Pulmonary function testing with tidal breath analyze technique is useful in predicting persistant small airway damage in infants with acute bronchiolitis

Infant lung function and early skin barrier impairment in the development of asthma at age 3 years

BACKGROUND

Largely unexplored, we investigated if lower lung function, impaired skin barrier function by transepidermal water loss (TEWL), eczema, and filaggrin (FLG) mutations in infancy were associated with asthma in early childhood.

METHODS

From the factorially designed randomized controlled intervention study PreventADALL, we evaluated 1337/2394 children from all randomization groups with information on asthma at age 3 years, and at age 3 months either lung function, TEWL, eczema, and/or FLG mutations. Lower lung function was defined as the time to peak tidal expiratory flow to expiratory time (tPTEF /tE ) <0.25, and skin barrier impairment as a high TEWL >9.50 g/m2 /h. Eczema was clinically observed, and DNA genotyped for FLG mutations. Asthma was defined as asthma-like symptoms (≥3 episodes of bronchial obstruction) between age 2-3 years as well as a history of doctor-diagnosed asthma and/or asthma medication use. Associations were analyzed in logistic regression models, presented with adjusted ORs (aOR) and 95% confidence intervals (CI).

RESULTS

Lower lung function and skin barrier impairment were associated with asthma in general; aOR (95% CI) 5.4 (2.1, 13.7) and 1.6 (1.1, 2.5), while eczema and FLG mutations were associated with asthma in children with atopic dermatitis or allergic sensitization only. Stratifying for sex, the risk of asthma was only increased in boys with lower lung function; aOR (95% CI) 7.7 (2.5, 23.6), and in girls with FLG mutations; aOR (95% CI) 3.5 (1.5, 8.2).

CONCLUSION

Lower lung function and impaired skin barrier function in infancy may increase the risk of asthma at age 3 years.

Beyond the Skin: Reduced Lung Function Associated With Atopic Dermatitis in Infants

BACKGROUND

Very few studies have examined lung function parameters using tidal breath analysis (TBA) in atopic dermatitis (AD) with its high potential for progression to asthma.

OBJECTIVE

To measure lung functions using TBA in infants with AD and in healthy controls (HCs), and to investigate the effects of disease severity, food sensitivity, and history of recurrent wheezing on TBA parameters in infants with AD.

METHODS

Two hundred thirty infants were included in this prospective cross-sectional study, including an AD group (n = 150) and an HC group (n = 80). Food sensitivity was assessed by means of food-specific IgE or the skin prick test. The severity of the disease was evaluated using the SCORing Atopic Dermatitis. Lung function was assessed using TBA.

RESULTS

The following TBA parameters were significantly lower in the AD group than in the HC group (P < .05): time to peak tidal expiratory flow, exhaled volume to peak tidal expiratory flow, ratio of time to peak tidal expiratory flow to expiratory time, ratio of exhaled volume to peak tidal expiratory flow to total expiratory volume, expiratory flow when 25% of tidal volume remains in the lungs, respiratory rate, and minute ventilation. No difference was observed in the AD group when TBA parameters were compared according to disease severity, food sensitivity, and history of recurrent wheezing (P > .05). The receiver-operating characteristic curve demonstrated by the ratio of time to peak tidal expiratory flow to expiratory time yielded an area under the curve of 0.826 (CI, 0.772-0.879), with a cutoff value of 31.65 or higher in differentiating AD, with a sensitivity of 78.7% and a specificity of 77.5%.

CONCLUSIONS

TBA curves can be a useful tool for demonstrating expiratory airway obstruction in AD and for providing objective information for the clinician. Bronchial obstruction was detected in young children with AD irrespective of the severity of the disease, food sensitivity, and history of recurrent wheezing.

Neonatal nutritional risk and pulmonary function

INTRODUCTION

The neonatal period is a critical initial stage of postnatal lung development and maturation. This study aimed to investigate the effects of the nutritional status on pulmonary function in late preterm and full-term neonates.

METHODS

A total of 172 newborns were included in the study. Nutritional risk screening, weight measurement, assessment of albumin and caloric intake, and a pulmonary function examination were conducted on the 7th day after birth.

