Langenbecks Arch Surg DOI 10.1007/s00423-014-1162-1
ORIGINAL ARTICLE
Predictors of mortality for necrotizing soft-tissue infections: a retrospective analysis of 64 cases Andreas Krieg & Levent Dizdar & Pablo Emilio Verde & Wolfram Trudo Knoefel
Received: 18 July 2013 / Accepted: 1 January 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose Necrotizing soft-tissue infection (NSTI) is a rare, but rapidly progressive and life-threatening disease with a high morbidity and mortality. The aim of the present study was to evaluate predictors of mortality in a group of patients with NSTIs treated at a single center. Methods The medical records of all patients that were treated because of a NSTI at our department between 1996 and 2011 were retrospectively analyzed. To identify factors that were associated with patients’ outcome variables including demographic, clinical, laboratory, and microbiologic parameters were compared between the group of survivors and non-survivors. Results Sixty-four patients with the diagnosis of a NSTI were identified. The overall mortality was 32.8 %. Multiple regression analyses identified the development of a renal failure during the hospital stay and more importantly, the presence of visible skin necrosis on the initial clinical examination as independent prognostic markers for NSTIs. Conclusion In patients with NSTIs, skin necrosis may serve as an indicator for an advanced stage of the disease. Thus, the presence of visible skin necrosis as an independent predictor of mortality emphasizes the outstanding importance of early diagnosis and prompt treatment to improve the prognosis of patients with NSTIs.
Andreas Krieg and Levent Dizdar contributed equally to this project. A. Krieg (*) : L. Dizdar : W. T. Knoefel (*) Department of Surgery (A), Heinrich-Heine-University and University Hospital Düsseldorf, Moorenstraße 5, 40225 Düsseldorf, Germany e-mail: [email protected] e-mail: [email protected] P. E. Verde Coordination Center for Clinical Trials, Heinrich-Heine-University and University Hospital Düsseldorf, Moorenstraße 5, 40225 Düsseldorf, Germany
Keywords Necrotizing soft-tissue infections . NSTI . Skin necrosis . Surgical debridement
Introduction In 1871, Joseph Jones, a surgeon in the Confederate Army, provided one of the earliest descriptions about a necrotizing soft-tissue infection (NSTI) in a large group of patients [1]. Since then, many efforts have been made on classifying these infections according to the affected tissue layers and anatomical areas or the bacteriological isolates. However, because all NSTIs share similar pathophysiological features, distinguishing between these various categories does not support the surgeon in making a decision for a prompt and adequate therapy [2]. NSTIs are characterized by extensive, rapidly progressive soft-tissue necrosis that usually involves the muscular fascia and subcutaneous tissue, but can also affect the skin and muscle [3]. This class of soft-tissue infections is typically induced by virulent, toxin-producing bacteria and can occur in any region of the body [4]. Preferred locations are the abdominal wall, the perineum, and the extremities [5, 6]. The diagnosis of a NSTI in the early stage is very difficult as most patients present with nonspecific signs of skin inflammation such as pain out of proportion, edema, and erythema that are also present in less serious conditions such as erysipelas and cellulitis [7]. Progression of the infection is marked by the development of bullae, necrosis, and crepitus and is often associated with severe sepsis [8]. Predisposing factors for the development of NSTIs are diabetes, obesity, alcohol, and intravenous drug abuse as well as immunosuppression and peripheral vascular disease [8–10]. The principles of treatment, including early and repeated surgical debridement, broad-spectrum antimicrobial drugs, fluid resuscitation, and nutritional support, are well established. Additional adjuvant therapeutic options such as hyperbaric oxygen therapy (HBO)
Langenbecks Arch Surg
are discussed extensively in the literature. Despite these aggressive therapeutic approaches and modern intensive care unit treatment, NSTIs are still highly lethal diseases with a mortality rate ranging between 16 and 34 % in most published series [2, 3, 11, 12]. The aim of our study was to identify demographic, clinical, laboratory, and microbiologic predictors of mortality in patients that were treated because of NSTIs at our surgical department with connection to an HBO therapy unit. Although, predictors of mortality in patients with a NSTI have been described in previous reports, unfortunately, the predictive value of many variables seems to be controversial. Accordingly, there is still a need to improve the understanding of factors that might influence the outcome of patients with NSTIs. Thus, our study analyzed an extensive set of data by univariate and multiple regression analyses, including comorbidities, physiological and clinical findings, as well as laboratory and microbiologic parameters.
