Perioperative Management of Patients with Glycogen Storage Disease Type Ia

Abstract

Sir: With an incidence of approximately one in 20,000 live births and a phenotype described for almost every enzyme involved in the processing of glycogen, it is not uncommon to encounter a patient with one of the various glycogen storage diseases. A 13-year-old boy presented with an abdominal wound around the site of a gastrostomy tube. Formal closure was required, yet the patient’s care was complicated by his history of von Gierke disease (glycogen storage disease type Ia). He required no special medication but could not be without nutrition for more than 2 to 3 hours because of uncontrolled hypoglycemia. At home, his mother fed him small portions throughout the day and night supplemented by frequent doses of uncooked cornstarch. The glycogen storage diseases result from a defect in an enzyme required for either glycogen degradation or storage. Glycogen storage disease type Ia refers to a deficiency in glucose-6-phosphatase, which is required for conversion of glucose-6-phosphate to glucose. Glycogen storage disease type Ia is specifically characterized by severe fasting hypoglycemia, fatty infiltration of the liver, hepatomegaly, hyperlacticacidemia, hyperuricemia, and an increased amount of glycogen storage. As a result of the rapid fall in glucose level with fasting, careful management of the patient’s electrolyte levels is critical to any surgical plan. Strict avoidance of catabolic periods is important, because even brief episodes can lead to profound hypoglycemia, lactic acidosis, and seizure development. Several recommendations have been proposed as a guide for the perioperative management of patients with a glycogen storage disease. The patient should be admitted to the hospital the night before the procedure so that a continuous supply of glucose can be provided as soon as the patient is placed on nothing-by-mouth status. The specific fluid should be 10% dextrose in half normal saline solution run at roughly 1.25 to 1.5 times maintenance. The intravenous fluids should run uninterrupted and be replaced expeditiously if lost, because even a brief period without glucose can result in severe hypoglycemia and seizures as a result of the high insulin state. Other solutions, such as the standard 5% dextrose in half normal saline and lactated Ringer’s solution, should not be used. The patient’s blood glucose should be checked on arrival and be assessed at least hourly until the blood glucose level is stable. Thereafter, it may be checked every 2 hours while fasting. The intravenous fluid rate should also be titrated to keep the blood glucose concentration above 75 mg/dl. Intraoperatively, surgical stress may result in profound lactic acidosis. It is important that the dextrose be continued at the aforementioned rate even if hyperglycemia is occurring. Lowering of the infusion rate can result in unopposed counterregulatory hormones, which lead to severe lactic acidosis from glycogen degradation. In the face of severe acidosis, bicarbonate may be administered. Postoperatively, the dextrose infusion should not be stopped until the patient is tolerating adequate food and starch intake. Once enteral intake has been tolerated, the dextrose infusion should be weaned slowly over 2 to 3 hours. Rapid discontinuation may similarly result in hypoglycemia because of the inability to counterregulate high insulin concentrations. By following these recommendations, it is possible to minimize complications in this challenging population of patients. Justin Lipper, B.A. Mount Sinai Medical Center David A. Weinstein, M.D., M.M.Sc. University of Florida College of Medicine Gainesville, Fla. Peter J. Taub, M.D. Mount Sinai Medical Center New York, N.Y.