Prospective longitudinal evaluation of lung function during the first year of life after extracorporeal membrane oxygenation.

OBJECTIVE: To collect longitudinal data on lung function in the first year of life after extracorporeal membrane oxygenation and to evaluate relationships between lung function and perinatal factors. Longitudinal data on lung function in the first year of life after extracorporeal membrane oxygenation are lacking. DESIGN: Prospective longitudinal cohort study. SETTING: Outpatient clinic of a tertiary level pediatric hospital. PATIENTS: The cohort consisted of 64 infants; 33 received extracorporeal membrane oxygenation for meconium aspiration syndrome, 14 for congenital diaphragmatic hernia, four for sepsis, six for persistent pulmonary hypertension of the neonate, and seven for respiratory distress syndrome of infancy. Evaluation was at 6 mos and 12 mos; 39 infants were evaluated at both time points . INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Functional residual capacity and forced expiratory flow at functional residual capacity were measured and expressed as z score. Mean (sem) functional residual capacities in z score were 0.0 (0.2) and 0.2 (0.2) at 6 mos and 12 mos, respectively. Mean (sem) forced expiratory flow was significantly below average (z score = 0) (p < .001) at 6 mos and 12 mos: -1.1 (0.1) and -1.2 (0.1), respectively. At 12 mos, infants with diaphragmatic hernia had a functional residual capacity significantly above normal: mean (sem) z score = 1.2 (0.5). CONCLUSIONS: Infants treated with extracorporeal membrane oxygenation have normal lung volumes and stable forced expiratory flows within normal range, although below average, within the first year of life. There is reason to believe, therefore, that extracorporeal membrane oxygenation either ameliorates the harmful effects of mechanical ventilation or somehow preserves lung function in the very ill neonate.

Methodological aspects of exhaled nitric oxide measurements in infants.

Guidelines for the measurement of fractional exhaled nitric oxide (FE(NO)) recommend refraining from lung function tests (LFT) and certain foods and beverages before performing FE(NO) measurements, as they may lead to transiently altered FE(NO) levels. Little is known of such factors in infants. The aim of the present study was to evaluate whether forced expiratory maneuvers, sedation, nasal contamination, and breastfeeding affect FE(NO) values in infants. FE(NO) was measured off-line during tidal breathing by means of a facemask covering nose and mouth. FE(NO) measurements were performed in 45 sedated infants (mean age 12.1 months) who underwent LFT because of airway diseases and in 83 unsedated healthy infants (mean age 4.3 months). In infants with airway diseases, no difference was found in FE(NO) values before and 5 min after LFT (n = 19 infants, p = 0.7) and FE(NO) values before sedation did not differ from FE(NO) values during sedation (n = 10 infants, p = 0.2). Oral FE(NO) values were significantly lower than mixed (nasal + oral) FE(NO) (n = 42 infants, p < 0.001). FE(NO) values before and 5 min after breastfeeding were not different (n = 11 healthy infants, p = 0.57). The short-term reproducibility in healthy infants (n = 54) was satisfactory (intraclass correlation coefficient = 0.94). We conclude that, in infants with airway diseases, LFT prior to FE(NO) measurement did not influence FE(NO) values and FE(NO) values did not change after sedation. Oral FE(NO) values were significantly lower than mixed (oral + nasal) FE(NO), and breastfeeding did not influence FE(NO). Short-term reproducibility in awake healthy infants was good.

Exhaled nitric oxide differentiates airway diseases in the first two years of life.

Fractional exhaled nitric oxide (FE(NO)) levels are increased in children and adults with asthma, whereas low levels have been found in cystic fibrosis and primary ciliary dyskinesia. The aim of this study was to investigate whether FE(NO) measurements could distinguish between children below the age of 2 with different airway diseases. FE(NO) measurements were performed in 118 infants aged between 4.6 and 25.2 mo: 74 infants with recurrent wheezing (RW), 24 with bronchopulmonary dysplasia (BPD), and 20 with cystic fibrosis (CF). FE(NO) was measured also in 100 healthy controls aged between 1.1 and 7.7 mo. Geometric mean (95% confidence interval) FE(NO) values were 10.4 (9.1-12.0) parts per billion (ppb) in healthy infants, 18.6 (15.6-22.2) ppb in wheezy infants, 11.7 (8.2-16.8) ppb in BPD infants and 5.9 (3.4-10.1) ppb in CF infants. FE(NO) in wheezers was higher than in controls, BPD, and CF (p = 0.009, p = 0.038, and p < 0.001, respectively). Atopic wheezers showed higher FE(NO) than nonatopic wheezers (p = 0.04). CF infants had lower FE(NO) than healthy controls and BPD infants (p = 0.003 and p = 0.043, respectively). FE(NO) values in BPD and control infants were not different. We conclude that FE(NO) is helpful to differentiate various airway diseases already in the first 2 y of life.

Efficacy of fluticasone propionate on lung function and symptoms in wheezy infants.

The role of inhaled corticosteroids in the treatment of recurrent or persistent wheeze in infancy remains unclear. We evaluated the effect of 3 months of treatment with inhaled fluticasone propionate, 200 microg daily (FP200), on lung function and symptom scores in wheezy infants. Moreover, we evaluated whether infants with atopy and/or eczema respond better to FP200 as compared with non-atopic infants. Forced expiratory flow (Vmax(FRC)) was measured at baseline and after treatment. Sixty-five infants were randomized to receive FP200 or placebo, and 62 infants (mean age, 11.3 months) completed the study. Mean Vmax(FRC), expressed as a Z score, was significantly below normal at baseline and after treatment in both groups. The change from baseline of Vmax(FRC) was not different between the two treatment arms. After 6 weeks of treatment, and not after 13 weeks, the FP200 group had a significantly higher percentage of symptom-free days and a significant reduction in mean daily cough score compared with placebo. Separate analysis of treatment effect in infants with atopy or eczema showed no effect modification. We conclude that in wheezy infants, after 3 months of treatment with fluticasone, there was no improvement in lung function and no reduction in respiratory symptoms compared with placebo.