Diagnosis Of Necrotizing Soft Tissue Infections Research Articles

Is Prompt Hyperbaric Oxygen Adjunctive Therapy Able to Reduce Mortality and Amputation in Management of Necrotizing Soft-Tissue Infection?

Background: Necrotizing soft-tissue infection (NSTI) is a rare and serious disease with high morbidity and mortality. Standard therapeutic concepts have included urgent surgical intervention, broad-spectrum antibiotic treatment, and intensive care. Hyperbaric oxygen therapy (HBOT) is used as adjuvant therapy in some centers, but its benefits remain controversial. Methods: A retrospective analysis was conducted in which 98 patients with a clinical diagnosis of NSTI were treated with standard treatments plus HBOT. The clinical outcomes were wound healing, performance status, hospital length, complication rate, recurrence rate, morbidity (amputation rate), and mortality. Primary or secondary outcomes were compared between the time interval of HBOT and the clinical outcomes. Results: The average times from diagnosis of NSTI to initial HBO treatment and from initial surgery to initial HBO treatment were both significantly longer in dead patients than in surviving patients (P = 0.031; P = 0.020). These two time intervals were both significantly longer in amputated patients than in preserved patients (P = 0.031; P = 0.037). Conclusions: Using combined treatment with early surgical debridement combined with HBOT, it is possible to reduce hospital stay, intensive care unit stay, number of debridements, improve complete wound healing rate, and lower amputation and mortality rates among patients with NSTI. The early onset of HBOT soon after diagnosis, especially during critical conditions, is proved to be associated with higher survival and preservation rates.

No role for standard imaging workup of patients with clinically evident necrotizing soft tissue infections: a national retrospective multicenter cohort study

PurposeTo assess the diagnostic contribution of different imaging studies to diagnose necrotizing soft tissue infections (NSTIs) and the time to surgery in relation to imaging with the hypothesis that imaging studies may lead to significant delays without being able to sufficiently dismiss or confirm the diagnosis since a NSTI is a surgical diagnosis.MethodsA retrospective multicenter cohort study of all NSTI patients between 2010 and 2020 was conducted. The primary outcome was the number of cases in which imaging contributed to or led to change in treatment. The secondary outcomes were time to treatment determined by the time from presentation to surgery and patient outcomes (amputation, intensive care unit (ICU) admission, length of ICU stay, hospital stay, and mortality).ResultsA total of 181 eligible NSTI patients were included. The overall mortality was 21% (n = 38). Ninety-eight patients (53%) received imaging in the diagnostic workup. In patients with a clinical suspicion of a NSTI, 81% (n = 85) went directly to the operating room and 19% (n = 20) underwent imaging before surgery; imaging was contributing in only 15% (n = 3) by ruling out or determining underlying causes. In patients without a clinical suspicion of a NSTI, the diagnosis of NSTI was considered in 35% and only after imaging was obtained.ConclusionIn patients with clinically evident NSTIs, there is no role for standard imaging workup unless it is used to examine underlying diseases (e.g., diverticulitis, pancreatitis). In atypical presenting NSTIs, CT or MRI scans provided the most useful information. To prevent unnecessary imaging and radiation and not delay treatment, the decision to perform imaging studies in patients with a clinical suspicion of a NSTI must be made extremely careful.

Sociodemographic Disparities in the Surgical Management and Outcomes of Necrotizing Soft Tissue Infections: A Nationwide Analysis

