RESUMO
Ornithine transcarbamylase deficiency (OTCD) is the most common inborn error of the urea cycle. Several specific factors require care during anesthesia in patients with this condition to avoid metabolic decompensation with acute hyperammonemia and encephalopathy. We report monozygous twins with severe neonatal-onset OTCD undergoing general anesthesia twice each, with midazolam, s-ketamine, fentanyl and isoflurane in combination with surgical field infiltration with ropivacaine. Alternative pathway medication and high-caloric diet with 10% glucose solutions were continuously administered during the perioperative course. Both children were extubated within 10 min of the final suture, and their neurological state remained unchanged. Perioperatively, blood ammonia levels remained within the normal range.