Subsequent infections in survivors of sepsis: epidemiology and outcomes

Abstract

Purpose: Sepsis is a devastating condition with considerable mortality. The causes of long-term mortality are poorly understood. To test the hypothesis that patients with sepsis are more susceptible to recurrent infections and death due to infectious complications, we investigated the outcomes of patients who survived sepsis, with regard to the incidence of recurrent infections and mortality.

Materials and methods: A retrospective study of the patients admitted to the intensive care unit (ICU) for sepsis from 2001 to 2002 who achieved 30-day survival (sepsis survivors [SSs], N = 78) and a control group of patients admitted to the ICU for noninfectious conditions with a similar severity of illness (N = 50) was performed. The primary end point was the number of recurrent infections in the first year posthospitalization.

Results: The SSs group had higher rates of infections following hospital discharge compared to controls. Using a multivariable model, having survived sepsis was the strongest predictor of the development of subsequent infections (rate ratio [RR]: 2.83, P= .0006), the need for rehospitalization for infection in the year after the initial hospitalization (RR: 3.78, P = .0009), and postdischarge mortality (hazard ratio = 3.61, P = .003).

Conclusions: Critically ill patients who survive sepsis have an increased risk of recurrent infections in the year following their septic episode that is associated with increased mortality.

Keywords: immunosuppression; outcomes; sepsis.

Figure 1

Mean cumulative frequencies of post-discharge infections were determined in the survivors of sepsis (“sepsis,” solid line) as compared to survivors of non-septic critical illness (“controls,” dashed line). The difference (unadjusted rate ratio = 5.68; *, p<0.00001) persisted out to one year. The lighter shaded lines represent 95% confidence intervals.

Figure 2

Mean cumulative frequencies of re-hospitalizations for infection were determined in survivors of sepsis (“sepsis,” solid line) as compared to survivors of non-septic critical illness (“controls,” dashed line). The difference (unadjusted rate ratio = 8, *, p<0.0001) persisted out to one year. The lighter shaded lines represent 95% confidence intervals.

Figure 3

Comparison of the sites of recurrent infection (A) and microorganisms implicated (B) in survivors of sepsis as compared to survivors of non-septic critical illness (controls). An increased rate of pneumonia and opportunistic pathogens were observed in the sepsis survivors as compared to control subjects.

Figure 4

The Kaplan-Meier curve of one-year survival is shown for sepsis survivors as compared to controls. The sepsis survivors (“sepsis,” solid line) had significantly lower survival (higher mortality) compared to survivors of non-septic critical illness (“controls,” dashed line). *, p-value <0.0001.