• plethysmography;
  • early childhood;
  • functional residual capacity;
  • asthma;
  • hemato-oncological diseases



Measurement of FRC in whole body plethysmography (FRCpleth) is not performed in young children (aged 3–5 years) because it involves sitting alone in a closed box and breathing attempts against occlusion.


To assess the feasibility of measuring FRCpleth in young children.

Methods and Results

Seventy-one of 102 children (age range 3.3–6.9 years) performed spirometry and FRCpleth measurements. Twenty-six children had controlled asthma (Group-A); 26 children were tested during asthma exacerbation had uncontrolled asthma (Group-UA), and 19 children were tested after receiving chemotherapy treatment (Group-C). Tests according to adult recommendations were first taught outside the plethysmograph and then performed with minor technical adaptations. Each test included two consecutive FRC measurements obtained during 2–3 sec of occlusion. Total lung capacity (TLC) and residual volume (RV) were calculated. Values were compared to FRC measured by Helium-dilution (FRC-He) in healthy preschool children and to extrapolated FRCpleth values of school children, and between the groups.


Group-A showed normal spirometry and normal TLC values, with mildly elevated FRCpleth and RV values (125 ± 20 and 153 ± 33 %predicted, respectively; P < 0.0001 for both values). Group-UA showed obstructed flows combined with high FRCpleth and RV (146 ± 26 and 189 ± 38 %predicted; P < 0.0001) and normal TLC. Group-C showed a restrictive spirometry pattern combined with lower than normal TLC (86  ±  15 %predicted; P < 0.0251).


Measuring absolute lung volumes by plethysmography in young children is feasible and can detect abnormal lung volumes. It is essential to study a larger group of healthy children for reference values and to allow for standardization of the procedure. Pediatr Pulmonol. 2009; 44:885–891. © 2009 Wiley-Liss, Inc.