Reference values of interrupter respiratory resistance in healthy preschool white children

Abstract

Background-Interrupter respiratory resistance (Rint) is reported to be useful in evaluating lung function in poorly collaborating patients. However, no reference values are available from large samples of preschool children using the standard interrupter method. The aim of this study was to define reference Rint values in a population of healthy preschool children. Methods-Rint was assessed without supporting the cheeks in children with no history of wheeze from six kindergartens. To evaluate the eVects of upper airway compliance on Rint in healthy children, an additional group of preschool children with either no history of wheeze or no respiratory symptoms at the time of testing underwent Rint measurements in our lung function laboratory with and without supporting the cheeks. Short term (about 1 minute apart) and long term (mean 2.5 months apart) repeatability of Rint measurements (2 SDs of the mean paired diVerence between measurements) was also assessed in children referred for cough or wheeze. Results-A total of 284 healthy white children (age range 3.0-6.4 years) were evaluated. Mean inspiratory and expiratory Rint (RintI and RintE) did not diVer significantly in boys and girls. Age, height, and weight showed a significant inverse correlation with both RintI and RintE in the univariate analysis with linear regression. Multiple regression with age, height, and weight as the independent variables showed that all three variables were significantly and independently correlated with RintI, whereas only height was significantly and independently correlated with RintE. (Thorax 2001;56:691-695)

Measurements of interrupter resistance: reference values for children 3-13 yrs of age

“…A few studies have reported reference equations for the interrupter technique in young school children [6,7,11,12], but for older children these are lacking. Because of the possible applications of this technique in a larger age range (epidemiological and clinical research, children unable to participate in active lung function measurements), normal values for Rint,e were obtained in 208 healthy Caucasian children aged between 3-13 yrs.…”

“…However, passive measurements of airway function may also be required for clinical research in older children or in older children who are unable to perform forced expiratory manoeuvres because of developmental disorders or neuromuscular disease. Reference data are available for young children [6,7,11,12] and adults [13], but not for children of w7 yrs of age. Therefore, the aim of the present study was to expand the previous data set to better describe relationships between expiratory resistance and body size.…”

Evaluación de la medición de las resistencias pulmonares por técnica de interrupción

“…[4][5][6][7] Además, la mayoría de las publicaciones incluyeron a niños menores de 7 años. El gran número de niños incorporados en este estudio (460), tanto sanos como enfermos, unido a la amplitud del rango de edad (2 a 18 años) hace que las observaciones obtenidas sean …”

“…El porcentaje global de mediciones aceptables fue del 82,6% (72,6% en < 7 años y 91,7% en > 7 años), intermedio entre los porcentajes publicados (64% a 95%). 4,5,25,26 El porcentaje de medidas aceptables en menores de 4 años obtenido es sensiblemente inferior al publicado por otros autores. 4,25 Una explicación es que estos autores no detallan las condiciones de aceptación empleadas para las mediciones.…”

“…Existen valores de referencia para Rint en la población infantil, encontrando una correlación inversa con la talla y la edad. [4][5][6][7][8] A p e s a r d e e l l o , s u u s o n o s e h a extendido, probablemente porque no fue evaluada en forma suficiente.…”