapy (Mahler, 2000). However, patients often present for medical attention as a result of their symptoms, particularly dyspnea and an impaired ability to perform activities of daily living, with both contributing to the interference of the patient’s perceived quality of life (Mahler, 2000). The patient’s perception of breathlessness that interferes with quality of life may not always be accurately reflected in the most recent spirometry evaluation (GOLD, 2003). As previously mentioned, simply asking the patient to rate his or her dyspnea or difficulty breathing from a numerical rating scale may serve as a useful indicator of the patient’s self-description of his or her discomfort. Other examples of dyspnea evaluation tools will be briefly described below. The patient’s physical status should be considered in instrument selection, since lengthy instruments are not generally appropriate in palliative care populations.

Patients experiencing the sensation of dyspnea or breathlessness will often seek medical attention. The clinician encountering the dyspneic patient should consider asking the patient specifically about his or her shortness of breath. Because dyspnea is considered a subjective complaint, it is important to note that patients may often present with tachycardia and look in distress yet may not describe being dyspneic or distressed versus the patient who is not tachypneic or in apparent distress yet may describe having severe breathlessness (Pereira & Bruera, 2001).

The etiology of dyspnea may be easy to discern in most patients by taking a complete history and performing a physical examination. A detailed examination with a focus on the cardiac and respiratory systems is essential (Bruera et al., 2002). Simple measures such as a chest radiograph, digital oximetry, and a complete blood count and comprehensive metabolic profile tests can help in differentiating the cause of dyspnea (Bruera et al., 2002). Pulmonary function tests (PFTs) are useful for the patient with obstructive and restrictive pulmonary disease. These tests are easy to perform at the bedside and can also provide the clinician with valuable information on how the patient responds to specific interventions. If done appropriately, the patient will use a bronchodilator after the first evaluation and measurements are considered before and after bronchodilator use.

Differential diagnostics are important as dyspnea is a complex symptom that may arise from multiple insults. Common contributions to dyspnea can include the following (Bruera et al., 2002; Pereira & Bruera, 2001):

Diagnostic procedures can provide assistance in identifying the causes of dyspnea and monitoring the course of the illness, but the practitioner must evaluate the appropriateness of such diagnostic tests in palliative care. A diagnosis can sometimes be made based solely on the clinical presentation alone; thus, the burden and cost incurred by the patient must be considered. When a diagnosis is more complicated, a clinician may have a clinical history, physical examination, laboratory tests (complete blood cell count, metabolic panel), and possibly a chest radiograph as an initial work-up. Pulmonary diagnostics, such as spirometry and PFTs (outlined later), provide supporting information to help the clinician make the diagnosis (West, 2003). Additionally, spirometry and PFTs are valuable in following the progress of a patient’s dyspnea over time. Other diagnostic tests that may not be used in palliative care include the following (Karnani, Reisfield, & Wilson, 2005; West, 2003):

The treatment of dyspnea begins with determining and treating the underlying cause. This includes the appropriate selection of disease-specific and palliative therapies, taking into account prognosis, adverse events, costs, and potential outcomes to the patient. The most common reversible causes of dyspnea are bronchospasm, hypoxia, and anemia (Dudgeon & Lertzman, 1998). Appropriate management of dyspnea requires pharmacological and nonpharmacological treatments. Two types of drugs that have proved useful in alleviating dyspnea in palliative care are opioids and drugs that decrease anxiety. Table 27-2 summarizes pharmacological options for the management of dyspnea based on cause. Many of the other medications described in this chapter concerning dyspnea relief have primarily been studied in other disease states such as asthma, COPD, and cancer.