C-reactive protein as a predictor of outcome after discharge from the intensive care: a prospective observational study

Background. Recent studies have found plasma C-reactive protein (CRP) to be a predictor of outcome after discharge from the intensive care unit (ICU). To assess the generalizability of this finding, we assessed the value of CRP on the day of ICU discharge as a predictor of unplanned ICU readmission and unexpected death within 2 weeks. Plasma albumin and white cell count at discharge were also considered as markers associated with ongoing inflammation. Methods. This was a single-centre observational study involving a medical-surgical ICU in a university teaching hospital. Data were prospectively collected from 1487 admissions involving 1401 patients over a 12 month period. Patients' admission details and APACHE II score were collected in addition to plasma CRP, white cell count, and albumin values from the day of discharge from ICU. We assessed the difference in these variables between patients who were readmitted, who died unexpectedly, and those who did not. Results. We found that 9.9% of patients discharged were either readmitted (7.0%) or died unexpectedly (2.9%). Patients who were readmitted had a lower plasma albumin concentration [20 (16, 24) vs 22 (19, 27), P<0.001] and a higher admission APACHE II score [median (inter-quartile range, IQR) 16.5 (13, 21) vs 15 (12, 18), P=0.02]. Patients who died unexpectedly on the ward were older [mean (SD): 76 (12) vs 59 (19), P<0.001] and had a higher APACHE II score [21 (17.25, 26) vs 15 (12, 18), P<0.001]. There was not a statistically significant difference in CRP concentration between patients who either required ICU readmissions or died unexpectedly on the ward and those who did not. Conclusions. In a mixed medical-surgical intensive care, plasma CRP measured at the day of discharge from intensive care is not a predictor of readmissions or deaths.