INTRODUCTION: Necrotizing soft tissue infections (NSTIs) are surgical emergencies that require an early diagnosis and aggressive surgical debridement. It has been established that disparities can influence surgical care. Our aim was to assess the association of sociodemographic variables in the surgical management and outcomes of NSTIs. METHODS: Using the Nationwide Inpatient Sample (2015 to 2018), we included patients with a primary diagnosis of NSTIs. We collected demographics and clinical characteristics. Outcomes were in-hospital mortality and number of debridements. Multivariable regression models were used to identify sociodemographic factors associated with the outcomes. RESULTS: A weighted total of 119,764 NSTI admissions were identified. The mean age was 55.4 years (SD 14.88), 65% were male, and 60% were white. Overall mortality was 6.8%, and the mean number of debridements per patient was 1.84 (SD 2.32). After adjusted analysis, female sex (odds ratio 1.21, 95% CI 1.09 to 1.35) and Hispanic ethnicity (odds ratio 1.20, 95% CI 1.02 to 1.42) were associated with increased mortality. Black (incidence rate ratio 0.90, 95% CI 0.86 to 0.94) and Hispanic patients (incidence rate ratio 0.91, 95% CI 0.86 to 0.96) along with those with public insurance (incidence rate ratio 0.93, 95% CI 0.89 to 0.96) were associated with a decreased number of debridements. CONCLUSION: This study shows that there are sociodemographic disparities in the care of NSTI patients based on sex, race/ethnicity, and insurance status. Mortality was higher among minority patients, and they underwent a lower number of surgical debridements. Further work is needed to understand the root cause of this problem and to develop appropriate interventions to ensure everyone receives the highest quality of care.

Patient Characteristics and Outcomes in Necrotizing Soft-tissue Infections: Results from a Prospective Cohort Study in a Tertiary Care Center Intensive Care Unit in South India.

BackgroundNecrotizing soft tissue infections (NSTIs) are life-threatening infections characterized by progressive destruction of muscle, fascia, and overlying subcutaneous tissue. Prospective studies in the field are few, and data from the Indian subcontinent are bleak. Prompt diagnosis and timely treatment are critical for optimal outcomes. The aims of this study are to provide detailed information on the clinical profile of patients with NSTIs and to identify predictors of mortality in order to pick up reversible factors that may improve outcomes.Materials and methodsThis study was a prospective cohort study of adult patients with NSTIs in a tertiary center in South India. All patients who were admitted to the surgical intensive care unit (ICU) of the institute with a diagnosis of NSTI were screened and enrolled. All patients were managed according to the local protocol for treatment of NSTIs and intensive care support.ResultsIn our cohort of patients, simple and multiple logistic regression analysis showed that four factors, namely, AKIN stage 3, shock, need for mechanical ventilation for more than 3 days, and low serum albumin values were found to be significantly associated with higher mortality.ConclusionThe successful management of these patients calls for early diagnosis, resuscitation, surgical debridement, appropriate and timely antibiotics, and early ventilatory weaning before multi-organ failure associated with shock and AKI occurs.How to cite this articleKurian GP, Korula PJ, Jacob JM, Desha AMK, Karuppusami R, Kandasamy S. Patient Characteristics and Outcomes in Necrotizing Soft-tissue Infections: Results from a Prospective Cohort Study in a Tertiary Care Center Intensive Care Unit in South India. Indian J Crit Care Med 2022;26(4):452–456.

Outcomes of Patients with Necrotizing Soft Tissue Infections: A Propensity-Matched Analysis Using the National Inpatient Sample.

Background: Necrotizing soft tissue infections (NSTIs) are severe, rapidly spreading infections with high morbidity and mortality. Attempts to identify risk factors for mortality and morbidity have produced variable results. We hope to determine which factors across the NSTI population impact mortality, morbidities, and discharge disposition. Patients and Methods: Retrospective data from the National Inpatient Sample from 2012-2018 of patients with primary diagnosis of NSTI (gas gangrene, necrotizing faciitis, cutaneous gangrene, or Fournier gangrene) were identified for analysis. A 1:4 greedy match was performed and risk factors for in-hospital mortality and discharge disposition were examined. Continuous variables were assessed using t-tests and Wilcoxon rank sum tests. Categorical variables were assessed using χ2 and Fisher exact tests. Statistical significance was defined as p < 0.05. Results: A total of 6,608 patients were identified. Weighted, this represents 33,040 patients; 32,390 are in the no-mortality cohort and 650 in the mortality cohort. Advanced age group was a risk factor for both in-hospital mortality and morbidity, but not for discharge to a skilled nursing or rehabilitation facility. Having two or more comorbidities was a risk factor for mortality, morbidity, and discharge to skilled nursing or rehabilitation facility. Cancer, liver disease, and kidney disease were predictors of in-hospital mortality. Diabetes mellitus and kidney disease were predictors of experiencing an in-hospital complication. Diabetes mellitus, heart disease, and kidney disease were predictors for discharge to skilled nursing or rehabilitation facility. Conclusions: Necrotizing soft tissue infections are associated with substantial morbidity and mortality. Identifying patients at higher risk for mortality, morbidity, and higher level of care at discharge can help providers properly allocate resources to improve patient outcomes and reduce the financial burden on patients and healthcare facilities. Special attention should be paid to those with existing or acute kidney dysfunction because this was the only comorbidity associated with increased risk mortality, morbidity, and discharge to higher level of care.

