Lung volume distribution in preterm infants on non-invasive high-frequency ventilation

Area of Science:

• Neonatal respiratory physiology
• Mechanical ventilation techniques
• Pulmonary imaging and monitoring

Background:

• Non-invasive high-frequency oscillatory ventilation (nHFOV) is an advanced form of nasal continuous positive airway pressure (nCPAP) for neonates.
• Understanding the distribution of lung volumes during these ventilatory modes is crucial for optimizing neonatal respiratory care.

Purpose of the Study:

• To compare the global and regional distribution of lung volumes between nHFOV and nCPAP in preterm infants.
• To assess differences in ventilation homogeneity and aeration between the two non-invasive ventilation strategies.

Main Methods:

• A randomized crossover trial involving 30 preterm infants compared nHFOV and nCPAP.
• Electrical impedance tomography (EIT) was used to record lung ventilation data in the prone position.
• Tidal volumes, ventilation homogeneity indicators, and end-expiratory lung impedance (EELI) were analyzed across 36 lung slices and regional areas.

Main Results:

• Relative tidal volumes were greater in most lung regions during nCPAP compared to nHFOV.
• Aeration was significantly increased during nHFOV, particularly in non-gravity-dependent lung regions (p=0.013).
• Aeration homogeneity was improved with nHFOV compared to nCPAP (p=0.0014).

Conclusions:

• While regional ventilation patterns were similar, nHFOV resulted in higher end-expiratory lung volume and improved aeration homogeneity.
• The observed increase in aeration, especially in non-gravity-dependent areas, may be attributed to the oscillatory pressure waveform of nHFOV.
• The precise clinical significance of these findings in neonatal respiratory support requires further investigation.