Necrotizing Soft Tissue Infections: A Review

Understanding limb necrotizing infections: A comprehensive approach

INTRODUCTION

Necrotizing soft tissue infections (NSTI) are increasing, posing a significant risk of morbidity and mortality. Due to nonspecific symptoms, a high index of suspicion is crucial. Treatment involves a multidisciplinary approach, with broad-spectrum antibiotics, early surgical debridement, and life support. This study analyzes the characteristics, demographics, complications, and treatment of NSTI in a hospital in Madrid, Spain.

METHODS

A retrospective observational study was conducted, including all surgically treated NSTI patients at our center from January 2016 to December 2022, examining epidemiological and clinical data. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) was prospectively calculated for all patients.

RESULTS

Twenty-two patients (16 men, 6 women, mean age 54.8) were included. Median time from symptom onset to emergency room visit was 3.5 days. All reported severe treatment-resistant pain; sixteen had fever exceeding 37.8°C (72.7%). Skin lesions occurred in twelve (54.5%), and thirteen had hypotension and tachycardia (59.1%). Treatment involved resuscitative support, antibiotherapy, and radical debridement. Median time to surgery was 8.25h. Intraoperative cultures were positive in twenty patients: twelve Streptococcus pyogenes, four Staphylococcus aureus, one Escherichia coli, and four polymicrobial infection. In-hospital mortality rate was 22.73%.

CONCLUSIONS

We examined the correlation between our results, amputation rates and mortality with LRINEC score and time to surgery. However, we found no significant relationship unlike some other studies. Nevertheless, a multidisciplinary approach with radical debridement and antibiotic therapy remains the treatment cornerstone. Our hospital stays, outcomes and mortality rates align with our literature review, confirming high morbimortality despite early and appropriate intervention.

Understanding limb necrotizing infections: A comprehensive approach

INTRODUCTION

Necrotizing soft tissue infections (NSTI) are increasing, posing a significant risk of morbidity and mortality. Due to nonspecific symptoms, a high index of suspicion is crucial. Treatment involves a multidisciplinary approach, with broad-spectrum antibiotics, early surgical debridement, and life support. This study analyzes the characteristics, demographics, complications, and treatment of NSTI in a hospital in Madrid, Spain.

METHODS

A retrospective observational study was conducted, including all surgically treated NSTI patients at our center from January 2016 to December 2022, examining epidemiological and clinical data. The Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) was prospectively calculated for all patients.

RESULTS

Twenty-two patients (16 men, 6 women, mean age 54.8) were included. Median time from symptom onset to emergency room visit was 3.5 days. All reported severe treatment-resistant pain; sixteen had fever exceeding 37.8°C (72.7%). Skin lesions occurred in twelve (54.5%), and thirteen had hypotension and tachycardia (59.1%). Treatment involved resuscitative support, antibiotherapy, and radical debridement. Median time to surgery was 8.25h. Intraoperative cultures were positive in twenty patients: twelve Streptococcus pyogenes, four Staphylococcus aureus, one Escherichia coli, and four polymicrobial infection. In-hospital mortality rate was 22.73%.

CONCLUSIONS

We examined the correlation between our results, amputation rates and mortality with LRINEC score and time to surgery. However, we found no significant relationship unlike some other studies. Nevertheless, a multidisciplinary approach with radical debridement and antibiotic therapy remains the treatment cornerstone. Our hospital stays, outcomes and mortality rates align with our literature review, confirming high morbimortality despite early and appropriate intervention.

Vulvar necrotizing wounds: Unveiling mortality-associated parameters and assessing the efficacy of VAC therapy

INTRODUCTION

Vulvar Necrotizing Fasciitis (VNF) is a critical, severe soft tissue infection characterized by aggressive progression and significant morbidity and mortality. Rapid diagnosis and immediate, comprehensive treatment, including antibiotic therapy, meticulous surgical debridement, and multidisciplinary care, are crucial for improving outcomes. This study aimed to investigate mortality-related factors in VNF and evaluate treatment modalities, focusing on Vacuum-Assisted Closure (VAC) therapy versus traditional debridement.

METHODS

This retrospective study analyzed data from 22 VNF patients. Criteria included adults diagnosed with vulvar necrotizing infections, excluding those transferred or not completing treatment at the center. The study examined mortality-related factors and the efficacy of VAC therapy compared to debridement, considering treatment costs and outcomes.

