Factors restricting the use of coma scales.

The Glasgow Coma Scale has been well established as the ideal scale for identifying specific levels of consciousness. It is widely used to provide a consistent entry criterion for series of head injuries under study, to create arbitrary thresholds for management decisions and as an important component of the data-set for comparative studies of patients in different centres with specified treatment regimes. Its international reputation for application to these 3 functions is well deserved but the dangers of summing the subscores have been rightly emphasized by the designers. Any further improvements may only cause confusion and it will undoubtedly continue as the recognized standard for many years. Unfortunately, this scale is very inadequate for monitoring head injured patients at risk of deterioration as it is insufficiently sensitive. The prompt recognition of the first signs of deteriorating consciousness is of paramount importance. A more sensitive scale encompassing more aspects of the response of the patient to the environment is required. For this purpose of trend detection, subscore summation is acceptable and nurses find a single graph easier to interpret.