Traumatic Brain Injuries: Initial Treatment

Last post, I have a primer on traumatic brain injuries (TBI) that you can find here. Today, I thought I’d give an overview of the treatment guidelines.

Remember, the basis of treating TBI is manipulation of the three components within the skull: the brain, the blood, or the cerebrospinal fluid (CSF). Additionally, sometimes a portion of the skull is removed.

1. Manipulating Brain Tissue.

Removing brain tissue is an option and may be done to tissue that has died. Recovery of the patient is dramatically influenced by what part of the brain was removed.

Another management strategy is to put the brain at rest by placing the patient in a medically induced coma. Medication is used to heavily sedate the patient. Typically, the patient is on continuous EEG monitoring to ensure a minimal amount of brain activity is present. The purpose of the coma is to reduce the metabolic demands of the brain in hopes of keeping swelling down and allowing the brain time to heal.

Additionally a diuretic, either hypertonic saline or Mannitol, can be given to draw water out of swollen brain cells.

2. Manipulating Blood Flow.

This can entail a couple of areas. Remove blood that has collected in the brain. Sometimes when the brain is injured, blood vessels within the brain are ripped open. Two types of bleeding can occur between the brain and the skull: a subdural or epidural hematoma. A subdural hematoma occurs from veins. An epidural hematoma occurs from an artery. Depending on the size of the hematoma, a neurosurgeon may choose to operate and remove it. Sometimes bleeding occurs within brain tissue. This type of bleeding can be small and more diffuse. Although a risk for the patient it may not be an option to surgically remove it.

Another way to change blood flow is to manipulate the size of the blood vessels inside the patient’s head. This can be done by increasing the rate of the patient’s breathing on the ventilator thereby decreasing their blood level of carbon dioxide. When this level is lower, the blood vessels inside the patient’s brain shrink in diameter. This therapy is controversial and if done, only a mild drop in carbon dioxide levels is the goal.

Lastly, the blood pressure can be manipulated. A certain blood pressure or blood flow to the brain must be maintained in order to keep the brain alive. This is called the cerebral perfusion pressure (CPP) and is calculated by using the patient’s blood pressure and their intracranial pressure (ICP). Reducing the blood pressure is an option but you must maintain the cerebral perfusion pressure as well. This can be a challenging balancing act.

3. Manipulating Cerebrospinal Fluid (CSF)

A drain is placed to remove excess cerebrospinal fluid.

4. Removing a Portion of the Skull.

This is a viable option for management of brain swelling. A portion of the skull is removed (hemicraniectomy) to allow the brain room to swell. The portion of the skull that is removed is preserved by freezing so that is can be reattached at a later point once the swelling has eased.

Have you had a character in your novel with a traumatic brain injury? If so, what type and why did you choose it?

***Reposted from January 19, 2011.***

Traumatic Brain Injuries: A Primer

The brain is our most complex organ and perhaps the most difficult to help heal. The biggest challenge is its protective covering: the skull. Management of acute traumatic brain injury, or TBI, typically involves manipulating the three components within the skull: the brain, the blood, and the cerebrospinal fluid (CSF).

What is the purpose of each of these components? The brain is the body’s supercomputer. The blood delivers oxygen and nutrients to feed the cells or neurons. The CSF nourishes the brain, helps remove waste products, and keeps the brain buoyant.

What happens when something is significantly injured? It swells. Think about a time you saw someone with a really bad sprained ankle. What happened? It blew up like a balloon. The same thing happens to the brain with a traumatic injury. It swells.

Unlike an ankle, brain swelling is inhibited by the skull but the pressure inside the head can continue to rise if swelling is unchecked. Too much pressure inside the skull (it can’t move) and blood flow diminishes, thereby starving cells of oxygen, which then swell more.

We can measure the pressure inside your skull, or intracranial pressure (ICP), by placing a sensor into a ventricle (a ventriculostomy).  A normal ICP is 7-15mmHg. Cerebral edema can be insidious as swelling peaks 48-72 hours post injury. A patient can initially present following commands. Then in 2-3 days, develop cerebral edema to the point of herniation (which means brain contents shifting) and die.

What happens when a patient develops significant cerebral edema and ICP pressures skyrocket?

First bad thing: Blood flow is reduced. The brain is very sensitive to blood flow and greedy for oxygen. If there is diminished blood flow, neurons (brain cells) begin to die. If there is no blood flow, the brain will die. You may have heard the term brain death. This is determined by several factors but the definitive one is by taking the patient to radiology and doing a brain flow study. Roughly, a dye is injected into the blood and x-rays are taken. If there is no blood flow, the patient is declared brain dead.

