SAFETY OF GENERAL-ANESTHESIA AND SURGERY IN ACUTE HEPATIC PORPHYRIA

Patients with acute hepatic porphyria are denied essential operations because of concern that general anaesthesia and surgery will precipita te a life threatening porphyric crisis. This study assessed the safety of surgery under general anaesthesia in these patients. A combined pr ospective and retrospective case note study, with a biochemical study, was conducted in 25 patients with acute hepatic porphyria undergoing 38 surgical operations. Clinical outcome measures were survival and oc currence of porphyric crisis after surgery. The biochemical activity o f porphyria was assessed by measurement of the perioperative 24 hour e xcretion of the haem precursors delta aminolaevulinic acid (ALA) and p orphobilinogen (PBG). There were no deaths or crises after 29 operatio ns in 19 patients who were known to have porphyria before their surger y, and therefore given only appropriate drugs. These operations includ e such major procedures as mitral valve replacement, hip replacement, coronary artery grafting, cholecystectomies, and renal transplantation . In eight of these patients the urinary excretion of ALA and PBG were studied, and showed no sustained postoperative increase. Nine operati ons were performed in eight patients before the diagnosis of porphyria was known and who thus received routine anaesthetic agents. Seven of these patients developed a postoperative porphyric crisis. Two of them died. It is concluded therefore that even the most major surgery can be undertaken safely in patients with porphyria. The risk is for undia gnosed cases.