Glycogen Storage Disease (GSD)

Get the subtype and the fasting tolerance - The plan hinges on which enzyme is missing. Ask the metabolic team for the specific type and for the patient's own documented fasting tolerance: symptoms after a short fast point to type I or III, symptoms only after an overnight fast to type 0, VI, or IX. Write NPO orders from that number, not from a standard schedule.

Shorten the fast and run dextrose - Book the case first on the list and keep a dextrose-containing infusion running through the fast and the case, with frequent point-of-care glucose. Hypoglycemia in these patients has caused seizures and, with repeated episodes, cerebral injury.

Glucagon will not rescue them - Glucagon only works for insulin-mediated hypoglycemia and will not raise glucose in a GSD patient. Treat hypoglycemia with a fast-acting carbohydrate source or parenteral glucose.

Follow lactate in type I - Type I runs a lactic acidosis, so trend serum lactate alongside a blood gas rather than assuming the base deficit is from perfusion. Persistent lactic acidosis in these patients is treated with oral citrate or bicarbonate.

Baseline ECG and echocardiogram - Hypertrophic cardiomyopathy is present in about 92% of infantile-onset Pompe disease with left ventricular outflow obstruction, and is a classic complication of type III. Get the echo and ECG. In Pompe with cardiac involvement, digoxin and inotropes worsen the outflow obstruction — pick a different way to support the pressure.

Airway and respiratory reserve in Pompe - Macroglossia occurs in about 62% of infantile-onset cases; expect a harder laryngoscopy. Respiratory failure is the most common cause of death in this disease, from diaphragm involvement in the late-onset form. Get a chest radiograph and a vital capacity where the patient can perform it, and plan for postoperative CPAP or BiPAP rather than assuming a straightforward extubation.

Aspiration risk with feeding difficulty - Poor feeding, gastroesophageal reflux, and swallowing dysfunction are common enough that video swallow studies are part of the workup in late-onset Pompe. Treat these patients as a full stomach and secure the airway accordingly.

Protect muscle in the myopathic types - Rhabdomyolysis in types V and XIII can drive acute renal injury and catastrophic hyperkalemia. The ischemic forearm test with a cuff was abandoned precisely because it caused rhabdomyolysis and compartment syndrome — the same logic argues against prolonged limb ischemia on the table. Send a baseline CK, watch urine color, and check a potassium if the urine darkens.

Bleeding tendency in type I - Type I patients can develop a bleeding disorder from impaired platelet function, and a normal platelet count does not exclude it. Check the hemoglobin, discuss with hematology before a case where hemostasis matters, and have blood available.

Renal function is not incidental - Type I brings proximal renal tubular and glomerular dysfunction and can progress to renal failure, with anemia of chronic kidney disease worsened by iron deficiency, chronic metabolic acidosis, or a bleeding diathesis. Get a creatinine and a hemoglobin, and dose renally cleared drugs from the result.

Neutropenia in type Ib - Type Ib patients have neutropenia ranging from mild to complete agranulocytosis and already show increased infection rates at surgical sites. Check a CBC with differential and hold a strict aseptic technique for lines and blocks.

Hepatomegaly changes the abdomen - Hepatomegaly is universal in type I from fat and glycogen deposition, with hepatic adenomas that can transform and, in type IV, progressive cirrhosis. It matters for positioning, for abdominal access, and as a marker of how advanced the disease is.

Surgery is a documented stress point - Pompe patients heading into a stressful state such as surgery or pregnancy are specifically flagged for close cardiac and respiratory surveillance. Plan a monitored bed rather than a same-day discharge.

Glycogen storage diseases are inherited inborn errors of carbohydrate metabolism in which a missing or defective enzyme blocks glycogen synthesis or breakdown. Most are autosomal recessive; type IX is X-linked. The liver holds about 10% of its weight as glycogen and muscle about 2%, and each pool serves a different job — hepatic glycogen defends serum glucose between meals, muscle glycogen fuels anaerobic work.

Hepatic forms (0, I, III, VI, IX) cannot release glucose into the blood, so fasting produces hypoglycemia, hepatomegaly, hyperuricemia, and hyperlipidemia; type I also generates lactic acidosis because accumulated glucose-6-phosphate drives glycolysis. Muscle forms (V, VII, XIII) present with cramps, exercise intolerance, rhabdomyolysis, and myoglobinuria. Type II (Pompe) is a lysosomal disease with glycogen accumulation in striated muscle, hypertrophic cardiomyopathy, and progressive respiratory failure. The subtype, not the label, drives the anesthetic.