C-reactive protein levels correlate with mortality and organ failure in critically ill patients.

Study Objectives: C-reactive protein (CRP) is an acute-phase protein, the blood levels of which increase rapidly in response to infection, trauma, ischemia, burns, and other inflammatory conditions. Although used frequently in the ICU as a sepsis marker, the relation of CRP levels to organ damage is not well known. This study assessed the association between early serum CRP concentrations and the development of organ failure and mortality in ICU patients.

Design: A prospective cohort study.

Setting: A 31-bed ICU in a university hospital.

Patients: All 313 patients admitted to the ICU during the 4-month study period.

Interventions: None.

Measurements And Results: Patients with high CRP levels at ICU admission had more severe organ dysfunction (higher sequential organ failure assessment scores, days of renal extracorporeal support therapy), longer ICU stays, and higher mortality rates than patients with normal ICU admission CRP levels. CRP concentrations were correlated with the presence and number of organ failures. ICU admission serum CRP levels > 10 mg/dL were associated with a significantly higher incidence of respiratory (65% vs 28.8%, p < 0.05), renal (16.6% vs 3.6%, p < 0.05), and coagulation (6.4% vs 0.9%, p < 0.05) failures, and with higher mortality rates (36% vs 21%, p < 0.05) than CRP levels < 1 mg/dL. In patients with CRP concentrations > 10 mg/dL on ICU admission, a decrease in CRP level after 48 h was associated with a mortality rate of 15.4%, while an increased CRP level was associated with a mortality rate of 60.9% (relative risk, 0.25; 95% confidence interval, 0.07 to 0.91; p < 0.05).

Conclusions: In a heterogeneous ICU population, elevated concentrations of serum CRP on ICU admission are correlated with an increased risk of organ failure and death. Moreover, persistently high CRP concentrations are associated with a poor outcome. Serial measurements may be helpful to identify those patients who require more aggressive interventions to prevent complications.