What are the indications and precautions for using D5NM (5% dextrose in normal saline) and Dextrose 10% in water for intravenous fluid management in patients?

D5NM (5% Dextrose in Normal Saline) and Dextrose 10% in Water: Clinical Applications and Precautions

D5NM (5% dextrose in 0.9% normal saline) should be reserved for specific scenarios including DKA management once glucose reaches 250 mg/dL, while Dextrose 10% in water is primarily indicated for pediatric hypoglycemia prevention and hypernatremic dehydration correction, with both solutions requiring careful monitoring to avoid hyperglycemia, electrolyte disturbances, and fluid overload. 1, 2

D5NM (5% Dextrose in Normal Saline) - Composition and Primary Indications

Composition

• Contains 50 grams of dextrose per liter (5% concentration) plus 0.9% sodium chloride (9 grams NaCl/L), providing both glucose supplementation and isotonic sodium replacement simultaneously 1, 3
• Delivers tonicity of approximately 300 mOsm/kg H₂O from the sodium chloride component 1

Primary Clinical Applications

Diabetic Ketoacidosis (DKA) Management:

• Switch from normal saline to D5NS when serum glucose reaches 250 mg/dL during DKA treatment to prevent hypoglycemia while continuing insulin therapy to clear ketoacidosis 1
• This recommendation carries Grade A evidence from the American Diabetes Association 1
• Alternative formulations include D10 with 0.45-0.75% saline for DKA after initial resuscitation 1

Anaphylaxis and Emergency Resuscitation:

• Can be used as a vehicle for epinephrine infusions in anaphylaxis management, where 1 mg (1 mL) of 1:1000 epinephrine is added to 250 mL of D5W to yield 4.0 mcg/mL concentration 4
• Normal saline is preferred for initial volume resuscitation in anaphylaxis; dextrose solutions are used primarily as medication vehicles 4

Medication Administration:

• Serves as a vehicle for vasopressor administration and other medications requiring glucose-containing solutions 3

Dextrose 10% in Water - Composition and Primary Indications

Composition

• Contains 100 grams of dextrose per liter (10% concentration) with no sodium 1
• Delivers essentially no renal osmotic load once dextrose is metabolized 1

Primary Clinical Applications

Pediatric Hypoglycemia Prevention:

• Infants dependent on IV fluids and at risk for hypoglycemia benefit from D10 normal saline to meet glucose requirements of 4-6 mg/kg/min 1
• This is particularly important for neonates and infants who cannot tolerate oral intake 1

Hypernatremic Dehydration:

• In hypernatremic dehydration, 5% or 10% dextrose is preferred over DNS or normal saline-containing solutions, as it prevents worsening of hypernatremia 1
• Allows for slow, controlled decrease in plasma osmolality without adding osmotic burden 1
• The European Society of Pediatric Nephrology recommends dextrose solutions for this indication 1

Prolonged Fasting (>4 hours):

• For patients who cannot self-regulate fluid intake and must fast for >4 hours, 5% dextrose in water at usual maintenance rate provides no renal osmotic load and typically decreases urine volume considerably 1

Critical Monitoring Requirements

Glucose Monitoring

• Monitor serum glucose hourly during acute resuscitation, then every 2-4 hours once stable (Grade A evidence from American Diabetes Association) 1
• The maximum rate at which dextrose can be infused without producing glycosuria is 0.5 g/kg of body weight/hour 2
• About 95% of dextrose is retained when infused at a rate of 0.8 g/kg/hr 2
• Blood glucose monitoring is essential, and insulin should be added if necessary to minimize hyperglycemia and consequent glycosuria 2

Electrolyte Monitoring

• Electrolyte deficits, particularly serum potassium and phosphate, may occur during prolonged use of concentrated dextrose solutions 2
• Blood electrolyte monitoring is essential and fluid and electrolyte imbalances should be corrected 2
• For hypernatremia correction, monitor serum sodium and osmolality to ensure correction rate does not exceed 8 mEq/day or 3 mOsm/kg H₂O per hour to prevent cerebral edema 1

