Management of a patient presenting with Increased Intracranial Pressure (ICP) can be scary for any provider. Here is an important method of ICP management to consider for the prehospital environment.
ICP Basics
- The cranial vault is a tightly sealed container
- ICP= Brain tissue volume + CSF volume + Blood volume
- Normal pressure inside the cranium is 5-15 mmHg
- If the pressure inside the cranial vault becomes too high, cerebral perfusion becomes restricted.
Signs & Symptoms of Increased ICP
Early Signs and Symptoms
- Headache
- Back pain
- Confusion
- Agitation
Late Signs
- Post-traumatic seizure
- Mydriasis (fixed & dilated pupil)
- Decreased level of consciousness
- Cushing’s Reflex (Triad)
- Bradycardia
- Hypertension
- Abnormal respirations
Management
In the prehospital environment, ICP management can be tough, but there are options. Here are a few techniques that may moderate ICP until you arrive at a definitive care facility.
- Elevate the head of the Pt– Of course, remember to be aware of spinal motion restrictions you have in place. This technique may not do much, but in these patients, every little bit helps.
- Hyperventilate the Pt– This one sure does sting the ears to hear, and I am certain that many of you feel the same. Indeed, we are learning more every day about the dangers of oxygen administration often outweighing the benefits. To make this an even touchier subject, the reason we are hyperventilating the patient is, ultimately, to improve cerebral perfusion. Sooo, if we hyperventilate too much, we are making matters worse by causing cerebral vasoconstriction. This is a double-edged sword, so be careful. Continuous waveform capnography should be monitored while doing this, and the ETCO2 should be maintained between 30-35 mmHg.
- Administer an osmotic agent– Typically mannitol or hypertonic saline is used and is reasonably effective in lowering ICP and keeping it at a much more acceptable level than without it. But wait. What if I don’t have an osmotic agent like mannitol or hypertonic saline? Ah! But you do! Here’s a picture of it below.
8.4% Sodium Bicarbonate for Increased ICP Management
8.4% NaHCO3 is-
- Roughly equivalent to 6% saline regarding Sodium ion concentration.
- Just as effective as traditional hypertonic saline at treating rises in ICP for at least 6 hours. (Bourdeaux, 2010)
- Widely available, to include on most prehospital ALS units.
- Going to reduce pH in your patient, but for most patients, the serum bicarbonate concentration will stay well within normal limits. (Farkas, 2016)
- Easy to use. It doesn’t get much easier than prepackaged ampules!
According to Dr. Josh Farkas, assistant professor of Pulmonary and Critical Care Medicine at the University of Vermont, “For [management of] elevated intracranial pressure, 80-120 ml of 8.4% sodium bicarbonate is a reasonable initial dose…”. Dr. Farkas further indicates that, if unsure about the precise amount to administer, two ampules (100 mL) is a good place to start.
Of course, using an osmotic agent for the treatment of increased ICP due to a bleed will likely have little or no effect on reducing it. However, if the cause of the elevated ICP is edema (often secondary to trauma), sodium bicarbonate will likely have real effects.
I hope you found this article to be informative and entertaining! Please keep in mind, that no information provided in this post, or any other location on DitchDocEM.com supersedes the protocols set by your institution. If your organization does not have a protocol for bicarb in the management of elevated ICP, get in touch with your medical director and get his/her take on it! Check out the references I used for this article below to get all the facts before you do.
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References
Bourdeaux C, Brown J. Sodium bicarbonate lowers intracranial pressure after traumatic brain injury. Neurocritical care. [accessed 2017 Mar 5]. https://www.ncbi.nlm.nih.gov/pubmed/20422466
Farkas J. Emergent treatment of hyponatremia or elevated ICP with bicarb ampules. EMCrit. 2016 Dec 13 [accessed 2017 Mar 5]. https://emcrit.org/pulmcrit/emergent-treatment-of-hyponatremia-or-elevated-icp-with-bicarb-ampules/
Neurotrauma : Intracranial Pressure. TRAUMA.ORG : Neurotrauma : Intracranial Pressure. [accessed 2017 Mar 5]. http://www.trauma.org/archive/neuro/icp.html