From the Guidelines
To determine if a patient is in a coma, healthcare providers should use the Glasgow Coma Scale (GCS) which assesses eye opening, verbal response, and motor response, with a GCS score of 8 or less generally indicating a coma, as recommended by the most recent and highest quality study 1. The GCS is a strong prognostic marker and indicator of need for surgery in traumatic brain injury (TBI) and has been validated in several studies, including the IMPACT and CRASH studies 1. The assessment of the patient's level of consciousness should also include checking pupillary responses to light, corneal reflexes, oculocephalic reflexes (doll's eyes), and respiratory patterns. Brain imaging such as CT or MRI scans and electroencephalography (EEG) may be performed to identify the underlying cause. Some key points to consider when assessing a patient for coma include:
- The GCS score should be described according to each of the 3 components, including Eye-Verbal-Motor response 1
- The motor component of the GCS remains robust in sedated patients and is well correlated with the severity of head trauma 1
- Pupillary responses can provide additional prognostic information and can be integrated with the GCS to provide greater specificity of outcome prediction 1
- The FOUR score, which measures ocular and limb responses to command and pain, along with pupillary responses and respiratory pattern, may provide a more complete assessment of brainstem function in non-sedated patients 1. It is also important to monitor vital signs, including blood pressure, heart rate, temperature, and oxygen saturation, and to perform blood tests to check for metabolic abnormalities, toxicology screens, and lumbar puncture as necessary, depending on the suspected cause of the coma 1. Overall, the assessment and management of a patient in a coma requires a comprehensive approach that takes into account the patient's level of consciousness, underlying cause of the coma, and overall medical condition, as recommended by the most recent and highest quality study 1.
From the Research
Determining Coma in Patients
To determine if a patient is in a coma, healthcare professionals use the Glasgow Coma Scale (GCS) [ 2 ], which is a standardized assessment tool. The GCS evaluates the patient's level of consciousness based on three components:
- Eye response
- Verbal response
- Motor response
Assessment Components
The motor component of the GCS is the most difficult to assess [ 2 ]. Proper training and understanding of the GCS components are essential for accurate assessment and communication among healthcare professionals. Some key points to consider when assessing a patient's level of consciousness include:
- The difference between peripheral and central stimuli [ 3 ]
- The need for clear and common language to describe the patient's motor response to a painful stimulus [ 2 ]
Glasgow Coma Scale Scores
The GCS classifies traumatic brain injuries as mild (14-15), moderate (9-13), or severe (3-8) [ 4 ]. However, the classification of a GCS score of 13 as mild or moderate TBI can affect mortality prediction [ 4 ]. Some studies suggest that immediate intubation of patients with a GCS score of 7 or 8 and isolated head injury may be harmful [ 5 ].
Clinical Practice Guidelines
The GCS has been widely used in clinical practice for over 50 years, with a significant impact on the scientific literature and clinical guidelines [ 6 ]. A comprehensive bibliometric analysis and systematic review of clinical practice guidelines have identified research hotspots and informed future research on the topic [ 6 ]. Key findings include:
- The compound annual growth rate of publications referencing the GCS was 16.7%
- The top trending author-supplied keyword was "traumatic brain injury"
- The GCS is most commonly employed in the fields of internal medicine, critical care, and neurotrauma