What is the difference between D5 (5% dextrose solution) and D50 (50% dextrose solution) in treating hypoglycemia?

D5 vs D50: Key Differences and Clinical Applications

Fundamental Composition Differences

D5 (5% dextrose) contains 5 grams of dextrose per 100 mL, while D50 (50% dextrose) contains 50 grams of dextrose per 100 mL—making D50 ten times more concentrated. 1

Concentration and Osmolarity

• D5 provides 0.05 grams per mL and has an osmolarity of approximately 252 mOsm/L (excluding dextrose, which is rapidly metabolized) 1
• D50 provides 0.5 grams per mL and is a hypertonic solution requiring careful administration 2, 3

Clinical Indications: When to Use Each

D5 (5% Dextrose Solution)

Use D5 for maintenance fluid therapy and prevention of hypoglycemia during insulin infusions, not for acute hypoglycemia treatment. 1, 3

• Maintenance IV fluids: D5 with 0.9% NaCl or lactated Ringer's is used for isotonic maintenance fluids in hospitalized children and adults 1
• DKA/HHS management: Switch to D5 with 0.45-0.75% NaCl when blood glucose reaches 250 mg/dL (DKA) or 300 mg/dL (HHS) to prevent hypoglycemia while continuing insulin 3
• Prevention during insulin therapy: Start 10% dextrose infusion immediately if enteral nutrition is interrupted in diabetic patients receiving insulin coverage 3
• Malaria treatment: D5 with half-normal saline is the IV fluid of choice in cerebral malaria to provide dextrose while minimizing salt leakage into tissues 1

D50 (50% Dextrose Solution)

Use D50 for acute treatment of severe hypoglycemia in patients with altered mental status or inability to take oral glucose. 2, 3, 4

• Severe hypoglycemia: Administer 10-20 grams (20-40 mL) of D50 intravenously, titrated based on initial blood glucose severity 2, 3, 4
• Emergency correction: D50 is the treatment of choice for hypoglycemia in critically ill patients due to faster onset compared to glucagon 3

Critical Safety Differences

D50 Administration Risks

Traditional 25-gram D50 boluses frequently cause overcorrection and hyperglycemia, with post-treatment glucose levels averaging 169 mg/dL versus 112 mg/dL with titrated lower doses. 2

• Cardiac complications: Rapid or repeated D50 boluses have been associated with cardiac arrest and hyperkalemia 2, 3, 4
• Overcorrection rate: Protocol-based D50 administration results in a 6.8% rate of hyperglycemia (>150 mg/dL) 5
• Venous irritation: D50 must be given slowly through a small-bore needle into a large vein to minimize thrombosis risk; concentrated solutions >10% requiring sustained infusion need central venous access 3, 4

D5 Safety Profile

• Hypotonic risk: D5 with 0.45% NaCl is hypotonic and can cause hyponatremia in acutely ill patients with SIAD-like states 1
• Insufficient for acute treatment: D5 alone is inadequate for rapid correction of severe hypoglycemia 4

Optimal Dosing Strategy for Hypoglycemia

For conscious patients with hypoglycemia, start with 10-15 grams (20-30 mL of D50) and reassess, rather than automatically giving the full 25-gram ampule. 2

Evidence-Based Titration Approach

• 5-gram aliquots: Administering 5-gram aliquots repeated every 1-2 minutes achieves symptom resolution with fewer adverse events than full 25-gram boluses 2, 6
• Recheck timing: Blood glucose must be rechecked at 15 minutes post-administration, as dextrose effects wane and hypoglycemia can recur 4, 5
• Target glucose: Aim for blood glucose >70 mg/dL (or >100 mg/dL in neurologic injury patients) while avoiding overcorrection 3, 4

Alternative: D10 Administration

Studies show D10 may be as effective as D50 at resolving symptoms with fewer adverse events, though taking approximately 4 minutes longer. 7, 6

• Symptom resolution: D10 achieved 95.9% symptom resolution versus 88.8% with D50, with no adverse events (0/1057) compared to 13/310 with D50 7
• Post-treatment glucose: D10 resulted in lower post-treatment glucose (6.2 mmol/L vs 8.5 mmol/L with D50) 7, 6
• Dosing: 5-gram aliquots of D10 (50 mL) repeated as needed, with median total dose of 10 grams versus 25 grams with D50 6

Common Pitfalls to Avoid

• Never administer D5 alone for acute hypoglycemia—it is insufficient for rapid correction 4
• Never delay repeat glucose checks beyond 15 minutes after D50 administration, as hypoglycemia can recur 4
• Never give full 25-gram D50 boluses routinely—this causes unnecessary hyperglycemia and increases adverse event risk 2, 7
• Never administer D50 rapidly through peripheral veins without proper technique to minimize venous damage 3, 4
• Never use hypotonic D5 solutions in acutely ill patients at risk for SIAD without careful sodium monitoring 1