Thoracic epidural anesthesia for cardiac surgery via left anterior thoracotomy in the conscious patient.
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BACKGROUND
Cardiac surgery is perceived to be maximally invasive and fraught with complications. In response to this perception, cardiothoracic surgeons have been refining traditional techniques to minimize their invasive nature. Epidural anesthesia has been used safely and effectively for numerous surgical procedures to reduce morbidity associated with general anesthesia. In hopes of achieving a similar result, we set out to determine the feasibility of using thoracic epidural anesthesia for limited cardiac surgery through a left anterior thoracotomy for patients who were awake and spontaneously breathing.
METHODS
A high thoracic epidural technique was used in all cases. In each instance, the chest was entered through a small left anterior thoracotomy. The procedures included minimally invasive direct coronary artery bypass (MIDCAB) and transmyocardial revascularization (TMR). These procedures were performed in routine fashion using standard techniques. Pulmonary function tests were performed preoperatively, and the adequacy of respiratory function was serially monitored throughout each operation. The epidural catheters were left in place for 24 hours after operation for pain control.
RESULTS
A total of 10 operations were performed. These included 7 MIDCAB, 2 TMR and 1 MIDCAB/TMR hybrid. The mean preoperative forced expiratory volume for one second (FEV1) was 1.9 liters. Significant intra-operative hypoxia or hypercarbia was not seen. One patient required intubation during the procedure for restlessness not associated with hypoxia. Two others required brief periods of assisted ventilation. All procedures were completed without incident. The mean operating time and length of stay were 70 minutes and 4.7 days. Postoperative pain control and patient satisfaction were excellent.
CONCLUSIONS
Thoracic epidural anesthesia for limited cardiac surgical procedures by means of a left anterior thoracotomy is feasible, even in patients with diminished pulmonary function. Furthermore, this method offered no significant technical hurdles. Nevertheless, the applicability of this technique to other procedures remains unclear. We believe that these results warrant controlled comparison of regional versus general anesthesia for limited cardiac surgery.
