Patterns and early evolution of organ failure in the intensive care unit and their relation to outcome

Abstract

Introduction: Recognition of patterns of organ failure may be useful in characterizing the clinical course of critically ill patients. We investigated the patterns of early changes in organ dysfunction/failure in intensive care unit (ICU) patients and their relation to outcome.

Methods: Using the database from a large prospective European study, we studied 2,933 patients who had stayed more than 48 hours in the ICU and described patterns of organ failure and their relation to outcome. Patients were divided into three groups: patients without sepsis, patients in whom sepsis was diagnosed within the first 48 hours after ICU admission, and patients in whom sepsis developed more than 48 hours after admission. Organ dysfunction was assessed by using the sequential organ failure assessment (SOFA) score.

Results: A total of 2,110 patients (72% of the study population) had organ failure at some point during their ICU stay. Patients who exhibited an improvement in organ function in the first 24 hours after admission to the ICU had lower ICU and hospital mortality rates compared with those who had unchanged or increased SOFA scores (12.4 and 18.4% versus 19.6 and 24.5%, P < 0.05, pairwise). As expected, organ failure was more common in sepsis than in nonsepsis patients. In patients with single-organ failure, in-hospital mortality was greater in sepsis than in nonsepsis patients. However, in patients with multiorgan failure, mortality rates were similar regardless of the presence of sepsis. Irrespective of the presence of sepsis, delta SOFA scores over the first 4 days in the ICU were higher in nonsurvivors than in survivors and decreased significantly over time in survivors.

Conclusions: Early changes in organ function are strongly related to outcome. In patients with single-organ failure, in-hospital mortality was higher in sepsis than in nonsepsis patients. However, in multiorgan failure, mortality rates were not influenced by the presence of sepsis.

Figure 1

Hospital mortality rates according to SOFA score on admission (gray columns) and the maximum SOFA score (black columns).

Figure 2

Error bars representing the delta SOFA scores (mean ± 95% CI) during the first 4 days in the ICU in survivors (solid circles) and nonsurvivors (solid triangles) in the whole cohort (A) (n = 2,933) and in patients without (n = 1,789) (B), or with sepsis (n = 1,144) (C). *P < 0.05 compared with ΔSOFA 24-0 (ANOVA with Bonferroni correction for multiple comparisons); †multifactorial ANOVA; P < 0.05 compared with survivors.