was used to select significant predictors. Total white cell count, hemoglobin, sodium, glucose, serum creatinine, and C-reactive protein were selected. The LRINEC score was constructed by converting into integer the regression coefficients of independently predictive factors in the multiple logistic regression model for diagnosing necrotizing fasciitis. The cutoff value for the LRINEC score was 6 points with a positive predictive value of 92.0% and negative predictive value of 96.0%. Model performance was very good (Hosmer-Lemeshow statistic, p .910); area under the receiver operating characteristic curve was 0.980 and 0.976 in the developmental and validation cohorts, respectively. Conclusions: The LRINEC score is a robust score capable of detecting even clinically early cases of necrotizing fasciitis. The variables used are routinely measured to assess severe soft tissue infections. Patients with a LRINEC score of >6 should be carefully evaluated for the presence of necrotizing fasciitis. (Crit Care Med 2004; 32:1535‐1541)

/pdf/the-lrinec-laboratory-risk-indicator-for-necrotizing-1d9c04guou.pdf

The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue infections.

background Necrotizing fasciitis is a life-threatening infection requiring urgent surgical and medical therapy. Staphylococcus aureus has been a very uncommon cause of necrotizing fasciitis, but we have recently noted an alarming number of these infections caused by communityassociated methicillin-resistant S. aureus (MRSA). methods

https://www.nejm.org/doi/pdf/10.1056/NEJMoa042683

Necrotizing Fasciitis Caused by Community-Associated Methicillin-Resistant Staphylococcus aureus in Los Angeles

Background: Necrotizing fasciitis is a life-threatening soft-tissue infection primarily involving the superficial fascia. The present report describes the clinical presentation and microbiological characteristics of this condition as well as the determinants of mortality associated with this uncommon surgical emergency.

Methods: The medical records of eighty-nine consecutive patients who had been admitted to our institution for necrotizing fasciitis from January 1997 to August 2002 were reviewed retrospectively.

Results: The paucity of cutaneous findings early in the course of the disease makes the diagnosis difficult, and only thirteen of the eighty-nine patients had a diagnosis of necrotizing fasciitis at the time of admission. Preadmission treatment with antibiotics modified the initial clinical picture and often masked the severity of the underlying infection. Polymicrobial synergistic infection was the most common cause (forty-eight patients; 53.9%), with streptococci and enterobacteriaceae being the most common isolates. Group-A streptococcus was the most common cause of monomicrobial necrotizing fasciitis. The most common associated comorbidity was diabetes mellitus (sixty-three patients; 70.8%). Advanced age, two or more associated comorbidities, and a delay in surgery of more than twenty-four hours adversely affected the outcome. Multivariate analysis showed that only a delay in surgery of more than twenty-four hours was correlated with increased mortality (p < 0.05; relative risk = 9.4).

Conclusions: Early operative debridement was demonstrated to reduce mortality among patients with this condition. A high index of suspicion is important in view of the paucity of specific cutaneous findings early in the course of the disease.

Level of Evidence: Prognostic study, Level II-1 (retrospective study). See Instructions to Authors for a complete description of levels of evidence.

Necrotizing Fasciitis: Clinical Presentation, Microbiology, and Determinants of Mortality

Necrotizing soft-tissue infections (NSTIs) are highly lethal. They are frequent enough that general and specialty physicians will likely have to be involved with the management of at least 1 patient with NSTI during their practice, but they are infrequent enough that familiarity with the disease will seldom be achieved. Establishing the diagnosis of NSTI can be the main challenge in treating patients with NSTI, and knowledge of all available tools is key for early and accurate diagnosis. The laboratory risk indicator for necrotizing fasciitis score can be helpful for distinguishing between cases of cellulitis, which should respond to medical management alone, and NSTI, which requires operative debridement in addition to antimicrobial therapy. Imaging studies are less helpful. The mainstay of treatment is early and complete surgical debridement, combined with antimicrobial therapy, close monitoring, and physiologic support. Novel therapeutic strategies, including hyperbaric oxygen and intravenous immunoglobulin, have been described, but their effect is controversial. Identification of patients at high risk of mortality is essential for selection of patients that may benefit from future novel treatments and for development and comparison of future trials.

Necrotizing Soft-Tissue Infection: Diagnosis and Management

M T b d d w f b a s i f t n ecrotizing soft-tissue infection (NSTI) was first described y Hippocrates circa 500 BC, when he wrote, “Many were ttacked by the erysipelas all over the body when the excitng cause was a trivial accident . . . flesh, sinews, and bones ell away in large quantities . . . there were many deaths.” espite many advances in our understanding of this disease nd great improvements in medical care, the mortality asociated with NSTI has not changed in the last 30 years and emains 25% to 35%. Mortality is directly proportional to ime to intervention. In addition, prevalence of this disase is such that the average practitioner will see only one or wo cases in his or her career. Physicians cannot be suffiiently familiar with NSTI to proceed rapidly with accurate iagnosis and the necessary management. The purpose of his article is to provide an evidence-based review of the icrobiology, pathophysiology, diagnosis, and treatment f NSTI. Because there are no adequately powered, ranomized, and blinded studies, the recommendations are ased on retrospective and nonblinded study data vailable. NSTI was described as “hospital gangrene” by British aval surgeons in the 18th and 19th century. Dr Joseph ones, a Confederate Army surgeon, was the first person to escribe this disorder in a large group of patients in 1871, hen he reported on 2,642 cases and found a mortality rate f 46%. In 1883, the French physician, Jean Alfred ournier, described a similar NSTI of the perineum in five ale patients—a process that continues to bear his name. It s now described in both male and female patients. In the nsuing years, many other terms, such as necrotizing erysiplas, streptococcal gangrene, and suppurative fasciitis, have een also been used. Because the gas-forming organism, lostridium perfringens, can be associated with this infecion, it has also been referred to as “Clostridial gangrene” or gas gangrene.” In 1951, Dr Wilson proposed the term necrotizing fascitis to include both gas-forming and non gas-forming ne-

https://www.journalacs.org/article/S1072-7515(08)01546-9/pdf

Necrotizing fasciitis: current concepts and review of the literature.

OBJECTIVE: The authors determined the risk factors of mortality in patients with necrotizing soft-tissue infections (NSTIs) and examined the incidence and mortality from NSTI secondary to Streptococcus pyogenes. METHODS: All patients with NSTIs who were treated between January 1989 and June 1994 were analyzed for presentation, etiology, factors important in pathogenesis and treatment, and mortality. RESULTS: Sixty-five patients were identified with NSTIs secondary to postoperative wound complications (18), trauma (15), cutaneous disease (15), idiopathic causes (10), perirectal abscesses (3), strangulated hernias (2), and subcutaneous injections (2). Necrotizing soft-tissue infections were polymicrobial in 45 patients (69%). S. pyogenes was isolated in only 17% of the NSTIs, but accounted for 53% of monomicrobial infections. Eight of ten idiopathic infections were caused by a single bacterium (p = 0.0005), whereas 82% of postoperative infections were polymicrobial. An average of 3.3 operative debridements per patient and amputation in 12 patients were necessary to control infection. The overall mortality was 29%; mortality from S. pyogenes infection was only 18%. The average time from admission to operation was 90 hours in nonsurvivors versus 25 hours in survivors (p = 0.0002). Other risk factors previously associated with the development of NSTIs did not affect mortality. CONCLUSIONS: Early debridement of NSTI was associated with a significant decrease in mortality. S. pyogenes infection was the most common cause of monomicrobial NSTI, but was not associated with an increased mortality.

Joseph J. Piotrowski

Papers

Determinants of mortality for necrotizing soft-tissue infections.