Pre‐operative assessment of anxiety and measurement of arterial plasma catecholamine concentrations The effect of oral β‐adrenergic blockade with metoprolol

A double-blind study of 40 patients who underwent elective hysterectomy was conducted to evaluate the role of arterial plasma catecholamine concentrations as an objective index of anxiety, and to assess the effect of pre-operative oral treatment with a beta-adrenoceptor blocking drug. The patients were premedicated with diazepam and either metoprolol or placebo 2-3 hours before surgery. The effect on anxiety was evaluated by the anaesthetist and by visual analogue scoring by the patients. Using pooled data, a significant decrease in both adrenaline and noradrenaline concentrations was demonstrated after premedication, but no difference was found between the groups. In general, patients were less anxious after premedication, but patients who received metoprolol had greater relief of anxiety (p = 0.0007). A significant change in perceived anxiety was found in patients who received metoprolol, but there was no significant change in the placebo group. The correlation between the observers' assessment and the patients' visual analogue scores was poor, but some correlation was found between the assessed relief of anxiety and the changes in visual analogue score. We could not demonstrate any correlations between anxiety and catecholamine concentrations, between relief of anxiety and changes in catecholamine concentrations, or haemodynamics and catecholamine concentrations.