Clinical scoring does not accurately assess hypoxemia in pediatric asthma patients

Management of acute asthma in the pediatric population is based almost entirely on clinical evidence of severity. Although pulmonary function testing has been advocated to improve evaluation, it is difficult in the pediatric patient and not routinely practiced. A clinical scoring system has been devised to help standardize evaluation, but has not been validated by comparison of the results of clinical scoring with those of arterial blood oxygen levels as determined by blood gas analysis. This study was undertaken to compare clinical scoring of pediatric asthma patients with the results of arterial blood gas analysis. Thirty-eight children between the ages of 2 and 13 having 42 episodes of acute asthma were evaluated. The average age was 5.4 years. The average clinical score was 2.62; arterial blood for analysis was obtained in 37 (88%), with an average PaO2 of 81.7 mm Hg. None of the children had CO2 retention. There was no correlation between the clinical score of the children on presentation and the severity of hypoxia (correlation coefficient = -0.149). Comparison of age and arterial oxygen tension revealed a trend toward worsening hypoxemia with diminishing age from 6 to 2 years, which was not identified by clinical scoring. We conclude that clinical scoring is inaccurate for the assessment of hypoxemia in the pediatric age group. Arterial blood gas determination should be used to assess the severity of hypoxemia in the emergency treatment of pediatric asthma patients.