The development of surgical risk score and evaluation of necrotizing soft tissue infection in 161 Naja atra envenomed patients.

BackgroundNaja atra bites cause wound necrosis, secondary infection, and necrotizing soft tissue infection (NSTI) requiring repetitive surgeries. Little information is known about the predictors for surgery after these bites.Materials and methodsWe retrospectively evaluated 161 patients envenomed by N. atra, 80 of whom underwent surgery because of wound necrosis and infection. We compared the patients’ variables between surgical and non-surgical groups. To construct a surgical risk score, we converted the regression coefficients of the significant factors in the multivariate logistic regression into integers. We also examined the deep tissue cultures and pathological findings of the debrided tissue.ResultsA lower limb as the bite site, a ≥3 swelling grade, bullae or blister formation, gastrointestinal (GI) effects, and fever were significantly associated with surgery in the multivariate logistic regression analysis. The surgical risk scores for these variables were 1, 1, 2, 1, and 2, respectively. At a ≥3-point cutoff value, the model has 71.8% sensitivity and 88.5% specificity for predicting surgery, with an area under the receiver operating characteristic curve of 0.88. The histopathological examinations of the debrided tissues supported the diagnosis of snakebite-induced NSTI. Twelve bacterial species were isolated during the initial surgery and eleven during subsequent surgeries.Discussion and conclusionsFrom the clinical perspective, swelling, bullae or blister formation, GI effects, and fever appeared quickly after the bite and before surgery. The predictive value of these factors for surgery was acceptable, with a ≥3-point risk score. The common laboratory parameters did not always predict the outcomes of N. atra bites without proper wound examination. Our study supported the diagnosis of NSTI and demonstrated the changes in bacteriology during the surgeries, which can have therapeutic implications for N. atra bites.

Necrotizing Soft-Tissue Infections: A Retrospective Review of Predictive Factors for Limb Loss.

BackgroundEmergent diagnosis and treatment are important for the survival of patients with necrotizing soft-tissue infections (NSTIs). Death is the most catastrophic outcome, but limb loss is also one of the most important complications that can have a significant impact on the rest of the patient’s life. The purpose of this study was to identify predictive factors for limb loss caused by NSTIs.MethodsThe data of patients at our center who were diagnosed with NSTIs from May 2003 to January 2019 were analyzed retrospectively. The inclusion criteria were patients with a definite diagnosis of NSTI involving the upper or lower limb. A total of 49 patient records were analyzed in terms of demography, laboratory data, microbiological causes, treatment, and final outcome. Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) scores at initial admission were also collected as laboratory data. Final outcomes were classified into survival with limb salvage and survival with limb loss.ResultsThe limb loss rate was 20.4% (10/49) in our study. On comparison between the limb salvage group and the limb loss group, independent risk factors of limb loss were as follows: presence of hypotension at admission (odds ratio [OR], 8.2; 95% confidence interval [CI], 1.7–38.3; p = 0.008); LRINEC score ≥ 9 (OR, 5.8; 95% CI, 1.3–25.6; p = 0.012), and glucose level > 300 mg/dL (OR, 4.5; 95% CI, 0.9–21.9; p = 0.041). Various microbiological organisms were isolated; the most prevalent specimen was streptococci (32.6%), followed by staphylococci (26.5%). Poor outcomes including limb loss and mortality had no correlation with microbiological organisms.ConclusionsFor patients with NSTIs, the presence of hypotension at admission, a high glucose level (> 300 mg/dL), and a high LRINEC score (> 9) were independent risk factors for limb loss.