RESULTS

Analysis divided patients into survivors (13) and non-survivors (9). Higher heart rate, elevated WBC and CRP levels, and higher Clavien-Dindo scores were associated with increased mortality. VAC therapy, compared to traditional debridement, resulted in significantly lower CRP levels and reduced treatment costs. However, other parameters such as the length of hospital stay and debridement frequency showed no significant differences.

CONCLUSION

The study highlights that older age, systemic inflammation, and severe postoperative complications are key factors associated with higher mortality in VNF. VAC therapy emerges as a promising modality, effectively reducing systemic inflammation and healthcare costs. Nonetheless, the retrospective nature and the small sample size of the study limit the generalizability of the findings. Future research, particularly larger, multicentric studies, is essential to further explore and validate the effectiveness of VAC therapy in VNF management.

Current diagnosis and management of necrotizing soft tissue infections: What you need to know

ABSTRACT

Necrotizing soft tissue infections are rare bacterial infections of the skin and soft tissues with a high morbidity and mortality rate, requiring prompt diagnosis and surgical intervention. These represent a spectrum of disease resulting in tissue necrosis that is rapidly progressive; however, they remain a diagnostic challenge because the average surgeon or emergency medicine provider may only see one or two over the course of their career. Diagnosis is largely clinical and based on subtle physical examination findings, physiologic instability, and laboratory derangements. Aids to diagnosis such as scoring systems and cross-sectional imaging may be used; however, the findings are not specific, so management should not be based on these alone. The most common cause of necrotizing soft tissue infection is polymicrobial infection; however, specific bacteria such as clostridial species, group A streptococcal, methicillin resistant Staphylococcus aureus , and aquatic bacteria may also be causative. Initial management includes broad spectrum antibiotics, fluid resuscitation for severe sepsis, and early aggressive surgical debridement. Often, these patients require multiple operative debridement to achieve source control, and a low threshold for repeat debridement should be maintained because these infections can progress rapidly. Once source control is achieved, patients may be left with extensive wounds requiring multidisciplinary care and wound management. Necrotizing infections have long been viewed based on mortality outcomes alone because of their rarity and severity. Over recent years, more reports have shown a decrease in the mortality rates from those previously reported, allowing for a focus on methods to improve morbidity of these infections.

Soft Tissue Reconstruction for Upper Extremity Necrotizing Soft Tissue Infections

INTRODUCTION

One of the main aspects of management for necrotizing soft tissue infection (NSTI) is surgical excision and debridement, which can result in large soft tissue defects. This study examined the reconstructive options and outcomes of patients with upper extremity NSTIs.

METHODS

A retrospective chart review was performed on patients from a single institution who were diagnosed with an upper extremity NSTI between 2014 and 2019. Patient characteristics, infectious etiology, surgical debridements, reconstructive procedures, and secondary procedures were analyzed.

RESULTS

There were 99 patients included in the study. The median size of the wound from the initial surgical debridement was 100 cm2 (interquartile range, 300 cm2). The mean number of debridements was 3.4. Seven patients underwent amputations, and 12 patients died. Most wounds were reconstructed via delayed primary closure (15 patients), skin grafting (16 patients), or a combination of the two (30 patients). Three patients underwent reverse radial forearm flaps, 1 patient underwent a groin flap, 3 patients underwent pedicled latissimus muscle flaps, and 2 patients underwent local flexor carpi ulnaris muscle flaps. Seven patients did not undergo any surgical reconstruction, and their wounds were managed with local wound care. Eight patients had complete or partial failure of their initial soft reconstruction requiring an additional operation, and 5 patients had secondary operations for neuromas and/or contractures.

CONCLUSIONS

Overall, patients with upper extremity NSTIs survive and undergo successful reconstruction of their wounds. Few patients required additional procedures for reconstructive failure or sequela of their wounds.

Necrotizing Fasciitis of the Hand After a Prolonged Endodontic Procedure: A Case Report

CASE

In this article, we present a case report of a patient with limited medical history and without apparent local injury, who developed left hand Group A Streptococcus-induced necrotizing fasciitis after undergoing a prolonged endodontic procedure.

CONCLUSION

In addition to host factors, perhaps, the virulence of the bacteria present in the oropharynx and the expected bacterial load based on the length and complexity of a dental procedure need to be considered when deciding on whether or not to administer prophylactic antibiotics to patients undergoing dental procedures.

Outcomes of β-Hemolytic Streptococcal Necrotizing Skin and Soft-tissue Infections and the Impact of Clindamycin Resistance

BACKGROUND

β-Hemolytic streptococci are frequently implicated in necrotizing soft-tissue infections (NSTIs). Clindamycin administration may improve outcomes in patients with serious streptococcal infections. However, clindamycin resistance is growing worldwide, and resistance patterns in NSTIs and their impact on outcomes are unknown.

