The Brain Trust: Severe Traumatic Brain Injury Management

The nurses had tied a bow of gauze around her head. This is the image that sticks with me. She was eerily pale, with swollen eyes, a neck brace and breathing tube, and a mass of wires coiled around her pillow. We were both seventeen, but on opposite sides of the same coin: she was the patient of the trauma surgeon I was shadowing.

caytie 12:7:14
Courtesy Dr. Richard Miller [1]

On the way to her after-school job, Caytie collided head on with an SUV, an accident which caused her serious injuries: broken back, neck, pelvis, legs, and sternum. However, these injuries were superficial compared to her devastating head injury. Traumatic Brain Injury (TBI) refers to “any brain injury produced by external force.”[2]

Such an injury can range in extent from a mild concussion with few or no lasting effects to a severe trauma resulting in brain death, vegetative state, or irreversible neurological impairment. When I saw her in the ICU, her doctors had placed her in a coma as a last-ditch effort to reduce the swelling of her brain. Even if she woke up, her chances of having lifelong neurological impairment were high. Caytie was fighting for her life, but she was also fighting for her identity.

Admission     

When a patient enters the emergency department of a hospital with critical injuries, he or she is assessed by the trauma team. Head injury management is most complicated for a multi-injured patient like Caytie but also depends on the classification and extent of the injury.[3]

The scale used to judge neurological function is the Glasgow Coma Scale (GCS). A patient’s GCS is determined by a neurological exam and ranges from 3 to 15, where 3 is unresponsive and 15 is normal function. A GCS of 8 or less indicates a severe brain injury.[4] Caytie had a GCS of 5 on scene. GCS is used in conjunction with imaging because it takes into account the patient’s mental status, which imaging cannot accurately predict.[5]

However, before scans are taken, the patient’s condition is stabilized with medications and/or fluids in a process called resuscitation. Research over the last 25 years and subsequent management guidelines published by the Brain Trauma Foundation indicate that the resuscitation of severe TBI patients should focus on avoiding low blood pressure (hypotension) and de-oxygenation of the brain (hypoxia).[3]

Imaging         

ct scan right sub hem
CT scan of a right subdural hematoma with midline shift.[7] Picture the patient face up with their feet pointing toward you (left and right are flipped). The hematoma (blood clot) appears in white/pale gray inside the skull. The ventricles, which contain spinal fluid and appear black, are pushed to the left side of the brain by the hematoma. Midline shift is evident, as a healthy brain is symmetric along the vertical axis. [6]

Once resuscitation has begun and the patient is no longer at risk of dying immediately, a computed tomography (CT) scan is taken. For severe TBI patients, CT scans are notoriously unreliable for predicting long-term outcomes. Radiologist Julie Kennon recalls a young patient who “should have died, looking at his initial CTs. But he’s back in school.”[6] Conversely, according to Dr. Miller of Vanderbilt’s ICU, “We’ve seen CT scans that didn’t look that bad, and the patient has chronic complications.”[2]

The purpose of these initial scans is to determine whether or not the injury is operative. CT scans can reveal bleeding and/or clotting in the brain, which can be surgically evacuated to relieve swelling.[5] These bleeds can be subdural (within the brain tissue) or epidural (between the brain tissue and the skull).[3]

A well-documented example of treatable brain bleed is that of actress Natasha Richardson, who suffered an epidural hematoma as a result of a skiing accident. Epidural hematomas have a good prognosis if they are recognized and evacuated quickly. However, when Richardson briefly regained consciousness, she refused medical care. Her intracranial pressure rose, her condition declined, and she passed away within a few days.[3]

Treatments and Risk           

The danger of a severe brain injury is that the brain will swell for several days after the initial injury. If the swelling is too intense, the patient herniates—that is, the brain is forced down the spinal column, resulting in death. As Dr. Spain of the Stanford Hospital explains, “Your brain is in a box—your skull—and there’s only one hole out the bottom where your brain stem is…when everything swells, the only way it can go is out the brain stem.”

Losses of neurological function occur sequentially according to what herniates first—pupillary reflexes, then corneal, then gag, and finally, the respiratory tract.[5] As mentioned, some pressure caused by bleeding can be relieved by drainage, but other procedures are also used to treat and monitor various injuries.

Placing an external ventricular drain (EVD) is useful because it not only monitors the intracranial pressure (ICP) but also drains spinal fluid to relieve pressure.[3] To place an EVD, a neurosurgeon drills through the skull and inserts a catheter into the ventricles of the brain.

