Acid-base balance and blood gases changes and "lactate excess" in acute respiratory alkalosis during general anaesthesia.

In 40 young males aged 18-20 years operated on for inguinal hernioplasty acute respiratory alkalosis was obtained in the 45th minute of general anaesthesia. The values of basic acid-base balance parameters, blood gases, pyruvate and lactate levels and "lactate excess" were determined before and after hyperventilation. Shifts in the concentrations of hydrogen and bicarbonate ions were found which are both typical of acute respiratory alkalosis. No changes were observed in the oxygenation of capillary blood and the values of "lactate excess" were normal which rules out tissue hypoxia during acute respiratory alkalosis. Passive hyperventilation being a less dangerous alternative of hypoventilation is a frequent occurrence during general anaesthesia and it causes transient respiratory alkalosis.