How to administer D5 0.5NS (5% dextrose and 0.5 normal saline) solution to a patient requiring hydration?

Administration of D5 0.5NS (5% Dextrose in 0.5 Normal Saline)

Critical Safety Principle

D5 0.5NS should be administered intravenously at maintenance rates calculated by the Holliday-Segar formula, avoiding rapid boluses, as this hypotonic solution can cause significant electrolyte disturbances and is generally not the preferred fluid for most acute clinical scenarios. 1

Standard Administration Rates

Maintenance Fluid Calculation (Holliday-Segar Method)

• First 10 kg of body weight: 100 mL/kg/24 hours 1
• Second 10 kg (11-20 kg): Add 50 mL/kg/24 hours 1
• Each kg above 20 kg: Add 20 mL/kg/24 hours 1
• Adults: 25-30 mL/kg/24 hours 1

Practical Example

For a 15 kg child:

• First 10 kg: 1000 mL/24h
• Next 5 kg: 250 mL/24h
• Total: 1250 mL/24h or approximately 52 mL/hour 1

Clinical Context and Appropriate Use

When D5 0.5NS May Be Considered

D5 0.5NS is specifically recommended for cerebral malaria and volume depletion scenarios where minimizing salt load is critical, as it provides dextrose to prevent hypoglycemia while delivering less sodium that could leak into pulmonary and cerebral tissues. 1

Critical Contraindications and Cautions

• Avoid in hypernatremic dehydration: Salt-containing solutions should be avoided in nephrogenic diabetes insipidus and similar conditions because the tonicity (~300 mOsm/kg H₂O) exceeds typical urine osmolality, requiring approximately 3 liters of urine to excrete the osmotic load from 1 liter of fluid 1
• Risk of hyponatremia: Hypotonic fluids (0.45% saline in 5% dextrose) cause significantly greater falls in serum sodium at 12 and 24 hours compared to isotonic solutions, with increased incidence of mild and moderate hyponatremia 2
• Not for rapid resuscitation: This is a maintenance fluid, not a resuscitation fluid 1

Administration Technique

Intravenous Setup

• Use standard IV tubing with appropriate pump or gravity drip 1
• Calculate hourly rate based on 24-hour maintenance requirements 1
• Infuse continuously at calculated maintenance rate (not as boluses) 1

Monitoring Requirements

• Electrolytes (Na, K, Cl, HCO₃): Every 2-3 months in infants, every 3-12 months in children for chronic use 1
• Blood glucose: Monitor for both hypoglycemia and hyperglycemia, especially in critically ill patients 1
• Fluid balance: Strict intake/output monitoring 1
• Clinical signs: Watch for fluid overload (pulmonary edema, ARDS, worsening cerebral edema) 1

Preferred Alternatives in Common Scenarios

For Acute Dehydration

Use 5% dextrose in water (D5W) without added salt for hypernatremic dehydration, as it delivers no renal osmotic load and allows slow decrease in plasma osmolality. 1

For Standard Maintenance in Hospitalized Children

Current evidence supports 0.9% normal saline in 5% dextrose over hypotonic solutions to prevent iatrogenic hyponatremia, with significantly lower risk of electrolyte disturbances at 12 and 24 hours. 2

For Resuscitation

Use isotonic crystalloid (0.9% normal saline or lactated Ringer's) without dextrose for volume resuscitation, as dextrose-containing solutions cause transient but significant hyperglycemia even with small volumes. 3

Special Considerations

Dextrose Component

• The 5% dextrose provides 50 grams of glucose per liter 1
• Prevents hypoglycemia but can cause hyperglycemia: 500 mL of dextrose-containing solution causes plasma glucose >10 mmol/L in 72% of patients 3
• Dextrose addition to IV saline has not been shown to improve clinical outcomes in dehydrated children, though confidence intervals are wide 4

Sodium Content

• 0.5 normal saline contains approximately 77 mEq/L of sodium (half of 0.9% NS which has 154 mEq/L) 1
• This hypotonic nature increases risk of hyponatremia compared to isotonic solutions 2

Common Pitfalls to Avoid

• Never use for rapid bolus resuscitation: This can precipitate pulmonary edema, ARDS, or worsen cerebral edema 1
• Do not use in hypernatremic states without careful calculation: The sodium content may worsen hypernatremia despite being "half normal" 1
• Avoid in patients requiring strict sodium restriction: Consider D5W instead 1
• Monitor closely for hyponatremia: Hypotonic fluids carry significant risk of iatrogenic electrolyte disturbances 2