Bacteriology of necrotizing infections of soft tissues

A Case of Necrotizing Soft Tissue Infection Secondary to Perforated Colon Cancer

Necrotizing soft tissue infections are aggressive infections that cause necrosis of muscle, fascia, and tissue. They typically follow fascial planes that lack insufficient blood supply. Early drainage and debridement are essential for survival in these patients. This is a case of a patient who presented in diabetic ketoacidosis with a necrotizing soft tissue infection localized to the left flank and abdomen with underlying colon cancer pathology.

The patient was a 54-year-old female who initially presented with acute dyspnea and left flank pain for two weeks. On admission, she was afebrile, tachycardic, tachypneic, and hypertensive. After being transferred to the ICU for diabetic ketoacidosis management, she began complaining of left abdominal pain and the CT showed concerns for a possible necrotizing soft tissue infection in the left flank region. She was taken to the operating room immediately for debridement and started on broad-spectrum antibiotics. The next day, an exploratory laparotomy was performed with a hemicolectomy and creation of an end colostomy due to concern for a perforated colonic malignancy. A final debridement was completed and a wound vacuum-assisted closure (VAC) was placed. Final pathology demonstrated well-differentiated colonic adenocarcinoma invading into the muscularis propria.

Overall, necrotizing soft tissue infections can be related to a perforated viscus especially a colonic malignancy and this case demonstrates the importance of proper surgical management and high clinical suspicion for possible underlying pathology in a soft tissue infection.

Fungal Infections Increase the Mortality Rate Three-Fold in Necrotizing Soft-Tissue Infections

BACKGROUND

Necrotizing soft-tissue infections (NSTIs) result in significant morbidity and mortality rates, with as many as 76% of patients dying during their index admission. Published data suggest NSTIs rarely involve fungal infections in immunocompetent patients. However, because of the recent recognition of fungal infections in our population, we hypothesized that such infections frequently complicate NSTIs and are associated with higher morbidity and mortality rates.

METHODS

A prospectively maintained Acute and Critical Care Surgery (ACCS) database spanning 2008-2015 and including more than 7,000 patients was queried for patients with NSTIs. Microbiologic data, demographics, and clinical outcomes were abstracted. Risk factors and outcomes associated with NSTI with positive intra-operative fungal cultures were determined. Frequencies were compared by χ² and continuous variables by the Student t-test using SPSS. Because the study included only archived data, no patient permission was needed.

RESULTS

A total of 230 patients were found to have NSTIs; 197 had intra-operative cultures, and 21 (10.7%) of these were positive for fungi. Fungal infection was more common in women, patients with higher body mass index (BMI), and patients who had had prior abdominal procedures. There were no significant differences in demographics, co-morbidities, or site of infection. The majority of patients (85.7%) had mixed bacterial and fungal infections; in the remaining patients, fungi were the only species isolated. Most fungal cultures were collected within 48 h of hospital admission, suggesting that the infections were not hospital acquired. Patients with positive fungal cultures required two more surgical interventions and had a three-fold greater mortality rate than patients without fungal infections.

CONCLUSIONS

This is the largest series to date describing the impact of fungal infection in NSTIs. Our data demonstrate a three-fold increase in the mortality rate and the need for two additional operations. Consideration should be given to starting patients on empiric anti-fungal therapy in certain circumstances.

Intravenous immunoglobulin in necrotizing fasciitis - A case report and review of recent literature

Introduction

Necrotizing fasciitis (NF) is an inflammatory disease of the soft tissue, which causes local tissue destruction and can lead to lethal septic shock. The therapy consists of early surgical treatment of the septic focus and an accompanying broad spectrum antibiotic therapy. Recent literature considers the additional use of immunoglobulin therapy in severe soft skin and tissue infections.

Presentation of case

In this report, we describe the case of a 33-year-old male patient treated at a university hospital intensive care unit because of an NF of his left leg. The patient rapidly developed a complicated septic disease after a minor superficial trauma. Despite intense microbiological diagnosis, no causative pathogens were identified. After non-responding to established broad anti-infective treatment, the patient received intravenous immunoglobulin, that rapidly improved his clinical condition.

Discussion

NF represents a disease processes, which is characterized by fulminant, widespread necrosis of soft tissue, systemic toxicity, and high mortality (>30%). Beside the surgical debridement and broad spectrum antibiotic therapy IVIg therapy might be an additional option in the treatment of NF. But the current literature supporting the use of IVIG in NF is largely based on retrospective or case-controlled studies, and only small randomized trials.

Conclusion

The demonstrated case suggests that IVIg treatment of patients with NF can be considered in case of hemodynamic unstable, critically ill patients. Although randomized controlled trials are missing, some patients might benefit from diminishing hyperinflammation by immunoglobins.

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Necrotizing fasciitis (NF) is an inflammatory disease, which causes local tissue destruction up to lethal septic shock.

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We describe the case of a 33-year-old male patient representing an NF of his left leg.

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After non-responding to established broad anti-infective treatment, the patient received immunoglobulin (IVIg).

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The presented case suggests that IVIg treatment of patients with NF might be considered in case of critically ill patients.

