From the Guidelines
Hypertonic saline is the primary alternative to mannitol for treating increased intracranial pressure (ICP), and it should be used instead of mannitol for this indication. According to the most recent and highest quality study 1, hypertonic saline is effective in reducing raised intracranial pressure, but it does not improve neurological outcomes or survival in states of raised intracranial pressure. The study recommends using intravenous hypertonic saline in the treatment algorithm for raised intracranial pressure, with 7.5% hypertonic saline boluses or 3% hypertonic saline continuous infusions being effective at reducing ICP in traumatic brain injury and subarachnoid haemorrhage.
Mechanism of Action
Hypertonic saline creates an osmotic gradient to pull fluid from brain tissue, reducing intracranial pressure. Other medications that can be used to treat increased ICP include:
- Loop diuretics like furosemide (20-40 mg IV), which reduce fluid volume
- Corticosteroids such as dexamethasone (4-10 mg IV every 6 hours), which decrease inflammation, but are not effective for traumatic brain injury
- Barbiturates like pentobarbital (loading dose 10 mg/kg followed by 1-3 mg/kg/hr) or propofol (starting at 10 mcg/kg/min, titrating up to 50-100 mcg/kg/min), which reduce cerebral metabolic demands
Non-Pharmacological Approaches
Non-pharmacological approaches to reduce ICP include:
- Head elevation to 30 degrees
- Maintaining normothermia
- Surgical interventions like decompressive craniectomy in extreme cases
Key Points
- Hypertonic saline is the primary alternative to mannitol for treating increased ICP
- Hypertonic saline should be used instead of mannitol for this indication
- The most effective concentrations of hypertonic saline are 7.5% boluses or 3% continuous infusions
- Other medications and non-pharmacological approaches can be used in conjunction with hypertonic saline to reduce ICP, as supported by studies 1.
From the Research
Alternatives to Mannitol for Increased Intracranial Pressure
- Hypertonic saline is a viable alternative to mannitol for the treatment of increased intracranial pressure, with some studies suggesting it may be more effective 2, 3, 4, 5, 6
- The optimal concentration of hypertonic saline for treating increased intracranial pressure is still a topic of debate, but 3% hypertonic saline has been identified as a potential optimal concentration 3
- Hypertonic saline has been shown to be equally effective as mannitol in reducing intracranial pressure in some studies 4, 5, while others suggest it may be superior 3, 6
- The choice between hypertonic saline and mannitol may depend on individual patient factors, such as serum sodium levels and systemic hemodynamics 5
Key Findings
- A systematic review of 19 studies found that hypertonic saline was equally efficacious as mannitol in 11 studies, and superior in 8 studies 3
- A study comparing equimolar doses of mannitol and hypertonic saline found that both treatments equally reduced intracranial pressure, but mannitol had additional effects on brain circulation 5
- An article reviewing the evidence for hypertonic saline and mannitol suggested that hypertonic saline should be considered the gold-standard medical therapy for intracranial hypertension 6