An evaluation of oxygen systems for treatment of childhood pneumonia

A Comprehensive Approach to Medical Oxygen Ecosystem Building: An Implementation Case Study in Kenya, Rwanda, and Ethiopia

Medical oxygen is an essential treatment for life-threatening hypoxemic conditions and is commonly indicated for the clinical management of most leading causes of mortality in children aged younger than 5 years, obstetric complications at delivery, and surgical procedures. In resource-constrained settings, access to medical oxygen is unreliable due to cost, distance from production centers, undermaintained infrastructure, and a fragmented supply chain. To increase availability of medical oxygen in underserved communities, Assist International, the GE Foundation, Grand Challenges Canada, the Center for Public Health and Development (Kenya), Health Builders (Rwanda), and the National Ministries of Health and Regional Health Bureaus in Kenya, Rwanda, and Ethiopia partnered to implement a social enterprise model for the production and distribution of medical oxygen to hospitals at reduced cost. This model established pressure swing adsorption (PSA) plants at large referral hospitals and equipped them to serve as localized supply hubs to meet regional demand for medical oxygen while using revenues from cylinder distribution to subsidize ongoing costs. Since 2014, 4 PSA plants have successfully been established and sustained using a social enterprise model in Siaya, Kenya; Ruhengeri, Rwanda; and Amhara Region, Ethiopia. These plants have cumulatively delivered more than 209,708 cylinders of oxygen to a network of 183 health care facilities as of October 2022. In Ethiopia, this model costs an estimated US$7.34 per patient receiving medical oxygen over a 20-year time horizon. Altogether, this business model has enabled the sustainable provision of medical oxygen to communities with populations totaling more than 33 million people, including an estimated 5 million children aged younger than 5 years.

Evaluation of an innovative low flow oxygen blender system for global access

BACKGROUND

Safe and effective oxygen delivery methods are not available for the majority of infants and young children globally. A novel oxygen blender system was designed to accurately deliver concentration-controlled, oxygen-enriched air to hypoxemic children up to age five. The system does not require compressed medical air, is compatible with both oxygen tanks and oxygen concentrators, and is low cost. This is the first study that tested the performance of the innovative oxygen blender system.

METHODS

The performance of the oxygen blender system was assessed in vitro based on delivered oxygen levels and flow rates with an oxygen tank, an oxygen tank using a nasal occlusion model, and an oxygen concentrator.

RESULTS

The measured %O₂ of the performance test was within ± 5% of full scale (FS) of the target value across all flows and all nasal cannulas. Occlusion testing demonstrated that 50% occlusion did not significantly affect the system outputs. The oxygen blender system was shown to be compatible with both oxygen tanks and oxygen concentrators.

CONCLUSIONS

The novel oxygen blender system accurately controls oxygen concentrations and blended air flow rates, and is compatible with both oxygen tanks and oxygen concentrators. This innovation may be an opportunity for improved infant and child oxygen treatment worldwide.

Technical results from a trial of the FREO2 Low-Pressure Oxygen Storage system, Mbarara Regional Referral Hospital, Uganda

Increased access to reliable medical oxygen would reduce the global burden of pneumonia. Oxygen concentrators have been shown to be an effective solution, however they have significant drawbacks when used in low-resource environments where pneumonia burden is the heaviest. Low quality grid power can damage oxygen concentrators and blackouts can prevent at-risk patients from receiving continual oxygen therapy. Gaps in prescribed oxygen flow can result in acquired brain injuries, extended hypoxemia and death. The FREO2 Low-Pressure Oxygen Storage (LPOS) system consists of a suite of improvements to a standard oxygen concentrator which address these limitations. This study reports the technical results of a field trial of the system in Mbarara, Uganda. During this trial, oxygen supplied from the LPOS system was distributed to four beds in the paediatric ward of Mbarara Regional Referral Hospital. Over a three-month period, medical-grade oxygen was made available to patients 100% of the time. This period was sufficient to quantify the ability of the LPOS system to deal with blackouts, maintenance, and an unscheduled repair to the LPOS store.

Efficacy and safety of oxygen-sparing nasal reservoir cannula for treatment of pediatric hypoxemic pneumonia in Uganda: a pilot randomized clinical trial

Background

Oxygen is an essential therapy for hypoxemia but is scarce in low-income settings. Oxygen conserving devices optimize delivery, but to date have been designed for adults in high-income settings. Here we present the development and clinical pilot study of an oxygen-sparing nasal reservoir cannula (OSNRC) for pediatric use in low-income settings.