Material and methods All patients that were treated at our university hospital because of a NSTI between March 1996 and September 2011 were included in this study. In order to identify patients with NSTIs, we performed a computer-based search of our medical documentation database using the International Classification of Diseases. The criteria confirming the diagnosis of NSTI consisted of clinical findings such as characteristic skin changes and intraoperative findings such as necrosis of the superficial fascia, fat or muscle, typical dishwater pus, as well as the final histopathology report. Patients with other soft-tissue infections, such as abscesses, cellulitis, erysipelas, or vascular gangrene were excluded from the study. Each patient’s record was reviewed to extract demographic information, preexisting comorbidities and risk factors, clinical and laboratory findings on the time of admission or presentation at an emergency department, as well as microbiologic results from swabs or tissue specimens that were obtained during the first surgical debridement. Clinical findings on time of admission that were determined included skin changes such as erythema, swelling, putride secretion, skin detachment, necrosis, crepitus or bullae formation, the primary site and cause of infection, as well as physiological parameters such as heart rate and blood pressure. In addition, the number and type of surgical procedures, postoperative complications, duration of hospitalization, and length of intensive care unit stay as well as the use of supporting modalities such as mechanical ventilation, dialysis, and inotropic drug support were extracted. The occurrence of an acute renal failure during the course of disease was defined according to the Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) classification (increase in serum creatinine
levels to more than three times of the baseline level or serum creatinine levels ≥4 mg/dl; acute rise ≥0.5 mg/dl, or oliguria (urine-output
ORIGINAL ARTICLE
Predictors of mortality for necrotizing soft-tissue infections: a retrospective analysis of 64 cases Andreas Krieg & Levent Dizdar & Pablo Emilio Verde & Wolfram Trudo Knoefel
Received: 18 July 2013 / Accepted: 1 January 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract Purpose Necrotizing soft-tissue infection (NSTI) is a rare, but rapidly progressive and life-threatening disease with a high morbidity and mortality. The aim of the present study was to evaluate predictors of mortality in a group of patients with NSTIs treated at a single center. Methods The medical records of all patients that were treated because of a NSTI at our department between 1996 and 2011 were retrospectively analyzed. To identify factors that were associated with patients’ outcome variables including demographic, clinical, laboratory, and microbiologic parameters were compared between the group of survivors and non-survivors. Results Sixty-four patients with the diagnosis of a NSTI were identified. The overall mortality was 32.8 %. Multiple regression analyses identified the development of a renal failure during the hospital stay and more importantly, the presence of visible skin necrosis on the initial clinical examination as independent prognostic markers for NSTIs. Conclusion In patients with NSTIs, skin necrosis may serve as an indicator for an advanced stage of the disease. Thus, the presence of visible skin necrosis as an independent predictor of mortality emphasizes the outstanding importance of early diagnosis and prompt treatment to improve the prognosis of patients with NSTIs.
