In vitro study on work of breathing during non-invasive ventilation using a new variable flow generator

Area of Science:

• Neonatal respiratory support
• Medical device engineering
• Pulmonary physiology

Background:

• Nasal synchronized biphasic positive airway pressure (BPAP) via the Infant Flow SiPAP system is increasingly used for preterm infants to reduce work of breathing (WOB) and respiratory failure risk.
• The existing generator's high resistance limits pressure amplitude (PA) and pressure build-up (PB), potentially compromising therapeutic effectiveness.

Purpose of the Study:

• To investigate the impact of a novel Infant Flow generator with enhanced fluid mechanics on WOB, PA, and PB during BPAP.
• To compare the performance of the new generator against the existing one in simulated clinical scenarios.

Main Methods:

• An in vitro low compliance lung model was utilized to measure WOB, PA, and PB.
• BPAP was delivered using both the old and new Infant Flow generators.
• Variations in airway resistance (tube sizes) and nasal interface sizes were employed, alongside different ventilator settings, to simulate diverse clinical conditions.

Main Results:

• The new generator demonstrated a significant reduction in WOB, ranging from 10% to 70% compared to the old generator.
• The maximum PA was substantially higher with the new generator (6-7 cmH2O) versus the old (3-4 cmH2O).
• The new generator achieved 33-40% of peak pressure within the first 100 ms of inspiration, compared to 11-20% for the old generator.

Conclusions:

• The new Infant Flow SiPAP generator significantly reduces WOB and enhances PA and PB during BPAP.
• These findings suggest improved respiratory support for preterm infants using the modified device.
• Further clinical validation in preterm infants under varied conditions is warranted to confirm these in vitro results.