Performance of forced expiratory manoeuvre in children

• Published in: The European respiratory journal Vol. 16; no. 6; pp. 1070 - 1074
• Main Authors: D'Angelo, E, Carnelli, V, Milic-Emili, J
• Format: Journal Article
• Language: English
• Published: Sheffield Eur Respiratory Soc 01.12.2000; Munksgaard International Publishers; Maney
• Subjects: Adolescent; Biological and medical sciences; Child; Detection of flow limitation; Female; Forced Expiratory Flow Rates - physiology; Forced Expiratory Volume - physiology; Humans; Investigative techniques of respiratory function; Investigative techniques, diagnostic techniques (general aspects); Lung Volume Measurements; Male; maximal expiratory flow‐volume curve; Medical sciences; negative expiratory pressure; normal values; Predictive Value of Tests; Pulmonary Ventilation - physiology; Reference Values; upper airway collapsibility; Vital Capacity - physiology; Human; Lung function; Exploration; Vital capacity; Expiratory flow rate; Forced expiration; Child
• ISSN: 0903-1936; 1399-3003
• DOI: 10.1034/j.1399-3003.2000.16f09.x

The negative expiratory pressure (NEP) method has been previously used to assess the performance of forced vital capacity (FVC) manoeuvre in normal adults. The aim of the present study is to assess whether flow limitation is achieved during FVC manoeuvres in children aged 6–14 yrs. NEP (‐10 cmH2O) was successfully applied in 177 normal children, the portion of FVC over which expiratory flow did or did not change with NEP being taken as effort‐dependent and effort‐independent, respectively. In all children peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1) increased with NEP, indicating that PEF was in the effort‐dependent portion of FVC. This portion decreased significantly with age (50–20% of FVC from 6–14 yrs). It is suggested that this mainly reflects the poorer coordination of specialized motor acts in younger children because of incomplete morphological and functional maturation of the relevant central nervous system (CNS) mechanisms. The results indicate that most unexperienced children aged 6–14 yrs can perform acceptable forced vital capacity manoeuvres, eventually achieving flow limitation over a portion of the forced vital capacity that increases with age. The negative expiratory pressure method can be used for online assessment of the performance of forced vital capacity manoeuvres and evaluation of treatment‐related effects.