P3.095: In vitro comparison of low-cost mushroom valve continuous positive airway pressure for use in low-resource countries

Background: Respiratory failure is a significant contributor to neonatal mortality in low-resource countries. The World Health Organization's (WHO) Every Newborn Action Plan (ENAP) recommends that 80% of district health facilities provide continuous positive airway pressure (CPAP) for treating respiratory failure. However, the available devices are expensive, subjectively complex, and fail to meet 90% of the CPAP target product profile outlined by WHO. We designed an ultra-low-cost mushroom valve CPAP device that satisfies over 90% of the product profile and compared it to the Fisher Paykel Bubble (F&Pb) CPAP and Neopuff devices (Fisher and Paykel, USA).

Methods: Using a high-fidelity lung simulator (Ingmar ASL5000) and a 3D-printed simple nasal airway, we assessed pressure stability and markers of imposed resistance among our prototype mushroom-valve CPAP, F&P bCPAP, and F&P Neo Puff coupled with a ram cannula. We analyzed 100 consecutive breaths at an airflow of 7 liters per minute and CPAP pressures of 5 and 7 cmH2O using passive and active neonatal respiratory distress syndrome breath models. Pressure and flow data points were extracted using the ASL5000 software. Imposed circuit resistance was evaluated through indirect measures: a) inhalation using the Peak Inspiratory Flow Rate (PIFR), where higher values indicate less airway resistance, and b) exhalation using the Peak Expiratory Flow Rate (PEFR), where lower values suggest less airway resistance. Student’s t-test was employed to compare their mean values.

Results: The mushroom valve CPAP produced consistent CPAP pressure compared to the F&P bubble CPAP, which fluctuated around the set CPAP pressure (Fig 1). The mean (standard deviation (SD)) PIFR of the mushroom valve CPAP was significantly lower than that of the F&P bCPAP (1.8 (0.01) vs. 3.0 (0.32)) and significantly lower than the F&P NeoPuff (1.8 (0.01) vs. 1.5 (0.00)). The mean PIFR (standard deviation (SD)) of the mushroom valve CPAP was significantly lower than that of the F&P bCPAP and significantly higher than that of the F&P NeoPuff (1.5 (0.00)). The mean PEFR of the mushroom valve CPAP was significantly higher compared to the F&P bCPAP (-2.0 (0.02) vs. -3.1 (0.41)) and significantly lower compared to the F&P NeoPuff (-2.0 (0.02) vs. -0.4 (0.42)).

Conclusion: The mushroom valve CPAP device maintained stable CPAP levels without the reverberations typically observed with bubble CPAP. During active breathing, the mushroom valve CPAP device demonstrated an intermediate level of imposed resistance compared to the F&P bCPAP device (lower) and the NeoPuff with the ram cannula (higher). The clinical implications of this should be examined, as the production cost, usability, and alignment with the WHO target product profile make it appropriate for low-resource countries.