Do NHLBI lung function criteria apply to children? A cross‐sectional evaluation of childhood asthma at National Jewish Medical and Research Center, 1999–2002

Abstract

Although National Heart Lung Institute (NHLBI) guidelines categorize asthma severity based on spirometry, few studies have evaluated the utility of these spirometric values in grading asthma severity in children. Asthma is thought to be progressive, but little is known about the loss of lung function in childhood. This study sought to determine the spirometric indices in children from 4-18 years of age. Retrospective cross-sectional analysis was performed on all spirometries done in children at the National Jewish Medical and Research Center from 1999-2002. In total, 2,728 children performed 24,388 measures. The mean +/- SD values for forced vital capacity (FVC), forced expired volume in 1 sec (FEV(1)), FEV(1)/FVC ratio, and forced expiratory flow (FEF)(25-75) were 92.7 +/- 16.2, 92.2 +/- 18.0, 85.3 +/- 9.3, and 78.0 +/- 36.5 percent predicted, respectively. Seventy-seven percent of FEV(1) values were >/= 80%, 18.6% were between 60-80%, and 3.1% were <60% of predicted. FEV(1) was highest in 5-year-old children; it declined thereafter, reaching a nadir at 11 years, followed by a partial recovery from 12-18 years. Expressed in liters, FEV(1) values were lower than expected at every age, with the greatest difference at 18 years. FEV(1)/FVC ratios declined through childhood, suggesting impaired airway but not lung growth in children with asthma. In conclusion, the majority of asthmatic children attending a tertiary care facility had FEV(1) values within normal range. With increasing age, the increase in FEV(1) lags behind that of nonasthmatics, so that by 18 years, maximum FEV(1) is impaired. The NHLBI FEV(1) cutoff values do not appear to accurately stratify pediatric asthma, and no useful FEV(1) cutoff could be generated.

Monitoring asthma in childhood: lung function, bronchial responsiveness and inflammation

“…However, there is insufficient data on the value of parameters of more peripheral airways, such as the forced expiratory flow at 50% of FVC (FEF50%) and/or forced expiratory flow at 25-75% FVC (FEF25-75%), in the monitoring of asthma in children. A large, retrospective cross-sectional analysis of the mean FEV1/FVC ratios from 4-18 years of age demonstrated a steep and consistent decline with increasing age in asthmatic children suggesting the FEV1/FVC ratios provide greater sensitivity in childhood asthma compared with FEV1 [18].…”

From asthma severity to control: a shift in clinical practice

“…12,13,[15][16][17] This discord between the clinical presentation and level of lung functionwhich is an important factor in the severity grading -can complicate the assessment of severity, leading to underestimation of disease severity and under-treatment with subsequent poor asthma control. This may contribute to the findings that a substantial number of children with fatal asthma exacerbations had been assessed as having mild disease and were not prescribed regular controller treatment.…”

Study on to assess pulmonary function test changes in asthmatic child using spirometry and its diagnostic and prognostic value

“…In the present study, the clinical and spirometry diagnosis of moderate asthma showed total positive correlation (100% [34][35][36] In asthma diffuse narrowing of the airways results in profound physiologic consequences. This narrowing has been thought an occur disproportionately in the small bronchi 37 .…”