Second bad thing: Brain contents shift into areas where they’re not supposed to be. This is called herniation. When neurons are compressed, they don’t function properly and will begin to die as well. When brain cells die, machines and medications have to take over their function to keep the patient alive.

Unfortunately, if brain death has occurred, the medical team will start discussing withdrawal of care with the family.

***Content reposted from January, 12, 2011.***

Cost of Medical Care on the Frontier

I’ve been reading through David Dary’s book Frontier Medicine as research for this blog and came across an interesting list of what it might cost for certain medical treatments. I found these to be fairly expensive in light of what a family might earn. Take a look.

For $0.50

Traveling more than 18 miles
Cathartic
Emetic
Tincture per oz
Blisters to ankles and wrists
Bleeding
$1

A visit
Tooth Extraction
$2

Administration fee for therapy

$5-20

Infant Delivery
Curing gonorrhea/venereal disease
Reducing Fracture
Reducing Kneecap Dislocation

$50
Amputation
Trepanning (skull-boring)

What do you think of these costs and what a family might make?

When Does a Person Require Blood Transfusion?

Sometimes, it’s hard to know when writing a scene when to pull the big guns out. If you have a character that is bleeding a lot (by whatever mechanism) when should you think about giving them blood? Or, better yet, when will the lack of blood begin to hamper their ability to function.

Fairly consistent among resources, hemorrhagic shock (shock related specifically to blood loss) is a life-threatening condition that results when you lose more than 20% or 1/5th of your blood supply. Patients will feel lightheaded, dizzy. Their respiratory rate and heart rate will be elevated. Their blood pressure might be low. They’ll look pale, pasty. Their skin might feel cool, clammy, dough-like.

But exactly how much blood does that translate to? I actually found this nifty little calculator that will give you a person’s estimated blood volume based on their age, sex, and weight. For instance, a man weighing 100 kg has an estimated blood volume of 7,500 ml. So losing 20% of his blood volume would be 1,500 ml of blood or approximately 3 pints of blood. A pint of whole blood (what you would donate) is approx 500 ml. A woman of the same weight has only 6,500 ml of circulating blood. An infant weighing 10 kg has only 800 ml of blood. You can see how that 20% translates much differently depending on the characters age, sex and weight.

History of Blood Transfusion

For historical authors, it’s important to know when a medical advancement takes place for novels that include these medical details. While researching a medical question for an author regarding blood transfusion I came across a very good timeline concerning this medical advancement. You can find that article here.  Additional resource found here.

1628: Dr. William Harvey discovers blood circulation.

1655: Dr. Richard Lower performs successful animal to animal blood transfusion using dogs.

1818: Dr. James Blundell performs first person to person blood transfusion. Blundell is a gynecologist and uses blood transfusions to treat postpartum hemorrhage.

1840: Successful blood transfusion of patient with hemophilia.

1901-1902: Karl Landsteiner discovers blood types. This is an important advancement because giving the patient the wrong blood type can well . . . kill them.

1914-1918: Dr. O.H. Robinson finds effective anticoagulant that aids in long-term blood storage. Adolf Hustin is also credited with discovering an anticoagulant as well.

1920’s: Percy Oliver develops donor system for British Red Cross.

1932: Leningrad Hospital houses first blood bank.

1939-1940: Rh Blood group is discovered which is determined to be the cause of most blood transfusion reactions.

1941: Red Cross U.S.A. is started.

1950: Use of plastic bags makes collecting and storing blood easier. Before this they used glass bottles. This I cannot imagine.

1972: Apheresis is discovered which can remove one component of blood and return the rest to the donor.

1983: Stanford Blood Center begins screening donated blood for AIDS.

1985: HIV screening licensed and implemented.

1990: Hepatitis C Screening initiated.

It’s amazing to look back on just how much was accomplished in blood transfusion, blood banking, and ensuring a safe blood supply in the 20th century.

Author Question: Transfusing Blood Post EMP Blast

Alyssa Asks:

An EMP took out all electricity 2 years ago— meaning no electricity, refrigeration, or other modern medical machines. The city has been isolated since then. Ruling gangs have raided the hospitals, but our gang of survivors managed to snag a number of essential hospital supplies including a field transfusion kit.

Patient is 6 years old. She has lost a large amount of blood from a scalp wound. They don’t know how much blood since it’s dark and they weren’t there when it happened, but she’s sheet-white, cold and clammy skin, blue lips and fingernails, shallow breath, quick pulse but low blood pressure. No access to Saline. Looks like blood is the only option.

