IMMEDIATE CHANGES IN PLASMA POTASSIUM, SODIUM AND CHLORIDE INDUCED BY INTRAVENOUS INDUCTION AGENTS

The influence of six intravenous induction agents (thiopentone, methohexitone, propanidid, Althesin, diazepam and ketamine) on plasma potassium, sodium and chloride concentrations was studied in 160 healthy female patients undergoing minor gynaecological operations. This investigation was limited to the first 10 minutes after induction. A significant decrease of plasma potassium concentration (0.24–0.29 m.equiv/1.) was observed with thiopentone, methohexitone and diazepam. Propanidid and Althesin were investigated at two dose levels. Propanidid 10 mg/kg showed a small but significant mean peak rise of 0.06 m.equiv/1. of plasma potassium. The induction agents investigated did not have a significant effect on the plasma sodium and chloride concentrations.