Perioperative Analgesia in Experimental Small Bowel Transplantation

Despite numerous studies in experimental rat small bowel transplantation (SBT), few authors make reference to perioperative analgesia. Recent changes to the Animals (Scientific Procedures) Act 1986 in the United Kingdom have made the use of analgesia in laboratory animals compulsory because pain is unnecessary in the majority of scientific procedures. Heterotopic SBT (PVG→DA) was performed on male rat recipients weighing 220 to 250 mg under isoflurane with a mean anesthetic time of 100 minutes. Recovery from anesthesia was usually within 15 minutes. Analgesia regimens were based on those in common use for other procedures. All drugs were administered in the 30 minutes prior to recovery from anesthesia. Group A received carprofen (2 mg/kg IM or SC). Group B was given buprenorphine (0.05 mg/kg either IM or SC). Group C received paracetamol (10– 30 mg) rectally. An early postoperative scoring system of four criteria was used, giving a maximum (least desirable) score of 16. Sixty transplants were performed, divided between the three groups. In group A animals scored a median of 1 of 16 but all except three recipients died within 3 hours. Those in group B scored a median of 8 of 16, but all animals except one died between 4 to 16 hours after surgery. Group C had a median score of 11 of 16, but there was no early mortality. Postmortem examination excluded technical failures in all but three animals. We recommend the use of paracetamol for perioperative analgesia in SBT because of the high mortality associated with other drugs when used in this procedure.