A study has proposed essential new guidelines to design mechanical ventilators that can work in low- and middle-income countries (LMICs).

The guidelines are based on the results of an original survey led by King’s College London (London, UK) of more than 50 expert anesthetists and intensivists from 23 LMICs in Africa, Asia, Central and South America, and on a critical analysis of the published literature. The findings of the study are vital for countries that have few mechanical ventilators, as low ventilation capacity limits access to critical care and surgery. The guidelines have been produced to define the key design features for a mechanical ventilator to be usable and sustainable in low-resource settings.

The COVID-19 pandemic has highlighted the lack of ventilators in many LMICs, and this study sought to characterize the infrastructure in which ventilators are needed. Ventilators produced for high income countries might not be sustainable in LMICs, because they may be too difficult or expensive to repair. The survey responses by larger LMICs hospitals showed electricity supply was interrupted daily (19%) and weekly (25%), although three quarters of these outages lasted less than two hours. As such, a relatively small battery in the ventilator could bridge the gaps in electricity availability. The study suggests that the design of a mechanical ventilator would also need to include an air compressor, and either a gas cylinder or an oxygen concentrator. The analysis also highlighted the existence of a wide range of infrastructure within low- and middle-income countries. A ventilator developed according to these guidelines, is likely to meet the demand in many of these countries.

“The pandemic highlighted the lack of mechanical ventilation capacity in many low and middle-income countries, where the use of ventilators designed for wealthier countries is not sustainable for technical and financial reasons,” said Dr. Federico Formenti, Reader in Physiology, from the School of Basic & Medical Biosciences. “Our study systematically investigated the infrastructure and context where ventilators are required and, based on a survey and expert opinion, we identified the fundamental guidelines that could enable the design of a context-specific and sustainable mechanical ventilator for larger hospitals in LMICs.”

“The global unreliability of electric power supply in low- and middle-income countries calls for designs of medical commodities and equipment to be customized,” said Dr. Mpoki Ulisubisya, Permanent Secretary at the Ministry of Health in Tanzania and co-author of the study. “This customization is essential if patient care is to be optimised and of a quality to meet patient’s needs. The pandemic exacerbated this need when mechanical ventilation equipment was in question hence this study and the raised recommendations for equipment meant for low- and middle-income countries.”

“COVID19 pandemic has highlighted the dearth of respiratory support equipment in low resource countries,” added co-author Professor Madiha Hashmi, from Ziauddin University in Pakistan. “Even when available these complex machines are unable to save lives when operated by untrained persons. Simple ventilators with auto-modes may bridge the equipment and human resource gap.”

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