Hi everyone!
My name is Nicky, and I will be your new admin resident for this block. You all know what that means - it's time for me to be on my soapbox for the next 4 weeks.
I'm going to start off my month by discussing traumatic brain injuries (TBIs), and as public health is a big interest of mine, I'm also going to discuss their impact on public health (later, in part 2).
What is a TBI, and what leads to worse outcomes?
A TBI is any kind of trauma to the brain - some may be mild, like a bump to the head, and some may be severe, such as a gunshot wound or a high mechanism fall. Morbidity and mortality from TBIs can come from primary injury, which is neuronal damage directly due to the traumatic event at the time of the traumatic event, or secondary injury, which is damage due to sequalae of the traumatic event.
Some things that may lead to secondary injury include:
- Edema and elevated ICP
- Hypotension
- Hypoxia
- Hyperoxia
- Fever
- Seizures
Given that the primary injury has already occurred by the time the patient is in the ED, our goal is to prevent secondary injury.
What can we do to optimize patient outcomes?
Studies have shown that goals for physiologic parameters are, more or less, the ranges of normal that we think of in the ED:
- SpO2 > 94% but less than 100%
- SBP > 100
- pH 7.35-7.45
- Glucose 80-180
And also...
- ICP (intracranial pressure) < 22mmHg
- CPP (cerebral perfusion pressure) > 60 mmHg
To measure ICP accurately, it requires a monitor placed directly in the ventricle, so oftentimes we do not have this in the ED. However, there are several signs we can look for of increased ICP, including the Cushing reflex (hypertension, bradycardia, and respiratory irregularity). Other signs include a fixed and dilated pupil in uncal herniation and bilateral pinpoint pupils in central transtentorial herniation and in cerebellotonsillar herniation.
Additionally, on imaging, if you see a significant ICH especially with midline shift, it's important to do frequent assessments of the patient as they are at high risk of increased ICP.
I won't discuss the other parameters as the management is typically self-explanatory, but specifically for elevated ICP, there are several things that can be done in the ED:
- Elevating the head of the bed to 30 degrees
- Mannitol or hypertonic saline
- Hyperventilation
- Antiemetics as vomiting will increase ICP
and ultimately, neurosurgical consultation as these patients may require surgical decompression.
And that's a quick and not at all comprehensive overview of TBIs and ED management. To keep things concise, I'll talk about public health implications in my next POTD. Stay tuned!
Resources:
https://emcrit.org/ibcc/tbi/#coagulation_management
https://www.emdocs.net/neurotrauma-resuscitation-pearls-pitfalls/
https://www.cdc.gov/traumatic-brain-injury/health-equity/
Thurman DJ, Alverson C, Dunn KA, Guerrero J, Sniezek JE. Traumatic brain injury in the United States: A public health perspective. J Head Trauma Rehabil. 1999;14(6):602-615. doi:10.1097/00001199-199912000-00009
Peterson AB, Zhou H, Thomas KE. Disparities in traumatic brain injury-related deaths-United States, 2020. J Safety Res. 2022 Dec;83:419-426. doi: 10.1016/j.jsr.2022.10.001. Epub 2022 Oct 18. PMID: 36481035; PMCID: PMC9795830.
Wilson MH. Traumatic brain injury: an underappreciated public health issue. Lancet Public Health. 2016;1(2):e44. doi:10.1016/S2468-2667(16)30022-6