Significance of different levels of the Edinburgh 2 coma scale calculated from the outcome of neurosurgical patients.

In the management of patients with acute cerebral disturbances, it is essential to determine precisely the degree of impaired consciousness. In order to secure the accuracy of observations, one must use a reliable coma scale. We have evaluated the Edinburgh 2 coma scale (E2CS) and explored the relationship between levels of the E2CS and the final outcome. Case notes and observation charts of the past 7 years were reviewed, covering neurosurgical operations on 406 patients, in each of whom the postoperative course was evaluated periodically by the E2CS and the outcome was determined by the Glasgow outcome scale. By matching the outcome with each level of impaired consciousness, about 22,000 pairs of data were obtained. In order to quantify the morbidity rate, different stages of the Glasgow outcome scale were rated from 100 through 0, arbitrarily. It was proved that levels of the E2CS were arranged in the correct order in respect to both mortality and morbidity rates. It was shown at the same time that each level has different prognostic significance and that the distance between each level is not identical. The recommendation is made to separate the levels on a chart not by an ordinal number but by the distance calculated on the basis of either mortality or morbidity rates. This will make it possible to get a rough estimate of the patients' prognoses by simply looking at a daily clinical chart.