Our nurse, she tells the others about the risks, even though the donor and recipient have the same blood type. Antibodies causing a reaction, infection, too much blood, etc. But it’s a dire situation.

Could they run an IV from the donor into a blood bag using gravity? Bags suspended in cold water to keep it cold and inject anticoagulant into the bag port once the blood starts filling it?

They’d only use one unit. Once they fill the bag, they’d use another blood tube to run it into an IV attached to our young recipient. Again, they’d use gravity, but the girl would be on a table and the blood bag suspended above her, maybe hanging on a hanger on a back of the door. Would this work?

Jordyn Says:

Thanks, Alyssa, for sending me your question. It is fairly complicated so I’m going to give a little background.

First of all, kids do not get the same amount of blood as an adult. We transfuse kids based on their weight. Your average 6 y/o weighs about 22 kg. Kids get 10ml/kg for their transfusion volume so this child needs approximately 220 ml of blood. We also don’t routinely transfuse whole blood. What we give is packed red blood cells— exactly as the name sounds. One unit of whole blood is split up into many different parts (packed red blood cells, platelets, and plasma).

What you’re talking about is giving whole blood which will lessen the amount of packed red blood cells your patient is getting. I’d stick with transfusing about 200 ml of whole blood as a marker to start. One unit of blood can hold up to 525 ml so your patient would need roughly half of one bag. It will be hard for your character to measure that in this situation so the nurse will have to go off improvement of her patient’s vital signs. These would include improved color, warmer skin, decreased heart rate and increasing blood pressure.

Bags that collect blood already have a component inside to keep the blood from clotting so I don’t think I’d even worry about an anticoagulant. I don’t even know that you’d really need to worry about cooling the blood. Collection takes somewhere between 10-30 minutes depending on the size of the vein accessed. Usually for blood collection the antecubital vein is used (the one at the crook of your elbow).

While the blood is being collected from the donor (yes, by gravity— the bag lower than the donor), the nurse can start an IV in her patient. You would need a set of IV tubing to puncture the blood bag, prime the tubing with the blood, and then give it to your patient. No air in the line, please. Hanging the unit by any means possible is fine as long as it is higher than the recipient.

Usually, blood is given with a filter in the line so if they had stolen a blood transfusion field kit then hopefully this would be part of it.

Your other option is to do old style person to person transfusion of which you can see a photo here and not mess with collecting the blood at all.

Hope this helps and good luck with your story!

Signs Versus Symptoms

Sometimes as a nurse, I wish I could live in a Star Trek episode and pull out my tricorder, grabbing my assessment with a quick hover of the device over my patient. Those crafty gadgets could tell you everything about your patient. Unfortunately, we aren’t blessed with these yet so it’s good academia to know the difference between a sign and a symptom when writing a medical scene.

Any guesses as to what the difference is?

A symptom is something subjective felt by the patient and told to the nurse or physician. It is not measurable. For instance, a person coming in with abdominal pain might say: “I feel like I’m going to throw-up. It feels like someone is stabbing me in the gut with a knife!” All of these things the patient describes are symptoms. We can’t measure them and we only know they’re present because the patient tells us so.

A sign in the medical sense is something we can measure or directly observe. Let’s take the same patient from above. He has relayed to the medical staff that he is having some pain. Some signs of pain are sweating (diaphoresis), increased heart rate (tachycardia), and increased blood pressure (hypertension). Some patients might writhe around in pain. These we can observe and measure.

Now to throw a wrench into my definition. At times, we try to measure symptoms like pain. This is why we have pain scales. A patient states they’re having pain. The nurse replies: “Sir, on a scale of 0-10, zero being no pain and ten being the worst pain you’ve ever had in your entire life, how bad is your pain?” We attempt to measure but it is still the patient’s subjective experience.

Here’s a very common ER set-up that can increase conflict between the patient and the medical staff.

A patient presents to the ED with complaint of a headache. There are several patients to be triaged and the person takes a seat in the waiting room. He strikes up conversation with another family. After that, he puts his ear buds in and is texting on his phone. I can see that this patient has signed in and what his complaint is on my computer screen. I decide, based on his complaint and his behavior in the waiting room, he’s okay to wait for me to triage the other patients.

In triage, he continues to complain of a headache. He is warm and dry. Sits comfortably. Heart rate and blood pressure are normal. I ask him to rate his pain. “It’s 15/10. This is the worst headache of my entire life!”

See the conflict? Do you believe this patient is in pain? If yes, why? If no, why?

***Content reposted from January 26, 2011.***