Dextrose Metabolism in the Body
Primary Metabolic Pathway
Dextrose (D-glucose) undergoes oxidation to carbon dioxide and water when administered intravenously, serving as the primary metabolic fuel for multiple organ systems. 1
Tissue Utilization and Distribution
Dextrose serves as metabolic fuel for muscle, liver, heart, kidneys, and gut, while functioning as the obligate energy source for brain, renal medulla, and erythrocytes. 2
Upon intravenous administration, dextrose is rapidly metabolized and distributed throughout body tissues, with water accounting for approximately 70% of total body weight and serving as the medium for dextrose distribution. 1
Glucose is utilized by all cells and represents the main carbohydrate reaching peripheral tissues from normal dietary intake. 2
Metabolic Effects and Functions
Dextrose administration restores blood glucose levels in hypoglycemia and provides a source of carbohydrate calories. 1
Carbohydrate in the form of dextrose aids in minimizing liver glycogen depletion and exerts a protein-sparing action. 1
During fetal life, approximately 5 mg/kg per minute (7 g/kg per day) of glucose crosses the placenta, establishing glucose as the main carbohydrate utilized during development. 2
Regulation During Illness and Stress
Glucose metabolism is highly modified during acute critical illness in neonates and children, with protein catabolism remaining unchanged despite increasing glucose intake. 2
Surgical stress blunts the inhibitory effect of intravenous dextrose on endogenous glucose production, with studies demonstrating that the normal suppression of hepatic glucose output is less pronounced during operative procedures. 3
The inhibitory influence of exogenous dextrose on endogenous glucose production is less pronounced during injury and sepsis compared to normal physiologic states. 3
Clinical Considerations for Metabolism
Slow infusion of hypertonic dextrose solutions is essential to ensure proper utilization and avoid production of hyperglycemia. 1
Even relatively small volumes (500 mL) of dextrose-containing solutions can cause significant hyperglycemia in non-diabetic patients, with plasma glucose exceeding 10 mmol/L in 72% of patients receiving 5% dextrose in normal saline. 4
Dextrose is rapidly metabolized upon infusion, which is why osmolarity calculations for dextrose-containing solutions typically exclude the dextrose component. 2
Age-Specific Metabolic Considerations
Glucose metabolism is influenced by age, acute illness, nutritional state, and concomitant provision of other macronutrients, requiring individualized dosing strategies. 2
In parenteral nutrition, dextrose (provided as D-glucose monohydrate) usually contributes most to the osmolality of the solution and should be balanced against the risks of overfeeding and excess glucose load. 2