Effects of acute hypercapnia and hypocapnia on plasma and red cell potassium, blood lactate and base excess in man during anesthesia

Acta Anaesthesiol Scand. 1978;22(4):353-66. doi: 10.1111/j.1399-6576.1978.tb01311.x.


In order to test the relationship between changes in plasma potassium concentration and pH changes of respiratory origin, we produced hypercapnia (mean PaCO2 71 mmHg = 9.5 kPa) in a group of 17 patients and hypocapnia (mean PaCO2 21 mmHg = 2.8 kPa) in another 20 patients during neurolept analgesia and intraabdominal operations. A control group of 19 patients was studied under normocapnia but otherwise identical conditions. During hypercapnia, serum potassium rose, deltaK/deltapH amounting to -0.82, -1.05 and -1.34 after 30, 60 and 90 min, respectively. During hypocapnia, serum potassium decreased, deltaK/deltapH being a little more negative than during hypercapnia (mean values -1.62, -2.44 and -1.60). Red cell potassium concentration decreased in all three groups to a similar extent. Blood lactate levels during hypercapnia decreased to 75% of control and during hypocapnia rose to a maximum of 186% of control. In order to obtain reasonable values for base excess in primarily respiratory acid-base disorders, it is necessary to use nomograms based on in vivo ECF-CO2-titration curves. With this premise, hypercapnia or hypocapnia in our patients was not associated with significant changes in base excess.

MeSH terms

  • Acid-Base Imbalance / blood
  • Acute Disease
  • Adult
  • Anesthesia, General*
  • Carbon Dioxide / blood*
  • Humans
  • Hydrogen-Ion Concentration
  • Hypercapnia / blood*
  • Hypercapnia / physiopathology
  • Lactates / blood
  • Middle Aged
  • Neuroleptanalgesia*
  • Potassium / blood*


  • Lactates
  • Carbon Dioxide
  • Potassium