Continuous display of plasma potassium during cardiac surgery

We have evaluated the use of an intravascular ion-selective electrode for continuous plasma potassium monitoring in patients during and after cardiac surgery. Potassium estimations from the indwelling electrode provided a rapid and sensitive, but only moderately reliable, indicator of potassium as confirmed by blood samples. Several significant changes in the plasma potassium were found to occur in the period studied and using this continuous monitor, the precise time course of these changes was recorded.