ECG changes after CABG: the role of the surgical technique

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.

Is new ST-segment elevation after coronary artery bypass of clinical importance in the absence of perioperative myocardial infarction?

OBJECTIVE

To determine the frequency and significance of new ST-segment elevation during the early postoperative period after coronary artery bypass grafting (CABG) in patients without enzymatic or electrocardiogram evidence of perioperative myocardial infarction (MI).

METHODS

Pre- and early postoperative electrocardiograms were reviewed in 506 patients undergoing CABG in whom MI was excluded by the absence of new Q waves or left bundle branch block and a peak postoperative troponin I less than 10 ng/mL.

RESULTS

New ST-segment elevation of 0.1 mV or greater was observed in 64 patients (12.6%). Patients with and without ST-segment elevation did not differ with regard to age, prior coronary artery bypass, number of grafts, use of the internal mammary artery, incidence of postoperative atrial fibrillation, length of stay in the intensive care unit, duration of hospitalization, or 30-day mortality.

CONCLUSIONS

ST-segment elevation not due to perioperative MI is common after CABG but is not associated with increased postoperative morbidity or mortality.