Methods

(1) Pre-clinical development of a novel OSNRC using a simulated respiratory circuit with metabolic simulator and anatomically accurate face-airway models. Simulated breathing waveforms were designed based on airway resistance, lung compliance, respiratory rate, and tidal volume of spontaneous breathing for three disease conditions. (2) Pilot, randomized, controlled, non-blinded, cross-over study of the OSNRC vs standard nasal cannula (SNC) among children hospitalized with hypoxemic pneumonia in Uganda. Eight children were randomized to OSNRC followed by SNC, and eight were randomized to SNC followed by OSNRC.

Results

The laboratory simulation showed that the OSNRC provided the same or higher fraction of inspired oxygen at approximately 2.5-times lower flow rate compared to SNC. The flow savings ratio exhibited a linear relationship with the OSNRC volume to tidal volume ratio with a slope that varied with breathing waveforms. The range of performance from different breathing waveforms defined a performance envelope of the OSNRC. Two mask sizes (30 mL and 50 mL) provided sufficient coverage for patients between the 3rd and 97th percentile in our targeted age range. In the clinical pilot study, the rise in capillary blood pCO₂ was similar in the OSNRC and SNC groups, suggesting that the OSNRC was not associated with CO₂ retention. There were no significant differences between OSNRC and SNC with respect to clinical adverse events, lactate levels, pH, and SpO₂. The OSNRC group had a higher mean SpO₂ than the SNC group (adjusted mean difference, 1.4, 95% confidence interval 1.1 to 1.8), showing oxygen delivery enhancement.

Conclusion

The OSNRC enhances oxygen delivery without causing CO₂ retention and appears to be well-tolerated by pediatric patients. If safety, efficacy and tolerability are confirmed in larger trials, this device has the potential to optimize oxygen delivery in children in low-resource settings, reducing the global burden of pediatric pneumonia.

Trial registration

The trial was retrospectively registered (International Standard Registered Clinical/Social Study Number (ISRCTN): 15216845; Date of registration: 15 July 2020).

Oxygen insecurity and mortality in resource-constrained healthcare facilities in rural Kenya

INTRODUCTION

Pneumonia is the leading cause of death globally in children. Supplemental oxygen reduces mortality but is not available in many low-resource settings. Inadequate power supply to drive oxygen concentrators is a major contributor to this failure. The objectives of our study were to (a) assess the availability of therapeutic oxygen; (b) evaluate the reliability of the electrical supply; and (c) investigate the effects of suboptimal oxygen delivery on patient outcomes in selected healthcare facilities in rural Kenya.

MATERIALS AND METHODS

A cross-sectional descriptive study on oxygen availability and descriptive case series of Kenyan children and youth hospitalized with hypoxemia.

RESULTS

Two of 11 facilities had no oxygen equipment and nine facilities had at least one concentrator or cylinder. Facilities had a median of seven power interruptions per week (range: 2-147). The median duration of the power outage was 17 minutes and the longest was more than 6 days. The median proportion of time without power was out 7% (range: 1%-58%). Fifty-seven patients hospitalized with hypoxemia (median oxygen saturation 85% [interquartile range {IQR}: 82-87]) were included in our case series. Patients received supplemental oxygen for a median duration of 4.6 hours (IQR: 3.0-7.8). Eighteen patients (32%) faced an oxygen interruption of the median duration of 11 minutes (IQR: 9-20). A back-up cylinder was used in 5/18 (28%) cases. The case fatality rate was 11/57 (19%).

CONCLUSION

Mortality due to hypoxemia remains unacceptably high in low-resource healthcare facilities and may be associated with oxygen insecurity, related to lack of equipment and/or reliable power.

Assessment of a storage system to deliver uninterrupted therapeutic oxygen during power outages in resource-limited settings

Access to therapeutic oxygen remains a challenge in the effort to reduce pneumonia mortality among children in low- and middle-income countries. The use of oxygen concentrators is common, but their effectiveness in delivering uninterrupted oxygen is gated by reliability of the power grid. Often cylinders are employed to provide continuous coverage, but these can present other logistical challenges. In this study, we examined the use of a novel, low-pressure oxygen storage system to capture excess oxygen from a concentrator to be delivered to patients during an outage. A prototype was built and tested in a non-clinical trial in Jinja, Uganda. The trial was carried out at Jinja Regional Referral Hospital over a 75-day period. The flow rate of the unit was adjusted once per week between 0.5 and 5 liters per minute. Over the trial period, 1284 power failure episodes with a mean duration of 3.1 minutes (range 0.08 to 1720 minutes) were recorded. The low-pressure system was able to deliver oxygen over 56% of the 4,295 power outage minutes and cover over 99% of power outage events over the course of the study. These results demonstrate the technical feasibility of a method to extend oxygen availability and provide a basis for clinical trials.

