Arterial Blood Gases and Pulmonary Function Testing in Acute Bronchial Asthma

Abstract

Pretreatment and posttreatment arterial blood gas and pulmonary function testing measurements were prospectively compared as to their ability to assess asthma severity accurately and, thus, predict the outcome in 102 episodes of acute bronchial asthma initially seen in the emergency department. The Pao₂, Paco₂, or pH was unable to separate these patients requiring admission from those that could be confidently discharged, while the 1-s forced expiratory volume (FEV₁) and peak expiratory flow rate (PEFR) did so both before and after treatment. Furthermore, virtually all patients with hypercarbia (Paco₂>42 mm Hg) and/or severe hypoxemia (Pao₂,below 1.0 L. Thus, selective use of arterial blood gas analysis should substantially decrease both diagnostic cost and patient discomfort without jeopardizing health care. (JAMA1983;249:2043-2046)