PURPOSE: Chronic dyspnea is a prevalent complaint often misdiagnosed for several reasons: 1) the gamut of causes is extensive; 2) clinical evaluation lacks sensitivity and specificity; 3) physicians commonly underutilize available diagnostic tests. We used a literature review to develop an algorithmic approach to chronic dyspnea.
METHODS: Patients referred to a pulmonary practice with a primary complaint of dyspnea for > 8 weeks were enrolled prospectively. After H&P each physician predicted the etiology of dyspnea. An algorithmic tiered approach was then used beginning with readily available, low cost, non-invasive tests (Tier 1). If diagnosis remained unclear, cardiopulmonary exercise testing (Tier 2) was performed. If a diagnosis was still not established, these results were used to guide more invasive/specific testing (Tier 3). If at any point evidence pointed towards a specific diagnosis, treatment was begun. The response was used either to confirm the diagnosis or to determine that further investigation was warranted.
RESULTS: 112 patients (69 women, 43 men) completed the protocol. The protocol led to one or more diagnoses in all but one patient. Major categories of disease were: respiratory (57%), circulatory (17%), obesity/deconditioning (11%), psychogenic (6%), and miscellaneous (9%). Lower airway diseases (asthma and/or COPD) comprised the largest category at 41%. The algorithm led to an accurate diagnosis in 99% of patients. In contrast, physician accuracy in predicting etiology after H&P was only 50%. An interesting finding in our study was the frequency of obesity. By body mass index (BMI), 46% were obese (BMI >30) and 18% were morbidly obese (BMI>40) (compared to 30% and 5%, respectively in the US population).
CONCLUSION: The accuracy of clinical diagnosis of dyspnea based on H&P is markedly inferior to a systematic algorithmic approach emphasizing targeted diagnostic testing. Using this algorithm, 26% of patients required only tier 1 testing. The other 74% required, on average, only 2 additional higher-level tests. Only 21% underwent invasive diagnostic testing.
CLINICAL IMPLICATIONS: This study demonstrates the efficiency and accuracy of this algorithmic approach to dyspnea.
DISCLOSURE: Wissam Abouzgheib, No Financial Disclosure Information; No Product/Research Disclosure Information