Absorption of bupivacaine from the pre-peritoneal space in laparoscopic hernia repair

SummaryLocal anaesthetic placed into the pre-peritoneal space during laparoscopic hernia repair may provide additional pain relief, reducing the requirement for post-operative analgesia. The systemic absorption of such drugs from this space has not previously been determined. Twenty patients undergoing laparoscopic transperitoneal hernia repair were randomly allocated to receive bupivacaine 1.5mg/kg or bupivacaine 1.5mg/kg with 1:200000 adrenaline. Venous blood samples were obtained at 10, 15, 30, 60 and 90 min following instillation of bupivacaine. Plasma levels of bupivacaine at these times were determined using high pressure gas liquid chromatography. No patient experienced signs or symptoms of bupivacaine toxicity. Mean plasma concentrations of bupivacaine peaked at 30 min and did not reach toxic levels. The addition of adrenaline did not significantly alter the systemic absorption of bupivacaine. Instilling bupivacaine 1.5mg/kg into the pre-peritoneal space is associated with a low risk of toxicity. The addition of adrenaline is unnecessary and can be omitted from further trials. This information should facilitate the study of post-operative analgesia requirements following laparoscopic hernia repair.