METHODS

Between 2015 and 2018, patients with NSTI at a quaternary referral center were followed up for the outcomes of death, limb loss, and streptococcal toxic shock syndrome. Surgical wound cultures and resistance data were obtained within 48 hours of admission as part of routine care. Risk ratios for the association between these outcomes and the presence of β-hemolytic streptococci or clindamycin-resistant β-hemolytic streptococci were calculated using log-binomial regression, controlling for age, transfer status, and injection drug use-related etiology.

RESULTS

Of 445 NSTIs identified, 85% had surgical wound cultures within 48 hours of admission. β-Hemolytic streptococci grew in 31%, and clindamycin resistance was observed in 31% of cultures. The presence of β-hemolytic streptococci was associated with greater risk of amputation (risk ratio, 1.80; 95% confidence interval, 1.07-3.01), as was the presence of clindamycin resistance among β-hemolytic streptococci infections (1.86; 1.10-3.16).

CONCLUSIONS

β-Hemolytic streptococci are highly prevalent in NSTIs, and in our population clindamycin resistance was more common than previously described. Greater risk of limb loss among patients with β-hemolytic streptococci-particularly clindamycin-resistant strains-may portend a more locally aggressive disease process or may represent preexisting patient characteristics that predispose to both infection and limb loss. Regardless, these findings may inform antibiotic selection and surgical management to maximize the potential for limb salvage.

Short Courses of Antibiotics Are Safe in Necrotizing Soft Tissue Infections

INTRODUCTION

Necrotizing soft tissue infections (NSTIs) carry high morbidity and mortality. While early aggressive surgical debridement is well-accepted treatment for NSTIs, the optimum duration of adjunct antibiotic therapy is unclear. An increasing focus on safety and evidence-based antimicrobial stewardship suggests a value in addressing this knowledge gap.

OBJECTIVE

To determine whether shorter antibiotic courses have similar outcomes compared to longer courses in patients with NSTI following adequate source control.

POPULATION

142 consecutive patients with surgically managed NSTI were identified on retrospective chart review between December 2014 and December 2018 at two academic medical centers.

RESULTS

Patients were predominately male (74%) with a median age of 52 and similar baseline characteristics. The median number of debridements to definitive source control was 2 (IQR 1-3) with the short course group undergoing a greater number of debridements control 2.57 ± 1.8 vs 1.9 ± 1.2, (P = .01). Of 142 patients, 34.5% received a short course and the remaining 65.5% received a longer course of antibiotics. There was no significant difference in the incidence of bacteremia or wound culture positivity between groups. There was also no significant difference in in-hospital mortality, 8% vs 6% (P = .74), incidence of C. difficile infection, median length of stay, or 30-day readmission.

CONCLUSION

Provided adequate surgical debridement, similar outcomes in morbidity and mortality suggest antibiotic courses of 7 days or less are equally safe compared to longer courses.

Lactate based Scoring System in the diagnosis of necrotizing fasciitis

INTRODUCTION

Necrotizing fasciitis (NF) is a rare and quickly progressing infection and leads to 100% mortality if untreated. Quick diagnosis and an early and radical surgical treatment are essential for stopping bacterial progression. Unfortunately, the absence of clear clinical signs makes the diagnosis often challenging. Therefore, we searched for easy determinable predictive laboratory markers for NF. This is the first study which includes lactate values in a new score.

MATERIAL AND METHODS

A retrospective analysis of patients with NF (n = 44) and patients with erysipelas (n = 150) was performed. Lactate values, patients` demographics, clinical presentations, site of infection, comorbidities, microbiological and laboratory findings, antibiotic therapies and LRINEC and modified LRINEC Scores were analyzed. Logistic regression analysis was used to derive adjusted weights, and final simple point score was assessed with a ROC curve analysis.

RESULTS

Patients with NF had a mean age of 57 years, patients with erysipelas 65 years. The median hospital length of stay was 8 and 49 days in patients with erysipelas and NF, respectively. While only one patient (0.7 %) in the group of erysipelas died, the mortality rate of patients with NF was 9/44 (20.5 %). The lactate values were statistically significant higher in the NF group 4.1 vs. 2.0 mmol/l (p < 0.001). The new created CologNe-FaDe-Score shows the highest AUC-value with 0.907.

CONCLUSION

With the help of lactate values the CologNe-FaDe-Score consists of easily practicable and highly available parameters, which could sensitize diagnosis.

