Spirometry is a widely known clinical pulmonary test measuring volumes and flows expired by patients that is used to confirm a diagnostic of respiratory disease or follow treatment. SCIREQ’s flexiVent’s offers an analogous test for preclinical research with its Negative Pressure Forced Expiration (NPFE) extension. By exposing the subject’s airway opening to a negative pressure to rapidly draw out air from the lungs, the system can generate flow-volume loops or volume-time plots, from which the flexiWare software can then extract clinically relevant volume and flow parameters (e.g. FEVx, FEFx, FVC, PEF).
A recent publication by Devos et al.1 characterized forced expiration measurements in some well-established mouse models of lung diseases, which specific phenotypes were confirmed by a concomitant respiratory mechanics assessment. The researchers observed that disease-induced changes in forced expiration-related charts and parameters were generally similar to what was observed in the clinic. For example, when compared to a control group of healthy mice.
- Mice with fibrosis exhibited a typical restrictive profile, with a reduced PEF & FVC and a normal FEV0.1/FVC ratio.
- Mice with emphysema displayed a decrease in PEF characteristic of an obstructive phenotype.
- Mice presenting an acute lung injury had significantly reduced PEF.
- Mice with features of asthma showed a decrease in FEV0.1 following methacholine challenges.
SCIREQ’s flexiVent is the first platform that allows forced expiratory manoeuvres to be performed side-by-side with respiratory mechanics, pressure-volume loops, or lung volume measurements in mice and rats. This unique feature enables a refined study design with outcomes susceptible to translate between preclinical research and clinical settings.
1Devos, FC et al. 2017. Forced expiration measurements in mouse models of obstructive and restrictive lung diseases. Respiratory Research 18: 123.