A detailed medical history often identifies the primary process resulting in dyspnea. 345and 6 Patients often have underlying chronic disorders and can frequently specifically and accurately self-diagnose their exacerbations. The medical history should include recent infectious and environmental exposures that may impair respiratory function. Patients who require daily medications for symptom control should be questioned carefully about compliance and possible drug interactions.
A number of ancillary tests aid in determining the severity and specific cause of dyspnea. Pulse oximetry is a rapid but insensitive screening test for disorders of gas exchange, and results may be normal in acute dyspnea. Arterial blood gas (ABG) analysis is more sensitive for detecting impaired gas exchange, but results may also be normal in acute dyspnea, and ABG analysis cannot evaluate the work of breathing. Rarely, patients who appear dyspneic or tachypneic but who exhibit no evidence of hypoxia or pulmonary disease are shown to be hyperventilating from metabolic acidosis on ABG testing. A chest radiograph may indicate the general category of primary disease (infiltrate, effusion, and pneumothorax) but also may be normal. Bedside spirometric analysis (peak expiratory flow, or PEF) before and after bronchodilator therapy can be used to diagnose and treat dyspnea resulting from asthma or CoPD, although it requires voluntary effort that might be difficult for dyspneic patients. other potentially useful tests include an electrocardiogram and determination of hemoglobin level. Uncommonly, the specific process resulting in dyspnea cannot be identified by the history, the physical examination, and these simple ancillary tests, and specialized testing, including cardiac stress testing, echocardiography, formal pulmonary function testing, computed tomography scanning of the chest, or combined cardiopulmonary exercise testing, is indicated.
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If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.