Comparison of Subjective and Objective Measures in Recurrently Wheezy Infants

Abstract

<i>Objectives:</i> The aim of this study was to compare subjective measures (overall health assessment both by the study physician and the child’s mother) with objective measurements of forced expiratory volumes (FEV<sub>t</sub>) and maximal flow at functional residual capacity v̇<sub>max</sub>FRC) in recurrently wheezy infants. <i>Methods:</i> Sixteen wheezy infants (12 boys) aged 8–26 months were studied. A clinical assessment at visit 1 was followed by the run-in period during which day- and nighttime asthma symptom scores were obtained. The actual study period consisted of 2 visits when patient’s lung function was assessed. The first of which was during an acute exacerbation (visit 2), while the second was when the infant was asymptomatic (visit 3). FEV<sub>t</sub> were obtained by the raised volume rapid thoracic compression technique (RVRTC) and v̇<sub>max</sub>FRC by the tidal volume rapid thoracic compression technique (TVRTC). <i>Results:</i> Mean FEV<sub>t</sub> but not mean v̇<sub>max</sub>FRC were significantly lower at visit 2 compared to visit 3 (FEV<sub>0.5</sub>: p = 0.005, and FEV<sub>0.75</sub>: p = 0.002; v̇<sub>max</sub>FRC: p = 0.15) and correlated well with overall health assessment by the study physician (FEV<sub>0.5</sub>: r = 0.82, and FEV<sub>0.75</sub>: r = 0.84), but not with the overall health assessment by the mother. <i>Conclusions:</i> We have shown in the present study that objective measurements of FEV<sub>t</sub> from a raised lung volume correlate well with the overall health assessment by the study physician; this was in contrast to measurements of v̇<sub>max</sub>FRC in the tidal volume range. We therefore conclude that the RVRTC technique is a feasible method to assess and monitor obstructive lung disease in infancy.