The Glasgow Coma Scale (GCS) is used to assess a patient’s level of consciousness. Level of consciousness is how alert and responsive a patient is to their environment and stimuli around them.
The Glasgow Coma Scale is a very helpful tool for evaluating a patient who has experienced a traumatic brain injury or other conditions where brain function or consciousness is altered.
To assess the GCS a baseline score should be obtained, and then it should be reassessed often through the nursing shift per the facility’s protocol to assess if the patient is improving, staying the same, or deteriorating.
It’s important to note that assessing a patient’s level of consciousness is very important because any changes in it could indicate something serious is happening to the patient and it needs to be investigated.
What the Glasgow Coma Scale Assesses?
The GCS scale assesses THREE responses by the patient to a type of stimuli.
These three responses are: Eye-opening response, Verbal response, Motor response
Stimuli used during the assessment can range from verbal or audible stimuli to painful/pressure stimuli.
There are two types of painful/pressure stimuli that can be used to achieve a response in a patient. These types include: central and peripheral stimuli
Central stimuli: pressure or pain is applied to the center of the body (hence its core) to create pain. This tests the brain’s response to it.
- Used first is the trapezius squeeze
- To do this: use the index finger and thumb and squeeze 1 ½ to 2 inches of this trapezius muscle.
- Start with slight pressure and then increase the pressure for up to 10 seconds… note patient’s motor movement
- No response…move to the supraorbital pressure:
- Find the notch under the inner part of the eyebrow
- Apply pressure to this notch with the thumb and gradually increase pressure for up to 10 seconds…. note patient’s motor movement
- Sternal rub is no longer recommended because it can cause bruising (BMJ case reports, 2014).
Peripheral stimuli: pressure or pain is applied to a peripheral extremity like the fingernail bed to create pain. This tests the spinal cords response to pain.
GCS Scoring
Glasgow Coma Scale scores can range from 3 to 15.
As pointed out above this scale is useful with patient’s who’ve sustained a head/brain injury. The score can be used to describe the injury.
3-8: severe brain injury
9-12: moderate brain injury
13-15: mild brain injury
*A GCS is never higher than 15 or lower than 3….the higher the score the better for the patient.
GCS 15: fully alert and awake
GCS 8 or less: the patient is in a coma and requires intubation due to the inability of airway reflexes that protect us from aspiration to work
GCS 3: lowest score possible and very high death rate…deep coma, severe brain injury
Each response category of the GCS has its own points, which are added up to give the total GCS. A total GCS score is obtained from adding up all the responses. Now the overall score is important but so are the subscores. The subscores are the scores from each of the three responses.
For example, you may see a Glasgow Coma Scale score reported like GCS 7 (E2 V2 M3). GCS 7 is the total score, while E2 V2 M3 are the subscores that describe each patient response category of the scale.
Before Assessing the GCS….
Before conducting the assessment, see what the patient’s baseline scores were, and if they have anything that would affect their response to stimuli or make testing a specific response category (eye-opening, verbal, motor) more difficult.
Examples of this would include that the patient is: sedated, hard of hearing, mental deficits, paralyzed, intubated, injury to bones, swelling etc.
For example, let’s say the patient is intubated. Well, it will be hard to get a verbal response out of the patient because they have a tube in their throat, so you can’t test this response category. Therefore, this part would be labeled NT for not testable. Note: you would not give them 1 point (no response) because you can’t test it and don’t know if they could respond verbally if they could.
So, the GCS may look like this GCS 7T (E3 Vt M4). This tell us the overall score is 7 but the patient is intubated (capital T tells us this).
