[Oxygen therapy in pneumology]

Circumstances under which the use of oxygen-therapy in lung disease can be effective and harmless, depend upon a careful evaluation of its indications: they are suggested by the clinical need of correction of hypoxaemia as well as by the awareness of factors determining respiratory failure and of problems concerning O(2) transport and supply to tissues in health and disease. Blood gases monitoring enables to control the effects of treatment on arterial O2 and CO2 tensions thus giving all the useful data for oxygen administering particularly as far as components of hyperoxygenated mixtures, flow rate, duration, use of very effective low-risk devices (Venturi masks) are concerned. Correction of hypoxaemia involves the reduction of hypertension of the pulmonary circulation and hyperglobulia, improvement of tolerance of exertion, and attention to the metabolic compensation of respiratory acidosis. These results are influenced by the nature of the pathogenetic factors behind broncho-obstructive disease, which may lead to either a primarily "bronchitis" or a primarily "emphysematous" syndrome. An interesting feature relates to prognosis in the case of patients making home use of hyperoxygenated mixtures as part of a rehabilitation program, or to improve their quality of life. The cost and benifits of such treatment should be carefully weighed. Lastly, in the event of protracted treatment, attention must be paid to the possibility of toxicity and the means to be adopted for its prevention.