Paravertebral vs. Epidural Analgesia for Liver Surgery (PEALS): Protocol for a randomized controlled pilot study [version 3; peer review: 1 approved, 1 approved with reservations, 1 not approved]

Background Perioperative thoracic epidural analgesia (TEA) is commonly used in hepatectomy patients since it is opioid-sparing. However, TEA has a high failure rate and is associated with potentially devastating complications (spinal haematoma) and the risk is increased with hepatectomy. Thus, some centres favour systemic opioid-based modalities which, in turn, are associated with inferior analgesia and well-known risks/side-effects. Hence, alternative analgesic methods are desirable. Paravertebral block (PVB) has been used in liver resection with advantages including haemodynamic stability, low failure rates, and low risk of spinal haematoma. The purpose of this pilot RCT is to compare continuous TEA (traditional standard of care is local anesthetic (LA) + opioids) with PVB (traditional standard of care is with LA without opioid) for patients undergoing hepatectomy. We hypothesise that pain outcomes will be comparable between groups, but PVB patients will require fewer perioperative vasopressors/blood products, have fewer opioid-related side effects and a shorter hospital length of stay. Methods With ethics approval, this non-inferiority, pilot RCT with a convenience sample of 50 hepatectomy patients will examine whether PVB imparts analgesia comparable to TEA but with fewer adverse effects. Primary outcomes are surrogates of analgesia for 72 h postoperatively (i.e., opioid consumption, time to first analgesic request and pain scores at rest and with coughing); Secondary outcomes are blood products/fluids administered; side effects/complications until 72 h postoperatively; length of hospital stay. The results will be used to plan a large multicentre trial comparing TEA vs. PVB in hepatectomy patients. This study has a high potential to positively impact the quality/safety of patient care. ClinicalTrials.gov registration NCT02909322 (09-21-2016); Available at URL: https://clinicaltrials.gov/ct2/show/NCT0290932