Incidence of hypotension and bradycardia during integrated epidural/general anaesthesia. An epidemiologic observational study on 1200 consecutive patients. Italian Study Group on Integrated Anaesthesia.

BACKGROUND

Combined epidural/general anaesthesia might theoretically emphasise the cardiovascular effects of epidural block alone. The goal of the present investigation was to evaluate the incidence of both hypotension and bradycardia during integrated epidural/general anaesthesia in a multicentric, observational study.

METHODS

The incidence of clinical hypotension (systolic arterial blood pressure decrease by 30% or more from baseline), and bradycardia (heart rate < 50 beats/min) and other side effects have been evaluated in 1200 consecutive patients receiving integrated epidural/general anaesthesia. The time from induction of epidural anaesthesia to induction of general anaesthesia was considered as preoperative; while the time after general anaesthesia induction was considered as intraoperative.

RESULTS

Preoperatively hypotension developed in 85 patients (2.8%), and bradycardia in 54 patients (4.5%). Intraoperatively, hypotension was observed in 380 patients (31.6%), and bradycardia in 153 patients (12.7%). Hypotension and bradycardia were not influenced by the type of surgical procedure, the type of maintenance of general anaesthesia (inhalational versus total intravenous general anaesthesia) and the level of epidural block (lumbar versus thoracic); but they were more frequent in patients with ASA physical status II and III-IV compared to patients with ASA physical status I (p < 0.05). Prophylactic volume preload decreased the incidence of hypotension from 41.5% to 22.4% (p < 0.0001), while prophylactic atropine before epidural block did not affect the incidence of bradycardia. Patients receiving epidural clonidine showed an increased incidence of intraoperative bradycardia compared to those who did not receive it (p < 0.0001).

DISCUSSION

Randomized, controlled studies should be advocated in order to compare the incidence of hypotension and bradycardia during integrated anaesthesia and during epidural block alone. Our results demonstrated that the use of integrated epidural/general anaesthesia produces an incidence of perioperative hypotension and bradycardia similar to that reported when central blocks are used alone.