The role of the multiple breath washout outcomes in the prediction of exacerbation in Iranian children with cystic fibrosis

Background: The early determination and treatment of lung exacerbation have a significant role in increasing the health and quality of life in patients with cystic fibrosis. The Multiple-breath washout (MBW) technique was used to discriminate between health and disease of the lungs recently, however, its role in the prediction of upcoming exacerbation is not clear .This study aims to clarify this ambiguity. Methods: : We recruited 60 clinically stable children with cystic fibrosis who were coming to the CF clinic for periodic care. In addition to the routine pulmonary function tests (PFT), we performed MBW technique for all subjects as an annual assessment. Subsequently, in the follow-up period, we admitted all patients who had experienced exacerbation within two weeks after the MBWT for proper antimicrobial therapy. During admission, we reevaluated the PFT results of hospitalized subjects and compared them with the PFT results of subjects who had no exacerbation. Results: : Overall 55 subjects finished the trial; 18 cases (32.7%) were hospitalized and 37 patients (67.3%) were not hospitalized. The LCI5% variable had no significant difference between hospitalized and non-hospitalized groups. The median of the LCI2.5% in the hospitalized group (13.26) was greater than in the non-hospitalized group(7.82), this difference was statistically significant (P = 0.0001). The mean value of M2 /M0 in hospitalized patients (16.31) was greater than in non-hospitalized patients (5.97) and this difference was statistically significant (P = 0.0001). Conclusion: Our study outcomes had a valuable ability to predict exacerbation, however, this hypothesis requires further studies with larger sample sizes.