Hyperglycemia

Hyperglycemia (>180 to 200 mg/dL) is most often caused by insulin deficiency, insulin receptor resistance, or glucose overadministration. Hyperglycemia produces osmotic diuresis; exacerbation of brain, spinal cord,^[61] and renal damage^[62] by ischemia; delayed gastric emptying^[63] ; hypophosphatemia^[63] ; delayed wound healing^{[63] [64]} ; and impaired white blood cell function.^{[64] [65]} Maternal hyperglycemia increases the risk of neonatal jaundice, the risk of neonatal brain damage, and fetal acidosis if the fetus becomes hypoxic.

Even with supramaximal levels of insulin, adults can only use glucose at a rate of 3 to 5 mg/kg/min at rest (approximately 240 mL/hour of 5% solutions). The maximal rate of metabolism is less in stress states and more with increased metabolic rates. In general, the rate of administration should be limited to 2 to 3 mg/kg/min (120 to 180 mg/kg/hour), which is 100 g/hour for a 70-kg person (200 mL of a 5% dextrose solution/hour). Healthy infants and children become hyperglycemic if 5% dextrose is included in maintenance fluids.^[66] The maximal rate of glucose disposition in young children is 4 to 8 mg/kg/min, and the optimal rate is less than 5 mg/kg/min.^[67] It is not clear that glucose administration is necessary for intraoperative management of most patients.^[68]