Abstracts

RATIONALE: The safety and physiologic effect of procedures requiring general anesthesia (GA) in children on the ketogenic diet (KD) has not been well described. This retrospective study was undertaken to better define the possible risks associated with such procedures. METHODS: The records of children treated with the KD at Children's Hospital (Boston, MA) from 1995 to present were reviewed. Seven children were identified who underwent procedures requiring GA. As a group, the 7 children had 20 such procedures. Each patient's clinical history including epilepsy type and treatment, anesthesia records, blood chemistries and postoperative course was reviewed in detail. RESULTS: The 7 children ranged in age from 1 to 6 years at the time of the surgeries. At time of the procedures, the children had been maintained on the KD diet for 2 to 55 months. The procedures ranged from central line placements to hemispherectomy. Anesthesia times ranged from 1 hour to 10 hours. The patients were managed perioperatively with only carbohydrate free solutions. During procedures longer than 1 hour, patients were monitored for electrolyte abnormalities, hypoglycemia and metabolic acidosis. Serum glucose remained stable in all patients throughout the procedures. Most of the patients experienced a decrease in serum pH and bicarbonate levels. Only on 3 occasions, intraoperative administration of IV bicarbonate was necessary. During the postoperative period, all of the patients continued on the KD without major disturbances in the mentioned parameters. During the perioperative period, no complications, other than the metabolic acidosis, occurred that could directly be related to the KD. No increase in seizure frequency was observed in the perioperative period. CONCLUSIONS: The risk of developing a metabolic acidosis appears to be increased in children on the KD who require GA for a surgical procedure. Despite the use of carbohydrate-free solutions, serum glucose levels remained fairly stable at low normal values. Procedures requiring GA appear safe in children on the KD; however, we recommend close monitoring of serum electrolytes and pH, with abnormalities treated when necessary.