Book excerpt: "Hypoxaemia is a major contributor to child deaths that occur worldwide each year; for a child with pneumonia hypoxaemia increases the risk of death by up to 5 times. Despite its importance in virtually all types of acute severe illness, hypoxaemia is often not well recognized or well managed, more so in settings where resources are limited. Oxygen therapy remains an inaccessible luxury for a large proportion of severely ill children admitted to hospitals in developing countries. This is particularly true for patients in small district hospitals, where, even if some facility for delivering oxygen is available, supplies are often unreliable and the benefits of treatment may be diminished by poorly maintained, inappropriate equipment or poorly trained staff with inadequate guidelines. Increasing awareness of these problems is likely to have considerable clinical and public health benefits in the care of severely ill children. Health workers should be able to know the clinical signs that suggest the presence of hypoxaemia and have more reliable means of detection of hypoxeamia. This can be achieved through more widespread use of pulse oximetry, which is a non-invasive measure of arterial oxygen saturation. At the same time oxygen therapy must be more widely available; in many remote settings, this can be achieved by use of oxygen concentrators, which can run on regular or alternative sources of power. Having effective systems for the detection and management of hypoxaemia are vital in reducing mortality from pneumonia and other severe acute illnesses. Oxygen therapy is essential to counter hypoxaemia and many times is the difference between life and death. This manual focuses on the availability and clinical use of oxygen therapy in children in health facilities by providing the practical aspects for health workers, biomedical engineers, and administrators. It addresses the need for appropriate detection of hypoxaemia, use of pulse oximetry, clinical use of oxygen and delivery systems and monitoring of patients on oxygen therapy. In addition, the manual addresses practical use of pulse oximetry, and oxygen concentrators and cylinders in an effort to improve oxygen systems worldwide."--Publisher's description.