Trauma scores in emergency medicine quantitatively characterise the severity of trauma victims' injuries and physiologic derangements. They are used to detect and assess patients and have applications in guiding patient care and early therapeutic decisions. In the pre-clinical setting, an effective trauma index meets the following criteria: It is highly reliable with regard to identifying high- and low-risk patients. It has high face-validity. It has high inter- and intra-rater reliability. It is easy to use and allows rapid, accurate measurements. The most widely accepted injury severity index is probably the Injury Severity Score (ISS). It is calculated as the sum of the squares of the three most severely injured body regions, and was originally developed as a means to standardise the description of injuries sustained in motor vehicle accidents. The Trauma Score (TS) represents the gold standard of physiologic scoring of injury severity. It summarises the numerical assessments of the central nervous and cardiopulmonary system functions. The recently developed Mainz Emergency Evaluation Score (MEES) is based upon numerical specification of the vital signs, including a pain scale, and has been designed as a dynamic score. Nevertheless, limitations of the established trauma score systems have been described. Mortality and patient out come do not strictly correlate with injury severity scoring. In addition, intubated or paralysed patients were excluded from outcome studies since the scoring systems lacked options for evaluation of pathophysiological conditions after therapeutic interventions. Thus, therapeutic efficacy could hardly be assessed, and subsequent scoring during time periods was impossible. The accurate definition of comprehensive evaluation of a trauma victim is challenging, for example, ''pain'' as chosen in the MEES must be regarded as a highly desirable piece of information although its rating may prove difficult, especially when classifying unconscious patients. Further criticisms of the above-mentioned trauma indices could include omission of the trauma victim's age, gender, pre-injury health status, or the influence of alcohol or additional medication. Moreover, questioning the interrater reliability of injury severity scoring, a recent study revealed bias in assigning values to trauma patients: trained raters classified injury severity with significantly higher indices than less experienced researchers. If trauma indices in pre-hospital emergency medicine were relied upon as the only means of evaluating a trauma patient and guiding therapeutic approaches, significant numbers of trauma victims requiring major interventions would be missed. Resuscitative treatment regimens must not be based solely upon indices, since, e.g., in states of shock injury scores do not correlate with fluid resuscitative requirements. Furthermore, a qualitative assignment of single vital-function parameters as crucial indices for a patient's condition never reflects the broad range of a patient's profile. Many multiple-trauma patients do benefit from controlled ventilation in clinical experience even though pulse oximetry values are within the physiological range, and the administration of analgesics or even pre-hospital anaesthesia has often proved advantageous for trauma patients in the field. Providing the opportunity of subsequent patient evaluation and the efficacy of acute care, the MEES has been developed as a dynamic scoring system. This design is extremely desirable and must be regarded as an indispensible criterion for future scoring systems. In view of the peculiarities of field emergency medicine, pre-hospital indices do have limitations. The parameters ''unkown patient'', time pressure, unprecise measurements, lack of diagnostic facilities, incomplete evaluation, and limited statistical power cannot be eliminated. Accurate prediction of outcome within early time-frames is therefore not possible, and patient care must focus on efforts to combine easily obtainable parameters characterising vital functions with high accuracy. Our policy in emergency medicine does not allow basing therapeutic decisions for individual patients on scoring values. Nevertheless, scoring systems can provide quantification and stratification of emergency patients for evaluation of an emergency medical system's efficiency and quality for comparison on national and international levels.
