[Changes in acid-base equilibrium of the arterial blood in hypoxemic-eucapnic subjects subjected to oxygen therapy with and without an antiphosphodiesterase drug].

The behaviour of the partial tensions of respiratory gases and the main parameters of acid base balance in hypoxaemic and eucapnic chronic bronchopneumopathics undergoing oxygen therapy has been assessed. The patiests were subdivided into two groups, the first consisting of subjects undergoing oxygen therapy alone, the second of subjects having oxygen and i.v. theophylline at the same time. Two subgroups were also distinguished. These consisted respectively of normochloraemic and hypochloraemic patients, the purpose being to reveal whether electrolytic changes could be attributed to the concentration of chlorine evaluated in basal conditions. The results obtained showed a disappearance of the hypoxaemic state without appreciable changes in paCO2 in all patients; in those undergoing oxygen therapy only, also observed were: 1) increase in plasmatic H+ and reduction in pH; 2) diminution in HCO3- and plasma Na+; 3) increase in plasma concentration of Cl-; 4) statistical significance of these data; 5) tendency of all values in the parameters considered to return to basal values upon suspension of oxygenation.