Pre-operative anxiety and serum potassium.

Small decreases in serum potassium in a study of 200 pre-operative patients were demonstrated in those who had an increase in anxiety, as measured on a linear analogue anxiety scale, in the 24 hours before anaesthesia. The possible aetiology and implications of this change are discussed. The combination of temazepam and a pre-operative visit by the anaesthetist effectively reduced pre-anaesthetic anxiety in 60% of patients.