Solar Powered Oxygen Delivery

Solar Powered Oxygen Delivery: An Open-label Non-inferiority Comparison to Standard Oxygen Delivery Using Oxygen Cylinders

Globally, approximately 2.1 million children die of pneumonia each year. Most deaths occur in resource-poor settings in Africa and Asia. Oxygen (O2) therapy is essential to support life in these patients. Large gaps remain in the case management of children presenting to African hospitals with respiratory distress, including essential supportive therapies such as supplemental oxygen. We hypothesize that a novel strategy for oxygen delivery, solar-powered oxygen, can be implemented in remote locations and will be non-inferior to standard oxygen delivery by compressed gas cylinders.

Arterial hypoxemia in pneumonia results from several mechanisms: pulmonary arterial blood flow to consolidated lung resulting in an intrapulmonary shunt, intrapulmonary oxygen consumption, and ventilation-perfusion mismatch. Hypoxemia is a risk factor for mortality in pediatric pneumonia, and was associated with a 5-fold increased risk of death in studies from Kenya and Gambia. In one report from Nepal, the prevalence of hypoxemia (SpO2 < 90%) in 150 children with pneumonia was 39% overall, with increasing rates of hypoxemia across strata of pneumonia severity (100% of very severe, 80% of severe and 17% of pneumonia patients). General features of respiratory distress were associated with hypoxemia in this study, including chest indrawing, lethargy, grunting, nasal flaring, cyanosis, inability to breastfeed or drink. Few studies have reported on the use of solar powered oxygen (SPO2) delivery. One online report describes the use of a battery-powered oxygenator in the Gambia that could be adapted to use solar power (http://www.dulas.org.uk). Otherwise, our intervention is to our knowledge the first example of SPO2 delivery. New ways to deliver oxygen for children with pneumonia in Africa could improve outcomes and save numerous lives. If this study documents the non-inferiority of SPO2 relative to standard oxygen delivery, this novel method of providing life-saving oxygen could be rolled out across centres in sub-Saharan Africa where oxygen cylinders are not widely available and electrical power is not reliable. The potential energy efficiency, low cost and ease of use make solar power an attractive avenue of investigation for use in resource-constrained settings. Proof-of-concept that the sun can be used to drive oxygen delivery could stimulate commercial interest in this technology. The SPO2 system could thus achieve rapid penetration into the most remote or rural settings in sub-Saharan Africa.

Solar panels used to drive an oxygen concentrator to deliver at stream of oxygen at approximately 90% FiO2 and a rate of 1-5L/min.

The number of days from admission to discharge. Criteria for discharge are standardized and are assessed daily.

Cost of oxygen cylinders (control arm) and cost of equipment (capital investment - solar oxygen intervention arm).

This simple published clinical score predicts mortality in children with malaria, but may also have prognostic value in pneumonia.

Inclusion Criteria: Age <13 years IMCI defined pneumonia, severe pneumonia or very severe disease Hypoxemia (SpO2<90%) based on non-invasive pulse oximetry Hospital admission warranted based on clinician judgment Consent to blood sampling and data collection Exclusion Criteria: SpO2 ≥90% Suspected pulmonary tuberculosis Outpatient management Denial of consent to participate in study

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Hawkes MT, Conroy AL, Namasopo S, Bhargava R, Kain KC, Mian Q, Opoka RO. Solar-Powered Oxygen Delivery in Low-Resource Settings: A Randomized Clinical Noninferiority Trial. JAMA Pediatr. 2018 Jul 1;172(7):694-696. doi: 10.1001/jamapediatrics.2018.0228.

Nyende S, Conroy A, Opoka RO, Namasopo S, Kain KC, Mpimbaza A, Bhargava R, Hawkes M. Solar-powered oxygen delivery: study protocol for a randomized controlled trial. Trials. 2015 Jul 9;16:297. doi: 10.1186/s13063-015-0814-y.