Pathogenic Mechanisms of Streptococcal Necrotizing Soft Tissue Infections

Necrotizing skin and soft tissue infections (NSTIs) are severe life-threatening and rapidly progressing infections. Beta-hemolytic streptococci, particularly S. pyogenes (group A streptococci (GAS)) but also S. dysgalactiae subsp. equisimilis (SDSE, most group G and C streptococcus), are the main causative agents of monomicrobial NSTIs and certain types, such as emm1 and emm3, are over-represented in NSTI cases. An arsenal of bacterial virulence factors contribute to disease pathogenesis, which is a complex and multifactorial process. In this chapter, we summarize data that have provided mechanistic and immuno-pathologic insight into host-pathogens interactions that contribute to tissue pathology in streptococcal NSTIs. The role of streptococcal surface associated and secreted factors contributing to the hyper-inflammatory state and immune evasion, bacterial load in the tissue and persistence strategies, including intracellular survival and biofilm formation, as well as strategies to mimic NSTIs in vitro are discussed.

Predictors of mortality, limb loss, and discharge disposition at admission among patients with necrotizing skin and soft tissue infections

BACKGROUND

Necrotizing soft tissue infections (NSTI) represent a heterogeneous group of rapidly progressive skin and soft tissue infections associated with significant morbidity and mortality. Efforts to identify factors associated with death have produced mixed results, and little or no data is available for other adverse outcomes. We sought to determine whether admission variables were associated with mortality, limb loss, and discharge disposition in patients with NSTI.

METHODS

We analyzed prospectively collected data of adult patients with surgically confirmed NSTI from an NSTI registry maintained at a quaternary referral center. Factors independently associated with mortality, amputation, and skilled nursing facility discharge were identified using logistic regression.

RESULTS

Between 2015 and 2018, 446 patients were identified. The median age was 55 years (interquartile range, 43-62). The majority of patients were male (65%), white (77%), and transferred from another facility (90%). The perineum was most commonly involved (37%), followed by the lower extremity (34%). The median number of operative debridements was 3 (interquartile range, 2-4). Overall mortality was 15%, and 21% of extremity NSTI patients required amputation. Age greater than 60 years; creatinine greater than 2 mg/dL; white blood cell count greater than 30 x 10^ /μl, platelets less than 150 × 10/μL, and clostridial involvement were independently associated with greater odds of death; perineal involvement was associated with lower odds of death. Age greater than 60 years; sex, male; nonwhite race; diabetes; chronic wound as etiology; leg involvement; transfer status; and sodium, less than 130 mEq/L were independently associated with amputation. Age greater than 60 years; sex, female; nonwhite race; perineal involvement; and amputation were associated with skilled care facility discharge.

CONCLUSION

Necrotizing soft tissue infections are a heterogeneous group of infections involving significantly different patient populations with different outcomes; efforts to differentiate and predict adverse outcomes in NSTI should include laboratory data, comorbidities, infection site, and/or etiology to improve predictions and better account for this heterogeneity.

LEVEL OF EVIDENCE

Prognostic, Level III.

Vacuum sealing drainage with instillation in the treatment of necrotising soft-tissue infection: a retrospective analysis

Objective:

Necrotising soft-tissue infection is a rare but life-threatening infectious disease with high morbidity and mortality. It is typically caused by toxin-producing bacteria and characterised clinically by a very rapid progression of the disease with significant local tissue destruction. In this study, we intend to explore effective wound management to control the invasive infection and to decrease the high mortality.

Method:

This retrospective analysis explored the wound management and mortality in patients with necrotising soft-tissue infection. Extensive debridement, vacuum sealing drainage (VSD) with normal saline instillation combined with broad-spectrum or sensitive antibiotics, and supportive therapies were used.

Results:

All 17 patients included in the analysis survived. The microbiology of 11 patients was found to be polymicrobial. Of the patients, 14 were discharged with completely healed wounds and three were transferred to a local hospital after the systemic and invasive wound infection was controlled.

Conclusion:

Our experiences revealed the outstanding effect of VSD with instillation in removing the debris of necrotising tissue on the wound bed, in the continual and complete drainage of wound exudates, and in prompting wound healing.

Necrotizing Soft Tissue Infections: A Focused Review of Pathophysiology, Diagnosis, Operative Management, Antimicrobial Therapy, and Pediatrics

Background: Necrotizing fasciitis is a major health problem throughout the world. The purpose of this review is to assist providers with the care of these patients through a better understanding of the pathophysiology and management options. Methods: This is a collaborative review of the literature between members of the Surgical Infection Society of North America and World Society of Emergency Surgery. Results: Necrotizing fasciitis continues to be difficult to manage with the mainstay being early diagnosis and surgical intervention. Recognition of at-risk populations assists with the initiation of treatment, thereby impacting outcomes. Conclusions: Although there are some additional treatment strategies available, surgical debridement and antimicrobial therapy are central to the successful eradication of the disease process.