Clinical Diagnosis, Management and Microbiological Profiling of Necrotizing Soft Tissue Infections - A Prospective Study of North India Region.

Background: Necrotizing Soft Tissue Infections (NSTIs) are rapidly progressive, potentially fatal illnesses characterized by necrosis of soft tissue. The disease is highly lethal if left untreated. However, its early diagnosis and management can result in significant decrease in mortality, saving the life of patient and preventing limb loss ; but its diagnosis in early stage is difficult. Therefore, the present work describes a step-by-step protocol for early diagnosis of NSTIs and its application for successful management of NSTIs (type III) in the North Indian population. Methods: This prospective study was conducted over a period of 1 year and 9 months (December 2017 to September, 2019) in a single tertiary center (Dayanand Medical College and Hospital, Ludhiana, Punjab, India) with 115 patients suffering from NSTIs. Demographic, symptomatic and clinical features were recorded. After initial resuscitation, debridement or amputation was done and collected samples were subjected to microbial profiling and drug sensitivity tests. Based on results, suitable pharmacological treatment was started to minimize the risk of mortality and fasten the recovery of patient. Results: The present work showed that in the selected population, monomicrobial gram negative infections are more prominent, more so, among diabetic males. The most prominent pathogen was found to be "Escherichia coli" (40% of cases). Enrolled patients had NSTIs in stage 1 and had no blood infection which means they sought medical attention in the early stages of the disease and the clinician was able to detect it. Debridement or amputation resulted in a significant decrease in the mortality rate (10.4%) even when the selected population had lethal Type III NSTIs. Conclusion: The presented approach can aid in early detection and management of NSTIs, thus, helping in saving patient's life and limb.

Differentiating Upper Extremity Necrotizing Soft Tissue Infection From Serious Cellulitis and Abscess.

IntroductionNecrotizing soft tissue infection (NSTI) of the upper extremity (UE) is a rapidly progressing infection that requires early diagnosis and emergent treatment to decrease risks of loss of limb or life. Clinical presentation, particularly of early NSTI, can appear similar to serious cellulitis or abscess. The purpose of this study was to identify factors that are associated with NSTI rather than serious cellulitis and abscess to differentiate patients with similar clinical presentations.MethodsThis study uses a retrospective cohort design that compares patients ultimately diagnosed with UE NSTI versus those diagnosed with UE serious cellulitis or abscess. Cohorts were matched using the Laboratory Risk Indicators for Necrotizing Fasciitis (LRINEC) score in the setting of UE soft tissue infection. Laboratory values, vital signs, subjective symptoms, and social factors including substance abuse and domiciled status were recorded. Continuous variables were compared using the Mann-Whitney U test, whereas categorical variables were compared using the chi-squared test or the Fisher exact test (for expected values less than 5). A binary logistic regression for continuous and categorical variables was also performed. Significance was set at p<0.05. Univariate and multivariate analyses were performed.ResultsMultivariate statistical analysis and clinical interpretation of data identified four factors more associated with a diagnosis of NSTI than serious cellulitis or abscess: elevated lactate on hospital presentation, a patient-reported history of fever, male gender, and homelessness. ConclusionsIn patients with upper extremity infections, the clinical presentation of NSTI and serious cellulitis or abscess may appear similar. In this retrospective cohort of patients matched with LRINEC scores, elevated lactate, subjective fever, male gender, and homelessness were significantly associated with NSTI rather than serious cellulitis or abscess.

Differentiating Lower Extremity Necrotizing Soft Tissue Infection from Severe Cellulitis by Laboratory Parameters and Relevant History Points

