Comparison of Subjective and Objective Measures in Recurrently Wheezy Infants

Objectives: 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 t ) and maximal flow at functional residual capacity v̇ max FRC) in recurrently wheezy infants. Methods: 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 t were obtained by the raised volume rapid thoracic compression technique (RVRTC) and v̇ max FRC by the tidal volume rapid thoracic compression technique (TVRTC). Results: Mean FEV t but not mean v̇ max FRC were significantly lower at visit 2 compared to visit 3 (FEV 0.5 : p = 0.005, and FEV 0.75 : p = 0.002; v̇ max FRC: p = 0.15) and correlated well with overall health assessment by the study physician (FEV 0.5 : r = 0.82, and FEV 0.75 : r = 0.84), but not with the overall health assessment by the mother. Conclusions: We have shown in the present study that objective measurements of FEV t from a raised lung volume correlate well with the overall health assessment by the study physician; this was in contrast to measurements of v̇ max 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.