Determinants of mortality for necrotizing soft-tissue infections

Coagulase-positive staphylococcal necrotizing fasciitis subsequent to shoulder sprain in a healthy woman

Necrotizing fasciitis (NF) is a deep infection of the subcutaneous tissue that progressively destroys fascia and fat; it is associated with systemic toxicity, a fulminant course, and high mortality. NF most frequently develops from trauma that compromises skin integrity, and is more common in patients with predisposing medical conditions such as diabetes mellitus, atherosclerosis, alcoholism, renal disease, liver disease, immunosuppression, malignancy, or corticosteroid use. Most often, NF is caused by polymicrobial pathogens including aerobic and anaerobic bacteria. NF caused by Staphylococcus aureus as a single pathogen, however, is rare. Here we report a case of NF that developed in a healthy woman after an isolated shoulder sprain that occurred without breaking a skin barrier, and was caused by Staphylococcus aureus as a single pathogen.

Port site necrotising fasciitis following laparoscopic appendicectomy

Necrotising fasciitis is a fast-spreading infection affecting the fascia and, with continued spread, causes secondary necrosis of the skin. A case has been previously described in association with laparoscopic appendicectomy but with a fatal outcome. We report a similar but successfully managed case and review the literature.

Imaging of musculoskeletal soft tissue infections

Prompt and appropriate imaging work-up of the various musculoskeletal soft tissue infections aids early diagnosis and treatment and decreases the risk of complications resulting from misdiagnosis or delayed diagnosis. The signs and symptoms of musculoskeletal soft tissue infections can be nonspecific, making it clinically difficult to distinguish between disease processes and the extent of disease. Magnetic resonance imaging (MRI) is the imaging modality of choice in the evaluation of soft tissue infections. Computed tomography (CT), ultrasound, radiography and nuclear medicine studies are considered ancillary. This manuscript illustrates representative images of superficial and deep soft tissue infections such as infectious cellulitis, superficial and deep fasciitis, including the necrotizing fasciitis, pyomyositis/soft tissue abscess, septic bursitis and tenosynovitis on different imaging modalities, with emphasis on MRI. Typical histopathologic findings of soft tissue infections are also presented. The imaging approach described in the manuscript is based on relevant literature and authors' personal experience and everyday practice.

Necrotizing soft tissue infections in the intensive care unit

Necrotizing soft tissue infection is a severe illness that is associated with significant morbidity and mortality. It is often caused by a wide spectrum of pathogens and is most frequently polymicrobial. Care for patients with necrotizing soft tissue infection requires a team approach with expertise from critical care, surgery, reconstructive surgery, and rehabilitation specialists. The early diagnosis of necrotizing soft tissue infection is challenging, but the keys to successful management of patients with necrotizing soft tissue infection are early recognition and complete surgical debridement. Early initiation of appropriate broad-spectrum antibiotic therapy must take into consideration the potential pathogens. Critical care management components such as the initial fluid resuscitation, end-organ support, pain management, nutrition support, and wound care are all important aspects of the care of patients with necrotizing soft tissue infection. Soft tissue reconstruction should take into account both functional and cosmetic outcome.

Necrotizing fasciitis following laparoscopic left hemicolectomy for diverticulitis

Necrotizing fasciitis (NF) is a rapidly progressing bacterial infection of soft skin tissue layers, combined with high mortality rates. Association with laparoscopic surgery is rare. In this article, we report a case of a 61-year-old patient suffering from severe NF after laparoscopic left hemicolectomy with low anterior resection due to diverticulitis of sigmoid colon. Skin discolorations, combined with critical illness of the patient, led to the diagnosis of NF. Early recognition, intensive care treatment with stabilization of vital parameters, broad-band antibiotics, and aggressive debridement are the cornerstones for successful treatment of NF.

Necrotizing fasciitis following saphenofemoral junction ligation with long saphenous vein stripping: a case report

Introduction

Necrotizing fasciitis is a rare condition with a mortality rate of around 34%. It can be mono- or polymicrobial in origin. Monomicrobial infections are usually due to group A streptococcus and their incidence is on the rise. They normally occur in healthy individuals with a history of trauma, surgery or intravenous drug use. Post-operative necrotizing fasciitis is rare but accounts for 9 to 28% of all necrotizing fasciitis. The incidence of wound infection following saphenofemoral junction ligation and vein stripping is said to be less than 3%, although this complication is probably under-reported. We describe a case of group A streptococcus necrotizing fasciitis following saphenofemoral junction ligation and vein stripping.

