PROGNOSTIC SCORES IN INTENSIVE-CARE

Since the development of prognostic score systems in intensive care me dicine in the 1980s score models have improved substantially and are n ow based on much larger databases. They have been validated in many mu lticenter and international studies all over the world. Prognostic sco ring systems may be used for assessment of severity of illness, strati fying patients prior to randomization in clinical trials, evaluation a nd comparing outcome and survival (hospital mortality), quality assess ment, cost-benefit analysis, and in clinical decision making. Validate d time points for predicting hospital mortality of ICU patients are at admission and at 24 hours. The relationship of the observed hospital mortality rate to the estimated mortality provides the basis for clini cal performance measurement. Since each ICU serves a different patient population, each score system must be calibrated in the individual ho spital to ensure that the model is applicable. General scores covering more than one disease are Acute Physiology And Chronic Health Evaluat ion (APACHE II, APACHE III), Simplified Acute Physiology Score (SAPS) and Mortality Predicting Model (MPM). The Therapeutic Intervention Sco ring System (TISS) and in part the Hannover Intensive Score (HIS) eval uate exclusively the amount of medical therapy required. The TISS-Scor e might serve as a possible measure of resource use for the ICU portio n of the hospital stay. Disease (e.g. Trauma Score, Injury of Severity Score) and patient (e.g. PRISM = Pediatric Risk of Mortality) specifi c scores take into account the influence of disease and patient popula tion in relation to outcome. They are not always of more predictive va lue than general score models. Score models have been criticized for a number of reasons. Outcome of ICU therapy should incorporate not only survival but should also take into account quality of life, morbidity and disability. Severity scores have no role in clinical decision mak ing for an individual patient (e.g. patient triage for ICU admission, discharge criteria, withdrawal of life support). This is due to the cu rrent low sensitivity. Subsequent validation of variables could improv e the sensitivity and the value of severity scoring in the future. Nev ertheless, illness severity scores will never be indicative of absolut e irreversibility of disease or impossibility of survival. Advances in computer technology should assist in achieving many of the future goa ls of prognostic scoring systems. Most of the physiological data are a vailable from ICU monitors and computerized laboratory systems. By ele ctronically interfacing with the ICU monitor an automated patient data entry is possible and will provide that prognostic scores can be made available to the clinician daily.