Readmissions for Recurrent Sepsis: New or Relapsed Infection?

Area of Science:

• Infectious Diseases
• Critical Care Medicine
• Hospital Epidemiology

Background:

• Sepsis hospitalizations often lead to readmissions, frequently for recurrent sepsis.
• Distinguishing between relapsed/recrudescent and new sepsis infections upon readmission is clinically important.

Purpose of the Study:

• To determine the proportion of 90-day sepsis readmissions attributed to the same infection site and pathogen as the initial sepsis episode.
• To differentiate between recurrent and new infections in patients readmitted for sepsis.

Main Methods:

• Retrospective cohort study conducted at the University of Michigan Health System.
• Inclusion of all sepsis, severe sepsis, or septic shock hospitalizations from May 2013 to May 2015.
• Manual chart abstraction to determine the site and organism of sepsis for initial admissions and 90-day readmissions.

Main Results:

• Of 472 sepsis readmissions, 137 (29.1%) were for sepsis. Common sites included urinary (29.2%) and gastrointestinal (20.4%); common organisms were Gram-negative (29.9%) and Gram-positive (16.8%).
• 68.6% of sepsis readmissions were for infection at the same site as the initial hospitalization.
• Only 19% of readmissions were confirmed as same site and same organism; however, up to 53.2% could plausibly be due to the same site and organism when considering culture-negative cases.

Conclusions:

• Two-thirds of 90-day sepsis readmissions involved infection at the same anatomical site as the initial sepsis.
• A small proportion (19%) of sepsis readmissions were definitively linked to the same pathogen.
• Approximately half of sepsis readmissions were clearly new infections, with a significant additional portion (34%) having uncertain etiology due to negative cultures.