Preventing Osmotherapy Inertia: A Reassessment-Based Strategy to Reduce Unnecessary Osmotic Therapy in Neurocritical Care

Hyperosmolar therapies like mannitol and hypertonic saline are commonly employed to treat elevated intracranial pressure (ICP) in traumatic brain injury (TBI), subarachnoid hemorrhage, and malignant cerebral edema.[1] [2] Once begun, however, these therapies are continued automatically—despite changes in clinical context or risk-to-benefit balance. This practice, which we call “osmotherapy inertia,” can lead to iatrogenic injury by creating persistent osmotic imbalance, electrolyte disturbances, or rebound cerebral edema.[3] Contemporary neurocritical care has a goal-oriented, personally directed style and frequent reassessment of therapy.[4] The present article suggests an easily implemented reassessment algorithm, a daily evaluation algorithm, and a “STOP criteria” checklist for facilitating safe osmotherapy reduction.

Understanding Osmotherapy Inertia

In certain clinical environments, initial osmotherapy use is appropriate—due to an acute increase in ICP or worsening neurological status. However, once osmotic therapy is begun, subsequent doses might be repeated routinely or according to protocol, instead of necessity. This can lead to unwarranted consequences including fluid shifts and electrolyte imbalance, rising serum osmolality to or above 320 mOsm/kg, deterioration of renal function, and delayed weaning of the treatment and observation for improvement.[5] A prolonged osmotherapy without clear indications also increases the likelihood of rebound intracranial hypertension, particularly when the treatment is abruptly discontinued after days of use.

 

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Challenges

To avoid osmotherapy inertia, we suggest a formal daily reassessment of key parameters. Daily reassessment should include bedside examination for improved consciousness, resolution of pupillary asymmetry, and other indicators of stabilization. The review of ICP trends includes that a single spike in ICP is not necessarily a reason for continued therapy. Other parameters include 24-hour trends in serum osmolality with > 320 mOsm/kg should lead to immediate reconsideration of continuing therapy.

 

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Introducing the STOP Criteria

The following checklist aids clinicians in ascertaining when it is optimal to STOP or taper osmotherapy ([Fig. 1]). Where two or more STOP criteria are present, tapering or discontinuation of osmotherapy must be given serious consideration, with proper clinical monitoring.

Fig. 1 The STOP criteria for osmotherapy discontinuation.

 

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Case Example

A 56-year-old man with severe TBI received 20% mannitol boluses every 6 hours for 3 days. On day 4, his neuro exam stabilized (Glasgow Coma Scale 10, reactive pupils), ICP level was < 15 mm Hg, and serum osmolality was 319 mOsm/kg. Adopting the STOP criteria:

• No elevation of ICP in 24 hours → Yes

• Stable neuro exam → Yes

• Osmotic risks are escalating → Yes

• Osmolality at ceiling → Yes

All of these were achieved. Mannitol was tapered over 24 hours and the patient remained stable without any rebound increase in ICP.

 

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Clinical Use

While abrupt cessation may be acceptable after brief use, patients treated for several days require careful weaning, particularly if signs of blood–brain barrier disruption or impaired autoregulation exist. For patients receiving osmotherapy for more than 48 to 72 hours, tapering rather than sudden withdrawal is recommended, wean slowly to prevent the rebound phenomenon.[6] Transition to enteral sodium therapy: Oral salt tablets or food sodium can be employed in maintenance in carefully chosen stable patients after intravenous therapy. Adopt protocolized weaning: Incorporate osmotherapy discontinuation milestones into daily intensive care unit (ICU) rounds or checklists. By implementing goal-driven reassessment and the STOP criteria, osmotherapy use becomes more efficient, rational, and patient-specific. Additionally, clinicians must strike a balance between preventing secondary brain injury and avoiding overtreatment.

 

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Conclusion

“Osmotherapy inertia” is an underrecognized but clinically important phenomenon in neurocritical care. We should recognize that osmotherapy inertia can lead to prolonged ICU stays, fluid-electrolyte disorders, and increased cost. Daily reassessment, guided by ICP trends, neurological recovery, and biochemical parameters, allows clinicians to make informed decisions about continuation or cessation. The STOP criteria serve as a practical framework to promote safe, timely deescalation, and to minimize osmotherapy-related harm.

 

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Conflict of Interest

None declared.

• References

• 1 Himmelseher S. Hypertonic saline solutions for treatment of intracranial hypertension. Curr Opin Anaesthesiol 2007; 20 (05) 414-426
• 2 White H, Cook D, Venkatesh B. The use of hypertonic saline for treating intracranial hypertension after traumatic brain injury. Anesth Analg 2006; 102 (06) 1836-1846
• 3 Kochanek PM, Adelson PD, Rosario BL. et al; ADAPT Investigators. Comparison of intracranial pressure measurements before and after hypertonic saline or mannitol treatment in children with severe traumatic brain injury. JAMA Netw Open 2022; 5 (03) e220891
• 4 Castillo LB, Bugedo GA, Paranhos JL. Mannitol or hypertonic saline for intracranial hypertension? A point of view. Crit Care Resusc 2009; 11 (02) 151-154
• 5 Hirsch KG, Spock T, Koenig MA, Geocadin RG. Treatment of elevated intracranial pressure with hyperosmolar therapy in patients with renal failure. Neurocrit Care 2012; 17 (03) 388-394
• 6 Kim JH, Jeong H, Choo YH. et al. Optimizing mannitol use in managing increased intracranial pressure: a comprehensive review of recent research and clinical experiences. Korean J Neurotrauma 2023; 19 (02) 162-176

Publication History

Article published online:
09 August 2025