Single Breath Counting for Diagnosis and Prediction of Severity of Acute Asthma Exacerbation in Children

Objectives To find correlation between single breath counting (SBC) and spirometry in acute exacerbation of asthma in children. Methods A cross-sectional observational study including all children aged 6–12 y age, who presented in outpatient department or emergency room with acute exacerbation of asthma, not fitting in exclusion criteria were enrolled. SBC and spirometry parameters were obtained before treatment and 1 h after initiating treatment (GINA 2017 Guidelines). Results Significant correlation was observed in SBC and FVC ( r = 0.349), FEV 1 ( r = 0.439), FEF 25-75 ( r = 0.424), and PEF ( r = 0.593). Cutoff value of SBC of 23 was found to be suggestive of severe/life-threatening asthma with sensitivity of 83.3% and specificity of 84.4%. No significant association was found between percent change in SBC and spirometry parameters in response to treatment. Conclusions SBC can be used to predict PEF, FEV 1 , FVC, and FEF 25-75 of a patient aged between 6 and 12 y during acute asthma exacerbation. The observed cutoff value of 23 of SBC score has a good sensitivity and specificity to identify life-threatening/severe exacerbation. SBC score significantly increases in response to therapy.