Children's Oxygen Administration Strategies Trial (COAST): A randomised controlled trial of high flow versus oxygen versus control in African children with severe pneumonia

Background: In Africa, the clinical syndrome of pneumonia remains the leading cause of morbidity and mortality in children in the post-neonatal period. This represents a significant burden on in-patient services. The targeted use of oxygen and simple, non-invasive methods of respiratory support may be a highly cost-effective means of improving outcome, but the optimal oxygen saturation threshold that results in benefit and the best strategy for delivery are yet to be tested in adequately powered randomised controlled trials. There is, however, an accumulating literature about the harms of oxygen therapy across a range of acute and emergency situations that have stimulated a number of trials investigating permissive hypoxia. Methods: In 4200 African children, aged 2 months to 12 years, presenting to 5 hospitals in East Africa with respiratory distress and hypoxia (oxygen saturation < 92%), the COAST trial will simultaneously evaluate two related interventions (targeted use of oxygen with respect to the optimal oxygen saturation threshold for treatment and mode of delivery) to reduce shorter-term mortality at 48-hours (primary endpoint), and longer-term morbidity and mortality to 28 days in a fractional factorial design, that compares: Liberal oxygenation (recommended care) compared with a strategy that permits hypoxia to SpO 2 > or = 80% (permissive hypoxia); andHigh flow using AIrVO 2 TM compared with low flow delivery (routine care). Discussion: The overarching objective is to address the key research gaps in the therapeutic use of oxygen in resource-limited setting in order to provide a better evidence base for future management guidelines. The trial has been designed to address the poor outcomes of children in sub-Saharan Africa, which are associated with high rates of in-hospital mortality, 9-10% (for those with oxygen saturations of 80-92%) and 26-30% case fatality for those with oxygen saturations <80%. Clinical trial registration: ISRCTN15622505 Trial status: Recruiting.

Children's Oxygen Administration Strategies Trial (COAST): A randomised controlled trial of high flow versus oxygen versus control in African children with severe pneumonia

Background: In Africa, the clinical syndrome of pneumonia remains the leading cause of morbidity and mortality in children in the post-neonatal period. This represents a significant burden on in-patient services. The targeted use of oxygen and simple, non-invasive methods of respiratory support may be a highly cost-effective means of improving outcome, but the optimal oxygen saturation threshold that results in benefit and the best strategy for delivery are yet to be tested in adequately powered randomised controlled trials. There is, however, an accumulating literature about the harms of oxygen therapy across a range of acute and emergency situations that have stimulated a number of trials investigating permissive hypoxia. Methods: In 4200 African children, aged 2 months to 12 years, presenting to 5 hospitals in East Africa with respiratory distress and hypoxia (oxygen saturation < 92%), the COAST trial will simultaneously evaluate two related interventions (targeted use of oxygen with respect to the optimal oxygen saturation threshold for treatment and mode of delivery) to reduce shorter-term mortality at 48-hours (primary endpoint), and longer-term morbidity and mortality to 28 days in a fractional factorial design, that compares: Liberal oxygenation (recommended care) compared with a strategy that permits hypoxia to SpO 2 > or = 80% (permissive hypoxia); andHigh flow using AIrVO 2TM compared with low flow delivery (routine care). Discussion: The overarching objective is to address the key research gaps in the therapeutic use of oxygen in resource-limited setting in order to provide a better evidence base for future management guidelines. The trial has been designed to address the poor outcomes of children in sub-Saharan Africa, which are associated with high rates of in-hospital mortality, 9-10% (for those with oxygen saturations of 80-92%) and 26-30% case fatality for those with oxygen saturations <80%. Clinical trial registration: ISRCTN15622505 Trial status: Recruiting.

