Use of pethidine for percutaneous liver biopsy - a randomised, placebo-controlled, double blind study

Background: Percutaneous liver biopsy (PLB) is the "gold standard" in the diagnosis of liver diseases. A pilot trial has shown pethidine may reduce anxiety and the need for post-procedural pain relief. The aim of this study was to investigate the role of pre-procedural pethidine. Methods: A double-blinded, randomized, placebo-controlled trial was conducted to assess the need for pethidine prior to PLB. 98 patients were randomly assigned to receive either 50 mg pethidine i.v. (n = 48), or an equal volume of 0.9% normal saline (n = 50). PLB was performed with ultrasound guidance after adequate local anaesthesia with xylocaine. Patients were asked to self-evaluate pain experienced using a visual analogue score (0-10) immediately and an hour after PLB. Patients were then followed up 24 hours after the procedure to assess their pain score, retrospective pain score and willingness to have a repeat procedure. Results: Pethidine administration resulted in significantly lower pain scores (0.60 +/- 0.1 vs 1.2 +/- 0.2, p = 0.006) and required less analgesia (0% vs 10%, p = 0.03) immediately after PLB in comparison to the placebo group. There was no significant difference in the pain score and analgesia requirement one hour after the procedure, the pain score at 24 hours after procedure and retrospective pain score. 94% of all patients of either group are willing to under go a repeat liver biopsy (NS). Conclusions: The administration of pethidine routinely prior to PLB reduces the immediate post procedural pain but has no lasting effect and does not influence the patients' decision making process for future investigations.