Evaluation of thoracic epidural analgesia in patients undergoing coronary artery bypass surgery – a prospective randomized trial

Introduction
Most recent studies tend to confirm the beneficial effect of thoracic epidural analgesia (TEA) in cardiac surgery.

Aim
To assess whether intensive care unit TEA has an influence on the perioperative course following low-risk coronary artery surgery.

Material and methods
This prospective, randomized trial was performed in patients scheduled for low-risk coronary artery surgery. Eighty patients undergoing off-pump or on-pump coronary artery bypass surgery were prospectively randomized to receive either combined general and epidural anesthesia or general anesthesia only. Time of postoperative ventilations and intensive care unit stay was compared between the groups. For all comparisons (p < 0.05) was considered statistically significant.

Results
The addition of TEA to general anesthesia significantly attenuated the stress response expressed by intraoperative heart rate, systolic blood pressure and cumulative doses of opioids. Time to the return of spontaneous respiration, time to extubation and time of stay in the postoperative care unit were all shorter in the study group, with no difference in hospital stay. Patients with TEA required midazolam less frequently (12.8% vs. 53.8%, p < 0.001). The percentage of patients given morphine in the study group was lower (46.2% vs. 89.7%, p < 0.001) and the mean dose given in patients receiving morphine was also lower (9.3 ±5.3 mg vs. 18.2 ±9.1 mg, p < 0.001).

Conclusions
Addition of TEA to general anesthesia shortens the return of respiratory function, duration of mechanical ventilation and ICU stay in the postoperative period after coronary artery surgery, providing comparable hemodynamic stability to general anesthesia alone.