[Anesthetic management of a patient with ornithine transcarbamylase deficiency]

A 6-year-old female with disturbance of consciousness (JCS: 3 points) due to hyperammonemia caused by ornithine transcarbamylase deficiency is presented. She underwent an emergency insertion of a catheter for peritoneal dialysis under general anesthesia. Anesthesia was induced by intravenous administration of thiamylal sodium and maintained with inhalation of sevoflurane and oxygen after tracheal intubation. One percent mepivacaine was infiltrated around the surgical field to diminish the dose of sevoflurane. The operation proceeded uneventfully, although her consciousness could not recover rapidly to the normal level during the emergence from anesthesia. Peritoneal dialysis was started immediately after the operation and her consciousness recovered to the normal level gradually during the following six days with decreasing plasma ammonia levels. Ten days later, extirpation of the peritoneal catheter was scheduled. The course of anesthesia and operation was uneventful using the same anesthetic method as with the former anesthesia. In the anesthetic management for a patient with ornithine transcarbamylase deficiency, we have to be careful about the nitrogen balance, which can be affected by the kind and doses of anesthetic drugs, to avoid hyperammonemia. From this point of view, local anesthesia combined with general anesthesia might be useful to prevent the serum ammonia level from increasing.