Procalcitonin concentrations as a predictor of unexpected readmission and mortality after intensive care unit discharge: A retrospective cohort study.

Procalcitonin (PCT) has been used to guide treatment in critically ill patients with sepsis, but whether PCT at intensive care unit (ICU) discharge can stratify risks of post-ICU readmission or mortality is unknown. This cohort study compared the ability of PCT with C-reactive protein (CRP) in predicting unexpected adverse post-ICU events. Of the 1877 patients admitted to the multidisciplinary ICU between 1 April 2012 and 31 March 2014, 1653 (88.1%) were discharged without treatment limitations. A total of 71 (4.3%) were readmitted and 18 patients (1%) died unexpectedly after ICU discharge during the same hospitalization. Both PCT (0.6 vs 0.4 μg/L, P = .002) and a high CRP concentration >100 mg/L (58% vs 41%, P = .004) at ICU discharge were associated with an increased risk of adverse post-ICU events in the univariate analyses; however, the ability of PCT to discriminate between patients with and without adverse post-ICU outcomes was limited (area under the receiver operating characteristic curve = 0.61; 95% confidence interval, 0.55-0.66). In the multivariable analysis, only a high CRP concentration (odds ratio, 1.92; 95% confidence interval, 1.12-3.11; P = .008) was associated with an increased adverse post-ICU events. Elevated PCT concentration at ICU discharge was inadequate in its predictive ability to guide ICU discharge.