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 greater than 42 mm Hg) and/or severe hypoxemia (Pao2 less than 60 mm Hg) had a PEFR below 200 L/min, or an FEV1 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.
Subject(s)
Asthma/diagnosis , Blood Gas Analysis , Carbon Dioxide/blood , Oxygen/blood , Respiratory Function Tests , Acute Disease , Adolescent , Adult , Asthma/blood , Asthma/therapy , Humans , Hydrogen-Ion Concentration , Partial Pressure , Prognosis , Prospective StudiesABSTRACT
One hundred nine episodes of acute bronchial asthma were studied utilizing PEFR and FEV1 measurements to determine objective patient disposition criteria. Of patients with both a pre-treatment PEFR less than 100 L/min, and a post-treatment value less than 300 L/min, 92% required admission or had an unsuccessful OPD course. Of patients with a pre-treatment PEFR less than 100 L/min and an improvement less than 60 L/min after initial terbutaline, 85% were admitted or had problems after discharge. PEFR correlated well with FEV1 at all stages of treatment.