RESULTS

There was a significant correlation between the nutritional risk and changes in body weight. Tidal volume (VT), minute ventilation (MV), VT per kg body weight (VT/kg), and MV per kg body weight (MV/kg) in the low nutritional risk group were significantly higher than those in the medium nutritional risk group (all P < .05). Albumin and caloric intake in the low nutritional risk group were significantly higher than those in the medium nutritional risk group (both P < .01). VT, VT/kg, MV, and MV/kg in the weight loss group were lower than those in the no weight loss group (all P < .05).

CONCLUSIONS

Changes in neonatal weight mainly affect lung volume (VT, VT/kg, MV, and MV/kg), suggesting that an improvement in the neonatal nutritional status is important for the development of lung volume.

Respiratory Oscillometry in Newborn Infants: Conventional and Intra-Breath Approaches

BACKGROUND

Oscillometry has been employed widely as a non-invasive and standardized measurement of respiratory function in children and adults; however, limited information is available on infants.

AIMS

To establish the within-session variability of respiratory impedance (Zrs), to characterize the degree and profile of intra-breath changes in Zrs and to assess their impact on conventional oscillometry in newborns.

METHODS

109 healthy newborns were enrolled in the study conducted in the first 5 postpartum days during natural sleep. A custom-made wave-tube oscillometry setup was used, with an 8-48 Hz pseudorandom and a 16 Hz sinusoidal signal used for spectral and intra-breath oscillometry, respectively. A resistance-compliance-inertance (R-C-L) model was fitted to average Zrs spectra obtained from successive 30-s recordings. Intra-breath measures, such as resistance (Rrs) and reactance (Xrs) at the end-expiratory, end-inspiratory and maximum-flow points were estimated from three 90-s recordings. All natural and artifact-free breaths were included in the analysis.

RESULTS

Within-session changes in the mean R, C and L values, respectively, were large (mean coefficients of variation: 10.3, 20.3, and 26.6%); the fluctuations of the intra-breath measures were of similar degree (20-24%). Intra-breath analysis also revealed large swings in Rrs and Xrs within the breathing cycle: the peak-to-peak changes amounted to 93% (range: 32-218%) and 41% (9-212%), respectively, of the zero-flow Zrs magnitude.

DISCUSSION

Intra-breath tracking of Zrs provides new insight into the determinants of the dynamics of respiratory system, and highlights the biasing effects of mechanical non-linearities on the average Zrs data obtained from the conventional spectral oscillometry.

Association of breastfeeding with tidal breathing analysis in infants with bronchiolitis

BACKGROUND

Tidal breathing flow-volume (TBFV) analysis provides important information about lung mechanics in infants.

AIM

To assess the effects of breastfeeding on the TBFV measurements of infants who recover from acute bronchiolitis.

METHODS

In this cross-sectional study, TBFV analysis was performed in infants with bronchiolitis prior to hospital discharge. The ratio of time to peak expiratory flow to total expiratory time (tPEF/tE) at baseline and after the administration of 400 mcg salbutamol was evaluated.

RESULTS

A total of 56 infants (35 boys), aged 7.4 ± 2.8 mo, were included. Of them, 12.5% were exposed to tobacco smoke and 41.1% were breastfed less than 2 mo. There were no differences in baseline TBFV measurements between the breastfeeding groups; however, those who breastfed longer than 2 mo had a greater change in tPEF/tE after bronchodilation (12% ± 10.4% vs 0.9% ± 7.1%; P < 0.001). Moreover, there was a clear dose-response relationship between tPEF/tE reversibility and duration of breastfeeding (P < 0.001). In multivariate regression analysis, infants who breastfed less (regression coefficient -0.335, P = 0.010) or were exposed to cigarette smoke (regression coefficient 0.353, P = 0.007) showed a greater change in tPEF/tE after bronchodilation, independent of sex, prematurity, and family history of asthma or atopy.

CONCLUSION

Infants who recover from bronchiolitis and have a shorter duration of breastfeeding or are exposed to cigarette smoke, have TBFV measurements indicative of obstructive lung disease.