When is D5 (5% dextrose in water) administered?

When D5W (5% Dextrose in Water) is Administered

D5W is primarily indicated for preventing hypoglycemia in patients who cannot maintain adequate oral intake, particularly in fasting states, and for treating hypernatremia, but should be avoided as routine maintenance fluid in most hospitalized children due to hyponatremia risk.

Primary Clinical Indications

Prevention of Hypoglycemia During Fasting

• D5W is recommended for patients with nephrogenic diabetes insipidus who must fast for prolonged periods (>4 hours), such as before anesthesia, administered at usual maintenance rates 1
• In these patients, D5W provides no renal osmotic load, which typically decreases urine volume considerably, though blood glucose monitoring is crucial as glucose infusion can paradoxically cause hyperglycemia with subsequent osmotic diuresis 1
• Despite average fasting times of nearly 13 hours in elective surgery patients, hypoglycemia does not typically occur, making routine D5W unnecessary for preventing hypoglycemia in non-diabetic surgical patients 2

Treatment of Hypernatremia

• D5W is the preferred fluid for treating hypernatremic dehydration in patients with nephrogenic diabetes insipidus because salt-containing solutions (like 0.9% NaCl) should be avoided due to their large renal osmotic load 1
• The tonicity of isotonic saline (300 mOsm/kg H₂O) exceeds typical urine osmolality in nephrogenic diabetes insipidus (100 mOsm/kg H₂O) by approximately 3-fold, requiring about 3 liters of urine to excrete the osmotic load from 1 liter of isotonic fluid, risking serious hypernatremia 1
• For ICU-acquired hypernatremia, parenteral D5W demonstrates slightly greater effectiveness than enteral free water, with an estimated mean decrease of -2.25 mEq/L per liter of D5W versus -1.91 mEq/L per liter of enteral free water 3

Diabetic Ketoacidosis Management

• In diabetic ketoacidosis, fluid should be changed to 5% dextrose with 0.45-0.75% saline once serum glucose reaches 250 mg/dL 1
• This prevents hypoglycemia while continuing insulin therapy and allows for continued correction of the underlying metabolic acidosis 1

Medication Vehicle

• D5W serves as a vehicle for specific medication infusions including dopamine (2-20 mcg/kg/min in 500 mL D5W), epinephrine (1 mg in 250 mL D5W yielding 4 mcg/mL), and sodium bicarbonate for tricyclic antidepressant toxicity (150 mEq NaHCO₃ per liter D5W) 4
• Amiodarone continuous infusion can be administered at concentrations not exceeding 2 mg/mL diluted with D5W 4

Important Contraindications and Cautions

Routine Maintenance Fluids in Children

• Hypotonic maintenance fluids including D5 0.45% NaCl (containing 77 mEq/L sodium) are associated with increased risk of hospital-acquired hyponatremia compared to isotonic fluids (140 mEq/L sodium) 1
• Hyponatremic encephalopathy is a medical emergency that can be fatal or lead to irreversible brain injury if inadequately treated 1
• Acutely ill children frequently have conditions associated with arginine vasopressin excess (pain, nausea, stress, postoperative state, pneumonia, meningitis) that impair free-water excretion and increase hyponatremia risk when hypotonic fluids are administered 1

Hyperglycemia Risk

• Administration of 500 mL of 5% dextrose in 0.9% normal saline causes significant hyperglycemia (mean 11.1 mmol/L) in 72% of non-diabetic patients 15 minutes after completion of infusion 2
• When D5W is used, the dextrose content must be considered in patients with diabetes or other glucose metabolism disorders, requiring blood glucose monitoring 5, 4
• Regular control of blood glucose is recommended when using D5W, as glucose infusion can lead to hyperglycemia 1

Electrolyte Considerations

• Changing drug diluent from D5W to saline significantly increases the incidence of hypernatremia (27.3% vs 14.6%) and hyperchloremia (36.9% vs 20.4%) 6
• Drug diluents can account for 21.4% of total infusion volume in critically ill patients, making the choice clinically significant 6

Monitoring Requirements

• Blood glucose levels should be monitored when using any dextrose-containing solution, especially in diabetic patients 4
• In diabetic emergencies, hourly monitoring is recommended 4
• Patients with cardiac or renal compromise should be monitored for fluid overload regardless of diluent choice 4
• The induced change in serum osmolality should not exceed 3 mOsm/kg H₂O per hour when treating hypernatremia 1