BackgroundNecrotizing soft tissue infection (NSTI) of the lower extremity (LE) is a rapidly progressing infection that requires early diagnosis and prompt treatment to decrease risks of loss of limb or life. Clinical presentation, particularly of early NSTI, can appear similar to severe cellulitis. The purpose of this study is to identify factors that are associated with NSTI rather than severe cellulitis to differentiate patients with similar clinical presentation.MethodsThis retrospective cohort design study compares patients finally diagnosed with LE NSTI versus those diagnosed with severe cellulitis. Cohorts were matched using the modified Laboratory Risk Indicator for Necrotizing Fasciitis (m-LRINEC) score in the setting of LE soft tissue infection. Laboratory values, vital signs, subjective symptoms, and social factors including substance abuse were recorded. Univariate and multivariate analyses were performed.ResultsMultivariate statistical analysis and clinical interpretation of data identified four factors more associated with a diagnosis of NSTI than severe cellulitis: elevated lactate, a patient-reported history of fever, male gender, and intravenous substance user.ConclusionIn patients with lower extremity infections, the clinical presentation of NSTI and severe cellulitis may appear similar. In this retrospective cohort of patients matched with m-LRINEC scores, elevated lactate, subjective fever, male gender, and intravenous substance abuser were significantly associated with NSTI rather than severe cellulitis. Further studies of these factors in the clinical setting can help tailor the differential diagnosis in the care of patients with severe lower extremity infections. Matched with m-LRINEC scores, elevated lactate, subjective fever, male gender, and intravenous substance abuser were significantly associated with NSTI rather than severe cellulitis. Further studies of these factors in the clinical setting can help tailor the differential diagnosis in the care of patients with severe lower extremity infections.

Cervical Necrotizing Fasciitis, Diagnosis and Treatment of a Rare Life-Threatening Infection.

Necrotizing fasciitis is a relatively uncommon and potentially life-threatening soft tissue infection, with morbidity and mortality approaching 25% to 35%, even with optimal treatment. The challenge of diagnosis for necrotizing soft tissue infections (NSTIs) is their rarity, with the incidence of approximately 1000 cases annually in the United States. Given the rapid progression of disease and its similar presentation to more benign processes, early and definitive diagnosis is imperative. Signs and symptoms of NSTIs in the early stages are virtually indistinguishable from those seen with abscesses and cellulitis, making definitive diagnosis difficult. The clinical presentation will depend on the pathogen and its virulence factors which ultimately determine the area and depth of invasion into tissue. There are multiple laboratory value scoring systems that have been developed to support the diagnosis of an NSTI. The scoring system with the highest positive (92%) and negative (96%) predictive value is the laboratory risk indicator for necrotizing fasciitis (LRINEC). The score is determined by 6 serologic markers: C-reactive protein (CRP), total white blood cell (WBC) count, hemoglobin, sodium, creatinine, and glucose. A score ≥ 6 is a relatively specific indicator of necrotizing fasciitis (specificity 83.8%), but a score <6 is not sensitive (59.2%) enough to rule out necrotizing fasciitis. In terms of imaging, computed tomography (CT) imaging, while more sensitive (80%) than plain radiography in detecting abnormalities, is just as nonspecific. Computed tomography imaging of NSTIs demonstrates fascial thickening (with potential fat stranding), edema, subcutaneous gas, and abscess formation. Magnetic resonance imaging (MRI) has demonstrated sensitivity of 100% and specificity of 86%, though MRI may not show early cases of fascial involvement of necrotizing fasciitis. Necrotizing soft tissue infections are rapidly progressive and potentially fatal infections that require a high index of clinical suspicion to promptly diagnose and aggressive surgical debridement of affected tissue in order to ensure optimal outcomes.Prompt surgical and infectious disease consultation is necessary for the treatment and management of these patients. While imaging is useful for further characterization, it should not delay surgical consultation. Necrotizing soft tissue infection remains a clinical diagnosis, although plain radiography, CT imaging, and ultrasound can provide useful clues. In general, the management of these patients should include rapid diagnosis, using a combination of clinical suspicion, laboratory data (LRINEC score), and imaging (MRI being the recommended imaging modality), prompt infectious disease and surgical consultation, surgical debridement, and delayed reconstruction. Laboratory findings that can more strongly suggest a diagnosis of NSTI include elevated CRP, elevated WBC, low hemoglobin, decreased sodium, and increased creatinine. Imaging findings include fascial thickening (with potential fat stranding), edema, subcutaneous gas, and abscess formation. Broad-spectrum antibiotics should be started in all cases of suspected NSTI. Surgical debridement, however, remains the lynchpin for treatment of cervical necrotizing fasciitis.

Utility of the Laboratory Risk Indicator for Necrotizing Fasciitis Score: Comorbid Conditions Do Matter.

