INTRACRANIAL HYPERTENSION

Despite controversy on the use of invasive monitoring to measure ICP, treatment of known or suspected intracranial hypertension remains a cornerstone of therapy in patients with severe brain injury.42

Intracranial hypertension should be suspected based on certain clinical criteria if no CT scan or intracranial monitor is available. These criteria include:

- GCS Motor Score < 4
- Pupillary asymmetry
- Interval development of pupillary asymmetry > 2mm
- Abnormal pupil reactivity
- Decrease of motor score by > 1
- New motor deficit
- Hypertension with Bradycardia
- If an automated pupillometer is present, an NPi < 3 on one or both eyes is concerning for raised intracranial pressure.

If treatment for intracranial hypertension is indicated prior to arrival to a neurosurgical capability, initiate hyperosmotic therapy with one of the following:

1. Hypertonic Saline42,43 (Appendix B)

- 250ml bolus of 3% saline administered over 10-15 minutes or a 30cc bolus of 23.4% saline.
- In a location with no neurosurgical capability for definitive treatment, infuse 3% saline at 50-100ml/hr for resuscitation with goal serum Na level of 150-160mmol/L. If in the rare circumstance, chronic hyponatremia is suspected, elevation of plasma sodium by 3-5mmol/L over 2-4 hours is recommended.
- Place central venous access to administer hypertonic saline and vasoactive medications, particularly if it is anticipated to be needed long term. Subclavian veins are preferred, followed by femoral, and lastly internal jugular.

2. Mannitol

Avoid Mannitol during the initial resuscitation period when ongoing bleeding has not been ruled out and in hypotensive casualties (or any casualty with the risk of bleeding).

Consider using Mannitol only if there is no availability of hypertonic saline and there is a significant concern for imminent herniation as evidenced by signs of intracranial hypertension described above.

- Mannitol 1g/kg bolus IV.25
- Hypotension after mannitol administration must be predicted and avoided. Urine output should be replaced with isotonic fluids.
- When treating patients with osmotic agents, monitor serum sodium at least every 6 hours.