The Value of Procalcitonin and the SAPS II and APACHE III Scores in the Differentiation of Infectious and Non-infectious Fever in the ICU: A Prospective, Cohort Study

Early and accurate differentiation between infectious and non-infectious fever is vitally important in the intensive care unit (ICU). In the present study, patients admitted to the medical ICU were screened daily from August 2008 to February 2009. Within 24 hr after the development of fever (>38.3℃), serum was collected for the measurement of the procalcitonin (PCT) and high mobility group B 1 levels. Simplified Acute Physiology Score (SAPS) II and Acute Physiology And Chronic Health Evaluation (APACHE) III scores were also analyzed. Sixty-three patients developed fever among 448 consecutive patients (14.1%). Fever was caused by either infectious (84.1%) or non-infectious processes (15.9%). Patients with fever due to infectious causes showed higher values of serum PCT (7.8±10.2 vs 0.5±0.2 ng/mL, P=0.026), SAPS II (12.0±3.8 vs 7.6±2.7, P=0.006), and APACHE III (48±20 vs 28.7±13.3, P=0.039) than those with non-infectious fever. In receiver operating characteristic curve analysis, the area under the curve was 0.726 (95% CI; 0.587-0.865) for PCT, 0.759 (95% CI; 0.597-0.922) for SAPS II, and 0.715 (95% CI; 0.550-0.880) for APACHE III. Serum PCT, SAPS II, and APACHE III are useful in the differentiation between infectious and non-infectious fever in the ICU.