Background: The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) has been proposed as a diagnostic tool for necrotizing soft tissue infection (NSTI). However, its utility remains underreported, particularly in patients with comorbid conditions. The purpose of this study was to identify the test characteristics of LRINEC for patients with various comorbid conditions. Patients and Methods: We conducted a retrospective study including patients with suspected NSTI. Our study patients were then relegated into the subgroups; intravenous drug use (IVDU), end-stage liver disease (ESLD), and diabetes mellitus (DM). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of a positive LRINEC score (≥ 6 or 8) were calculated in reference to intra-operative findings or results of the pathologic examination. Area under the curve (AUC) using receiver operating characteristic (ROC) plots were compared between each subgroup and the overall study population using DeLong test. Results: A total of 220 patients were included for the analysis. Overall, the sensitivity was 76%, specificity of 52%, PPV of 32%, and NPV of 88%. The subgroup analysis showed low PPVs in all subgroups. The DM and ESLD groups had a high NPV (90.5% and 88.0%, respectively), whereas NPV in the IVDU group was 70.6%. The AUC and DeLong test for the subgroups were 0.649 (p = 0.902) for ESLD, 0.699 (p = 0.683) for DM, and 0.565 (p = 0.034) for IVDU. Conclusions: The LRINEC can be a useful adjunct to rule out the diagnosis of NSTI with exception of IVDU. In contrast, further diagnostic workup might be still required in those patients with positive LRINEC.

354 Diagnostic Utility of Point-of-Care Ultrasound in the Evaluation of Necrotizing Soft Tissue Infections

Necrotizing soft-tissue infections (NSTIs) are potentially life-threatening medical emergencies that require rapid identification and aggressive treatment. Emergency physicians are utilizing point-of-care ultrasound (POCUS) for a wide variety of applications. The objective of this study was to determine the diagnostic utility of POCUS in the evaluation of patients with suspected SSTI in the emergency department (ED). This was a retrospective review of ED patients presenting to an academic center with symptoms suspicious for NSTI and received a POCUS. POCUS findings were collected from ED POCUS archiving database. Medical records were then reviewed for history, physical examination findings, laboratory results, additional diagnostic testing, operative intervention, disposition, and final diagnosis. POCUS findings were compared with LRINEC scores and operative findings. A total of 65 patients (15 females, 50 males; mean age, 55 years +/- 13.6) were included in this study. Patients presented with pain (46/65), swelling (33/65), redness (28/65) and open wound (21/65). Most common symptomatic sites were feet (27%) and upper arm (21%). Nineteen patients reported injection drug use. In triage, 53% patients were tachycardiac and 5 patients were hypotensive. Pain out of proportion was documented in 3 patients. Based on operative findings, 38% (25/65) patients were found to have NSTI. All patients with final diagnosis of NSTI had sonographic findings (hypoechoic fluid tracking along the deep fascial layers, fluid accumulation > 4 mm in depth along the deep fascial layers, air in the soft tissues) indicating NSTI on POCUS. In addition, POCUS demonstrated abscess (28%), cellulitis (62%), pyomyositis (2.9%) and superficial Fasciitis (27%). Subcutaneous gas was noted in 11 patients. Early surgical consultation was obtained in these eleven patients prior to laboratory results and additional imaging studies. Six patients with LRINEC Score < 6 were found to have NSTI and all 6 patients had sonographic findings suggestive of NSTI on POCUS. Only one of these patients had abnormal vital signs in triage. Our study suggests that POCUS can be a useful adjunct in the evaluation of patients with NSTI. Integration of POCUS findings into LRINEC Score could improve risk stratification.

