Analgesia within the Initial Management of Acute Pancreatitis: A Systematic Review and Meta-analysis of Randomised Controlled Trials

Abstract

Introduction: The optimal analgesic strategy for patients with acute pancreatitis (AP) is unclear. The present systematic review and meta-analysis compares the efficacy of different analgesic modalities trialled in AP. Methods: A systematic search of PubMed, MEDLINE and EMBASE was conducted up until June 2021, identifying all randomised control trials (RCTs) comparing analgesic modalities in AP. A pooled analysis performed for the primary outcome measure: improvement in pain scores as reported on visual analogue scale (VAS) on day 0, day 1 and day 2. Results: Twelve RCTs including 542 patients were identified. Seven trial agents were compared: opiates, non-steroidal anti-inflammatories (NSAIDs), metamizole, local anaesthetic, epidural, paracetamol, and placebo. Pooled VAS scores improved globally across all modalities between baseline and day 2. Epidural analgesia appears to demonstrate greatest improvement in VAS within the first 24hrs, however at 48hrs it performed similarly to opiates. Within the first 24hrs, NSAIDs offered similar pain-relief to opiates. Placebo also performed comparably to other modalities within 24hrs however this effect subsequently plateaued. Local anaesthetics demonstrated least overall efficacy. VAS scores for opiate and non-opiate analgesics were comparable at baseline and day 1. The identified RCTs demonstrated significant statistical and methodological heterogeneity in pain-relief reporting. Conclusions: There is remarkable paucity of level 1 evidence to guide pain management in AP despite its prevalence in acute takes, with relatively small datasets per study. Epidural administration may be most effective within the first 24hrs of AP. NSAIDs are an effective opiate sparing alternative during this same timeframe.