EFFECTS OF THE EXTRADURAL ADMINISTRATION OF LOCAL ANAESTHETIC AGENTS AND MORPHINE ON THE URINARY EXCRETION OF CORTISOL, CATECHOLAMINES AND NITROGEN FOLLOWING ABDOMINAL SURGERY

Twenty patients undergoing major abdominal surgery were allocatedrandomly to receive either general anaesthesia with low-dosefentanyl plus intermittent systemic morphine for postoperativepain or the same general anaesthetic plus extradural analgesiaduring and following surgery (local anaesthetics from beforeskin incision until 24 h after skin incision plus extraduralmorphine 4 mg every 12 h from 3 h to 72 h after skin incision).Postoperative pain scores were lower (P < 0.05) in the groupreceiving extradural analgesia, but this regimen failed to preventthe increase in the urinary excretion of cortisol, adrenaline,noradrenaline and nitrogen both on separate days and on cumulativemeasurements over 4 days. Pain scores did not correlate to urinaryexcretion of the various endocrine-metabolic indices eitheron separate days or over the cumulative 4-day period. It isconcluded that the relief of pain per se has no major influenceon the catabolic response to abdominal surgery.