[Changes in the acid-base and water-electrolyte balance induced by salbutamol. "In vivo" studies in patients with chronic broncho-pulmonary disease and "in vitro" by tonometry of venous blood].

The Authors studied the effects of e.v. Salbutamol evaluating the acute "in vivo" variations of acid-base and hydro-electrolitic balance in 16 chronic obstructive lung patients undergoing e.v. drug administration, and also ionic variations "in vitro" of venous blood samples incubated and tonometrated with the drug. The results "in vivo" do not show variations of acid-base equilibrium (paO2, paCO2, pH, HCO3-); whereas diminution of haematocrit (Ht), rise of urinary osmolarity and variations of hydro-electrolitic balance (Na+, K+, Cl-) are demonstrated. The results "in vitro" do not show considerable variations on ionic assessment. These data, according to the other latest result, indicate the possible role of haemodilution. We think that the explanation of these phenomena could be a modification of renal water and electrolytes reabsorption, likely under the influence of antidiuretic hormone (ADH), stimulated in the hypothalamus and activated also by the beta-stimulant drug at tubular cell receptors.