Comparison of continuous thoracic epidural and paravertebral blocks for postoperative analgesia after minimally invasive direct coronary artery bypass surgery

Abstract

Objective: To compare continuous thoracic epidural analgesia (TEA) and paravertebral block (PVB) for postoperative analgesia in patients undergoing minimally invasive direct coronary artery bypass (MIDCAB) surgery for quality of analgesia, complications, compliance to chest physiotherapy, hemodynamics, and respiratory effects. Design: Prospective, randomized study. Setting: Specialty research hospital. Participants: Forty-one consenting patients undergoing MIDCAB surgery. Interventions: Patients in the TEA group had an epidural catheter inserted at the T4-5 interspace, whereas patients in the PVB group had a catheter inserted in the paravertebral space on the left side at the T4-5 level. Measurements and Main Results: Parameters evaluated included visual analog scale pain scores at rest and while coughing, supplemental analgesic requirement, complications, hemodynamics, and respiratory parameters. Measurements were made at 2-hour intervals for 12 hours beginning at 10 minutes after endotracheal extubation. There was no statistically significant difference in visual analog scale scores and requirement of supplemental analgesia between the 2 groups. Cardiac index at 4 hours and 6 hours was significantly higher in the TEA group. Patients in the PVB group had significantly lower respiratory rates at 8, 10, and 12 hours. All other parameters were comparable. In 1 patient, the epidural space could not be catheterized. One patient in the TEA group had transient hypotension, and 1 patient complained of backache at the site of the epidural catheter insertion. Conclusion: PVB is as effective as TEA for postoperative analgesia after MIDCAB surgery. PVB is technically easier than TEA and may be safer than TEA because no complications were seen in the PVB group. Copyright © 2001 by W.B. Saunders Company