In a one-day snapshot of intensive care units around the world, more than half of the patients had acquired an infection during their stay, a major study revealed.
And the mortality rate among infected patients was more than double that of patients without an infection, according to Jean-Louis Vincent, MD, PhD, of Erasme University Hospital in Brussels, and colleagues.
The findings come from the Extended Prevalence of Infection in Intensive Care (EPIC II) study, which collected data over a 24-hour period from 1,265 intensive care units in 75 countries on May 8, 2007, the researchers reported in the Dec. 2 issue of the Journal of the American Medical Association.
The study is a follow-up to an earlier one-day snapshot of ICU infections in Western Europe, the European Prevalence of Infection in Intensive Care study, conducted on April 29, 1992.
The prevalence of infection is important because of the increased risk of death, according to co-author John Marshall, MD, of St. Michael’s Hospital in Toronto.
“There is an additional perhaps 10% to 15% mortality risk associated with acquiring an infection in the ICU,” Marshall said. For that reason, he said, prevention strategies “assume a substantial degree of importance when you look at this as a global health problem.”
The study also offers “several noteworthy insights into the current practice patterns of antibiotic use and infection risks in ICU patients,” according to Steven Opal, MD, of Warren Alpert Medical School of Brown University in Providence, R.I., and Thierry Calandra, MD, PhD, of Centre Hospitalier Universitaire Vaudois in Lausanne, Switzerland.
In an accompanying editorial, they said the study showed — among other things — a “striking” burden of infection among critically ill patients that increased to 51% from the 44.8% seen in the earlier study.
The editorialists also noted that the study found that gram-negative bacterial infections now outnumber gram-positive infections in ICU patients — a “concerning” development because resistance among those organisms is growing and therapeutic options are declining.
The researchers collected demographic, physiological, bacteriological, therapeutic, and outcome data on 14,414 patients, but for this analysis they focused on the 13,796 who were 18 or older.
On the day of the study, the researchers found: 7,087 of the 13,796 adult patients — or 51% — were considered infected. Nearly three-quarters — 9,084 or 71% — were receiving antibiotics either as prophylaxis or treatment. Of the infected patients, 4,503 (64%) had a respiratory infection. Microbiological culture results were positive in 4,947, or 70%, of the infected patients and 62% of the isolates were gram-negative organisms, 47% were gram-positive, and 19% were fungi. The infection rate was 32% for patients who had been in the ICU for one day or less and rose to more than 70% for patients who had been in intensive care for more than seven days, a difference that was significant at P<0.001. The mortality rate of infected patients in the ICU was 25%, compared with 11% for noninfected patients, a difference that was significant at P<0.001. The inhospital mortality rate was also significantly higher, at P<0.001 — 33% versus 15%.
One of the study’s strengths is its international nature, Vincent and colleagues said. But they cautioned against simplistic interpretations across geographic boundaries “because clearly there are large differences in healthcare systems, ICU facilities, and regional policies for infectious disease management.”
Limitations included the voluntary design of the study, which might have introduced a bias, and the lack of data monitoring, which might mean that some definitions were incorrectly interpreted.
Nonetheless, they concluded, the study “demonstrates that infections remain a common problem in ICU patients.”
The researchers did not report any external support for the study or any financial conflicts.
Opal and Calandra reported no conflicts.