Andreas Krieg and Levent Dizdar contributed equally to this project. A. Krieg (*) : L. Dizdar : W. T. Knoefel (*) Department of Surgery (A), Heinrich-Heine-University and University Hospital Düsseldorf, Moorenstraße 5, 40225 Düsseldorf, Germany e-mail: [email protected] e-mail: [email protected] P. E. Verde Coordination Center for Clinical Trials, Heinrich-Heine-University and University Hospital Düsseldorf, Moorenstraße 5, 40225 Düsseldorf, Germany
Keywords Necrotizing soft-tissue infections . NSTI . Skin necrosis . Surgical debridement
Introduction In 1871, Joseph Jones, a surgeon in the Confederate Army, provided one of the earliest descriptions about a necrotizing soft-tissue infection (NSTI) in a large group of patients [1]. Since then, many efforts have been made on classifying these infections according to the affected tissue layers and anatomical areas or the bacteriological isolates. However, because all NSTIs share similar pathophysiological features, distinguishing between these various categories does not support the surgeon in making a decision for a prompt and adequate therapy [2]. NSTIs are characterized by extensive, rapidly progressive soft-tissue necrosis that usually involves the muscular fascia and subcutaneous tissue, but can also affect the skin and muscle [3]. This class of soft-tissue infections is typically induced by virulent, toxin-producing bacteria and can occur in any region of the body [4]. Preferred locations are the abdominal wall, the perineum, and the extremities [5, 6]. The diagnosis of a NSTI in the early stage is very difficult as most patients present with nonspecific signs of skin inflammation such as pain out of proportion, edema, and erythema that are also present in less serious conditions such as erysipelas and cellulitis [7]. Progression of the infection is marked by the development of bullae, necrosis, and crepitus and is often associated with severe sepsis [8]. Predisposing factors for the development of NSTIs are diabetes, obesity, alcohol, and intravenous drug abuse as well as immunosuppression and peripheral vascular disease [8–10]. The principles of treatment, including early and repeated surgical debridement, broad-spectrum antimicrobial drugs, fluid resuscitation, and nutritional support, are well established. Additional adjuvant therapeutic options such as hyperbaric oxygen therapy (HBO)
Langenbecks Arch Surg
are discussed extensively in the literature. Despite these aggressive therapeutic approaches and modern intensive care unit treatment, NSTIs are still highly lethal diseases with a mortality rate ranging between 16 and 34 % in most published series [2, 3, 11, 12]. The aim of our study was to identify demographic, clinical, laboratory, and microbiologic predictors of mortality in patients that were treated because of NSTIs at our surgical department with connection to an HBO therapy unit. Although, predictors of mortality in patients with a NSTI have been described in previous reports, unfortunately, the predictive value of many variables seems to be controversial. Accordingly, there is still a need to improve the understanding of factors that might influence the outcome of patients with NSTIs. Thus, our study analyzed an extensive set of data by univariate and multiple regression analyses, including comorbidities, physiological and clinical findings, as well as laboratory and microbiologic parameters.
Material and methods All patients that were treated at our university hospital because of a NSTI between March 1996 and September 2011 were included in this study. In order to identify patients with NSTIs, we performed a computer-based search of our medical documentation database using the International Classification of Diseases. The criteria confirming the diagnosis of NSTI consisted of clinical findings such as characteristic skin changes and intraoperative findings such as necrosis of the superficial fascia, fat or muscle, typical dishwater pus, as well as the final histopathology report. Patients with other soft-tissue infections, such as abscesses, cellulitis, erysipelas, or vascular gangrene were excluded from the study. Each patient’s record was reviewed to extract demographic information, preexisting comorbidities and risk factors, clinical and laboratory findings on the time of admission or presentation at an emergency department, as well as microbiologic results from swabs or tissue specimens that were obtained during the first surgical debridement. Clinical findings on time of admission that were determined included skin changes such as erythema, swelling, putride secretion, skin detachment, necrosis, crepitus or bullae formation, the primary site and cause of infection, as well as physiological parameters such as heart rate and blood pressure. In addition, the number and type of surgical procedures, postoperative complications, duration of hospitalization, and length of intensive care unit stay as well as the use of supporting modalities such as mechanical ventilation, dialysis, and inotropic drug support were extracted. The occurrence of an acute renal failure during the course of disease was defined according to the Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) classification (increase in serum creatinine
levels to more than three times of the baseline level or serum creatinine levels ≥4 mg/dl; acute rise ≥0.5 mg/dl, or oliguria (urine-output
