What are the recommended IV fluids for managing brain injury?

Recommended IV Fluids for Managing Brain Injury

Isotonic crystalloids, particularly 0.9% saline, are recommended as first-line fluid therapy in patients with acute brain injury to reduce mortality and improve neurological prognosis. 1

First-Line Fluid Therapy

• Isotonic crystalloids should be used as first-line fluid therapy in brain injury patients, with 0.9% saline being the most commonly recommended option 1
• Solutions are considered isotonic when their osmolarity ranges from 280 to 310 mOsm/L (examples include 0.9% NaCl, Plasma-Lyte, Isofundine) 1
• Isotonic fluids should be administered cautiously to maintain hydration while preventing volume overload during patient transfer 1

Fluids to Avoid

• Hypotonic solutions (< 280 mOsm/L) should be avoided in patients with acute brain injury due to the risk of inducing cerebral edema 1
• Gelatins, Ringer's lactate (compound sodium lactate), and Ringer's acetate are hypotonic when real osmolality is determined and should be avoided 1
• A multicenter study comparing pre-hospital use of hypotonic solutions (Ringer Lactate) to isotonic solutions (0.9% NaCl) in traumatic brain injury patients reported higher mortality in the Ringer Lactate group 1

Colloids and Albumin

• Synthetic colloids are not recommended for brain injury patients as they may be associated with worse neurological prognosis 1
• Albumin should be avoided in traumatic brain injury patients as it has been associated with increased mortality 1
• The SAFE study reported increased mortality in the subgroup of traumatic brain injury patients treated with 4% albumin (RR 1.63, p = 0.003) 1

Special Considerations

• Hypertonic saline solutions may be beneficial in specific scenarios:

  • In situations combining hemorrhagic shock with severe head trauma and focal neurological signs, administration of a hypertonic saline bolus is recommended due to its osmotic effect 1
  • Mannitol (0.25 to 2 g/kg body weight as a 15% to 25% solution) can be used for reduction of intracranial pressure and brain mass 2

• Fluid management goals:

  • Maintain euvolemia - both hypovolemia and hypervolemia can be detrimental 1, 3
  • Avoid fluid restriction to excess as it may result in hypotension episodes, which can increase ICP and are associated with worse neurological outcomes 4

Monitoring Parameters

• Monitor electrolyte levels regularly, as fluid therapy can lead to electrolyte imbalances 3, 5
• Watch for signs of hyperchloremic metabolic acidosis with prolonged use of 0.9% saline 1
• Discontinue mannitol if renal, cardiac, or pulmonary status worsens 2

Common Pitfalls to Avoid

• Administering hypotonic solutions like 5% dextrose in water, which can reduce serum sodium and increase brain water and ICP 4
• Pursuing excessive fluid restriction, which may lead to hypotension and worsen neurological outcomes 4
• Using albumin in traumatic brain injury patients due to increased mortality risk 1
• Administering large volumes of fluid aimed at achieving hypervolemia, which has shown evidence of harm in cases of subarachnoid hemorrhage 5

While there is some evidence suggesting that balanced crystalloids may reduce the risk of hyperchloremia compared to 0.9% NaCl, current guidelines cannot positively affirm their superiority in brain injury patients 1. The most recent and highest quality evidence strongly supports the use of isotonic crystalloids, particularly 0.9% saline, as the first-line fluid therapy for managing patients with brain injury.