Cardiovascular and Volume Status Monitoring

• Frequent assessment of cardiac, renal, and mental status during fluid resuscitation is required (Grade A evidence from American Heart Association) 1
• The intravenous administration can cause fluid and/or solute overloading resulting in dilution of serum electrolyte concentrations, overhydration, congested states, or pulmonary edema 2

Critical Precautions and Contraindications

Hyperglycemia Risk

• Even a relatively small volume of 500 mL D5NS causes significant, albeit transient, hyperglycemia in non-diabetic patients, with 72% exceeding 10 mmol/L plasma glucose 5
• Solutions containing dextrose should be used with caution in patients with known subclinical or overt diabetes mellitus 2
• Significant hyperglycemia and possible hyperosmolar syndrome may result from too rapid administration 2

Hyponatremia Risk

• D5-containing fluids can contribute to hyponatremia and cerebral edema in vulnerable populations 1
• The fall in serum sodium values is significant with hypotonic dextrose solutions, with significant risk of hyponatremia at 12 and 24 hours 6, 7

Neurosurgical Patients - ABSOLUTE CONTRAINDICATION

• In neurosurgical patients, hypotonic solutions including those with dextrose should be avoided to prevent cerebral edema 1
• For traumatic brain injury, 0.9% saline is recommended as first-line therapy, NOT dextrose-containing solutions 1
• Maintaining normal plasma osmolarity is crucial in neurosurgical patients 1

Administration Precautions

• 50% Dextrose is hypertonic and may cause phlebitis and thrombosis at the site of injection 2
• For peripheral vein administration, the solution should be given slowly, preferably through a small-bore needle into a large vein to minimize venous irritation 2
• Concentrated dextrose should be administered via central vein only after suitable dilution 2
• Care should be exercised to ensure that the needle is well within the lumen of the vein and that extravasation does not occur 2
• Concentrated dextrose solutions should NOT be administered subcutaneously or intramuscularly 2

Rebound Hypoglycemia Prevention

• When a concentrated dextrose infusion is abruptly withdrawn, follow with administration of 5% or 10% dextrose injection to avoid rebound hypoglycemia 2

Special Populations

Geriatric Patients

• Careful monitoring for fluid overload in geriatric patients receiving D5NS is required (Grade A evidence from American Geriatrics Society) to minimize risk of pulmonary edema 1
• Subcutaneous rehydration can use 5% dextrose solutions effectively in geriatric dehydration management 1

Pediatric Patients

• Particularly close observation for cerebral edema during osmolality correction in pediatric patients under 20 years is required (Grade A evidence from American Academy of Pediatrics) 1
• Pediatric patients unable to take oral intake should receive 2-3 L/m²/d of one quarter normal saline/5% dextrose 1

Patients with Renal or Cardiac Compromise

• Frequent reassessment to avoid iatrogenic fluid overload in patients with renal or cardiac compromise is required (Grade A evidence from American Heart Association) 1
• Patients with congestive heart failure or chronic renal disease should be observed cautiously to prevent volume overload 4

Common Pitfalls to Avoid

1. Using dextrose-containing solutions for initial volume resuscitation in anaphylaxis - Normal saline is preferred; dextrose is rapidly extravasated from intravascular circulation to interstitial tissues 4

2. Initiating IV fluid replacement with dextrose-containing solutions in elective surgery - This is not required to prevent hypoglycemia and causes significant hyperglycemia 5

3. Ignoring sodium and osmolality effects - D5-containing fluids can be dangerous in vulnerable populations, particularly neurosurgical patients 1

4. Failing to monitor for osmotic diuresis - Hyperglycemia from glucose infusion can lead to osmotic diuresis and worsen outcomes 1

5. Abrupt discontinuation of concentrated dextrose - Always transition to lower concentration dextrose to prevent rebound hypoglycemia 2