1. General consideration
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Raised Intracranial Pressure (ICP) is a very commonly encountered problem especially in patients with severe traumatic brain injury. |
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ICP > 22 mmHg is considered a raised ICP and is associated with increased mortality. |
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ICP monitoring and measurement can be done by using ICP monitoring catheters which can be placed in either brain parenchyma or ventricles of the brain. |
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Optic Nerve sheath diameter (ONSD) can be used as a surrogate measure for raised ICP in patients in whom ICP cannot be measured invasively or when invasive monitoring facility is unavailable. ● ONSD is a non-invasive method of ICP monitoring. ● ONSD cut off of > 5 mm usually corresponds to an ICP > 20 mmHg. ● While measuring ONSD, care should be taken not to cause any ophthalmic injury to the eyeball by avoiding application of excess pressure. Proper aseptic technique should be exercised. |
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Raised ICP if left unaddressed can lead to catastrophic consequences in the form of brain herniation and eventually death. |
2. Management of raised ICP
The management of ICP can be divided into 4 tiers which are discussed below. By Tier; it means different sets of treatment according to the severity of ICP. The tier of treatment subsequently increases as the severity of ICP increases.
2.1. Tier Zero (should be followed in all patients with neurological injury or patients at risk of developing increase in ICP)
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Serial evaluations of neurological status and pupillary reactivity. |
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Elevate Head of Bed 30-45 degrees. |
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Analgesia for management of pain. |
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Sedation to prevent agitation, ventilator asynchrony etc. |
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Temperature management to prevent fever. Treat if temperature >38 degrees Celsius. |
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Optimize venous return from head (keep head in midline position, ensure cervical collar is not too tight). |
2.2. Tier One
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Increase analgesia to achieve adequate pain control. Inadequate pain control can lead to sympathetic stimulation which eventually can raise the ICP. |
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Increase sedation to lower ICP. |
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Maintain normocapnia. (PaCO2:35-40 mmHg). |
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Maintain Cerebral Perfusion pressure (CPP) 60-70 mmHg. CPP can be calculated by deducting Central Venous Pressure from the Mean Arterial Pressure (MAP-CVP) |
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Administer Mannitol by intermittent bolus injection at a dose of (0.25- 1 g/kg). The bolus dose can be administered over duration of 30 minutes. |
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Administer hypertonic saline by intermittent bolus. It is recommended to consider sodium level and osmolality limits of 155 mEq/L and of 320 mEq/L as administration limits for hypertonic saline and mannitol respectively. |
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CSF drainage if EVD in situ. |
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Consider anti-seizure prophylaxis for 1 week unless there is an indication to continue further. |
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Consider EEG monitoring to detect non convulsive status epilepticus which is a potential cause of raised ICP. |
2.3. Tier Two
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Maintain mild hypocapnia (PaCO2:32-35 mmHg). |
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Neuromuscular paralysis in adequately sedated patients if efficacious (First, use a trial dose of neuromuscular blocking agents. If this proves effective, then continuous infusion of a neuromuscular blocking agent may be considered). |
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Raise CPP with fluid boluses, vasopressors and/or inotropes to lower ICP when autoregulation is intact. |
2.4. Tier Three
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Barbiturate coma (Sodium thiopentone) can be titrated to ICP control if efficacious. Barbiturate administration should only be continued when a beneficial effect on ICP is demonstrated. Titrate barbiturate to achieve ICP control but do not exceed the dosage which achieves burst suppression. |
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Secondary Decompressive craniectomy. |
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Mild hypothermia (35-36 degree Celsius) using active cooling measures. |
Following points should be considered when using ICP tiers to manage ICP.
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When possible, use the lowest tier treatment sufficient for ICP control. |
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Any therapy within a tier can be used for ICP control. There is no specific sequence for using therapies within one tier. |
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It is not necessary to use all modalities in a lower tier before moving to the next tier. |
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If considered advantageous, tier can be skipped when advancing treatment. |
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Meanwhile, when moving from a lower tier to a higher one, ● Re-examine the patient and consider repeat CT to re-evaluate intracranial pathology. ● Reconsider surgical options for potentially treatable surgical lesions. ● Consider extra-cranial causes of ICP elevation. ● Review that basic physiologic parameters are in desired range (e.g., CPP, blood gas values). |
Further Readings:
1. Hawryluk, G. W., Aguilera, S., Buki, A., Bulger, E., Citerio, G., Cooper, D. J., ... & Chesnut, R. M. (2019). A management algorithm for patients with intracranial pressure monitoring: the Seattle International Severe Traumatic Brain Injury Consensus Conference (SIBICC). Intensive care medicine, 45, 1783-1794.
2. Carney, N., Totten, A. M., O'Reilly, C., Ullman, J. S., Hawryluk, G. W., Bell, M. J., ... & Ghajar, J. (2017). Guidelines for the management of severe traumatic brain injury. Neurosurgery, 80(1), 6-15.
3. Le Roux, P., Menon, D. K., Citerio, G., Vespa, P., Bader, M. K., Brophy, G. M., ... & Taccone, F. (2014). Consensus summary statement of the international multidisciplinary consensus conference on multimodality monitoring in neurocritical care: a statement for healthcare professionals from the Neurocritical Care Society and the European Society of Intensive Care Medicine. Neurocritical care, 21, 1-26.
4. Shirodkar, C. G., Rao, S. M., Mutkule, D. P., Harde, Y. R., Venkategowda, P. M., & Mahesh, M. U. (2014). Optic nerve sheath diameter as a marker for evaluation and prognostication of intracranial pressure in Indian patients: An observational study. Indian journal of critical care medicine: peer-reviewed, official publication of Indian Society of Critical Care Medicine, 18(11), 728.