Case Presentation

A 39-year-old woman presented three days following a left sided saphenofemoral junction ligation with long saphenous vein stripping at another institution. She had a three day history of fever, rigors and swelling of the left leg. She was pyrexial and shocked. She had a very tender, swollen left groin and thigh, with a small blister anteriorly and was in acute renal failure. She was prescribed intravenous penicillin and diagnosed with necrotizing fasciitis. She underwent extensive debridement of her left thigh and was commenced on clindamycin and imipenem. Post-operatively, she required ventilatory and inotropic support with continuous veno-venous haemofiltration. An examination 12 hours after surgery showed no requirement for further debridement. A group A streptococcus, sensitive to penicillin, was isolated from the debrided tissue. A vacuum assisted closure device was fitted to the clean thigh wound on day four and split-skin-grafting was performed on day eight. On day 13, a wound inspection revealed that more than 90% of the graft had taken. Antibiotics were stopped on day 20 and she was discharged on day 22.

Conclusion

Necrotizing fasciitis is a very serious complication for a relatively minor, elective procedure. To the best of our knowledge, this is the first report in the English-language literature of this complication arising from a standard saphenofemoral junction ligation and vein stripping. It highlights the need to be circumspect when offering patients surgery for non-life-threatening conditions.

Long-term outcomes of patients with necrotizing fasciitis

CONTEXT

Necrotizing fasciitis is an aggressive infection affecting the skin and soft tissue. It has a very high acute mortality. The long-term survival and cause of death of patients who survive an index hospitalization for necrotizing fasciitis are not known.

OBJECTIVE

To define the long-term survival of patients who survive an index admission for necrotizing fasciitis. We hypothesize that survivors will have a shorter life span than population controls.

DESIGN

Long-term follow-up of a registry of patients from 1989 to 2006 who survived a hospitalization for necrotizing fasciitis. Last date of follow-up was January 1, 2008.

SETTINGS

A university-based Burn and Trauma Center.

PATIENTS

A prospective registry of patients with necrotizing fasciitis has been collected from 1989 to 2006. This registry was linked to data from the Department of Health, Department of Motor Vehicles, and the University Hospital Medical Records Department in January 2008 to obtain follow-up and vital status data.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Date and cause of death were abstracted from death certificates. Date of last live follow-up was determined from the medical record and by the last driver's license renewal. The death rate of the cohort was standardized for age and sex against 2005 statewide mortality rates. Cause of death was collated into infectious and noninfectious and compared with the statewide causes of death. Statistical analysis included standardized mortality rates, Kaplan-Meier survival curves, and Aalen's additive hazard model.

RESULTS

Three hundred forty-five patients of the 377 in the registry survived at least 30 days and were analyzed. Average age at presentation was 49 years (range, 1-86; median, 49). Patients were followed up an average of 3.3 years (range, 0.0-15.7; median, 2.4). Eighty-seven of these patients died (25%). Median survival was 10.0 years (95% confidence interval: 7.25-13.11). There was a trend toward higher mortality in women. Twelve of the 87 deaths were due to infectious causes. Using three different statistical analytic techniques, there was a statistically significant increase in the long-term death rate when compared with population-based controls. Infectious causes of death were statistically higher than controls as well.

CONCLUSIONS

Patients who survive an episode of necrotizing fasciitis are at continued risk for premature death; many of these deaths were due to infectious causes such as pneumonia, cholecystitis, urinary tract infections, and sepsis. These patients should be counseled, followed, and immunized to minimize chances of death. Modification of other risk factors for death such as obesity, diabetes, smoking, and atherosclerotic disease should also be undertaken. The sex difference in long-term survival is intriguing and needs to be addressed in further studies.

Predicting death in necrotizing soft tissue infections: a clinical score

BACKGROUND

Necrotizing soft tissue infections (NSTIs) are associated with a high mortality rate; however, there is no uniform way to categorize the severity of this disease early in its course. The goal of this study was to develop a clinical score based on data available at the time of initial assessment to aid in stratifying patients according to their risk of death.

METHODS

A cohort of all 350 patients admitted with NSTI to two institutions over a nine-year period was examined retrospectively. Using random split sampling, two datasets were created: Prediction (PD) and validation (VD). Multivariable stepwise regression analysis of the PD identified independent predictors of death using data available at the time of admission. Model performance was evaluated for accuracy, discrimination, and calibration. A clinical score to predict death was created, and using the Trauma and Injury Severity Score (TRISS) methodology, the score was validated on the VD (z-statistic).

