Small for gestational age birth may increase airflow limitation in bronchopulmonary dysplasia

Reduced pulmonary oxygen diffusion at 36 weeks of postmenstrual age in small-for-gestational-age preterm infants of less than 32 weeks without bronchopulmonary dysplasia

BACKGROUND

Small-for-gestational-age (SGA) preterm infants are at increased risk of developing bronchopulmonary dysplasia (BPD). There is limited information on pulmonary oxygen diffusion of SGA preterm infants, particularly in those without BPD.

OBJECTIVE

To compare the pulmonary oxygen diffusion of SGA to that of appropriate-for-gestational-age (AGA) preterm infants without BPD.

STUDY DESIGN

Preterm infants with a gestational age (GA) between 24.0 and 31.6 weeks were studied. The oxygen saturation (SpO2 ), fraction to inspired oxygen (FiO2 ), and the SpO2 to FiO2 ratio (SFR) were compared between SGA and AGA infants. The association between SGA and SFR at 36 weeks was assessed using a multiple regression analysis. In the subgroup without BPD, SGA were match-paired for GA and gender with AGA infants.

RESULTS

We analyzed 1189 infants surviving at 36 weeks: 194 (16%) were SGA and 995 (84%) AGA. The incidence of BPD was significantly higher in SGA than AGA infants (32% vs. 13%; p = .000). Out of the 995 infants without BPD, 132 (13%) were SGA and 863 (87%) AGA. SGA was negatively associated with the SFR value at 36 weeks, independently from BPD. SGA infants without BPD had significantly higher (better) SFR at birth, but lower (worse) SpO2 and SFR and from 33 to 36 weeks than their matched AGA counterpart. At 36 weeks, median SpO2 and SFR values were 97.7 versus 98.4 (p = .006) and 465 versus 468 (p = .010) in match-paired SGA and AGA, respectively.

CONCLUSION

Among preterm infants of less than 32 weeks and without BPD, SGA infants had a reduced pulmonary oxygen diffusion at 36 weeks in comparison with AGA infants.

Association between bronchopulmonary dysplasia and early respiratory morbidity in children with respiratory distress syndrome: a case-control study using nationwide data

Bronchopulmonary dysplasia (BPD) can cause respiratory morbidity beyond the neonatal period. We aimed to analyze the association of BPD on childhood lower respiratory illness (LRI) and asthma among patients diagnosed with respiratory distress syndrome (RDS). This case–control study analyzed data between 2002 and 2015 from a nationwide database. We included 55,066 children with RDS. Two-year LRI and asthma at ages 3 and 5 were assessed. Readmission for LRIs within 2 years of birth occurred in 53.9% and 37.9% of the BPD (n = 9470) and non-BPD (n = 45,596) cases, respectively. In the BPD group, the median number of hospitalizations, mechanical ventilation and oxygen use rates were significantly higher, while the hospitalization duration was significantly longer (P < 0.001 for all). The relative risk of BPD was 1.42 (1.39–1.45) on total readmission and 6.53 (5.96–7.15) on intensive care unit readmission. Asthma prevalence was significantly higher in BPD group (57.6% vs. 48.9% at age 3 and 44.3% vs. 38.2% at age 5, P < 0.001). In children with RDS, BPD could affect repetitive and worse LRI as an independent risk factor for respiratory morbidity during the first 2 years of life. BPD may also be a crucial risk factor for asthma in preschoolers.

Effect of human milk and other neonatal variables on lung function at three months corrected age

OBJECTIVE

To evaluate the impact of human milk and different neonatal variables on tidal breathing flow-volume loop (TBFVL) parameters within three months' corrected age (CA) in infants born ≤32 wks or weighing <1500 g.

METHODS

We retrospectively studied 121 infants with gestational age (GA) ≤ 32 weeks or birth weight (BW) <1500 gr who had lung function assessment within three months' CA by TBFVL analysis between June 2009 and April 2018. We investigated the impact of GA, gender, being Small for GA (SGA), sepsis, days of mechanical ventilation (MV) and human milk feeding (HMF) on later respiratory function, both in the entire group and according to BW ( ≤1000 g and >1000 g).

RESULTS

The mean(SD) z-score for tidal volume (Vt) and time to peak expiratory flow to expiratory time (tPTEF/tE) were respectively -4.3 (2.5) and -0.8 (2.0) for the overall population with no significant differences between infants <1000 g or ≥1000 g. The mean(SD) Vt standardized for body weight was 6.2(2.0) ml/kg. Being female was associated with better Vt/Kg, whereas longer MV or being born SGA were associated with worst tPTEF/tE. For infants with BW < 1000 gr, tPTEF/tE was positively associated with HMF.

CONCLUSION

An early TBFVL assessment within three months' CA already reveals lung function alteration in preterm infants. Being female is associated with better Vt/Kg, while longer duration of MV or being born SGA negatively affect tPTEF/tE. The positive association between HMF and better tPTEF/tE in infants with BW <1000 g has emerged, which deserves further investigation.

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.