Teaching Pediatric Life Support in Limited-Resource Settings: Contextualized Management Guidelines

Of the estimated 6.3 million global annual deaths in children younger than the age of 5 years, nearly all (99%) occur in low- to middle-income countries (LMIC). Existing management guidelines for children with emergency conditions as taught in a variety of current pediatric life support courses are mostly applicable to high-income countries with a different disease range and full resources compared with LMIC. A revised curriculum with evidence-based application to limited-resource settings would expand their potential for reducing pediatric mortality worldwide. This review provides a supplemental curriculum of standards for selected pediatric emergency conditions with attention to the context of disease range and level-specific resources in LMIC. During training sessions, contextualized management guidelines create the framework for realistic and fruitful case simulations.

Community-acquired pneumonia in children - a changing spectrum of disease

Pneumonia remains the leading cause of death in children outside the neonatal period, despite advances in prevention and management. Over the last 20 years, there has been a substantial decrease in the incidence of childhood pneumonia and pneumonia-associated mortality. New conjugate vaccines against Haemophilus influenzae type b and Streptococcus pneumoniae have contributed to decreases in radiologic, clinical and complicated pneumonia cases and have reduced hospitalization and mortality. The importance of co-infections with multiple pathogens and the predominance of viral-associated disease are emerging. Better access to effective preventative and management strategies is needed in low- and middle-income countries, while new strategies are needed to address the residual burden of disease once these have been implemented.

Reservoir Cannulas for Pediatric Oxygen Therapy: A Proof-of-Concept Study

Hypoxemia is a complication of pneumonia-the leading infectious cause of death in children worldwide. Treatment generally requires oxygen-enriched air, but access in low-resource settings is expensive and unreliable. We explored use of reservoir cannulas (RCs), which yield oxygen savings in adults but have not been examined in children. Toddler, small child, and adolescent breathing profiles were simulated with artificial lung and airway models. An oxygen concentrator provided flow rates of 0 to 5 L/min via a standard nasal cannula (NC) or RC, and delivered oxygen fraction (FdO₂) was measured. The oxygen savings ratio (SR) and absolute flow savings (AFS) were calculated, comparing NC and RC. We demonstrated proof-of-concept that pendant RCs could conserve oxygen during pediatric therapy. SR mean and standard deviation were 1.1 ± 0.2 to 1.4 ± 0.4, 1.1 ± 0.1 to 1.7 ± 0.3, and 1.3 ± 0.1 to 2.4 ± 0.3 for toddler, small child, and adolescent models, respectively. Maximum AFS observed were 0.3 ± 0.3, 0.2 ± 0.1, and 1.4 ± 0.3 L/min for the same models. RCs have the potential to reduce oxygen consumption during treatment of hypoxemia in children; however, further evaluation of products is needed, followed by clinical analysis in patients.

Hypoxaemia as a Mortality Risk Factor in Acute Lower Respiratory Infections in Children in Low and Middle-Income Countries: Systematic Review and Meta-Analysis

Objective

To evaluate the association between hypoxaemia and mortality from acute lower respiratory infections (ALRI) in children in low- and middle-income countries (LMIC).

Design

Systematic review and meta-analysis.

Study Selection

Observational studies reporting on the association between hypoxaemia and death from ALRI in children below five years in LMIC.

Data Sources

Medline, Embase, Global Health Library, Lilacs, and Web of Science to February 2015.

Risk of Bias Assessment

Quality In Prognosis Studies tool with minor adaptations to assess the risk of bias; funnel plots and Egger’s test to evaluate publication bias.

Results

Out of 11,627 papers retrieved, 18 studies from 13 countries on 20,224 children met the inclusion criteria. Twelve (66.6%) studies had either low or moderate risk of bias. Hypoxaemia defined as oxygen saturation rate (SpO2) <90% associated with significantly increased odds of death from ALRI (OR 5.47, 95% CI 3.93 to 7.63) in 12 studies on 13,936 children. An Sp02 <92% associated with a similar increased risk of mortality (OR 3.66, 95% CI 1.42 to 9.47) in 3 studies on 673 children. Sensitivity analyses (excluding studies with high risk of bias and using adjusted OR) and subgroup analyses (by: altitude, definition of ALRI, country income, HIV prevalence) did not affect results. Only one study was performed on children living at high altitude.

Conclusions

The results of this review support the routine evaluation of SpO2 for identifying children with ALRI at increased risk of death. Both a Sp02 value of 92% and 90% equally identify children at increased risk of mortality. More research is needed on children living at high altitude. Policy makers in LMIC should aim at improving the regular use of pulse oximetry and the availability of oxygen in order to decrease mortality from ALRI.

