Postsurgical ICU Patients May Have Higher Death Risk

A moderate increase in blood troponin levels in postsurgical patients in an intensive care unit (ICU) has been found to be associated with an increased risk of death and longer ICU stay, and may indicate an unknown ongoing heart injury, according to a study reported in the November 2003 issue of Critical Care Medicine.

An estimated 15% of ICU patients have unrecognized injury to the heart. Researchers studied 869 surgical ICU patients, excluding those who had previously had heart surgery, to determine the significance of moderate troponin elevations. They found that those with mildly elevated troponin levels who were receiving beta-blockers and aspirin had better survival rates than untreated patients. The researchers hypothesized that a shortage of oxygen to the heart, short of heart attack, increases blood levels of troponin I in proportion to the decrease in oxygen.

"Since completing this research, we have been monitoring troponin levels more carefully,” said senior author Gregory J. Beilman, M.D., associate professor of surgery and anesthesia at the University of Minnesota (St. Paul/Minneapolis, USA). "For mild elevations, I order noninvasive tests such as an echocardiogram to see if there is any abnormal cardiac function.”