Accurate and quick predictor of necrotizing soft tissue infection: Usefulness of the LRINEC score and NSTI assessment score

ObjectiveThe Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score is a diagnostic tool for necrotizing soft tissue infection (NSTI), which is validated and is considered to have high diagnostic value. However, some experts criticize LRINEC score for consisting of laboratory test results only. MethodsIn this single-center retrospective study, we created a new scoring system (NSTI assessment score; NAS), which also incorporated vital signs as another diagnostic tool for NSTI using cases from our hospital and also evaluated diagnostic accuracy of LRINEC score. We identified NSTI predictors by comparing 24 NSTI patients and 80 non NSTI patients using uni- and multivariate logistic regression analysis, and created NAS based on odds ratio of variables which are statistically significant in the multivariate model. ResultsWe identified mean arterial pressure, C-reactive protein, hemoglobin, serum creatinine, and glucose as a predictor for NSTI. The maximum value of NAS was 11 points with the cut-off value of 6. Sensitivity, specificity, positive predictive value, and negative predictive value of the NAS for diagnosis of NSTI were 87.5%, 91.3%, 75.0%, and 96.1%, respectively. Area under the receiver operating characteristic curve was 0.926 (0.851–1.00) for the NAS and 0.903 (0.833–0.973) for the LRINEC score, and they were not statistically different (p = 0.167). ConclusionThe NAS has high diagnostic accuracy in predicting NSTI, and is comparable with the LRINEC score. The NAS needs to be validated in other cohorts in the future.

440. Necrotizing Soft-Tissue Infections Involving Actinomyces Species

Background Actinomyces sp. are associated with numerous clinical diseases in humans; however, there are few case reports of necrotizing soft-tissue infections (NSTIs) involving these organisms. Their role in NSTIs has not been well described. At our medical center, we noted an increase in Actinomyces sp. isolated from the tissue specimens of patients with NSTIs, prompting further evaluation.MethodsMicrobiology databases were utilized to identify patients with clinical cultures growing Actinomyces sp. from January 2008 to December 2018. Adult patients admitted to the R Adams Cowley Shock Trauma Center with a diagnosis of NSTI were included for analysis.ResultsNine patients were identified meeting inclusion criteria, the first in February 2018–none prior. Organisms isolated from culture included Actinomyces turicensis (n = 3), Actinomyces europeaus (n = 1), and five organisms identified only as Actinomyces species. 89% of patients had additional co-pathogens identified in their tissue cultures. Eight patients had NSTIs of the lower extremity (n = 5) and/or the genitourinary area (n = 6), and one had chronic decubitus ulcers. Comorbidities included diabetes mellitus (77%), chronic kidney disease (33%). 44% patients were in septic shock at presentation. Surgical debridement was performed in all patients. Eight patients were discharged on amoxicillin, with a mean treatment duration of 75 days (range 31–90). One patient was treated with ampicillin–sulbactam. Readmission rate at 90 days was 37%; only one was related to the index infection. One death occurred during the index hospitalization, secondary to NSTI. No patients experienced adverse drug reactions during therapy.ConclusionWe describe one of the largest case series to date of Actinomyces sp. associated with NSTI. The startling appearance of Actinomyces sp. at our institution directly followed the implementation of matrix-assisted laser desorption/ionization time of flight mass spectrometry in January 2018. Actinomyces sp. may act as co-pathogens contributing to the severity of NSTIs, augmenting the virulence of other organisms. As more advanced technology is used in laboratories to identify these organisms, further study is needed to determine pathogenicity and appropriate treatment.Disclosures All authors: No reported disclosures.

Molecular profiling of tissue biopsies reveals unique signatures associated with streptococcal necrotizing soft tissue infections

Necrotizing soft tissue infections (NSTIs) are devastating infections caused by either a single pathogen, predominantly Streptococcus pyogenes, or by multiple bacterial species. A better understanding of the pathogenic mechanisms underlying these different NSTI types could facilitate faster diagnostic and more effective therapeutic strategies. Here, we integrate microbial community profiling with host and pathogen(s) transcriptional analysis in patient biopsies to dissect the pathophysiology of streptococcal and polymicrobial NSTIs. We observe that the pathogenicity of polymicrobial communities is mediated by synergistic interactions between community members, fueling a cycle of bacterial colonization and inflammatory tissue destruction. In S. pyogenes NSTIs, expression of specialized virulence factors underlies infection pathophysiology. Furthermore, we identify a strong interferon-related response specific to S. pyogenes NSTIs that could be exploited as a potential diagnostic biomarker. Our study provides insights into the pathophysiology of mono- and polymicrobial NSTIs and highlights the potential of host-derived signatures for microbial diagnosis of NSTIs.

