Use of pulse oximetry in the hospital management of acute asthma in childhood.

Oxyhemoglobin saturation values were recorded before and 10 minutes after 5 mg of nebulized salbutamol in 75 children (age, 1.5-14.6 years) admitted to hospital with acute asthma. Other assessments included heart rate, respiratory rate, peak expiratory flow rate, pulsus paradoxus, and an asthma severity score. All assessments were performed by the same observer (GC) and subsequent hospital care was transferred to the on-call pediatricians, who were not told the initial saturation values. Six children required intravenous therapy after hospital admission when their symptoms were not improved after nebulized salbutamol. Cutoff points for each continuous variable were selected so that they identified at least 5 of these 6 children (i.e., with a sensitivity of at least 83 percent). The resulting specificities and positive predictive values were calculated for each variable before and after nebulized therapy. A postnebulizer saturation of less than 91% had a sensitivity of 100% [95% confidence interval (CI), (54-100] with a specificity of 98% (95% CI, 92-100) and a positive predictive value of 86%. This was the best predictor of the need for intravenous (IV) therapy. Correlation coefficients were calculated for the 75 admissions and 2 others who required immediate IV treatment to determine how closely saturation values were related to the other recorded clinical variables. Saturation values were significantly, though weakly, correlated with asthma severity scores and prenebulizer heart rate, but they were not associated with any of the other variables. These results highlight the difficulties encountered when assessing acute asthma in a hospital population with a large number of preschool children.(ABSTRACT TRUNCATED AT 250 WORDS)