Childhood anemia at high altitude: risk factors for poor outcomes in severe pneumonia

BACKGROUND

Pneumonia is the leading cause of mortality in young children globally, and factors that affect tissue delivery of oxygen may affect outcomes of pneumonia. We studied whether altitude and anemia influence disease severity and outcomes in young children with World Health Organization-defined severe pneumonia.

METHODS

We analyzed data from the SPEAR (Severe Pneumonia Evaluation Antimicrobial Research) study, a World Health Organization- and USAID-sponsored multinational randomized controlled trial of antibiotics for severe pneumonia among children aged 2 to 59 months in resource-poor settings. The trial enrolled 958 children in 8 sites at varying elevations, classified as high (≥ 2000 m) or low (<2000 m) altitude. We compared illness severity and assessed the effect of anemia on treatment outcome at high and low altitudes, adjusting for potential confounders and study site.

RESULTS

Children at high altitudes had significantly lower oxygen saturation on presentation, more cyanosis, lower systolic blood pressure, and higher hemoglobin. After adjusting for potential confounders, anemia predicted treatment failure in children living at high altitude (relative risk: 4.07; 95% confidence interval: 2.60-6.38) but not at low altitude (relative risk: 1.12; 95% confidence interval: 0.96-1.30). Children at high altitude took longer to reach normoxemia than did children at lower altitudes (5.25 vs 0.75 days; P < .0001).

CONCLUSIONS

Children at high altitude present with more severe disease, and children with anemia at high altitude are at greater risk of poor outcome when being treated for severe pneumonia. Given the high global prevalence of anemia among young children, prevention and treatment of anemia should be a priority in children living at high altitude and could improve outcomes of pneumonia.

An evaluation of the emerging vaccines against influenza in children

BACKGROUND

Influenza is an under-appreciated cause of acute lower respiratory infections (ALRI) in children. It is estimated to cause approximately 20 million new episodes of ALRI in children annually, 97% of these occurring in developing countries. It is also estimated to result in 28000 to 112000 deaths annually in young children. Apart from hospitalisations and deaths, influenza has significant economic consequences. The current egg-based inactivated influenza vaccines have several limitations: annual vaccination, high production costs, and cannot respond adequately to meet the demand during pandemics.

METHODS

We used a modified CHNRI methodology for setting priorities in health research investments. This was done in two stages. In Stage I, we systematically reviewed the literature related to emerging cross-protective vaccines against influenza relevant to several criteria of interest: answerability; cost of development, production and implementation; efficacy and effectiveness; deliverability, affordability and sustainability; maximum potential impact on disease burden reduction; acceptability to the end users and health workers; and effect on equity. In Stage II, we conducted an expert opinion exercise by inviting 20 experts (leading basic scientists, international public health researchers, international policy makers and representatives of pharmaceutical companies). They answered questions from the CHNRI framework and their "collective optimism" towards each criterion was documented on a scale from 0 to 100%.

RESULTS

The experts expressed very high level of optimism for deliverability, impact on equity, and acceptability to health workers and end users. However, they expressed concerns over the criteria of answerability, low development cost, low product cost, low implementation cost, affordability and, to a lesser extent sustainability. In addition they felt that the vaccine would have higher efficacy and impact on disease burden reduction on overall influenza-associated disease rather than specifically influenza-associated pneumonia.

CONCLUSION

Although the landscape of emerging influenza vaccines shows several promising candidates, it is unlikely that the advancements in the newer vaccine technologies will be able to progress through to large scale production in the near future. The combined effects of continued investments in researching new vaccines and improvements of available vaccines will hopefully shorten the time needed to the development of an effective seasonal and pandemic influenza vaccine suitable for large scale production.

Pneumonia in low and middle income countries: progress and challenges

Pneumonia remains the leading cause of childhood mortality and the most common reason for adult hospitalisation in low and middle income countries, despite advances in preventative and management strategies. In the last decade, pneumonia mortality in children has fallen to approximately 1.3 million cases in 2011, with most deaths occurring in low income countries. Important recent advances include more widespread implementation of protein-polysaccharide conjugate vaccines against Haemophilus influenzae type B and Streptococcus pneumoniae, implementation of case-management algorithms and better prevention and treatment of HIV. Determining the aetiology of pneumonia is challenging in the absence of reliable diagnostic tests. High uptake of new bacterial conjugate vaccines may impact on pneumonia burden, aetiology and empiric therapy but implementation in immunisation programmes in many low and middle income countries remains an obstacle. Widespread implementation of currently effective preventative and management strategies for pneumonia remains challenging in many low and middle income countries.