Feasibility of the frugally-engineered ‘LeVe CPAP’ from pilot data in healthy volunteers at Mengo Hospital, Uganda; with potential for use in patients with acute hypoxaemic respiratory failure associated with COVID-19 and other respiratory illnesses

Feasibility of the frugally-engineered ‘LeVe CPAP’ from pilot data in healthy volunteers at Mengo Hospital, Uganda; with potential for use in patients with acute hypoxaemic respiratory failure associated with COVID-19 and other respiratory illnesses

Peter Culmer , Edith Namulema
University of Leeds, Leeds, United Kingdom

Introduction: Continuous positive airway pressure (CPAP) is the gold-standard non-invasive ventilatory support in many cases of acute hypoxaemic respiratory failure (AHRF), which increased exponentially during the COVID-19 pandemic. However, such ventilatory systems are not designed for use in resource-limited settings.

Methodology Due to the sudden increase in cases of AHRF in low-resource settings during the COVID-19 pandemic, we engineered a frugal ‘LeVe’ CPAP flow generator. This device uses a lowvoltage electric fan-blower, with an oxygen source and humidifier, to deliver oxygen-enriched airflow at pressure levels between 5-12cm H20. A safety and tolerability pilot study was conducted in healthy volunteers from local healthcare staff in the Intensive Care Unit (ICU) at Mengo Hospital, Kampala. This is the initial stage of a planned cross-over randomisation trial using the device for severe cases of COVID-19. Ethical and administrative approval was gained from the Ugandan National Council for Science and Technology (UNCST), the National Drug Authority, and Mengo Hospital Research & Ethics Committee (REC).

Results: Ten healthy participants were recruited, 50:50 male:female ratio, mean age 24.9 years (range 22-30). The LeVe CPAP Flow Generator was initiated through escalation of pressures in four stages (5, 7.5, 10, 12.6 cm H20). Monitoring of oxygen saturation revealed oxygen saturation was well maintained >95% for all participants at all pressures (median minimum SpO2 97.3%, range 95- 98%). Monitoring of end tidal CO2 levels revealed safe pressures maintained < 3.6KPa for all participants at all pressures (median maximum ETCO2 4.4 KPa, range 3.6-4.9). The median respiratory rate was within normal range at pressures of 10cm H20 was 17.8 (range 10-25). Participants reported overall comfort of the device 4.4 median (Likert-Scale of 5 being ‘very comfortable’). Levels of anxiety, claustrophobia and difficult breathing were self-reported as low (<2.1 on Likert-Scale).

Discussion/Conclusion: Outcomes from the pilot study demonstrates that the LeVe CPAP flow generator is safe and well tolerated in healthy volunteers. Due to the significant reduction in COVID19 cases in Uganda, we have not yet conducted the next phase of study. However, we are exploring the potential use of the LeVe CPAP system to address other acute respiratory conditions in low resource settings.

Keywords: CPAP, AHRF, Covid-19