The fourth Millennium Development Goal has concentrated efforts on addressing priority areas for improving worldwide child survival, with the aim of reducing national child mortality rates by two-thirds between 1990 and 2015. The 30th anniversary of the Alma Ata conference rightly emphasised that advances in primary health-care interventions are needed if the fourth Millennium Development Goal is to be achieved. As part of the primary-care approach, children with severe illness require access to good quality basic first-referral-level care. Pneumonia is the leading cause of death in children younger than 5 years, being responsible for at least 19% of the annual 9.7 million deaths in this age-group. Advances in the case management of major causes of child death, such as pneumonia and neonatal conditions, should be a priority in improving child survival. In pneumonia, hypoxaemia is a predictor of severe disease and has been shown to be a risk factor for death.
There is now evidence that ensuring ample supplies of oxygen and promoting a routine and systematic approach of screening for hypoxaemia using pulse oximetry is associated with improved quality of care and reduced mortality, and that the technology required to do so is sustainable and affordable in district hospitals in developing countries. Despite such evidence, oxygen remains inaccessible for a substantial proportion of severely ill children admitted to hospitals in developing countries. The inaccessibility of oxygen is particularly true for those admitted to district-level hospitals, where even if some facility for delivering oxygen is available, supplies are often unreliable, equipment is poorly maintained, or there is a lack of staff training or guidelines. Moreover, oxygen therapy in developing countries continues to be a low priority on the child health agenda. Oxygen was not mentioned, for example, in the recent publication by WHO and UNICEF on efforts to control pneumonia.
Studies have explored the possibility of managing children with WHO-defined severe pneumonia and no danger signs at home, thereby directing the limited facility-based health-care resources to children most in need of them. For home management to be safe and ethical, it is essential that only children without hypoxaemia are managed outside health-care facilities. Children with hypoxaemic pneumonia need to be identified (which is difficult using only clinical signs), admitted, and given supplemental oxygen and close monitoring. This necessitates a heightened awareness of the prevalence and risk of hypoxaemia among children presenting to health-care facilities, and robust mechanisms to detect it.
Increased awareness of the important role of oxygen in improving child survival requires a better understanding of the global burden of hypoxaemia in children. In this systematic review we bring together the current knowledge from published and unpublished data on the prevalence of hypoxaemia amongst acutely ill children and neonates in developing countries.