Significance of exhaled breath temperature monitoring during and after acute attack of asthma in children

Objective To observe change of exhaled breath temperature(EBT)during and after acute attack of asthma in children. Methods Totally 30 hospitalized children aged 6 to 12 years due to acute attack of asthma were selected. Changes of EBT, fraction of exhaled nitric oxide(FeNO)and pulmonary function parameters at different time points were compared, and correlations between EBT and FeNO as well as pulmonary function were analyzed. Results There were significant differences in EBT values in children with acute attack of asthma at the time points of the first day after hospital admission, one week after discharge, and one month after discharge(P<0.05). EBT was negatively correlated with forced vital capacity forced expiratory volume to in the first second ratio(FEV₁/FVC)(r=-0.363, P=0.031), but had no correlations with forced vital capacity as a percentage of predicted value(FVC% pred), forced expiratory volume in the first second as a percentage of predicted value(FEV₁% pred)and forced mid-expiratory flow(FEF 25%~75%). There were no correlations between EBT and FeNO at the time points of hospital admission, one week and one month after discharge. Conclusion EBT increases significantly in children with acute asthma, and is negatively correlated with FEV₁/FVC, which can reflect the degree of airway inflammation.