Delivery of carbohydrate at a rate > 4-5 mg per kg per minute will exceed the maximum rate of glucose oxidation. In the past it was not uncommon to find dextrose content at or exceeding this level.
Complications of dextrose overfeeding:
(1) hyperosmolar state, with osmotic diuresis, dehydration and potential for coma
(2) steatohepatitis
(3) respiratory depression with risk of progression to failure
(4) rebound hypoglycemia
(5) immunosuppression with increased risk of sepsis
(6) altered perfusion secondary to release of catecholamines
(7) impaired renal function
(8) acidosis (? mixed metabolic and respiratory)
(9) electrolyte imbalances
Laboratory findings:
(1) hyperglycemia
(2) azotemia
(3) acidosis
(4) hypertriglyceridemia
(5) abnormal liver function tests
(6) positive blood cultures
In a critically ill patient these findings may be ascribed to concurrent diseases and the link to parenteral nutrition may not be recognized.
Current recommendations (Maloo and Forse) is to not exceed 4 mg per kg per minute of carbohydrate. The infusion estimates needs to consider all sources of dextrose, since medications may be suspended in dextrose solutions that can add to the carbohydrate load.
