Effect of continuous positive airway pressure versus nasal cannula on late preterm and term infants with transient tachypnea of the newborn

Evaluating Clinical Outcomes and Physiological Perspectives in Studies Investigating Respiratory Support for Babies Born at Term With or at Risk of Transient Tachypnea: A Narrative Review

Respiratory distress in the first few hours of life is a growing disease burden in otherwise healthy babies born at term (>37 weeks gestation). Babies born by cesarean section without labor (i.e., elective cesarean section) are at greater risk of developing respiratory distress due to elevated airway liquid volumes at birth. These babies are commonly diagnosed with transient tachypnea of the newborn (TTN) and historically treatments have mostly focused on enhancing airway liquid clearance pharmacologically or restricting fluid intake with limited success. Alternatively, a number of clinical studies have investigated the potential benefits of respiratory support in newborns with or at risk of TTN, but there is considerable heterogeneity in study designs and outcome measures. A literature search identified eight clinical studies investigating use of respiratory support on outcomes related to TTN in babies born at term. Study demographics including gestational age, mode of birth, antenatal corticosteroid exposure, TTN diagnosis, timing of intervention (prophylactic/interventional), respiratory support (type/interface/device/pressure), and study outcomes were compared. This narrative review provides an overview of factors within and between studies assessing respiratory support for preventing and/or treating TTN. In addition, we discuss the physiological understanding of how respiratory support aids lung function in newborns with elevated airway liquid volumes at birth. However, many questions remain regarding the timing of onset, pressure delivered, device/interface used and duration, and weaning of support. Future studies are required to address these gaps in knowledge to provide evidenced based recommendations for management of newborns with or at risk of TTN.

Association of delayed initiation of non-invasive respiratory support with pulmonary air leakage in outborn late-preterm and term neonates

The frequency of non-invasive respiratory support use has increased in neonates of all gestational ages with respiratory distress (RD). However, the impact of delayed initiation of non-invasive respiratory support in outborn neonates remains poorly understood. This study aimed to identify the impact of the delayed initiation of non-invasive respiratory support in outborn, late-preterm, and term neonates. Medical records of 277 infants (gestational age of ≥ 35 weeks) who received non-invasive respiratory support as primary respiratory therapy < 24 h of age between 2016 and 2020 were retrospectively reviewed. Factors associated with respiratory adverse outcomes were investigated in 190 outborn neonates. Infants with RD were divided into two groups: mild (fraction of inspired oxygen [FiO₂] ≤ 0.3) and moderate-to-severe RD (FiO₂ > 0.3), depending on their initial oxygen requirements from non-invasive respiratory support. The median time for the initiation of non-invasive respiratory support at a tertiary center was 3.5 (2.2-5.0) h. Male sex, a high oxygen requirement (FiO₂ > 0.3), high CO₂ level, and respiratory distress syndrome were significant factors associated with adverse outcomes. Subgroup analysis revealed that in the moderate-to-severe RD group, delayed commencement of non-invasive respiratory support (≥ 3 h) was significantly associated with pulmonary air leakage (p = 0.033).

CONCLUSION

Our study shows that outborn neonates with moderate-to-severe RD, who were treated with delayed non-invasive respiratory support, were associated with an increased likelihood of pulmonary air leakage. Additional prospective studies are required to establish the optimal timing and methods of non-invasive respiratory support for outborn, late-preterm, and term infants.

WHAT IS KNOWN

• Non-invasive respiratory support is widely used in neonates of all gestational ages. • Little is known on the impact of delayed initiation of non-invasive respiratory support in outborn, late preterm, and term neonates.

WHAT IS NEW

• Male sex, high oxygen requirement (FiO2 >0.3), high initial CO2 level, and respiratory distress syndrome significantly correlated with adverse outcomes. • Outborn late-preterm and term neonates with high oxygen requirement who were treated with delayed non-invasive respiratory support indicated an increased likelihood of pulmonary air leakage.

Decreasing delivery room CPAP-associated pneumothorax at ≥35-week gestational age

OBJECTIVE

We previously reported an increase in pneumothorax after implementing delivery room (DR) continuous positive airway pressure (CPAP) for labored breathing or persistent cyanosis in ≥35-week gestational age (GA) neonates unexposed to DR-positive pressure ventilation (DR-PPV). We hypothesized that pneumothorax would decrease after de-implementing DR-CPAP in those unexposed to DR-PPV or DR-O₂ supplementation (DR-PPV/O₂).

STUDY DESIGN

In a retrospective cohort excluding DR-PPV the primary outcome was DR-CPAP-related pneumothorax (1st chest radiogram, 1st day of life). In a subgroup treated by the resuscitation team and admitted to the NICU, the primary outcome was DR-CPAP-associated pneumothorax (1st radiogram, no prior PPV) without DR-PPV/O₂.

RESULTS

In the full cohort, occurrence of DR-CPAP-related pneumothorax decreased after the intervention (11.0% vs 6.0%, P < 0.001). In the subgroup, occurrence of DR-CPAP-associated pneumothorax decreased after the intervention (1.4% vs. 0.06%, P < 0.001).

CONCLUSION

The occurrence of CPAP-associated pneumothorax decreased after avoiding DR-CPAP in ≥35-week GA neonates without DR-PPV/O₂.