Scoring systems for assessing organ dysfunction and survival

Sepsis is an ongoing disease process carrying a high risk of organ failure and death. Scoring systems to determine disease severity and risk of mortality may be useful in patient management and clinical trial enrollment, although the role of either type of score in the determination of admission or discharge criteria or in decisions relating to the continuation or withholding of treatment remains controversial. General scoring systems have been developed to quantify the severity of illness and the risk of mortality in ICU patients. Ideally, these should be customized before use in patients with septic shock, but in general noncustomized models are used, and this potential limitation should be acknowledged. Prognostic scores are remarkably reliable at predicting outcome in groups of patients and give an indication of severity of disease on admission, but they are unable to provide detail on how a patient is responding to treatment or on the disease progression. Organ function scores, however, can be assessed repeatedly and used to define a patient's progress. This approach can thus be used to evaluate individual patient care, to identify patients for enrollment in clinical trials or epidemiologic analyses, and to assess morbidity measures in clinical trials of new interventions. Organ dysfunction scores are just that, descriptors of organ dysfunction, and although high values correlate well with mortality, prognostication is not their prime aim; organ dysfunction scores and outcome prediction scores should rather be viewed as complementary systems in the description of ICU populations.