A coma is a continuous state of unconsciousness, generally involuntarily, often the result of a traumatic injury or other serious condition that affects the brain. The first step in dealing with a comatose patient is to discover the cause of the coma, followed by determining the likely outcome of the patient -- essentially, classifying the seriousness of the coma. Here’s a look at how comas are classified.
What are Coma Classification Scales?
One of the more commonly used scales when classifying comas is the Glasgow Coma Scale. It provides an easier means of explaining the recovery of a comatose patient than by relying on standard medical and anatomical jargon, as well as a basis of comparison. The Glasgow scale is most helpful in determining how serious the injury that caused the coma is in relation to the likely outcome of the patient by determining the patient’s awareness of the environment and what is being said. Other common coma classifying scales include the Ranchos Los Amigos Scale, a pediatric version of the Glasgow scale, the Blantyre Coma Scale, and FOUR score.
What is the Glasgow Coma Scale?
According to The Glasgow Structured Approach to Assessment of the Glasgow Coma Scale, the goal of this scale is to assess the impairment of a comatose patient’s conscious level in response to defined stimuli. Essentially, the scale uses a predetermined method to see how much consciousness someone in a coma has retained in their comatose state -- and thus, can be a predictor of how likely they are to wake up in a functional state. Additionally, scores can be indicative of attempting new means of treatment. The latter aspect of the scale also provides medical staff with a quantitative means of explaining to concerned loved ones the expected outcome of the patient.
How Does the Glasgow Scale Work?
The scale operates on a range of three to fifteen points. Mild injuries are generally indicated by a score of thirteen to fifteen, moderate injuries rate nine to twelve, and severe injuries range from three to eight. The three key aspects of the Glasgow Scale are the patient’s eyes opening, verbal responses, and motor responses. The eyes are monitored for and scored on a scale of one to four, ranging from spontaneous opening (four), opening in response to verbal cues (three), opening in response to pressure (two), or do not open at all (one).
Verbal responses may be classified as “orientated” (five) or “confused” (four), meaning the patient is able to provide verbal cues that they comprehend what they are saying or seem to have very little idea as to what they are saying or hearing. Verbally, the patient may also be speaking nonsense words (three) simply making sounds (two), or providing absolutely no verbal responses at all, regardless of stimuli (one).
Motor control is scored depending on whether the patient can: provide at least two separate movements in response to commands (six), moves only one part of the body (generally the arm) as a means to remove painful stimuli thus exhibiting an ability to locate the placement of the pain (five), or moves the arm in an attempt to withdraw from pain but doesn’t quite manage to figure out where it is coming from (four). Lower motor scores are the result of normal arm movement responses by bending or flexing the elbow more slowly than normal (three), extending the arm in response to painful stimuli (two), or does not respond at all (one).
