What is the recommended choice of fluid for neonates in the intensive care unit (ICU)?

Recommended Choice of Fluid for Neonates in the ICU

Isotonic saline (0.9% saline) is the first-choice fluid for resuscitation and maintenance in neonates in the intensive care unit. 1

Rationale for Isotonic Saline as First Choice

• Isotonic saline is recommended as the first-line fluid for neonates with hypovolemia based on comprehensive evidence review by the Dutch Pediatric Society, which found no advantage of colloids over crystalloids 1
• Crystalloid solutions are specifically indicated as the fluid of choice in neonates with hemoglobin >12 g/dL according to the American College of Critical Care Medicine guidelines 1
• Isotonic saline is significantly more cost-effective than colloid solutions (approximately 1.5 Euro vs. 140 Euro for albumin), providing similar clinical outcomes at substantially lower cost 1

Clinical Benefits of Isotonic Saline

• Isotonic saline helps reduce the incidence of hospital-acquired hyponatremia compared to hypotonic solutions, which is particularly important in critically ill neonates 2
• Full-volume isotonic maintenance fluids have been associated with shorter ICU stays compared to hypotonic fluid regimens 2
• In neonates with septic shock, fluid resuscitation should be directed at clinical endpoints including perfusion and central venous pressure, with crystalloids being the recommended initial choice 1

Special Considerations for Fluid Administration

• Initial fluid volume should be 10-20 ml/kg, with repeated doses based on individual clinical response 1
• For neonates with hemoglobin <12 g/dL, packed red blood cells can be considered for transfusion rather than crystalloids 1
• When large amounts of fluids are required (e.g., in sepsis), synthetic colloids may be considered as a second-line option due to their longer duration in circulation 1

Potential Alternatives in Specific Situations

• Balanced crystalloid solutions (like Ringer's lactate or Plasma-Lyte) may be beneficial in certain circumstances, particularly for reducing the risk of acute kidney injury in septic shock 3
• Recent evidence suggests balanced solutions may result in:
  • Slight reduction in hospital stay compared to 0.9% saline 4
  • Lower incidence of hypokalaemia after intravenous correction 4
  • Better correction of metabolic acidosis with higher increases in blood pH and bicarbonate levels 4

Cautions and Contraindications

• Hypotonic solutions should be avoided in neonates at risk for cerebral edema 5
• Albumin and other colloids carry potential risks including:
  • Infection hazard due to being biological products 1
  • Risk of anaphylactic reactions 1
  • Significantly higher cost without proven benefits over crystalloids 1
• In neonates who become 10% fluid overloaded and unable to maintain fluid balance with native urine output, diuretics or continuous renal replacement therapy should be considered 1

Monitoring During Fluid Administration

• Therapeutic endpoints to monitor include: capillary refill ≤2 seconds, normal pulses, warm extremities, urine output >1 mL/kg/h, normal mental status, normal blood pressure for age, and arterial oxygen saturation >95% 1
• A D10%-containing isotonic IV solution run at maintenance rate can provide age-appropriate glucose delivery to prevent hypoglycemia 1