Introduction Rheology can be a tool to diagnose COPD and assess the efficiency of treatments on market or in development, by evaluating the consistency of sputum. Rheology allows a better understanding of the expectoration deficiencies in patients with COPD. The study aims to find out whether rheology can be used in a clinical context.
Material & Methods The Rheomuco device was used to measure the viscoelastic properties in a clinical study (NCT02682290) called “Assessment of Rheological Parameters of Human Sputum”. Two properties are mainly extracted: elastic modulus (G’) at 1Hz and viscous modulus (G’’) at 1Hz. The study was led by and in the Grenoble University Hospital (France) with 3 groups: 10 COPD, 10 ASH and 10 HV. The study is still going on and will end by late July 2017. During the visits, COPD, ASH and HV have a spontaneous expectoration and an induced expectoration with hypertonic saline solution (4.5%). Partial Results & Analysis The Figure shows that COPD group is significantly different from HV and ASH.
Extra results show that hypertonic saline solution reduces G’ by 56% and G’’ by 48% for COPD, and the rheological behavior tends to HV one. Sputum in general are more viscous than elastic, and those properties can cluster COPD patients. Conclusion Rheology can be used as a tool to diagnose and monitor treatment efficiency for COPD.