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should be initiated, and options include mannitol and hyper- Conclusion
tonic saline. The idea behind hyperosmolar therapy is to re-
duce the brain volume by pulling fluid away from it through TBI management is complex, dynamic, and ever evolving.
the blood–brain barrier. Again, an indwelling catheter is nec- Many interventions and guidelines for TBI are not supported
essary along with hyperosmolar therapy because of the fluid by a high level of evidence (i.e., randomized clinical trial) due
shift and increased diuresis. Mannitol is a diuretic that con- to the complex, multifactorial nature of the injuries, diversity
sists of large sugar molecules that pull fluid across biologi- of the patient population, and incomplete understanding of the
cal membranes. Mannitol should be used with caution in TBI brain and TBI pathophysiology. What is clear is that the brain
patients because the molecules can cross into the injured brain is a sensitive, high maintenance organ that loses its ability to
and cause a paradoxical increase in ICP. Also, because it is take care of itself upon injury, and our primary mission is to
a diuretic, mannitol should be avoided in TBI patients with achieve and maintain optimal levels of CBF from the moment
hypotension, hypovolemia, or kidney disease unless there is an of injury until recovery. The entire TBI management revolves
impending herniation. Hypertonic saline (HTS) comes in vari- around this key concept. As a prehospital provider, keep your
ous concentrations and also pulls fluid from the brain through management simple and focused on the fundamentals. These
an osmotic gradient. HTS can lead to a rapid increase serum include maintaining adequate oxygen saturation and blood
sodium, which can be harmful to the kidneys. Although both pressure using ABCs or the MARCH algorithm, early recog-
mannitol and HTS reduce ICP, HTS may be superior in speed nition of TBI, frequent exams, detailed charting and hand-off,
of onset, efficacy, and duration. 29,30 Also, HTS has the theoreti- and fast transport to the next echelon of care. These can all
cal advantages of volume expansion, neuroprotection, and im- make a significant impact in reducing long-term disability and
25
mune modulation. However, it remains unclear whether one improving outcomes. Severe TBI patients can appear visually
agent is better than the other and the most recent Cochrane devastating at the scene, but how they appear at the scene does
review has concluded that more evidence is needed to make not necessarily determine their outcome months to years down
the determination. 31 the road. Always remember that prehospital providers can sig-
nificantly influence the outcome of TBI patients!
Hyperventilation should not be used prophylactically. It
should only be used as a last resort therapy for intracranial Funding
The authors received no funding for this effort.
hypertension. If there is a clinical evidence of herniation or
32
rapid neurological deterioration, then the patient should be Disclaimer
briefly hyperventilated to PaCO of 30–35mmHg. Do not Opinions or assertions contained herein are the private views
2
hyperventilate to PaCO < 30mmHg because this can lead to of the authors and are not to be construed as official or as re-
2
33
significant reduction in CBF with minimal reduction in ICP. flecting the views of the Department of Defense or its Services.
Also, beware that hyperventilation can rapidly lower blood
CO levels (causing alkalosis), which can cause tetany due Author Contributions
2
to lowering of ionized calcium levels. Continue to examine BYH and RMD are co-lead authors. BYH, RD, JHS, and
the patient and the return to normal PaCO levels once the GSFL all participated in manuscript conception. BYH wrote
2
signs and symptoms of the ICP crisis resolve. Repeat the hy- the first draft, and all authors read, revised, and approved the
perventilation treatment as needed. Ultimately, TBI patients final manuscript.
with intracranial hypertension must be managed by neurosur-
geons and neuro-intensivists. Therefore, rapid transport to a Disclosures
high-volume civilian trauma center or Role 3 medical facility The authors have indicated that they have no financial rela-
is the best plan for these patients. tionships to disclose.
References
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2
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