Applicability of interrupter resistance measurements using the MicroRint® in daily practice

AbstractThis study was performed to evaluate the applicability of a simple device (MicroRint®) for measuring airway resistance, to derive normal values and to compare values with maximal expiratory flow volume (MEFV) parameters in asthmatic and healthy children. Repetitive Rint measurements were performed in 125 healthy children and 107 asthmatic children (age range 0.8–16.8 years). In 42 asthmatic patients Rint and MEFV values were compared and in 29 asthmatic children bronch-odilation testing was performed. Successful Rint measurements were possible in 91% of the children. The mean coefficient of variation of repeated measurements was 7.1(±6.1)%. Rint values of healthy children showed a significant curvilinear correlation with age (r=−0.80, P<0.001) and height (r=−0.81, P<0.001). In asthmatic and healthy children Rint values were comparable. A significant inverse correlation was found betweenRint and MEFV values (for FEV1 and Rintr=−0.80,P