Use of lung clearance index to assess the response to intravenous treatment in cystic fibrosis.

BACKGROUND

Progressive lung disease is the main cause of clinical deterioration and mortality in cystic fibrosis (CF) patients. Being able to assess the effectiveness of interventions is very significant.

OBJECTIVES

To assess the response to intravenous (IV) treatment among CF patients, using forced expired volume in 1(st) second (FEV1) and Lung Clearance Index (LCI) as outcome measures and to compare the effect of IV treatment on lung function and LCI between CF children being treated on a regular basis, or in case of a pulmonary exacerbation.

SUBJECTS AND METHODS

Thirty-two CF patients (15 males) with mean age 9.90 (range: 2-23) years, performed spirometry and multiple breath washout (MBW) before and one month after IV antibiotic treatment. Nineteen patients received a course of elective treatment (group A) and 13 received IV antibiotic regimens for an acute exacerbation (group B).

RESULTS

Statistically significant differences after treatment were seen in LCI (p≤0.001), and Forced Expiratory Flow (FEF) z-scores (p<0.05). FEV1 did not change significantly after drug intervention. Dividing patients into two groups, only LCI showed significant change (p<0.05), when treatment was administered on a regular basis. Patients being treated for an acute pulmonary exacerbation showed significant improvement in most of the lung function parameters: LCI (p=0.0001), FEV1% (p=0.05), FEV1 z-score (p=0.033) and FEF25-75 (p=0.046). The mean LCI difference was significantly greater in group B compared to group A (p=0.001).

CONCLUSION

LCI is more sensitive marker than FEV1 to assess the effect of IV antibiotic treatment among CF children. IV antibiotics are more effective on lung function parameters, when they are administered for an acute exacerbation, than when they are given on a regular basis. Hippokratia 2015, 19 (1): 47-52.