Thoracic epidural analgesia improves pulmonary function in patients undergoing cardiac surgery.
OBJECTIVE
Pulmonary dysfunction commonly occurs following coronary artery bypass graft (CABG) surgery, increasing morbidity and mortality. We hypothesized that thoracic epidural anesthesia (TEA) would improve pulmonary function and would decrease complications in patients undergoing CABG surgery.


METHODS
This prospective, randomized, controlled trial was conducted with Ethics Board approval. Fifty patients, undergoing CABG surgery, were randomized to the epidural group or to the patient-controlled analgesia morphine group. Patients in the epidural group received a high, thoracic epidural, preoperatively. Intraoperatively, 0.75% ropivacaine was infused, followed postoperatively, by 0.2% ropivacaine for 48 hr. Outcome measurements included: visual analogue pain scores; spirometry; atelectasis scores on chest radiographs; and the incidence of atrial fibrillation.


RESULTS
Twenty-five patients were enrolled in each group. Patients in the epidural group had significantly less pain on the operative day, and for the subsequent two days. Compared to baseline, the forced expiratory volume in one second was significantly higher in the epidural group, on the first and second postoperative days (43.7 +/- 12.2% vs 36.4 +/- 12.0%, p < 0.002, and 43.3 +/- 12.5% vs 38.4 +/- 11.0%, p <0.05). There was significantly more atelectasis in the control group, four hours postoperatively (p < 0.04); however, on the third, postoperative day, the groups were similar with regards to this outcome. The incidence of atrial fibrillation was similar in both groups, and there were no complications related to the epidural.


CONCLUSIONS
High TEA decreases postoperative pain and atelectasis and improves pulmonary function in patients undergoing CABG surgery. Our results support the use of TEA in this group of patients.
Department of Anesthesia, University of Manitoba, 60 Pearl Street, Winnipeg, Manitoba, Canada.
Paul K
PK
Tenenbein
Roland
R
Debrouwere
Doug
D
Maguire
Peter C
PC
Duke
Brian
B
Muirhead
James
J
Enns
Michael
M
Meyers
Kevin
K
Wolfe
Stephen E
SE
Kowalski
D015360:Analgesia, Epidural; D016058:Analgesia, Patient-Controlled; D001026:Coronary Artery Bypass; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D010147:Pain Measurement; D011446:Prospective Studies; D013904:Thoracic Vertebrae