Where's the difference? Presentation of nosocomial infection in critically ill trauma versus general surgery patients.

Background: Diagnosing infection efficiently is integral to managing critically ill patients. Knowing if and how trauma and general surgery patients differ in their presentation of new infectious complications could be useful. We hypothesized these populations would differ in presentation in the intensive care unit (ICU).

Methods: We analyzed data collected prospectively from all 1,657 trauma and general surgery patients admitted to the surgical and trauma ICU (STICU) over a 21-month period. Clinical data from the first day of a newly diagnosed infection were compared for trauma (82% of the series) and general surgery (18%) patients.

Results: A total of 10,424 STICU days were included, and 267 nosocomial infections were diagnosed. Trauma patients were younger (50 vs. 62 years; p<0.001) and more likely to be male (78% vs. 46%; p<0.001) than were general surgery patients. Similar percentages of the two groups were infected (11% and 13%, respectively), and infections occurred after a similar number of days in the STICU. The mean maximum temperature on the day prior to diagnosis was higher in trauma patients (38.4°C vs. 37.7°C; p<0.001), and the mean leukocyte count was lower (13,500 vs. 15,800 10(6)/L; p=0.013). General surgery patients were more likely to be hypotensive (13% vs. 2%; p=0.002) and to have a positive fluid balance >2 L on the first day of infection (27% vs. 13%; p=0.02). Respiratory infections were more common in trauma patients (40% vs. 7%; p<0.001), and urinary tract infections were less common (19% vs. 36%; p=0.011).

Conclusion: Differences exist in how new infections manifest in trauma and general surgery patients in the ICU. General surgery patients appeared sicker on their first day of infection, as evidenced by a higher leukocyte count, lower blood pressure, and substantial positive fluid balance. Intensivists may need differing thresholds for triggering infection workups when employed in a mixed unit.