Composition of 5% Dextrose Saline
5% dextrose saline contains 50 grams of dextrose per liter (5 grams per 100 mL) plus 0.9% sodium chloride (9 grams of NaCl per liter), providing both glucose supplementation and isotonic sodium replacement simultaneously. 1
Detailed Composition
- Dextrose component: 5% concentration equals 5 grams of dextrose per 100 mL, totaling 50 grams per liter 1
- Saline component: 0.9% sodium chloride solution, which equals 9 grams of sodium chloride per liter 1
- Osmolality: Approximately 560 mOsm/L total (300 mOsm/L from the sodium chloride component plus 260 mOsm/L from dextrose) 2
Clinical Context
The solution delivers both metabolic substrate (glucose) and electrolyte replacement, making it distinct from either component alone. 1 Once the dextrose is metabolized, the remaining osmotic load comes primarily from the sodium chloride, effectively functioning as normal saline. 2
Key Clinical Applications
- Medication vehicle: Used as a diluent for vasopressors like dopamine (400 mg in 500 mL) and vasopressin (25 units in 250 mL) 3
- Surgical rehydration: Can be used for postoperative fluid replacement, though causes transient hyperglycemia (72% of patients exceed 10 mmol/L glucose after 500 mL infusion) 4
- DKA management: Appropriate when serum glucose reaches 250 mg/dL during diabetic ketoacidosis treatment to prevent hypoglycemia while continuing insulin therapy 2
Important Caveats
- Hyperglycemia risk: Even 500 mL causes significant transient hyperglycemia (mean 11.1 mmol/L at 15 minutes post-infusion) in non-diabetic surgical patients 4
- Not for head trauma: Worsens cerebral edema compared to normal saline alone in closed head trauma due to hyperglycemia effects 5
- Diabetes consideration: The dextrose content must be factored into glucose management in diabetic patients receiving this as a medication vehicle 1