Alexander S. Niven, MD

Although the results of a thorough history and physicalexamination often suggest the diagnosis of asthma, confirmatorytesting is required and may be helpful in more subtlecases. Spirometry before and after bronchodilator administrationis the first step for the initial diagnosis; it also is an importantcomponent of the long-term assessment of asthma control.When the results of spirometry are normal in a patient in whomasthma is suspected, bronchoprovocation challenge testingwith methacholine is generally considered the next diagnosticstep. Numerous alternative methods of bronchoprovocationtesting have been developed, such as the challenge with adenosine5'-monophosphate. Novel methods such as the forced oscillationtechnique and the measurement of exhaled nitric oxidehold promise for more effective diagnosis and monitoringof asthma in the future. (J Respir Dis. 2008;29(4):157-169)

Abstract: Shortness of breath is a common complaint associated with a number of conditions. Although the results of the history and physical examination, chest radiography, and spirometry frequently identify the diagnosis, dyspnea that remains unexplained after the initial evaluation can be problematic. A stepwise approach that focuses further testing on the most likely diagnoses is most effective in younger patients. Early bronchoprovocation challenge testing is warranted in younger patients because of the high prevalence of asthma in this population. Older patients require more complete evaluation because of their increased risk of multiple cardiopulmonary abnormalities. For patients who have multiple contributing factors or no clear diagnosis, cardiopulmonary exercise testing can help prioritize treatment and focus further evaluation. (J Respir Dis. 2006;27(1):10-24)