One surgical intervention for extremely intense swelling is a decompressive craniectomy, in which a piece of skull is removed to allow the brain to swell outside the skull instead of down the brain stem. Though this prevents herniation, such severe swelling has often already caused irreversible damage to the brain tissue. Therefore, aggressive craniectomy can result in a patient who would have herniated and died instead transitioning to a chronic vegetative state, regaining minimal levels of consciousness but no cognitive function.[3,8]

For some patients, induced coma via the drug pentobarbital is a viable treatment that can decrease swelling and improve outcomes. These patients are, with few exceptions, young people under the age of thirty. Physicians commit to 3-5 days of coma, during which monitoring the patient’s condition is difficult. After this time, the patient’s brain pressures and neurological function are reassessed.[3]

Ethical Dilemmas

As teased above, severe TBI regularly creates ethical dilemmas for physicians and families alike. Decision-making becomes extremely difficult as cultural and religious beliefs come into conflict with the patient’s wishes.

During my time in the trauma unit, two young men came in with gunshot wounds to the head. The first died within 24 hours, but the second had better brain function and underwent a decompressive craniectomy. For days, when we entered his room on rounds, he was unresponsive. One eye bulged, pushed outward by his swollen brain. Half of his head had been shaved, and a piece of paper taped to his bed read “No bone flap R side.” His family insisted on continuing treatment, though the physicians feared he would enter vegetative state. By the end of his time in the ICU, he was able to move one eye and some fingers on one hand. Though his cognitive function might have improved since then, it is highly unlikely he will ever lead an independent life.

Quality of life issues are something many people don’t know to include in their end-of-life considerations. “Society never weighed in on quality of life,” stated Dr. Jamshid Ghajar, speaking to the all-or-nothing perception of severe trauma. “You’re you, or you’re on this respirator paralyzed, and you can’t do anything. It’s a pretty easy decision, right? [But] it’s usually something in between.”[8]

6186786217_f136fd53c4_b
Courtesy J.E. Theriot [10]

The advent of the ventilator in the 1950s created a “something in between” for death itself. With a machine supporting oxygen distribution to the heart and the brain, comatose patients can circumvent standard cardiac death. Despite a lack of measurable brain function, the oxygen-perfused heart continues to beat. Comatose patients on ventilators could be sustained for months and years without demonstrating neurological improvement. Patients who would have died and donated their organs continued in suspended animation.[8]

Ultimately, to conserve medical resources and accelerate organ donation, a group at Harvard invented the concept of brain death, a state in which brain stem function has ceased and the organs are supplied oxygen by ventilator power alone.[5,8] In such a state, the brain tissues are damaged beyond repair.

The specific criteria of brain death differ state to state, but most hospitals use an apnea test to determine whether or not there is blood flow to the brain. The patient is taken off the ventilator and given oxygen until their blood gases come to normal levels. They are then monitored for a period of time, after which their blood gases are measured again. If the numbers indicate they are not breathing (e.g., high CO2 concentration), a second, independent physician is brought in to confirm the test, and the patient is declared brain dead. [3,5]

Brain dead patients are legally dead, and therefore can receive no further treatment. Organ donation services are often called in at this stage. Care is withdrawn, and once the patient has had a cardiac death, organs can be harvested.[3]

The use of brain death to facilitate organ donation has been a topic of controversy since the advent of the classification.[8] However, what cannot be disputed is that these organs save lives, and that countries with the concept of brain death are able to do more transplants than those without. Brain death is not recognized in Japan, so fewer organ donations mean fewer liver transplants are performed there than in the US.[5]

Additionally, brain death prevents valuable resources (ventilators, drugs, funds) from being spent on individuals with no hope of a positive outcome. For many self-sufficient individuals who contribute to society and economy, the worst fate imaginable is draining society’s resources in addition to losing the ability to contribute. The concept of brain death means that those affected by such a tragedy are able to give back all they have and save lives before passing away.[5]

Research       

Historically, the cutting edge of severe TBI treatment has been resuscitation. Patient resuscitation en route to hospitals used to be very minimal for fear of brain swelling. Patients were given very little fluid and were hyperventilated to increase oxygen levels. However, both of these techniques have been proven to decrease blood pressure and constrict veins, preventing adequate blood flow to the brain. By refocusing resuscitation efforts, physicians have greatly decreased the incidence and extent of secondary injuries to the brain, improving long-term outcomes. [8] However…

“The primary injury is what it is. You can’t correct that, it’s already happened.”
– Jamshid Ghajar MD, PhD, FACS
President, Brain Trauma Foundation
Director, Stanford Concussion and Brain Performance Center

“That area that’s injured [is] dead when they come in, I can’t make it come back to life, I can’t improve it.”
– David Spain MD
Chief of Trauma and Critical Care Surgery, Stanford University Hospital

