Is it appropriate to bolus with D5 (5% dextrose) 1/2 normal saline?

Do Not Bolus with D5 1/2 Normal Saline

D5 1/2 normal saline should never be administered as a rapid bolus due to the serious risk of rapid sodium decrease, cerebral edema, and hyponatremic encephalopathy. 1

Why D5 1/2 NS is Dangerous as a Bolus

D5 1/2 normal saline is a hypotonic solution containing only 77 mEq/L of sodium (compared to 154 mEq/L in normal saline), and rapid administration causes dangerous hyponatremia. 1 The American College of Nephrology explicitly recommends against bolus administration of this solution. 1

Mechanism of Harm

• Hypotonicity drives water into cells: The low sodium content causes rapid intracellular fluid shifts, particularly dangerous in the brain where swelling is constrained by the skull. 1
• Dextrose is ineffective for volume expansion: Dextrose rapidly extravasates from the intravascular space to the interstitial space, making it useless for actual volume resuscitation. 1
• SIAD risk in acutely ill patients: Non-osmotic stimuli for antidiuretic hormone release are frequently present in sick patients, making hypotonic fluid administration particularly dangerous as it can precipitate syndrome of inappropriate antidiuresis. 1
• Hyponatremic encephalopathy is a medical emergency that can be fatal or cause irreversible brain injury if inadequately treated. 1

What to Use Instead for Bolus Resuscitation

For any acute fluid resuscitation scenario requiring a bolus, use isotonic crystalloids only:

• 0.9% normal saline at 10-20 mL/kg boluses is the standard approach. 1
• Lactated Ringer's solution is an appropriate balanced crystalloid alternative, and the Surviving Sepsis Campaign now recommends balanced crystalloids over normal saline for sepsis resuscitation. 2
• D5 0.9% normal saline (which is isotonic) only if dextrose supplementation is specifically needed. 1

For septic patients specifically, the Society for Maternal-Fetal Medicine recommends an initial bolus of 1-2 L, increasing to 30 mL/kg within the first 3 hours for patients in septic shock or those with inadequate response. 2

Appropriate Uses of D5 1/2 NS (Never as Bolus)

D5 1/2 normal saline has legitimate clinical applications, but only as controlled infusions, never as boluses:

• Standard infusion rate in adults: 4-14 mL/kg/hour (approximately 100-280 mL/hour for a 70 kg adult), adjusted based on hydration status and corrected serum sodium. 3
• Maintenance fluid therapy in specific clinical contexts where hypotonic fluid replacement is appropriate. 3

Critical Monitoring Required

When using D5 1/2 NS even as an infusion:

• Monitor blood glucose levels frequently to avoid hyperglycemia. 3
• Check sodium and potassium levels regularly. 4
• Assess fluid input/output and hemodynamic parameters. 3
• In patients with renal or cardiac compromise, monitor serum osmolality and perform frequent cardiac, renal, and mental status assessments to avoid iatrogenic fluid overload. 3

Common Pitfalls to Avoid

• Do not assume adding dextrose to hypotonic saline makes it "safer" – tonicity is determined by sodium/potassium content, not glucose. 1
• Do not use hypotonic fluids in high-risk scenarios including CNS disorders, postoperative states, respiratory infections, or any condition predisposing to SIAD. 1
• Do not confuse maintenance fluids with resuscitation fluids – the 500 mL of D5 0.9% NS used in elective surgery caused significant hyperglycemia (>10 mmol/L in 72% of patients) even in non-diabetic patients, demonstrating that even modest dextrose loads can cause problems. 5