Studies in acid-base balance. I. Effect of alkali therapy in newborn dogs with mechanically fixed ventilation.
The effect of rapid or slow infusion of hypertonic sodium bicarbonate on acid-base balance and serum osmolality was studied in 36 acidotic newborn dogs. Respiratory acidosis and hypoxia were produced by mechanically fixed hypoventilation. One group of animals breathed 100% O2 to prevent hypoxemia. Rapid infusion of HCO3- in acidotic and hypoxic animals resulted in only a transient (1 minute) and small (0.05 pH units) elevation of arterial pH followed by a continuous fall, resulting in a lower pH and a worsened metabolic condition than in the nontreated controls. In nonhypoxic acidotic animals, rapid infusion of HCO3- had little effect on arterial pH. PaCO2 increased suddenly by 17 Torr in hypoxic and, by 13 Torr, in nonhypoxic animals. There was a concomitant fall in PaO2 (15 Torr). Serum osmolality rose rapidly after rapid infusion of HCO3-. Rapid infusion of hypertonic bicarbonate into an animal or infant whose ventilation is fixed thus results in a less than predicted elevation of arterial pH. PaCO2 rises, PaO2 falls, and serum osmolality rises. The net result may be a worsening rather than an improvement in the animals' metabolic state.
D000136:Acid-Base Equilibrium / Q000187:drug effects*; D000138:Acidosis / Q000097:blood; D000142:Acidosis, Respiratory / Q000097:blood; D000818:Animals; D000831:Animals, Newborn; D001237:Asphyxia / Q000097:blood; D001639:Bicarbonates / Q000008:administration & dosage*; D001798:Blood Proteins / Q000032:analysis; D002245:Carbon Dioxide / Q000097:blood; D004285:Dogs; D006400:Hematocrit; D006863:Hydrogen-Ion Concentration; D007040:Hypoventilation / Q000097:blood; D000860:Hypoxia / Q000097:blood; D009994:Osmolar Concentration; D010100:Oxygen / Q000097:blood; D012122:Ventilators, Mechanical
D001639:Bicarbonates; D001798:Blood Proteins; D002245:Carbon Dioxide; D010100:Oxygen