Efficacy of National Nosocomial Infection Surveillance score, acute-phase proteins, and interleukin-6 for predicting postoperative infections following major gastrointestinal surgery

Abstract

Context and Objective: Postoperative infections should be detected earlier. We investigated the efficacy of the National Nosocomial Infection Surveillance (NNIS) score, interleukin-6 (IL-6) and various ocute-phase proteins for predicting postoperative infections. Design and Setting: Case series study at the Júlio Müller University Hospital. Methods: Thirty-two patients who underwent major gastrointestinal procedures between June 2004 and February 2005 were studied. The NNIS score and the evolution of serum IL-6 and various acute-phase proteins (C-reactive protein (CRP), albumin, prealbumin and transferrin) were correlated with postoperative infections and length of hospital stay (LOS). Results: NNIS > 1 (p = 0.01) and low preoperative albumin (p = 0.02) significantly correlated with infection. IL-6 and CRP increased significantly more in patients with infections. Multivariate analysis showed greater risk of infection when NNIS > 1 (odds ratio, OR = 10.66; 95% confidence interval, Cl: 1.1-102.0; p = 0.04); preoperative albumin < 3 g/dl (OR = 8.77; 95% Cl: 1.13-67.86; p = 0.03), CRP > 30 mg/l on the second postoperative day (OR = 8.27; 95% Cl: 1.05-64.79; p = 0.03) and > 12 mg/l on th fifth postoperative day (OR = 25.92; 95% Cl: 2.17-332.71; p < 0.01); and IL-6 > 25 pg/ml on the fifth postoperative day (OR = 15.46; 95% Cl: 1.19-230.30; p = 0.03). Longer IOS was associated with cancer, transferrin, IL-6 and albumin (p = 0.05). Conclusions: NNIS, albumin, CRP and IL-6 may be useful as predictive markers for postoperative infections. For predicting IOS, malignant condition, transferrin, albumin and IL-6 are useful.