Elevated C-reactive protein levels at ICU discharge as a predictor of ICU outcome

Before discharging a patient from the ICU, an adequate patient evaluation is needed to detect individuals as high risk for unfavorable outcome. A pro- or anti-inflammatory status is a potential risk factor for an adverse outcome, and elevated CRP concentrations have shown to correlate with organ failure. Several studies have been performed to evaluate the use of CRP as a marker of post-ICU prognosis. Results are seemingly conflicting, and it is worthwhile to investigate these markers further as CRP is an adequate marker of pro- and anti-inflammatory status of the patient.

The authors aimed to test the hypothesis that elevated CRP levels at ICU discharge are associated with an increased risk of ICU readmission and in-hospital mortality in patients with a prolonged ICU stay.

A retrospective cohort study was performed in a single-center hospital with an 18-bed mixed medical/surgical ICU. Patients discharged alive from the ICU with at least 48-h ICU length of stay were evaluated.

A total of 998 patients were included. Compared to the ‘low CRP’ group, patients in the ‘high CRP’ group had a higher readmission rate. Combined readmission and mortality rates were significantly higher in the ‘high CRP’ group in comparison with the ‘low CRP’ group. Hospital mortality in patients readmitted to the ICU was significantly higher than in non-readmitted patients. Strikingly, the ‘high CRP’ group had significantly lower APACHE II and SOFA scores at ICU admission compared to the ‘low CRP’ group. This highlights the potential for ICU-acquired risk factors, including CRP.

A high CRP concentration (≥75 mg/L) within 24 h before ICU discharge is associated with an increased risk of adverse outcome post-ICU discharge. However, CRP at discharge represents only a very moderate risk factor and may not be used for individual clinical decision-making.