The Glasgow Coma Scale (GCS) is a clinical diagnostic tool widely used since the 1970s to assess a patient's level of consciousness. While initially primarily utilized in patients with traumatic brain injuries, its utilization has extended to assess the level of consciousness in a wide range of settings, illnesses, and injuries. The GCS score takes into consideration three components: eye movements, verbal response (e.g., speech), and motor response (e.g. purposeful body movements). A GCS score can range from the lowest possible score of 3, in which a patient is completely unresponsive and is associated with a state of coma, to the best score possible of 15, in which a patient is fully alert and interactive. An initial score is used to guide immediate medical care after traumatic brain injury (such as a car accident) and a post-treatment score can monitor hospitalised patients and track their recovery. The total GCS score is not recommended to be used by itself to predict patient outcomes.
Scoring The Glasgow Coma Scale is used for people above the age of two and is composed of three tests: eye, verbal, and motor responses. The scores for each of these tests are indicated in the table below.
The Glasgow Coma Scale is reported as the combined score (which ranges from 3 to 15) and the score of each test (E for eye, V for Verbal, and M for Motor). For each test, the value should be based on the best response that the person being examined can provide. For example, if a person obeys commands only on their right side, they get a 6 for motor. The scale also accounts for situations that prevent appropriate testing (Not Testable). When specific tests cannot be performed, they must be reported as "NT" and the total score is not reported. The results are reported as the Glasgow Coma Score (the total points from the three tests) and the individual components. As an example, a person's score might be: GCS 12, E-3 V-4 M-6. In a patient who is intubated with an endotracheal tube an unable to speak, but fully conscious, their GCS score breakdown would be: GCS E-3, V-1T, M-6. In a patient who is both intubated and sedated, they will likely have lower eye and motor component scores in addition to their verbal score of V-1T (e.g., GCS E-2, V-1T, M-5).
Pediatric scoring
Children below the age of two struggle with the tests necessary for assessment of the Glasgow Coma Scale. As a result, a version for children has been developed, and is outlined below.
Interpretation Individual elements as well as the sum of the score are important. Hence, the score is expressed in the form "GCS 9 = E2 V4 M3 at 07:35". Patients with scores of 3 to 8 are usually considered to be in a coma. Generally, traumatic brain injury is classified as:
Severe, GCS ≤ 8 Moderate, GCS 9–12 Minor, GCS ≥ 13. Tracheal intubation and severe facial/eye swelling or damage make it impossible to test the verbal and eye responses. In these circumstances, the score is given as 1 with a modifier attached (e.g. "E1c", where "c" = closed, or "V1t" where t = tube). Often the 1 is left out, so the scale reads Ec or Vt. A composite might be "GCS 5tc". This would mean, for example, eyes closed because of swelling = 1, intubated = 1, leaving a motor score of 3 for "abnormal flexion". Many people have difficulty remembering the difference between decorticate and decerebrate posturing. One way to remember the difference is by remembering, deCOREticate means arms are flexing inwards towards the body. You can also remember that deCEREbrate posturing has a lower score (meaning it is worse), by thinking of the E's and remembering extension for decerebrate, and extreme for bad. Special considerations: Potential non-traumatic underlying causes of decreased responsiveness include toxins, metabolic derangements (e.g. high or low temperature, high or low glucose, high or low electrolytes), infections, stroke, and seizures. Baseline patient characteristics that may affect GCS include language barriers, hearing difficulty, speech difficulty, and pre-existing intellectual or neurological abnormalities. Other injuries such as eye or facial trauma, extremity (arm, leg) trauma, or spinal cord injuries can also affect the GCS. Elderly patients warrant special consideration as they are at risk for under-triage from relatively minor injuries, such as a fall from standing. Providers should have higher concern for an underlying severe injury in this patient population even if their initial GCS is high or near normal. As such, age and frailty are being recognized as important factors to consider in conjunction with GCS. The GCS has limited applicability to children, especially below the age of 36 months (when the verbal performance of even a healthy child would be expected to be poor). Consequently, the Paediatric Glasgow Coma Scale was developed for assessing younger children.
History
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