Postoperative Analgesia after Open Liver Surgery: Systematic Review of Clinical Evidence.

Background: The existing recommendations for after open liver surgery, published in 2019, contains limited evidence on the use of regional analgesia techniques. The aim of this systematic review is to summarize available clinical evidence, published after September 2013, on systemic or blended postoperative analgesia for the prevention or treatment of postoperative pain after open liver surgery.

Methods: The PUBMED and EMBASE registries were used for the literature search to identify suitable studies. Keywords for the literature search were selected, with the authors' agreement, using the PICOS approach: participants, interventions, comparisons, outcomes, and study design.

Results: The literature search led to the retrieval of a total of 800 studies. A total of 36 studies including 25 RCTs, 5 prospective observational, and 7 retrospective observational studies were selected as suitable for this systematic review.

Conclusions: The current evidence suggests that, in these patients, optimal postoperative pain management should rely on using a "blended approach" which includes the use of systemic opioids and the infusion of NSAIDs along with regional techniques. This approach warrants the highest efficacy in terms of pain prevention, including the lower incretion of postoperative "stress hormones", and fewer side effects. Furthermore, concerns about the potential for the increased risk of wound infection related to the use of regional techniques have been ruled out.