Multiple Organ Failure Main ICU Death Cause

INNSBRUCK, Austria, Nov. 3 -- Multiple organ dysfunction syndrome is the main cause of death in the intensive care unit, according to researchers here.

Nearly half the patients who died in from Jan. 1, 1997, through Dec. 31, 2003, suffered refractory multiple organ failure, found Viktoria Mayr, M.D., of the hospital's department of anesthesiology and critical care medicine.

The main risk factors for death on entering the ICU were central nervous system failure and cardiovascular failure, Dr. Mayr and colleagues reported online today in the journal Critical Care.

The design of the single-center cohort study "precludes wide generalization of our results to other centers because of institution-based differences in treatment, patient population, and admission policies," Dr. Mayr and colleagues noted.

But it does add to the limited knowledge of the causes of death of patients in the ICU and afterward, they said, as well as "short- and long-term outcomes of critically ill patients and associated risk factors."

Over the study period, the hospital's 12-bed general and surgical ICU admitted 4,055 patients. Complete data were available on 3,700 patients -- for the ICU stay, subsequent hospitalization, and the year following discharge -- and only they were included in the analysis.

The study found:

• Overall, 353 patients, or 9.5%, died in the ICU.
• Another 144 -- or 4.3% of the remaining 3,347 -- died in hospital after discharge from the ICU.
• After discharge from the hospital, 286 patients, or 8.9% of 3,203, died within a year after admission to the ICU.

Of those who died in the ICU, 47% suffered acute, refractory multiple organ dysfunction syndrome, 17.8% had refractory cardiovascular failure, and 11.6% had refractory chronic multiple organ dysfunction syndrome, the researchers found.

The most important independent risk factors for death included:

• Central nervous system failure. The odds ratio was 16.07 (with a 95% confidence interval from 8.2 to 31.4), which was statistically significant at P<0.001.
• Cardiovascular failure. The odds ratio was 11.83 (with a 95% confidence interval from 5.2 to 27.1), which was statistically significant at P<0.001.
• Acute renal failure. The odds ratio was 2.7 (with a 95% confidence interval from 1.7 to 4.3), which was statistically significant at P<0.001.
• Admission from the recovery room. The odds ratio was 2.2 (with a 95% confidence interval from 1.4 to 3.4), which was statistically significant at P<0.001.

Cancer and exacerbation of chronic cardiovascular disease were the most frequent causes of death both in the hospital (31.3% and 19.4%, respectively) and a year after discharge (33.2% and 16.1%, respectively).

"In this primarily surgical critically ill patient population, acute or chronic (multiple organ dysfunction syndrome) prevails by far over single-organ failure or unexpected cardiac arrest as cause of death in the ICU," the researchers concluded.