Trauma patient hospital-associated infections: risks and outcomes

Trauma patients with surgical procedures, acute lung injury (ALI), systemic inflammatory response syndrome (SIRS), and longer exposure to invasive devices may be at increased risk for hospital-associated infection (HAI). HAIs have been shown to affect outcome measures, but the extent is not well studied.

An infection control team identified HAIs in trauma patients from 1996 through 2001. The authors evaluated the relation of HAI to surgical procedures, ALI, SIRS, and device exposure time by comparing groups with and without HAI using Fisher's exact and Mann-Whitney tests. Using multiple linear and logistic regressions, the authors evaluated associations of HAI, age, and Injury Severity Score (ISS) with length of stay (LOS), cost of care, and mortality. They used Cox proportional hazard regression to further explore the relations of HAI, age, and ISS to LOS.

In 501 of 5,537 trauma patients with HAI (9.1%), the percent having surgical procedures, ALI, and SIRS was significantly higher (p < 0.001). Exposure to all devices studied was significantly longer (p < 0.001) in HAI patients. When the population was controlled for age and ISS, HAI patients had longer lengths of stay (LOSs) and higher costs. Age had less effect than ISS on LOS, and the effect of increases in age was greater as ISS increased. ISS had a greater effect than HAIs on LOS. HAIs increased LOS more in patients less severely injured. When comparing patients with and without HAI, no difference in mortality rates was detected.

In this study of trauma patients, ISS had the greatest effect on LOS, but increased age and presence of HAI did increase LOS and cost of care. HAI increased LOS more in the less severely injured patients.