Progressive subcutaneous emphysema of unknown origin: a surgical dilemma

Objective: Subcutaneous emphysema can be an alarming sign of a necrotizing soft tissue infection. However, non-infectious etiologies exist that can be treated conservatively. This case report describes a subcutaneous emphysema of unknown origin and highlights the importance of distinguishing these clinical entities. Methods: We present a 17-year old female with pain and subcutaneous emphysema of the left arm. There were no systemic symptoms. Inflammatory parameters were slightly elevated. Computed tomography (CT) scan of the chest excluded intrathoracic abnormalities. Despite antibiotic treatment, the pain increased and the emphysema extended. Necrotizing fasciitis was feared. A surgical exploration was performed and hyperbaric oxygen therapy was started. Results: Intraoperatively, puncture marks were identified on the left arm. Air noticeably escaped, but normal, unaffected tissues were identified and microbiological cultures remained negative. We observed a good clinical evolution. Conclusion: The lack of apparent causes, the unexplained puncture marks and psychiatric comorbidity suggests the possibility of subcutaneous emphysema due to factitious manipulations. Patients with subcutaneous emphysema who remain clinically stable, have minimal pain and no significant inflammatory changes could be treated conservatively. Close clinical monitoring is essential to avoid delayed intervention in case of a necrotizing soft tissue infection.

Obligate anaerobes are abundant in human necrotizing soft tissue infection samples - a metagenomics analysis

Necrotizing soft tissue infections (NSTIs) are associated with high morbidity and mortality and are increasing in incidence. Proper identification of the microbial causes of NSTIs is a crucial step in diagnosis and treatment, but the majority of data collected are culture based, which is biased against fastidious organisms, including obligate anaerobes. The goal of this study was to address this gap in knowledge by characterizing NSTI microbial communities through molecular diagnostics. We performed 16S rRNA sequencing on human NSTI samples and identified five genera most commonly found in NSTIs (Prevotella, Bacteroides, Peptoniphilus, Porphyromonas, and Enterococcus). We found that a >70% contribution of obligate anaerobes to the bacterial population distribution was associated with NSTI mortality, and that NSTI samples, from both survivors and non-survivors, had an increased relative abundance of gram negative bacteria compared to those of abscess patients. Based on our data, we conclude that obligate anaerobes are abundant in NSTIs and a high relative abundance of anaerobes is associated with a worse outcome. We recommend increasing anaerobe antibiotic coverage during the treatment of NSTIs even when anaerobes are not found by traditional clinical microbiology methods, and especially when there is a clinical suspicion for anaerobe involvement.

The Role of Streptococcal and Staphylococcal Exotoxins and Proteases in Human Necrotizing Soft Tissue Infections

Necrotizing soft tissue infections (NSTIs) are critical clinical conditions characterized by extensive necrosis of any layer of the soft tissue and systemic toxicity. Group A streptococci (GAS) and Staphylococcus aureus are two major pathogens associated with monomicrobial NSTIs. In the tissue environment, both Gram-positive bacteria secrete a variety of molecules, including pore-forming exotoxins, superantigens, and proteases with cytolytic and immunomodulatory functions. The present review summarizes the current knowledge about streptococcal and staphylococcal toxins in NSTIs with a special focus on their contribution to disease progression, tissue pathology, and immune evasion strategies.

Successful management of a 24-year-old pregnant woman with necrotising fasciitis of the forearm

A 24-year-old woman who was 24 weeks pregnant presented to the emergency department with septic shock and an elbow wound that had become infected. She sustained an injury to the tip of the right elbow on a light switch 4 days prior. In the space of 1 day, she developed a necrotising soft tissue infection, which was rapidly spread to the forearm with florid sepsis. Her initial serum C reactive protein was 392 mg/L, and white cell count was 32×10⁹/L. The patient was treated promptly with aggressive surgical debridement and broad-spectrum antibiotics. An early multidisciplinary approach including orthopaedic surgeons, anaesthetics, intensive care, obstetrics, microbiologists and paediatrics was taken. Ultimately, both mother and child had an excellent outcome, the former of whom only had minimal soft tissue resection and primary wound closure. Emphasis is made on first treating the mother as the patient and priority.