Causes of Unconsciousness [Micro Lecture]

In this micro-lecture, we discuss the common causes of unconsciousness. Enrolled students have unlimited access to a rich library of learning materials such as this.


Today we’re going to talk about common causes of unconsciousness. Now, as a paramedic you are going to be dealing with many patients who present to you in an unconscious, semi-conscious, or a post-conscious state.

So by semi-conscious, we mean somebody who is on the way down to being unconscious, but is not quite there yet. In other words, they still have a level of GCS about them, but they’re not quite GCS of three, being unresponsive.

By post-unconsciousness we mean after the event and starting to come around. Another term you might use is postictal.

And typical examples of postictal situations are usually when somebody’s had a seizure, or when somebody’s had a hypoglycemic episode.

Now, when a person is completely unconscious this means they’re not responding to you verbally or by applying any type of pressure, so we call that unconsciousness. Now, this patient will have a GCS of three because their eyes are not opening at all.

That’s when they’re not responding to you verbally. That’s a one. And they’re not responding to any motor prompts either. That’s another one.

So let’s take a look at some of these causes of unconsciousness, because you are going to need to use this to work out the reason why they’re unconscious to be able to treat it.

Number one is shock. Now there are five classifications of shock. We’re going to have another session on that, but basically whenever there’s reduced oxygen to the tissues this is a state of shock, which causes hypoxia.

Asphyxia. So asphyxia is something that is caused by a lack of oxygen so it could be the shock. Now the five types of shock all lead to that lack of oxygen to the tissue. The word asphyxia means suffocation. So think about it, either your tongue is blocking the airway, the patient’s tongue is blocking the airway to stop the oxygen getting in, or if there’s a type of shock the blood isn’t getting to the target organs, which are the brain and the main organs.

Poisoning can either be accidental or intentional. So, for example, accidental poisoning could be when you’re walking into a situation whereby there’s gasses in a room., maybe in an industrial environment, or they can be intentional through a drug overdose.

Head injury can be caused accidentally or intentionally. Accidentally, if somebody’s assaulted them, assaulted your patient, maybe they’ve had a slip or a fall, or intentionally if they’ve tried to self harm themselves, they’ve tried to kill themselves.

So head injuries are a pretty big topic, and with a head injury for the force to cause unconsciousness, on many occasions there is an underlying condition known as traumatic brain injury, but not always. Cerebral vascular accidents, or a stroke, is caused by either a bleed or a blockage. A bleed is called a hemorrhagic stroke, and a blockage is called an ischemic stroke.

Epilepsy is a type of convulsion. In other words, they’ve been diagnosed as having mal electric impulses in the brain, which cause all over convulsions. Hysteria or extreme emotional estates are quite common.

So if somebody is hyperventilating, for example, the body will just switch off and just reset itself. Infantile convulsions are usually caused, on most occasions, by a state of hyperactivity. Children can’t control their body temperature the same way that we do as adults, so in other words, they don’t have the shivering mechanism.

And then hypothermia or hyperthermia. So hypo is low, hyper is high. And again, if your patient’s body temperature is too low or too high absolutely they can become unconscious.

Now, the good news is managing these patients is exactly the same. So you arrest any major hemorrhage, you manage the airway using one of the airway adjuncts. So, for example, an OP airway or an NP airway.

Plus you might use a head tilt chin-lift if they’re unconscious with non-trauma related incidents, or a jaw thrust or triple manouver if they’re traumatised. Okay guys, well I hope you’ve enjoyed this micro lecture on causes of unconsciousness.

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