Red cell distribution width: the crystal ball in the hands of intensivists?

Critically ill patients admitted to intensive care unit (ICU) are at a high risk of morbidity and mortality (1), with significantly increased medical costs. In the meanwhile, intensive care resources are limited, especially in developing countries such as China (2). As a result, rational allocation of limited intensive care resources to those patients who are more likely to benefit from intensive care may depend upon the accurate assessment of clinical prognosis. Therefore, many investigators have developed different prognostic tools, in the form of single parameter, composite indices, and even complicated scores (3-5), in order to assess the severity of illness, predict prognosis, or benchmarking different ICUs. Despite all these efforts, ideal prognostic tools are still lacking, so that investigators are trying to explore new prognostic indices that prove to be accurate, cheap, and readily available.