Lung Volume Changes in Stable Preterm Infants Weaned From Nasal CPAP to High Flow: A Prospective Cohort Study

Area of Science:

• Neonatal respiratory support
• Pediatric pulmonology
• Critical care medicine

Background:

• Nasal high-flow therapy is increasingly used for weaning preterm infants from nasal CPAP.
• The impact of this weaning strategy on lung volumes remains poorly understood.
• Stable preterm infants (30-35 weeks postmenstrual age) were studied.

Purpose of the Study:

• To investigate the effects of transitioning from nasal CPAP to high flow therapy on lung volumes in preterm infants.
• To assess how varying high flow levels influence end-expiratory lung volume (EELV).
• To evaluate cardiorespiratory parameters during the weaning process.

Main Methods:

• Prospective cohort study involving 19 preterm infants.
• Utilized electrical impedance tomography (EIT) to measure EELV.
• Infants transitioned from nCPAP to high flow (8 L/min), with stepwise reductions and escalations in flow, while monitoring cardiorespiratory data.

Main Results:

• Significant changes in EELV were observed during the high flow weaning process (P = .002).
• Lung volume loss occurred during decreasing high flow levels (6 and 4 L/min) and was only partially recovered during re-escalation.
• Minute ventilation decreased (P = .004), heart rate increased (P = .02), and oxygen saturation/FiO2 ratio decreased (P < .001).

Conclusions:

• Transitioning from nCPAP to high flow therapy in preterm infants can lead to reduced EELV.
• Physiological changes in heart rate and oxygenation accompany these lung volume alterations.
• High flow therapy alone may not fully restore lung volumes lost during the weaning process from nCPAP.