Role of C-reactive protein and interleukin-6 in predicting the prognosis of ICU-admitted patients with acute exacerbation of COPD

Background and ObjectiveChronic obstructive pulmonary disease (COPD) is a leading and increasing cause of worldwide morbidity and mortality. No universal predictor of mortality and outcome was defined especially in intensive care unit (ICU)-admitted patients with acute exacerbation of COPD (AECOPD). The objective was to detect the possible role of C-reactive protein (CRP) and interleukin-6 (IL-6) levels in predicting the prognosis of ICU-admitted patients with AECOPD.MethodsThis prospective cohort study enrolled 50 adult patients with AECOPD who were admitted in the ICU. Serum CRP and IL-6 levels were measured on admission. The primary endpoint was any-cause mortality during ICU stay or 28 days after discharge. Lengths of ICU and hospital stay besides complications encountered were recorded.ResultsSerum CRP level was significantly elevated in patients with prolonged mechanical ventilation (MV) days, ICU stay and hospital stay (r = 0.406, p = 0.007; r = 0.411, p = 0.006; r = 0.387, p = 0.010, respectively). Similar results were noted for serum IL-6 level (r = 0.554, p=<0.001; r = 0.533, p=<0.001; r = 0.508, p = 0.001, respectively). Combined CRP and IL-6 serum levels predicted 28 day mortality at a cut-off value of 110 mg/dl and 347.8 pg/ml respectively (AUC = 0.851, p = 0.006) with 83.33% sensitivity, 75.68% specificity, 35.71% PPV and 96.55% NPV. This was significantly greater than that for CRP alone (p = 0.040) or IL-6 alone (p = 0.004).ConclusionsSerum levels of CRP and IL-6 (either individually or combined) were useful markers in predicting the mortality, complications and outcome in ICU-admitted patients with AECOPD.