Epidural Versus Paravertebral Nerve Block for Postoperative Analgesia in Patients Undergoing Open Liver Resection: A Randomized Clinical Trial

Abstract

Background and objectives: Although many studies have found no difference between thoracic epidural block and unilateral thoracic paravertebral block after thoracotomy, no previous studies have compared epidural block with bilateral thoracic paravertebral block (bTPVB) in patients undergoing open liver resection. We aimed to investigate whether there was a significant analgesic advantage of thoracic epidural over bTPVB after liver resection.

Methods: This randomized, prospective, open-label study included adult patients undergoing elective open liver resection. Patients were randomized to receive either thoracic epidural block or bTPVB, through which ropivacaine (0.2%) was infused for 3 days. The primary outcome was pain Verbal Rating Scale (VRS) score (0-10) at rest and with postoperative incentive spirometry. Secondary outcomes included VRS at rest, inspired volumes during incentive spirometry, patient-controlled analgesia hydromorphone utilization, measures of hemodynamic stability, and postoperative bowel function.

Results: Eighty patients completed the study and received thoracic epidural block (n = 41) or bTPVBs (n = 39). No catheter-related complications were noted. The primary outcome, pain (VRS) with incentive spirometry, was significantly lower in the epidural group (epidural vs bTPVB, mean [SD]) (4.5 [2.7] vs 5.4 [2.7] at 24 hours postoperatively, and 3.2 [2.1] vs 4.6 [2.4] at 48 hours postoperatively). Maximal inspired volumes at 24 hours postoperatively (917 [379] vs 1042 [468] mL) and cumulative utilization of patient-controlled analgesia hydromorphone during the first 48 hours postoperatively (10.7 [7.9] vs 13.6 [8.5] mg) were not significantly different between groups. Decrease in mean arterial pressure from baseline at 24 hours postoperatively was greater for the epidural group (-12.6 [15.8] vs -3.8 [16.2]; P = 0.016).

Conclusions: This study suggests that there is a modest analgesic advantage of thoracic epidural over bTPVBs for patients after open liver resection.