Pulmonary function in hospitalized infants and toddlers with cystic fibrosis.
In older children with cystic fibrosis (CF), well-documented improvements in lung function occur during hospitalization for treatment of pulmonary exacerbations.


OBJECTIVE
(1) To test the hypothesis that improvement in lung function occurs in infants and toddlers hospitalized because of CF pulmonary exacerbations. (2) To compare changes in lung function measured during forced expiratory flow and tidal breathing.


METHODS
Seventeen infants and toddlers with CF were evaluated at the beginning and end of hospitalization by the rapid thoracic compression technique to yield maximal flow at forced residual capacity. Tidal mechanics were measured by the esophageal balloon technique to yield lung conductance and compliance.


RESULTS
Lung function improved during the course of hospitalization. The greatest change was observed in measurements of maximal flow at functional residual capacity (.VmaxFRC), increasing from 38.5% +/- 6% predicted (mean +/- SEM) to 59.8% +/- 6% at the end (p < 0.005). Lung conductance (GL) increased from 60% +/- 6% to 78% +/- 8% (p < 0.02); lung compliance (CL) increased from 66% +/- 5% to 75% +/- 5% (p < 0.03). The degree of improvement of .VmaxFRC, GL, and CL was related to baseline measurements; those with poorer pulmonary function at baseline had the greatest degree of improvement during hospitalization.


CONCLUSIONS
Assessments of airflow obstruction from measurements of .VmaxFRC and GL do not necessarily demonstrate similar findings in a given infant with CF, perhaps because these two techniques measure different physiologic properties. Changes in .VmaxFRC may best reflect the predominant pathophysiology of lung disease in infants and toddlers with CF.
Clayton
R G
RG
Department of Pediatrics, Temple University School of Medicine, St. Christopher's Hospital for Children, Philadelphia, Pennsylvania 19134, USA.
Diaz
C E
CE
Bashir
N S
NS
Panitch
H B
HB
Schidlow
D V
DV
Allen
J L
JL
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001993:Bronchodilator Agents / Q000627:therapeutic use; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000503:physiopathology* / Q000628:therapy; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007902:Length of Stay; D008297:Male; D026741:Physical Therapy Modalities; D012044:Regression Analysis; D012129:Respiratory Function Tests / Q000379:methods*; D015656:Respiratory Mechanics
D000900:Anti-Bacterial Agents; D001993:Bronchodilator Agents