[Perioperative cardiovascular reactions and the noradrenaline plasma level in patients on chronic antidepressant medication]

It is still controversial whether the perioperative incidence of cardiovascular complications is increased in patients on chronic treatment with cyclic antidepressants (AD) and whether AD medication should be discontinued prior to surgery. METHODS. We measured perioperative cardiovascular variables in 31 patients on chronic treatment with tri- and tetracyclic AD and 31 patients without AD medication. Heart rate, blood pressure, and noradrenaline plasma concentrations were compared between the two groups at nine points in time. During induction of anaesthesia, the ECG was recorded continuously. After the administration of 0.01 mg/kg atropine i.v., all patients received opiate-supplemented enflurane anaesthesia.

Re-uptake inhibition of noradrenaline by AD resulted in significantly higher noradrenaline plasma concentrations before and during anaesthesia in the AD-treated group. The incidence of arrhythmias, blood pressure elevations, and tachycardia was not increased in patients in AD treatment. Arrhythmias during induction of anaesthesia were seen in 6 of the AD-treated patients and 5 of the controls. Blood pressure elevations by more than 35% were seen in 10 patients on AD treatment and 8 controls. The heart rate prior to induction of anaesthesia and 2 h after the end of surgery was significantly higher in the AD-treated group. During anaesthesia the heart rate was higher at two points in time only. The incidence of tachycardia was similar in both groups. Intravenous administration of 0.01 mg/kg atropine prior to induction of anaesthesia increased the heart rate of the patients on chronic AD medication by 11.4%. This increase was significantly higher in the control group (16.2%), suggesting that patients with chronic AD treatment do not have a higher sensitivity to atropine.

The elevated noradrenaline plasma levels in patients on chronic AD treatment did not result in a higher incidence of arrhythmias, blood pressure elevations, or tachycardia perioperatively. Taking these results into account, we do not consider it necessary to discontinue chronic AD medication prior to surgery in patients without cardiovascular disease.