Health-Related Quality of Life Is Decreased After Necrotizing Soft-Tissue Infections

BackgroundA necrotizing soft-tissue infection (NSTI) is a rare but severe infection with a high mortality rate of 12%-20%. Diagnosing is challenging and often delayed. Treatment consists of surgical debridement of all necrotic tissue and administration of antibiotics. Despite adequate treatment, survivors are often left with extensive wounds, resulting in mutilating scars and functional deficits. Both the disease and the subsequent scars can negatively influence the health-related quality of life (HRQoL). The present study was performed to contribute to the knowledge about HRQoL in patients after NSTI. MethodsWe retrospectively identified patients treated for NSTI in a tertiary center in the Netherlands. Patient and treatment characteristics were collected and patients were asked to fill in a Short Form 36 questionnaire. ResultsForty-six patients with a diagnosis of NSTI were identified. Twenty-eight (61%) were male and mean age was 57 y. Thirty-nine patients (80%) survived. Thirty-one (84%) of the survivors returned the questionnaire after a median follow-up of 4.1 y (interquartile range [IQR], 2.4-5.9 y). Statistically significantly decreased scores when compared to the Dutch reference values were observed for the Short Form 36 domains, physical functioning, role-physical functioning, general health, and the combined Physical Component Score. No differences were observed for the other five domains or for the Mental Component Score. ConclusionsThis study confirms that NSTI negatively affects HRQoL as reported by the patient, especially on the physical domains. To learn more about HRQoL in patients after NSTI, studies in larger groups with a more disease-specific questionnaire should be performed. Level of EvidenceLevel 3, prognostic and epidemiological.

29-Year-Old Woman With Fever and Bilateral Lower Extremity Lesions

29-Year-Old Woman With Fever and Bilateral Lower Extremity Lesions

Red Blood Cell Transfusions and Anemia on Admission Are Associated with Poor Outcomes in Necrotizing Soft Tissue Infections.

Necrotizing soft tissue infections (NSTIs) are highly morbid infections often requiring critical care and transfusion support. We explored a large 2-year experience from a regional trauma center with a dedicated soft tissue service (STS) in an attempt to identify factors in current care with potential for improving outcomes for these critically ill patients. New adult (>17 years) STS admissions, 2008-2009, were identified from the Trauma Registry. Patient records were extracted and assessed via descriptive statistics, univariate analysis, and multivariable logistic regression models. Mortality among 253 eligible primary admissions was 8.3% overall and 10.3% for those with an admission diagnosis of NSTI. No significant differences in wound characteristics, use of VAC (vacuum-assisted closure) dressing or hyperbaric oxygen, or wound microbiology emerged between survivors and nonsurvivors. Median time to first debridement was 5 h (interquartile range, 2-21 h). Multivariable modeling indicated association of worse outcome (death or discharge to chronic/rehab care) with age >60 years [odds ratio (OR), 3.82; P < 0.001], anemia (OR, 0.98; P = 0.03), increasing number of transfusions (OR, 1.09; P < 0.001), NSTI diagnosis (OR, 2.47; P = 0.005), preexisting diabetes mellitus (OR, 3.20; P = 0.001), and low admission hemoglobin (OR, 0.80; P = 0.004). Mortality was less than previously reported. Number of transfusions and anemia at admission emerged as risk factors for poor outcomes. Future research should focus on the effects of transfusion on NSTI outcomes, on potentially confounding factors, and on whether a restrictive transfusion strategy reduces mortality.

Aggressive Soft Tissue Infections.

Necrotizing soft tissue infections (NSTI) are characterized by rapidly progressive infection that causes tissue necrosis with associated sepsis and multisystem organ failure. A rapid diagnosis is essential to decreasing the morbidity and mortality of NSTIs. There must be a high index of suspicion based on history and physical examination. There are no adjunct laboratory values or imaging that have high sensitivity and specificity in the diagnosis of NSTI. The treatment involves emergent, radical surgical debridement of involved tissues and broad spectrum antibiotics. Follow-up should include close monitoring of the wound and repeat debridements in the operating room.