Polymyxin B (PLB) is a cationic antibiotic which stoichiometrically neutralizes the lipid A moiety of endotoxin. We evaluated the safety and effectiveness of PLB administration in preoperative patients in a randomized controlled and open clinical trial. Twelve thousand five hundred units of PLB were given intravenously every 6 hours to the patients of hepatectomy or esophagectomy from the beginning of the operation and was continued until postoperative day 5. Postoperative laboratory data, plasma endotoxin, serum interleukin (IL)-6 and IL-8, parameters of systemic inflammatory response syndrome (SIRS) score, acute physiology and chronic health evaluation (APACHE) II score, multiple organ failure (MOF) score, length of ICU and hospital stay, morbidity, and mortality were evaluated. No adverse effects of PLB administration were detected. The plasma endotoxin levels on postoperative days (POD) 0 and 1 in the PLB groups were 8.2±2.3pg·ml-1 and 5.5±2.1, whereas those of the control group were 21.7±11.3 and 8.2±4.5. Serum IL-6 and IL-8 during the five postoperative days in patients with PLB were lower than those of control patients. However, the difference was not significant. Maximum levels of laboratory data (white blood cell counts, glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, total bilirubin, C-reactive protein) within 2 weeks after the operation, length of high body temperature, the number of the positive parameters of SIRS definitions, and length of SIRS in the PLB group tended to be lower than those of control group, but no significance was noted between the groups. PLB administration significantly lowered MOF score (4.0±0.7 in control group vs 2.4±0.2 in PLB group, P=0.045) and hospital stay (53.3±8.9 days in control group vs 30.8±3.3 in PLB group, P=0.027). It also lowered the initial 24-hour APACHE II score (22.3±3.2 vs 13.4±4.9), and the number of dysfunctioned organs (2.3±0.4 organs vs 1.6±0.4) and ICU stay (4.0±1.4 days vs 1.2±0.6, P=0.055). Preoperative PLB administration reduced both postoperative MOF score and length of hospital stay, and may be useful in preventing MOF.
