Forced expiratory flows and volumes in a Swedish cohort of healthy term infants

Tidal breathing lung function analysis of wheezing and non-wheezing infants with pneumonia: A retrospective observational study

To compare lung function in wheezing and non-wheezing infants with pneumonia through tidal breathing analysis and explore the correlation between tidal breathing lung function and clinical characteristics. This retrospective observational study included infants with pneumonia hospitalized in the Affiliated Hospital of Guizhou Medical University between January 2018 and December 2018. Medical records were used to obtain the demographic characteristics, clinical characteristics, tidal breathing lung function results before and after a bronchodilator test, and positive remission rates after the bronchodilator test for each patient. Eighty-six wheezing infants (64 males, aged 6.5 [4.8, 9] months) and 27 non-wheezing infants (18 males, aged 7 [5, 12] months) were included. Non-wheezing infants were more likely to have normal airway function compared to wheezing infants (44.4% vs 23.3%, P = .033). Peak tidal expiration flow/tidal expiratory flow (TEF)25 in wheezing infants was significantly higher than that in non-wheezing infants (162.4 [141.2, 200.7] vs 143.3 [131, 178.8], P = .037). The positive remission rate of tidal inspiratory flow (TIF50)/TEF50 (53.5% vs 29.6%, P = .03) and TEF50 (58.1% vs 33.3%, P = .024) were significantly higher in the wheezing infants compared to non-wheezing infants (P = .03 and P = .024, respectively). Furthermore, respiratory rate, tidal volume, peak expiration flow, TEF25, TEF50, and TEF75 were significantly correlated to the age, height, weight, and platelet counts of infants in both the wheezing and non-wheezing infants (all P < .05). Wheezing infants with pneumonia were more likely to have worse tidal breathing lung function compared to non-wheezing infants with pneumonia. The tidal breathing lung function parameter (respiratory rate, tidal volume, peak expiration flow, TEF25, TEF50, and TEF75) were correlated to the age, height, weight, and platelet counts of both wheezing and non-wheezing infants.

Air pollution exposure impairs lung function in infants

Aim

To assess associations between air pollution exposure and infant lung function.

Methods

Healthy infants from Stockholm were recruited to two cohorts (n = 99 and n = 78). Infant spirometry included plethysmography and raised volume forced expiratory flows. In pooled analyses, lung function at ~6 months of age was related to time‐weighted average air pollution levels at residential addresses from birth until the lung function test. The pollutants included particulate matter with an aerodynamic diameter < 10 μm (PM₁₀) or <2.5 μm and nitrogen dioxide.

Results

There were significant inverse relations between air pollution exposure during infancy and forced expiratory volume at 0.5 s (FEV_0.5) as well as forced vital capacity (FVC) for all pollutants. For example, the decline was 10.1 ml (95% confidence interval 1.3–18.8) and 10.3 ml (0.5–20.1) in FEV_0.5 and FVC, respectively, for an interquartile increment of 5.3 μg/m³ in PM₁₀. Corresponding associations for minute ventilation and functional residual capacity were 43.3 ml/min (−9.75–96.3) and 0.84 ml (−4.14–5.82).

Conclusions

Air pollution exposure was associated with impaired infant lung function measures related to airway calibre and lung volume, suggesting that comparatively low levels of air pollution negatively affect lung function in early life.

Pediatric pulmonology year in review 2020: Physiology

Pulmonary physiology is a core element of pediatric pulmonology care and research. This article reviews some of the notable publications in physiology that were published in Pediatric Pulmonology in 2020.