RESULTS

Six admission parameters independently predicted death: Age > 50 years, heart rate > 110 beats/min, temperature <36 degrees C, white blood cell count > 40,000/mcL, serum creatinine concentration > 1.5 mg/dL, and hematocrit > 50%. The accuracy of this model was 86.8%; the area under the receiver-operating characteristic curve was 0.81, and the Hosmer-Lemeshow statistic was 11.8. Additionally, the score had excellent performance in evaluation on the VD (z-score/statistic 0.23 to - 0.83).

CONCLUSION

A clinical score that categorizes patients with NSTI according to the risk of death was created. It uses simple variables, all available at the time of first assessment. It stratifies patients according to disease severity and can guide the use of aggressive or novel therapeutic strategies and selection of patients for clinical trials.

Necrotizing fasciitis of the paraspinous muscles

Necrotizing fasciitis (NF) is a rare and lethal soft tissue infection that requires urgent surgical intervention. It is most often found in the extremities occurring with precipitating trauma or in immunocompromised states. Signs and symptoms are often vague or missing making early diagnosis very difficult. Our patient presented with flank pain and altered mental status but no known precipitating factors. Computed Tomography showed gas within and around the right paraspinous muscle suspicious for NF. Given NF's high lethality, early suspicion by emergency physicians of NF in patients with soft tissue infections or with systemic findings of unknown etiology is necessary.

A case of necrotising fasciitis caused by Pseudomonas aeruginosa

Necrotising fasciitis is a rare but severe infection of soft-tissue associated with rapid progression, systemic toxicity and high mortality. Monomicrobial necrotising fasciitis caused by Pseudomonas aeruginosa is exceptionally uncommon with only 12 cases reported in the literature. We describe a fatal case with an atypical presentation in a patient following spinal decompression for a metastasis from prostate cancer.

Case report: Bowel perforation presenting as subcutaneous emphysema of the thigh

Necrotizing fasciitis is recognized as a surgical emergency. Early detection and aggressive surgical débridement are crucial to reduce patient mortality and morbidity. There are, however, other causes of subcutaneous emphysema. We present the case of a 64 year-old patient with a history of postsurgical radiation for rectal carcinoma with subcutaneous emphysema of the thigh in the presence of urinary sepsis. Surgical exploration revealed the source of the emphysema to be an enterocutaneous fistula. The patient had an unstable and prolonged hospitalization after débridements of the thigh and abdominal surgery and was readmitted for recurrence of thigh drainage, but eventually was discharged; nine months after the initial diagnosis all wounds had healed and he was walking with a walker. Despite an otherwise benign clinical appearance, the radiographic finding of subcutaneous emphysema in the absence of penetrating trauma must be considered a case of a necrotizing soft tissue infection until proven otherwise.

Necrotizing fasciitis

Necrotizing fasciitis (NF) is a necrotizing soft tissue infection that can cause rapid local tissue destruction, necrosis and life-threatening severe sepsis. Predisposing conditions for NF include diabetes, malignancy, alcohol abuse, and chronic liver and kidney diseases. NF is classified into two categories (types 1 and 2) based on causative microorganisms. The initial clinical picture of NF mimics that of cellulitis or erysipelas, including fever, pain, tenderness, swelling and erythema. The cardinal manifestations of NF are severe pain at onset out of proportion to local findings, hemorrhagic bullae and/or vital sign abnormality. In such cases, NF should be strongly suspected and immediate surgical intervention should be considered, along with broad-spectrum antimicrobials and general supportive measures, regardless of the findings of imaging tests.

Necrotizing fasciitis: review of 82 cases in South Auckland

BACKGROUND

Early recognition of necrotizing fasciitis (NF) can be difficult, but is important as infections progress rapidly and have significant mortality. The aim of this study of patients with NF was to determine the clinical characteristics at presentation, causative pathogens and subsequent clinical outcome.

METHODS

We retrospectively reviewed consecutive patients with NF presenting to Middlemore Hospital from January 2000 to June 2006.

