Medical Aspects of Disease
Since the introduction of angiotensin-converting enzyme inhibitors and their remarkable success in managing scleroderma renal crisis, pulmonary complications have assumed ever greater importance as a source of morbidity and mortality in this disease. Prior to the use of captopril, renal failure was the leading cause of death in scleroderma. Now renal failure accounts for fewer than 10% of scleroderma-related deaths.
At present, the majority (nearly 80%) of deaths now are attributable to interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). Other pulmonary complications may occur, but ILD and PAH are the major complications experienced by our patients. (See Table 1, page 17.)
As pulmonary manifestations have assumed greater importance, new treatments now offer hope to SSc patients. Now that treatment is available, it is essential for the rheumatologist to screen patients for the presence of ILD and PAH, so that treatment can be instituted before the disease becomes irreversible. Similar to our current approach to patients with rheumatoid arthritis or lupus nephritis, there may be a window of opportunity to successfully intervene and treat ILD and PAH.
My approach to the evaluation and management of the SSc patient with dyspnea is described below. First, I will describe the major clinical and laboratory investigations available for the evaluation of dyspnea.
Since the introduction of angiotensin-converting enzyme inhibitors and their remarkable success in the management of scleroderma renal crisis, pulmonary complications have assumed ever greater importance as a source of morbidity and mortality in this disease.
Signs and Symptoms
Dyspnea is the most common complaint of patients with ILD or PAH. Like hunger or thirst, dyspnea can be characterized as a “synthetic sensation” in that it often arises from multiple sources of information rather than from stimulation of a single neural receptor. Severity of dyspnea as well as qualitative aspects of unpleasant breathing experiences vary widely among patients.1 Dyspnea usually signals the presence of lung or heart disease (or rarely, coexisting muscle disease). Standardized tools exist to quantify dyspnea, and these are often used in clinical trials; in the office it is more practical to assess dyspnea in terms of self-reported activities (e.g., walking, carrying, and climbing stairs).
Paul Klee, the famous 20th-century artist who suffered from scleroderma, described his symptoms while hiking in the mountains: “I inhale as deep as possible. My dyspnea depends on the trail, whether going up or going down. It also depends upon the weather … and it also depends on how much food I have in my stomach.”2 With progressive disease, even simple tasks may prove difficult. Near the end his life, Klee noted that the small incline to his house was difficult to traverse: “This is now my Matterhorn.”
