[Risk predictors, scoring systems and prognostic models in anesthesia and intensive care. Part I: anesthesia]

Risk predictors and scoring systems are commonly used in medicine to provide a reliable and objective estimation of disease prognoses, probability of adverse events and outcome. Furthermore, they were designed to classify severity of illness or the course of diagnostic and therapeutic interventions and to perform a risk stratification for scientific studies in a standardized way. In quality management and cost control, scoring systems and predictors are used for risk adjustment and evaluation of care performance. The aim of this review article was to describe common risk indices and scoring systems in anesthesia (part I) and intensive care (part II), and to point out their possible benefits and limitations. Different scoring systems and classifications are available to stratify perioperative risk and adverse events in anesthesia. Especially in cardiac surgery, an increasing interest in risk-adjusted outcome studies led to the modeling and validation of different prognostic systems for postoperative morbidity, mortality and length of stay. Furthermore, there are scoring-systems for special events, such as difficult laryngoscopy or postoperative nausea and vomiting (PONV). Risk check lists and risk indices are superior to the ASA classification of physical status in providing more exact results and the possibility of statistic risk calculation. Nevertheless, they are not frequently used in clinical routine. Because of its simplicity and easy handling the ASA classification has worldwide popularity and recent studies demonstrated at least equal prognostic performance.