Assessment and Diagnostic Tools

While laboratory testing is not definitive for diagnosing asthma exacerbations, certain tests can help exclude alternative diagnoses, such as measuring BNP for heart failure or D-dimer for pulmonary embolism in select patients. Assessments like venous blood gas (VBG) can provide significant insights, particularly in identifying hypercarbia, with low PCO2 initially indicating tachypnea and potential deterioration as PCO2 increases during more severe episodes. Capnography can further assist in assessing respiratory status by measuring end-tidal CO2 levels, which inform on ventilation efficacy. Point-of-care ultrasound emerges as a beneficial tool in evaluating lung and heart conditions rapidly, and while routine chest X-rays are typically unnecessary, they are warranted when specific complications or alternative diagnoses are suspected.