Published online Nov 26, 2019. doi: 10.12998/wjcc.v7.i22.3711
Peer-review started: June 4, 2019
First decision: August 1, 2019
Revised: August 30, 2019
Accepted: October 15, 2019
Article in press: October 15, 2019
Published online: November 26, 2019
Processing time: 181 Days and 19.7 Hours
The relationship between hyperkalaemia and metabolic acidosis is well described in the critical care setting; however, the relationship between acute respiratory acidosis and plasma potassium concentration is less well understood. In a controlled model of increasing levels of hypercarbia, we tested the hypothesis of whether increasing levels of hypercarbia are associated with changes in plasma potassium concentrations.
To determine whether increasing levels of hypercarbia are associated with changes in plasma potassium concentrations.
We performed a post-hoc study examining changes in serum potassium in 24 patients who received increased levels of hypercarbia during cardiac surgery. Arterial blood gases and plasma concentrations of potassium were measured at baseline, 3 min prior to, and then every 3 min for 15 min during the intervention of hypercarbia. The primary endpoint was the absolute change in serum K+ at 15 min compared to the baseline K+ value. The following secondary endpoints were evaluated: (1) The association between CO2 and serum K+ concentration; and (2) The correlation between plasma pH and serum K+ concentrations.
During the intervention, PaCO2 increased from 43.6 mmHg (95%CI: 40.1 to 47.1) at pre-intervention to 83.9 mmHg (95%CI: 78.0 to 89.8) at 15 min after intervention; P < 0.0001. The mean (SD) serum potassium increased from 4.16 (0.35) mmol/L at baseline to 4.28 (0.33) mmol/L at 15 min (effect size 0.09 mol/L; P = 0.22). There was no significant correlation between PaCO2 and potassium (Pearson’s coefficient 0.06; 95%CI: -0.09 to 0.21) or between pH and potassium (Pearson’s coefficient -0.07; 95%CI: -0.22 to 0.09).
Acute hypercarbia and subsequent respiratory acidaemia were not associated with hyperkalaemia in patients undergoing major surgery.
Core tip: Acute hypercarbia results in respiratory acidosis and subsequent respiratory acidaemia. Acute hypercarbia does not affect serum potassium concentrations in the setting of anaesthesia and major surgery. Respiratory acidaemia does not affect serum potassium concentrations in patients undergoing major surgery.