Can D5 (5% dextrose) 1/2 normal saline be given as a bolus?

D5 1/2 Normal Saline Should NOT Be Given as a Bolus

D5 1/2 normal saline (D5 0.45% NS) should not be administered as a rapid bolus due to the serious risk of rapid sodium decrease, cerebral edema, and hyponatremic encephalopathy. 1

Why Bolus Administration Is Dangerous

The primary concern with bolusing hypotonic dextrose solutions is the risk of precipitous decline in serum sodium concentration:

• D5 1/2 NS is hypotonic (containing only 77 mEq/L sodium compared to 154 mEq/L in normal saline), and rapid administration can cause dangerous hyponatremia 2
• Dextrose 5% solutions should not be administered as a bolus because of the risk of rapid decrease in serum sodium, which can lead to brain edema 1
• In acutely ill patients, non-osmotic stimuli for antidiuretic hormone release (pain, nausea, stress, postoperative states) are frequently present, making hypotonic fluid administration particularly dangerous as it can precipitate syndrome of inappropriate antidiuresis (SIAD) 2
• Hyponatremic encephalopathy is a medical emergency that can be fatal or cause irreversible brain injury if inadequately treated 2

Specific Clinical Scenarios Where This Is Contraindicated

Neurological Injury

• In patients with closed head trauma or stroke, hypotonic solutions like D5 1/2 NS worsen cerebral edema 3
• Research demonstrates that 0.45% saline significantly worsens brain tissue specific gravity (1.0366 ± 0.0025) compared to isotonic solutions (1.0389 ± 0.0049) two hours after closed head trauma 3

Resuscitation Scenarios

• For acute fluid resuscitation in hypovolemic shock, isotonic fluids are appropriate 1
• Normal saline boluses (10 mL/kg) are specifically recommended for hypotension in anaphylaxis and other shock states 1
• Dextrose is rapidly extravasated from intravascular to interstitial space, making it ineffective for volume resuscitation 2

When Dextrose-Containing Solutions ARE Appropriate

D5-containing solutions have specific roles, but not as boluses:

As Drug Diluents (Infusions, Not Boluses)

• Epinephrine infusions: 1 mg in 250 mL D5W yielding 4 mcg/mL 1, 4
• Sodium bicarbonate for tricyclic antidepressant toxicity: 150 mEq NaHCO3 per liter of D5W 1, 4
• Dopamine for refractory hypotension: 2-20 mcg/kg/min in 500 mL D5W 4

Special Exception: Nephrogenic Diabetes Insipidus

• In patients with nephrogenic diabetes insipidus (NDI), dextrose 5% solutions match the hypotonic urinary losses (very low sodium concentration) 1
• However, even in NDI patients, dextrose 5% solution should not be administered as a bolus due to the risk of rapid sodium decrease 1
• Isotonic fluids remain appropriate for acute fluid resuscitation even in NDI patients with hypovolemic shock 1

Recommended Alternatives for Bolus Administration

Use isotonic crystalloids for any bolus scenario:

• 0.9% normal saline is the standard for bolus resuscitation (10-20 mL/kg boluses) 1, 2
• Lactated Ringer's solution is an appropriate balanced crystalloid alternative 1, 2
• D5 0.9% normal saline (isotonic) if dextrose supplementation is specifically needed 2

Critical Pitfalls to Avoid

• Do not assume adding dextrose to hypotonic saline makes it "safer" - tonicity is determined by sodium/potassium content, not glucose 2
• Do not use hypotonic fluids in high-risk scenarios including CNS disorders, postoperative states, respiratory infections, or any condition predisposing to SIAD 2
• Transient hyperglycemia from dextrose boluses (plasma glucose >10 mmol/L in 72% of patients receiving 500 mL D5NS) is an additional concern, even in non-diabetic patients 5
• In pediatric gastroenteritis, while D5NS boluses (20 mL/kg) reduced ketone levels more than NS alone, there was no difference in hospitalization rates, questioning the clinical benefit 6