C-Reactive Protein: A Potential Biomarker for Length of Stay Prediction in Critically Ill Patients

Background: Intensive care units (ICU) are a cornerstone component of hospital resource utilization. Expected length of ICU stay is important in patient flow management within the healthcare facility. We intended in this study to evaluate the role of admission CRP as a predictor of ICU length of stay (ICU-LOS). Methods: We included 56 critically ill patients admitted to the medical ICU of Assalam International Hospital, Cairo, Egypt from March 2013 to October 2013 in this study. Patient assessment on admission stressed on Acute Physiology and Chronic Health Evaluation II (APACHE II) score and/or sequential organ failure assessment (SOFA) score. Beside the routine laboratory investigations and routine cultures of suspected infection sites, CRP assay on admission was done. According to presence or absence of infection identified within 48 hours of admission, our patients were divided into sepsis group and non-sepsis group. Results: Patient population of the current study had mean age of 57.3±18.3 year old, including 26 males (46.4%) and 30 females (53.6%). The CRP and SOFA score were positively correlated with the ICU-LOS ( r=0.27, p=0.04 and r=0.48, p<0.001 respectively) however, there was no correlation between APACHE II score and the ICU-LOS ( r=0.05, p=0.85). The admission CRP and SOFA score were significantly higher in the patients with ICU-LOS more than 7 days than in the shorter stay group (CRP was 56.5±16.7mg/L vs 47.9±8.7mg/L, p=0.02 and SOFA score was 6.9±3.5 vs 4.4±2.8, p=0.006 in long and short stay groups respectively). We found an admission CRP level of 51mg/L to be 80% sensitive and 73% specific and a SOFA score of 4 to be 73% sensitive and 67% specific to predict more than 7 days ICU stay. In the sepsis group that comprised 27 patients (48.2%), the SOFA score was positively correlated with the ICU-LOS ( r=0.48, p=0.01) however, the admission CRP revealed no significant correlation with the LOS (r=0.28, p=0.16). Both CRP and SOFA score revealed no significant difference between long and short stay in septic patients (CRP of 60.5±10.8mg/L vs 50.2±11.2mg/L, p=0.06 and SOFA score of 7.2±3.6 vs 4.4±3.4, p=0.1 for long and short stay respectively). Conclusion: We concluded that the admission CRP and SOFA scores can predict ICU length of stay yet their sensitivity Correspondence to: Dr. Khaled M. Taema, The Department of Critical Care Medicine, Faculty of Medicine, Cairo University and specificity for detecting more than 7 days ICU stay is fair.