In a previous post, we discussed assessing a patient’s LOC, or level of consciousness. You may have heard this called level of responsiveness, or LOR, as well; LOC is a bit easier to type, so that’s what I’m going to stick with. Today, we’re going to springboard off of that topic and discuss altered mental status.
When a patient’s LOC is not fully AO x 4, we say the patient has altered mental status, or AMS. This is also called altered level of consciousness, or ALOC; once again, AMS is way easier to type. As you may recall from our previous discussion, AMS is a secondary problem; in other words, its being caused by a larger problem. Another way of putting this is to say that AMS is caused by “insults” to the brain. My intention today is to talk about the most common causes of AMS, or the most common insults, and then discuss in more detail AMS in the wilderness environment in a later post.
We love mnemonic devices in wilderness medicine; they provide an easy way to remember a lot of information. When we’re talking about AMS, we use the mnemonic AEIOU-TIPS. This one may be new for you, so I added a handy chart that I pulled from The Survival Doctor (you should check his website out). Each letter in AEIOU-TIPS stands for what we have found to be the most common things causing a patient to be altered. Let’s look at them in more detail.
- Alcohol: This shouldn’t surprise you. Just about everyone has either been drunk, or seen someone who is. Alcohol intoxication can range from giggly and slightly confused all the way to unresponsive. For a good discussion of alcohol as an intoxicant, I urge you to take some time and watch the following “instructional video.”
- Epilepsy: Epilepsy is a neurological condition that causes seizures. Your brain transfers signals between neurons (brain cells) using small electrical impulses. When these electrical impulses become erratic, we call this a seizure. There are many, many types of seizures. The classic seizure is a Grand Mal, or generalized seizure, which is characterized by full-body, thrashing or trembling movements. Other seizures, such as the absence seizure, are characterized by a moment of staring off into space, or disorientation. After the seizure has finished, patients are typically disoriented and lethargic, and may be combative, for varying amounts of time. This is called the postictal period.
- Environment: Some AEIOU-TIPS charts also list environment under E. This should come as no surprise to wilderness medical folks. Hypothermia and hyperthermia both alter the brain’s ability to function, and can cause AMS. We’ll go over this in more detail later.
- Insulin: We’re not specifically referring to insulin causing AMS, but instead to diabetes, specifically hypoglycemia. The brain is a picky, touchy organ. If the brain does not get exactly the right amounts of glucose or oxygen, the brain will not function properly. When the brain does not function properly, AMS is frequently the result. Patients who are diabetic cannot control the flow of sugar from their blood stream into their cells. Patients who are hypoglycemic will be altered at various levels depending on their physiology. Some patients will be completely unresponsive. Others were present anywhere between slightly confused/”goofy,” to combative. Very high levels of blood sugar may also cause AMS; this is much less common.
- Overdose: This is a catch-all for mind-altering (or expanding, depending on your perspective) substances. People get high on a multitude of substances, so I’m not going to go into exhaustive detail. People who have used too much narcotic or opiate substances (percocet, heroin, oxycodone, morphine, etc.) are typically lethargic or unresponsive, with labored or agonal respirations (occasional, not-sufficient-for-life). On the other hand, folks who have used stimulants (methamphetamines, cocaine, etc.) are typically hyperactive with rapid, shallow respirations, bounding heart rates, and sweaty, hot skin.
- Uremia: This ones a bit technical. Your body is like a factory; you take in raw materials (oxygen and sugar), you convert them into product (energy molecules, heat, tissue), and you get rid of waste byproducts (carbon dioxide, water, nitrogen wastes). The waste products are released into the blood stream, where they are subsequently filtered out by the kidneys and removed from the body when you urinate. If the kidneys stop working, waste products build up in the blood stream. This is bad. In order for your body to function properly, the pH (the measure of how acid or base your body is) of your body has to be right around 7.4. When waste, especially CO2 and nitrogen compounds, build up in your blood stream they alter the pH of the blood stream. Remember how we said earlier that the brain is a very picky, touchy organ, and that when conditions aren’t perfect the brain doesn’t work right? This causes the same thing.
- Trauma: Wilderness medical folks, take note. A good shot to the head can damage the brain tissue directly, and cause it not to work properly. Think about everything we do in the outdoors that can cause direct trauma to the head; rock climbing falls, mountain bike crashes, ski accidents, etc.
- Infection: When I was a new EMT, I was taught about a condition called sepsis, which is an infection that has gone systemic throughout the whole body. I have to admit, I wasn’t very impressed until I saw my first truly septic patient. Major infections wreak havoc on the body, and can cause AMS in many ways. Running a high fever requires higher metabolism, which can cause the patient to become hypoglycemic. The high temperature may cause the brain to be unable to function properly. Blood vessels in septic patients become “leaky,” causing the patient to become hypovolemic and to go into shock; this causes the brain to not get as much oxygen-carrying blood as it needs. Lack of blood flow to the kidneys can cause them to shut down, causing the aforementioned uremia. The list goes on and on.
- Psychiatric: The brain works in mysterious ways. Occasionally, changes in the way the brain works, or processes input, causes the brain to not work as well, and leads to AMS. Folks with disorders such as schizophrenia or bipolar disorder, due to changes in the brain, experience sensory input which is not real (hearing voices, seeing things), and have difficulty modulating their emotional levels (hence the up and down swings experienced by folks with bipolar). Patients having psychiatric issues may be disoriented, or may just seem “off.” They may also show extreme happiness/excitement, or depression/lethargy.
- Poisons: External toxins can be absorbed through the skin, injected into the body, ingested, or inhaled. Poisons can either impair important bodily functions and chemical reactions needed to maintain normal brain function, or they can alter chemical structures in the body to make them non-functional. The important thing to find out is which toxin was the patient exposed to.
- Stroke: A stroke is caused by lack of oxygen-carrying blood flow to brain tissue. This is called cerebral ischemia. If the brain tissue is left without oxygen for too long, it can die; this is known as cerebral infarction. There are two major types of stroke, ischemic and hemorrhagic. Ischemic strokes are caused by a blood clot in one of the arteries which supplies oxygen to brain tissue. Hemorrhagic strokes are caused by bleeding inside the skull, which increases pressure within the skull, and subsequently chokes off blood flow. If not corrected promptly, both can cause permanent brain damage and/or death. Patients with strokes are frequently altered, and usually show signs of impairment such as the inability to speak clearly, move one side of their body, or smile evenly. Time of onset is particularly important!
Later this week, we’ll go into more detail about AMS in a wilderness context. Keep your eyes open; on Wednesday, I’ll be posting the next installment of “What Would You Do?” Wednesdays; as a hint, it may or may not involve some AMS caused by head trauma!