“Once you injure your brain…you’re never quite the same again.”
– Richard Miller MD, FACS
Chief of Trauma and Surgical Critical Care, Vanderbilt University Hospital

People die from the deterioration of their brains and hearts. Problems with clots or other blockages can be addressed with “clot-busting” drugs or surgical procedures. But as I realized over the course of three interviews, if the cells die, nothing can be done. “There have been almost 40 drug trials for severe TBI that have all failed,” says Dr. Ghajar.[8] Dr. Miller spoke of his high hopes for the progesterone drug trial, which in a few cases seemed to miraculously bring patients back. However, along with the others, progesterone ultimately demonstrated statistical failure.[3]

One exciting area of research is stem cell technology. In the context of severe TBI, stem cells may someday be able to generate new brain tissue. The question then becomes, if damaged pieces of a patient’s brain are replaced with new cells, will it be the same person who wakes up? The nuance of brain injury is that the brain houses one’s personality. Will the pre-injury individual come back intact if parts of their old, damaged brain are replaced with brand new neurons? The experts doubt it.[8]

Conclusion

The brain is still full of mysteries. Some research is promising, but it is unlikely that huge strides will be made in healing damaged brain tissues in the near future, if ever. This means that not only resuscitation but also prevention is absolutely key.

Helmets provide an extra layer of protection outside the skull to diffuse the force of impacts to the head. Natasha Richardson wasn’t wearing a ski helmet when she suffered her fatal accident. There are some arguments against the efficacy of helmets for head injuries caused by whiplash, when the injury occurs because the brain hits the inside of the skull. However, it’s common sense that helmets do protect the head to some degree from direct impact with hard surfaces. Wearing a seatbelt is another easy and obvious choice to decrease risk of all sorts of horrible injuries. In the event of a car accident, seatbelts prevent you from flying through the windshield head first, reducing your chance of truly devastating brain trauma.[3]

Though severe TBI is always life-altering if not life-ending, the brain’s ability to heal is still not well understood. The degree of recovery of a patient directly corresponds to their brain’s capacity to re-circuit itself around the damaged area. Young brains are better at this than old ones; as noted, therapies like induced coma are often only effective in patients under age thirty.[3]

caytie prom queen
Courtesy Dr. Richard Miller [9]

Take, for example, Caytie. She came out of the coma and improved steadily until she could be discharged to a rehabilitation center. There, she relearned the basics of functionality, from speaking to walking to self-care. In a truly astounding display of strength, she returned to high school and completed her senior year. Caytie was prom queen, and walked proudly to accept her diploma at graduation.

Perhaps someday we will have more effective treatments to offer severe TBI patients beyond prevention of secondary injury. For the time being, however, we are all invested in the everyday brain trust—the commitment to safeguard the organ that makes us who we are.

Further Reading:
Caytie’s story: ABC News, WKRN-TV Nashville
Jahi McMath case
Glasgow Coma Scale (GCS)

 

References

  1. Impending herniation[Photograph]. (2015, December 7). Caytie Gascoigne, Vanderbilt Division of Trauma and Surgical Critical Care, Nashville In R. Miller MD, FACS (Comp.).
  2. The Brain Trauma Foundation glossary. Retrieved November 9, 2015, from https://www.braintrauma.org/
  3. Miller, R., MD, FACS. (2015, October 30). Traumatic brain injury [Telephone interview].
  4. Brainline Team. (2013). What is the Glasgow Coma Scale? Retrieved November 17, 2015, from http://www.brainline.org/
  5. Spain, D., MD. (2015, November 6). Traumatic brain injury [Personal interview].
  6. Kennon, J., MD. (2015, November 4). CT scans [E-mail to the author].
  7. Marbacher, S. (2012). Figure 2 [Right subdural hematoma with midline shift]. Retrieved November 16, 2015, fromhttp://www.hindawi.com/journals/ijvm/2012/753596/fig2/
  8. Ghajar, J., MD, PHD, FACS. (2015, October 30). Brain injury research [Personal interview].
  9. Prom[Photograph]. Caytie Gascoigne, Vanderbilt Division of Trauma and Surgical Critical Care, Nashville In R. Miller MD, FACS (Comp.).
  10. Theriot, J.E. brain 2. (2011, August 29). Retrieved fromhttps://www.flickr.com/

Brain Trauma Foundation. (2010). Online TBI guidelines. Retrieved November 10, 2015, from http://tbiguidelines.org/glHome.aspx

Sade, R. M. (2011). Brain death, cardiac death, and the dead donor rule. Journal of the South Carolina Medical Association (1975), 107(4), 146-149. Retrieved November 16, 2015, fromhttp://www.ncbi.nlm.nih.gov/

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