Oxygen therapy in diseases of the chest

Abstract

Summary This article aims to make the following points: 1. A distinction must be made between hypox˦mia (less than a normal amount of oxygen in the blood) and hypoxia (the disordered function of tissues due to partial or complete failure of oxidative metabolism). 2. The hypoxia due to lung disease can be abolished by moderate relief of the hypox˦mia. 3. Moderate relief of the hypox˦mia is readily accomplished by increasing the inspired oxygen concentration by only 4–8 per cent. 4. Higher inspired oxygen concentrations may seem to be desirable because hypox˦mia can be abolished, but the complications of under-ventilation outweigh this fringe benefit. 5. The most spectacular successes claimed for dramatic, expensive, time-consuming and often risky measures such as respiratory stimulants, tracheostomy and artificial ventilation are reported in patients whose respiratory failure has been needlessly intensified by uncontrolled oxygen therapy. 6. The necessary control of inspired oxygen concentration which is not provided by conventional methods can be achieved by making use of the principle of high air flow with oxygen enrichment. 7. The principles of the present Hammersmith regimen are: control of the inspired O2, close observation and frequent measurements of PCO2, the intensive use of conservative measures proceeding to tracheostomy within a few hours if progress is unsatisfactory.