Nosocomial infection after septic shock among intensive care unit patients

To measure the incidence of nosocomial infection (NI) among patients with septic shock according to the place of septic shock acquisition and to evaluate the increase in the risk of pulmonary infection associated with septic shock.

Prospective cohort study.

Two intensive care units (ICUs) of a French university hospital.

The study included a total of 209 septic shock patients during the period December 1, 2001 through April 30, 2005. The place of septic shock acquisition for 108 patients was the community; for 87, the hospital; and for 14, the ICU. To evaluate the impact of septic shock on the development of pulmonary infection, a competitive and adjusted hazard ratio (aHR) model was applied to nontrauma ICU patients.

Among the 209 study patients, 48 (23%) experienced 66 NIs after septic shock. There was no significant difference in the NI attack rates according to place of acquisition: for the community acquisition group, 24 cases per 100 patients (95% confidence interval [CI], 16-32); for the hospital acquisition group, 20 cases per 100 patients (95% CI, 11-28); and for the ICU acquisition group, 36 cases per 100 patients (95% CI, 11-61) (P = .3). For nontrauma ICU patients, the presence of community-acquired septic shock was found to be independently associated with a higher incidence of pulmonary infection, compared with the absence of septic shock (aHR, 2.12 [95% CI, 1.08-4.16]; P = .03).

The risk of NI did not differ by the place of septic shock acquisition. The risk of pulmonary infection was higher for ICU patients with community-acquired septic shock who were admitted for underlying nontrauma disease. Studies are needed to investigate the pathogenic mechanisms that facilitate pulmonary infection in this population, taking into account exposure to invasive devices and immunosuppression after the initial phase of septic shock.