6. Krieg:Umbruchvorlage 12.01.2009 9:39 Uhr Seite 30 30 Eur J Med Res (2009) 14: 30-36 EUROPEAN JOURNAL OF MEDICAL RESEARCH January 28, 2009 © I. Holzapfel Publishers 2009 NECROTIZING FASCIITIS: MICROBIOLOGICAL CHARACTERISTICS AND PREDICTORS OF POSTOPERATIVE OUTCOME A. Krieg1, A. Röhrborn1, J. Schulte am Esch2nd 1, D. Schubert2, L. W. Poll2, C. Ohmann3, S. Braunstein4, W. T. Knoefel1 1Department of General Surgery, 2Institute of Diagnostic Radiology, 3Coordination Centre for Clinical Trials, 4Institute of Pathology, Heinrich Heine University Duesseldorf, Germany Abstract Objective: Necrotizing fasciitis is a life threatening soft-tissue infection with a high morbidity and mortal- ity. Prompt treatment based on extensive surgical de- bridement and antibiotic therapies are the therapeutic principles. Methods: The medical records of patients with necro- tizing fasciitis (n = 26) from 1996 to 2005 were retro- spectively analyzed. Results: The localization of necrotizing fasciitis was most commonly the trunk (42.3 %). Type I polymicro- bial infection was the dominating infection. The in- volvement of anaerobic bacteria was associated with an increase in the number of surgical revisions ( p = 0.005). Length of postoperative intensive care unit stay, duration of postoperative ventilation and mortali- ty were significantly increased in the ASA IV-V group. Computed tomography displayed only a limited signif- icance as diagnostic tool for initial diagnosis. Conclusions: In severe cases the combination of necrotic skin and soft tissue gas facilitates the correct diagnosis, which should than be followed by immedi- ate – and most often – repeated debridement. If anaerobes are isolated an early and aggressive second look is necessary. Key words: Necrotizing fasciitis, soft tissue infection, ASA classification INTRODUCTION Necrotizing fasciitis is a rare but aggressive soft-tissue infection, which involves the fascial layers and the sub- cutaneous tissue, while skin and muscle initially remain intact [1]. This infection, which is usually induced by virulent, toxin producing bacteria, can occur in any re- gion of the body but it is predominantly located in the abdominal wall, perineum and extremities [2, 3]. On the basis of microbiological cultures Giuliano and col- leagues [4] divided the necrotizing fasciitis into two distinct groups. Type I infections are polymicrobial and involve non-group-A streptococci, aerobes and/or facultative anaerobic bacteria. Type II is usual- ly caused by β-haemolytic group-A streptococci alone or in combination with staphylococci. Predisposing factors of the disease are diabetes, alcohol and intra- venous drug abuse as well as immunosuppression and peripheral vascular disease [5, 6]. However, necrotizing fasciitis has also been reported in young and previous- ly healthy individuals. An early sign of necrotizing fasciitis is local erythe- ma and pain out of proportion to findings of physical examination as well as fever. Skin necrosis due to thrombosis of blood vessels at the fascial level is a se- quel of the initiating process and is often associated with severe sepsis [7-10]. Histomorphological hall- marks are necrosis of the superficial fascia with blood vessel thrombosis, severe inflammation of the dermis and subcutaneous fat as well as subcutaneous fat necrosis. Sometimes myonecrosis of underlying skele- tal muscle is obvious [11-13]. Diagnostic clues include clinical findings and detection of soft-tissue gas or in less obvious cases edema and stranding of the fascial layers by computed tomography (CT) scanning as well as soft-tissue fluid by magnetic resonance imaging (MRI) [14-17]. Because of the high mortality ranging between 6 and 76 % in different reports, prompt and aggressive therapy based on early and extensive surgical debride- ment, antibiotics and intensive care is necessary [7]. The aim of the present study was to analyze the factors affecting the outcome of patients with necro- tizing fasciitis treated at our institution over the past 9 years. At the beginning of this time period a necrotiz- ing fasciitis alertness “attitude” was instituted, present- ing every dubious case to particularly involved staff surgeons. MATERIAL AND METHODS The medical results of patients who had been treated at our department for necrotizing fasciitis between 1996 and 2005 were analyzed retrospectively. The di- agnosis of necrotizing fasciitis was established based on clinical findings such as characteristic skin changes, pain out of proportion to physical findings, fever, leu- cocytosis and elevated c-reactive protein levels as well as intraoperative findings such as necrosis of the su- perficial fascia and fat and the presence of foul- smelling fluid known as „dishwater pus“. In 10 cases (n = 10) a CT scan was performed. CT examinations were reviewed separately and blinded by two radiologists. To assess the predictive value of CT, CT scans from 10 patients with other soft tissue infec-