Necrotizing soft-tissue infections

NSTI is a life-threatening, surgical, and medical emergency. Clinical presentation, at least in the initial phase, can be misleading. Various studies have shown that delay in surgical debridement is associated with increased mortality. A high index of suspicion is important in early recognition and in instituting prompt therapy without delay. Early diagnosis, aggressive surgical debridement, aggressive supportive care, and optimal presumptive antibiotic therapy significantly improve morbidity and mortality associated with NSTIs.

Abdominoplasty as an adjunct to the management of peri-Caesarian section necrotising fasciitis

Necrotising fasciitis is a rare but potentially lethal condition, often requiring extensive soft tissue debridement and complex reconstructive surgery. The disease has been noted to complicate Caesarian section wounds, and our department has recently managed three such patients. They all required extensive abdominal wall debridements which would traditionally be closed initially by split skin grafting. We report on the clinical course of three patients, two of whom had their defects closed successfully by abdominoplasty without recourse to initial skin grafting.

Necrotizing soft-tissue infection: diagnosis and management

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 infections: are we making any progress?

BACKGROUND

Necrotizing soft tissue infections are a group of diseases with significant associated mortality. A wide spectrum of bacteria can be involved, and diagnosis can be difficult.

METHODS

Review of pertinent literature of the diagnosis and therapy of necrotizing soft-tissue infection.

RESULTS

Mortality and other adverse outcomes are directly related to advanced age, the presence of organ system failure, lactic acidemia, the percentage of body surface area involved with infection, and delays in operative management. Patients usually die early from the consequences of septic shock, whereas late mortality is related to multiple organ failure.

CONCLUSION

Early recognition and treatment can lower mortality from necrotizing soft tissue infection. Prompt operative debridement, broad-spectrum antimicrobials, and physiologic support are important components of treatment.

Deep soft tissue infections in the neutropenic pediatric oncology patient

PURPOSE

Necrotizing fasciitis and myonecrosis can be rapidly fatal without prompt and aggressive medical and surgical therapy. We reviewed our experience with necrotizing fasciitis and myonecrosis in neutropenic pediatric oncology patients to describe associated clinical characteristics and outline therapeutic interventions.

PATIENTS AND METHODS

A retrospective chart review was performed for all cases of deep soft tissue infection found in neutropenic pediatric oncology patients during an 11-year period.

RESULTS

Seven cases of necrotizing fasciitis and/or myonecrosis associated with chemotherapy-induced neutropenia were diagnosed during the study period. Deep soft tissue infection was diagnosed a median of 14 days after the initiation of chemotherapy. All of the patients presented with fever and pain, generally out of proportion to associated physical findings. Most patients (86%) also had tachycardia and subtle induration at the site of soft tissue infection. The pathogenic organism in four of seven patients originated in the gastrointestinal tract. Patients were treated with antibiotics, surgical debridements, granulocyte colony-stimulating factor, and hyperbaric oxygen. Granulocyte transfusions were administered if there were no signs of neutrophil recovery. Five patients survived their deep soft tissue infection.

CONCLUSIONS

The diagnosis of necrotizing fasciitis and/or myonecrosis should be considered in any neutropenic patient with fever, tachycardia, and localized pain out of proportion to the physical findings. Appropriate therapy includes broad-spectrum intravenous antibiotics and urgent surgical intervention. Granulocyte colony-stimulating factor should be administered to all patients to enhance neutrophil recovery. Granulocyte transfusions should be considered if a prolonged period of neutropenia is anticipated.

The microbiology of necrotizing soft tissue infections

OBJECTIVE

A large number of necrotizing soft tissue infections (NSTI) treated at a single institution over an 8-year period were analyzed with respect to microbial pathogens recovered, treatment administered, and outcome. Based on this analysis, optimal empiric antibiotic coverage is proposed.

METHODS

A retrospective chart review of all patients with documented NSTI was conducted. Microbiologic variables were tested for impact on outcome using Fisher's exact test and multivariate analysis by logistic regression.

RESULTS

Review of the charts of 198 patients with documented NSTI revealed 182 patients with sufficient microbiologic information for analysis. These 182 patients grew an average of 4.4 microbes from original wound cultures, although a single pathogen was responsible in 28 patients. Eighty-five patients had combined aerobic and anaerobic growth, the most common organisms being, in order, Bacteroides species, aerobic streptococci, staphylococci, enterococci, Escherichia coli, and other gram-negative rods. Clostridial growth was common but did not affect mortality unless associated with pure clostridial myonecrosis. Mortality was affected by the presence of bacteremia, delayed or inadequate surgery, and degree of organ system dysfunction on admission.

CONCLUSIONS

NSTI are frequently polymicrobial and initial antibiotic coverage with a broad-spectrum regimen is warranted. The initial regimen should include agents effective against aerobic gram-positive cocci, gram-negative rods, and a variety of anaerobes. The most common organisms not covered by initial therapy were enterococci. All wounds should be cultured at initial debridement, as changes in antibiotic coverage are frequent once isolates are recovered.

Necrotizing fasciitis due to appendicitis

Necrotizing fasciitis, although rare, is one of the more serious, life-threatening complications of missed acute appendicitis. Patients who are predisposed to developing necrotizing fasciitis, regardless of the cause, are typically immunocompromised. We present a case of a 49-year-old immunocompetent female whose diagnosis of acute appendicitis was missed and who subsequently developed necrotizing fasciitis of the abdominal wall and flank. She recovered 1 month after admission due to aggressive surgical and medical therapy.