Rapid and portable MBW measurements for clinical application of LCI in routine clinics

Gilchrist

Abstract

Background: Assessment of lung clearance index (LCI) is typically a prolonged process (>20mins), performed in physiology labs. This has hindered routine clinical application and restricted repeat assessments to annual reviews. We have developed a portable (battery-assisted) LCI system that measures LCI using a closed circuit washin. This requires no external gas source or power supply and can be taken to patients for routine measurement of LCI in clinic (www.LCI-SEARCH.com). In this report we have assessed test time and success rates for first assessment in predominantly MBW-naïve children and adults

Methods: LCI was performed in 85 CF patients (40 adults), median age 15yrs (range 5-63yrs). Patients had mild-moderate CF (median FEV1 92% predicted, range 46-119%) and were free of chronic infection with Pseudomonas. Test time was taken from the washout file, and includes time between repeats but does not include time to explain procedures beforehand. 10 adult patients had experienced MBW previously, all other patients were new to the measurement.

Results: Median (IQR) test time was 14.8 (12.6-17.9) mins in children and 22.3 (20.8-25.1) mins in adults. Overall, 57% completed 3 washouts in under 20mins. Median CoV of FRC repeats was 5.4%, LCI 4.6%. 1 adult and 2 children (both 5yrs) were unable to complete LCI. Overall, 15 washout repeats were subsequently discarded for technical reasons/leak: success rate 94%.

Discusssion: As well as allowing development of a fully portable system, closed circuit washin permits rapid test times, and triplicate measurements in a clinically feasible time period for routine testing. Test times are longer in adults and those with more severe disease.

Citation

Gilchrist. Rapid and portable MBW measurements for clinical application of LCI in routine clinics. Presented at ERS Lung Science Conference 2016

• Conference Name: ERS Lung Science Conference 2016
• Acceptance Date: Sep 1, 2016
• Publication Date: Sep 1, 2016
• Publisher URL: https://erj.ersjournals.com/content/48/suppl_60/PA1847