June 27 (HealthDay News) -- Levels of a naturally occurring blood protein can help doctors assess illness severity and the risk of death in very sick patients, a new study suggests.

"Protein C" is found in blood and prevents blood clotting, the German researchers say, and it also acts as an indicator of inflammation in the body.

A simple laboratory test can be used to measure patient's protein C levels, according to a report in the July issue of the journal Anesthesiology.

The researchers examined the link between protein C levels and indicators of organ failure in 312 patients who were admitted to an intensive care unit (ICU) after they had major surgery.

The team from Friedrich Schiller University, in Jena, found that lower protein C levels were associated with increased severity of sepsis (blood infection) and with greater organ dysfunction. The study also found that patients whose minimum protein C level was below a certain point were four times more likely to die than other patients.

"Protein C may be a new target for therapy for patients with non-infectious organ failure/dysfunction in the intensive care unit," study author Dr. Frank Brunkhorst said in a prepared statement.

"The possibility to measure protein C levels at bedside in critically ill patients -- without time delay by the central lab -- would be a great step forward in assessing prognosis and may influence clinical decision making at an early stage of the evolution of organ dysfunction," he said.

Severe sepsis kills about 750,000 people each year in the United States, Dr. Michael A. Gropper of the University of California, San Francisco, wrote in an accompanying editorial to the study.

"The ability to identify these patients and treat them early will significantly improve their chances of survival. This study is important, because it identifies a strategy to easily identify patients with severe sepsis and multisystem organ failure," Gropper wrote.