Glasgow Coma Scale in Detail
To help you remember what to assess and how to score it while you’re at the bedside remember EVM = 4,5,6
E: Eye-opening response: patient can receive a max of 4 points and a minimum of 1 in this part of the scale rating. Therefore, the patient can be assigned either 1,2,3, 4 or NT (non-testable)
4 Points: eyes spontaneously open (walk to the bed side and just look at the patient… are the eyes open?)
3 Points: eyes open to sound, speak in a tone that is loud and clear to be heard (note if the patient has hearing difficulties before attempting or injuries that can prevent hearing clearly)
2 Points: eyes open to pressure applied to nail bed (use an object like a pen light or pen to gradually increase pressure on the nail bed for up to 10 seconds….note eye-opening response)
1 Point: no response to any of the above stimuli
*NT: example…eye swelling or an injury that prevents the eyes from opening
V: Verbal response: patient can receive a max of 5 points and minimum of 1 points or NT (non-testable). Therefore, the patient can be assigned either 1, 2, 3, 4, 5 or NT (non-testable)
5 Points: oriented (ask a series of questions: can you state your name, month and year, where you are at?)
4 Points: confused (answers the questions but with incorrect answers…example they are in the hospital but they say at home or they give an incorrect year or name)
3 Points: inappropriate words (says random words that don’t make sense to the questions)
2 Points: makes only sounds but no words to the questions
1 Point: no response
*NT: example…patient is intubated
M: Motor response: patient can receive a max of 6 points or a minimum of 1 point or NT (non-testable). Therefore, the patient can be assigned either 1, 2, 3, 4, 5, 6 or NT (non-testable)
6 Points: obeys a motor command (tell patient to do something that requires two steps….open your mouth and stick out your tongue or lift your hands and squeeze my fingers and let go)
If the patient doesn’t obey verbal stimulus to perform a motor command, use a central pressure stimuli by using the trapezius muscle squeeze. If no response, use supraorbital pressure.
5 Points: Localizes the pressure/pain (the brain will try to locate and remove the painful stimulus)
- When stimuli is applied (example: trapezius squeeze) the patient bends the elbow (elbow flexion) and moves the arm and hand up above the collar bone trying to remove the pain/pressure. With this movement the patient is trying to LOCATE (hence localizes) the pressure/pain.
4 Points: Withdrawal (also called normal flexion)…the brain will try to withdraw from the painful stimulus
- When stimuli is applied (example: trapezius squeeze) the patient flexes hence bends the elbow (elbow flexion) but quickly withdraws it. The hand and arm never make it up to the stimuli or up to the collar bone (so the patient doesn’t locate the pain but withdraws from it).
3 Points: Abnormal flexion (decorticate posturing) remember “COR” from the word decorticate
- When stimuli is applied (example: trapezius squeeze) the patient flexes hence bends the elbow gradually and moves the arm to the center (hence CORE) of the body with pronation of the forearm and flexion of the wrist and the hands will turn into fists. There won’t be the withdrawal from the stimuli like in the previous response. This is NOT a good finding and means the cortex is affected.
2 Points: Extension (decerebrate posturing): Remember all the “e” in decerebrate for Extension.
- When stimuli is applied (example: trapezius squeeze) the patient will extend the arm at the elbow with internal rotation of the arm. This is the worst type of posturing and is not a good sign. It indicates the brainstem is affected.
1 Point: no response
*NT: example…patient on sedation and paralyzed
Let’s Practice:
You find the following in your patient:
Eyes open only when pressure is applied to nail bed, patient makes only sounds and no words to the questions, and patient can’t obey a verbal motor command but when you apply a trapezius squeeze the patient bends the elbow and moves the arm and hand up above the collar bone trying to remove the pain/pressure.
Answer: GCS 9 (E2 V2 M5)
Test your knowledge with this Glasgow Coma Scale Quiz.
References:
Centers for Disease Control and Prevention. Glasgow Coma Scale [Ebook] (pp. 1-2). Retrieved from https://www.cdc.gov/masstrauma/resources/gcs.pdf
Jain S, Iverson LM. Glasgow Coma Scale. [Updated 2021 Jun 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513298/
Naalla, R., Chitirala, P., Chittaluru, P., & Atreyapurapu, V. (2014). Sternal rub causing presternal abrasion in a patient with capsuloganglionic haemorrhage. BMJ case reports, 2014, bcr2014204028. https://doi.org/10.1136/bcr-2014-204028