Raised C-reactive protein on ICU discharge is not associated with subsequent poor outcome

Introduction

It has been suggested that plasma C-reactive protein (CRP) levels measured on discharge from the ICU may be a useful predictor of either unplanned readmission or unexpected death on the ward. Previous work has found that raised plasma CRP independently predicted, in separate studies, each of these two poor outcomes [1, 2]. We investigated whether these results could be repeated in our mixed medical/surgical ICU for a composite poor outcome measure combining death and readmission.

Methods

We prospectively enrolled a cohort comprised of all ICU admissions over 1 year. We collected admission clinical and demographic data and APACHE II scores. At discharge we recorded the white cell count and serum levels of CRP and albumin, and we observed death and readmission outcomes up to 2 weeks after ICU discharge. This time period was chosen on the grounds that an association between discharge CRP and postdischarge outcome should relate to persisting inflammatory activity and would be of most relevance in the short term.

Results

Of 1,487 admissions to our ICU, 181 (12.2%) resulted in the patient's death on the ICU and 110 (7.4%) ended with either the patient's discharge to another hospital or ICU and thus their loss to follow up. Eleven patients discharged for palliation were excluded from analysis. A total of 1,185 (79.7%) were discharged to a ward in the hospital and so could potentially have suffered an unexpected deterioration resulting in ICU readmission or death. Of these, 117 (9.9%) of the discharge episodes were followed by an unexpected poor outcome of either readmission (n = 83, 7.0%) or death (n = 34, 2.9%) within 2 weeks. A composite outcome measure combining these two poor outcomes was associated with age, higher APACHE II score, and a low plasma albumin on ICU discharge. Means and median values were compared using P < 0.05 as the test of significance. Plasma CRP on discharge from the ICU was not associated with this composite measure.

Conclusion

In a mixed medical/surgical ICU, CRP on the day of discharge is not associated with a poor outcome measure of unexpected readmission or ward death.