Glasgow Coma Scale: Definition, Use And Benefits

The Glasgow Coma Scale (GCS) is a neurological evaluation tool used by physicians to assess the level of consciousness of a person with a brain injury. It allows us to explore or quantify three parameters or criteria for observation. They are 1) eye response, 2) verbal response, and 3) motor response.

The Glasgow Coma Scale is the  most widely used tool in hospital and prehospital settings. Some of the benefits of GCS are that it is easy to use and it simplifies a common language and goals. This in turn makes communication between healthcare professionals much easier.

What is the Glasgow Coma Scale?

The Glasgow Coma Scale was designed in 1974 by two English neurologists named Bryan Jennett and Graham Teasdale. They were members of the Department of Neuroscience and Psychology. They published the first version of this scale in  The Lancet magazine. The title of their article was Assessment of Coma and Impaired Consciousness.

In the 60’s, Jennet created a database of all the patients he saw in Glasgow with traumatic brain injury (TBI). His partners in the Netherlands and the United States did the same. This database was the basis on which he and his colleague created the Glasgow Coma Scale.

Little by little, it became an important tool for objectively assessing the level of consciousness in patients suffering from a traumatic brain injury. It was divided into three categories that individually evaluated three aspects of consciousness: eye response, verbal response, and motor response. The sum of all the points was fourteen.

The addition of one point

The final version of the scale was created two years later, in 1976. They decided to add a new point to evaluate the level of cerebral stiffness, a sign of severe brain damage. This is an abnormal body position where the arms are bent towards the body, the hands are in tight fists and the legs are very straight. The whole body is stiff and inflexible.

The three sub-scales remained, but this addition took the total score from 14 to 15.  In total today it is still 15. 

Applications

Initially, the Glasgow Coma Scale was created to estimate the severity of traumatic brain injury. Today, doctors use it to assess less severe altered levels of consciousness in post-traumatic situations. They also use it for things like the depth and duration of the coma.

When someone suffers a blow to the head, doctors must examine them as soon as possible. The neurological evaluation must be simple, objective and fast. The most important aspect to keep in mind is the level of awareness. Consequently, GCS is crucial in these cases. The patient’s score on the scale helps us understand the severity of the injury.

On the other hand, it also helps to identify the condition of the coma and see their development. Physicians can use the scale in length (over time) to understand the fluctuations in these changes.

Result and interpretation

The doctors evaluate each of the three aspects and give points for the best answer in each category. The lowest possible score is 3 (1 + 1 + 1) and the highest is 15 (4 + 5 + 6). Healthcare professionals determine the severity of TBI using this score and the classification Gennarelli contributed to:

• Mild: 14-15 points
• Moderate: 9-13 points
• Serious: <9 points

With regard to the changed level of consciousness (state of coma), the gradient varies:

• Mild: > 13 points. The duration of the coma tends to be less than 20 minutes.
• Moderate: 9-12 points. The duration of the coma is greater than 20 minutes, but less than 6 hours after the patient was admitted.
• Serious or serious: <8 points. The duration is longer than 6 hours after the patient was admitted.

Benefits of the Glasgow Coma Scale

When it comes to health, the more precise we can be with the terms we use, the better. That’s why the Glasgow Coma Scale is so useful. It allows those who come with the patient to avoid ambiguities such as “the patient is drowsy or unconscious”. We can also be more accurate in terms of the patient’s clinical condition and evolution. Glasgow Coma Scale provides relatives with precision and safety. 

In addition, the precision and relative simplicity of this scale make it universally popular. Experts use it for other traumatic and non-traumatic pathologies. Professionals in various fields use it for emergencies.

GCS is a complete tool that evaluates three important aspects. The best part of it all is that healthcare professionals can use it again and again. This scale provides long-term information on the development of coma. It is therefore very useful in the early stages of treatment.