RESULTS

Eighty-two patients were evaluated: 56% male, mean age 54.9 years (standard deviation 18.5), 40% Pacific Islanders. The site of infection was the lower limb in 46 (56%) patients, upper limb in 12 (15%) patients and perineum in 13 (16%) patients. Twenty-two (27%) patients were taking non-steroidal anti-inflammatory drugs, 29 (35%) had diabetes mellitus, 25 (30%) had gout and 17 (21%) had congestive heart failure. Forty-nine (60%) patients had a surgical procedure within 24 h of admission. Streptococcus pyogenes was isolated from tissue or blood cultures in 33 (40%) patients and 26 (32%) patients had polymicrobial infection. Twenty-five (30%) patients died, 17 (68%) within 72 h of admission. Independent predictors of mortality include congestive heart failure (P = 0.033) and a history of gout (P = 0.037).

CONCLUSION

NF remains an important disease in our community with significant morbidity and mortality. Pacific Islanders were disproportionately represented. Early diagnosis of NF can be difficult and requires a high index of suspicion in all patients presenting with cellulitis or unexplained sepsis. Congestive heart failure and gout are independent predictors of mortality and patients with these conditions and sepsis need early assessment with more aggressive hospital triaging.

[Necrotizing fasciitis after "banal" back pain. An unusual course of a retrocoecal appendicitis and its sequellae]

Necrotizing fasciitis is a life-threatening disease which can only be successfully treated by an interdisciplinary team. An immediate and radical debridement with opening of all compartments and debridement of the affected fascia is the basis for a successful therapy. We report about the treatment of a 21-year-old man who was taken to hospital due to "banal" back pain which was caused by a perforated appendicitis. In only 2 days necrotizing fasciitis developed which spread out over the complete right leg.

Severe soft tissue infections

Severe skin and soft tissue infections (SSTIs) frequently require management in the ICU, in part related to associated septic shock or toxic shock syndrome or associated organ failure. Four fundamental management principles are key to a successful outcome in caring for patients who have severe SSTIs, including (1) early diagnosis and differentiation of necrotizing versus nonnecrotizing SSTI, (2) early initiation of appropriate empiric broad-spectrum antimicrobial therapy with consideration of risk factors for specific pathogens and mandatory coverage for methicillin-resistant Staphylococcus aureus (MRSA), (3) source control (ie, early aggressive surgical intervention for drainage of abscesses and debridement of necrotizing soft tissue infections), and (4) pathogen identification and appropriate de-escalation of antimicrobial therapy. MRSA has emerged as the most common identifiable cause of severe SSTIs; therefore, initiation of empiric anti-MRSA antimicrobials is warranted in all cases of severe SSTIs. In addition, appropriate critical care management-including fluid resuscitation, organ support and nutritional support-is a necessary component in treating severe SSTIs.

Postirradiation Klebsiella pneumoniae-associated necrotizing fasciitis in the western hemisphere: a rare but life-threatening clinical entity

Necrotizing fasciitis (NF) caused by Klebsiella spp. is a unique entity, particularly, in Asia, where virulent strains of Klebsiella predominate. It is now clear that Klebsiella spp. are capable of causing NF either isolated or in the context of disseminated disease. We present a unique case of NF caused by Klebsiella pneumoniae in the Western hemisphere after radiotherapy in a hospitalized patient with significant comorbidities. Physicians should be aware of nosocomially acquired K. pneumoniae fasciitis after radiotherapy in the setting of chronic comorbidities, such as diabetes and malignancy. Early diagnosis, surgical intervention, and appropriate empirical antibiotics are essential for a favorable outcome in such rare but life-threatening cases of NF.

Skin and soft tissue infections

Skin and soft tissue infections are a common cause of hospitalization and use of antibiotic therapy, and may result in significant disability. Infections managed by surgeons may vary from simple, noncomplicated cellulitis to severe necrotizing soft tissue infections. The differentiation of necrotizing infections from nonnecrotizing infections is critical to achieving adequate surgical therapy. An understanding of the changing epidemiology of all complicated skin and soft tissue infections is required for selection of appropriate empiric antibiotic therapy.

Necrotizing fasciitis of the lower extremity: a case report and current concept of diagnosis and management

Necrotizing fasciitis is a severe soft tissue infection characterized by rapidly progressing necrosis, involving subcutaneous tissues. This rare condition carries high mortality rate and require prompt diagnosis and urgent treatment with radical debridement and antibiotics. We describe a case of 21-year old man who presented with the history of trivial injury to the knee. Initially he was admitted and treated for septic arthritis but later was diagnosed as necrotizing fasciitis which was successfully treated with no ill effects what so ever from this devastating condition. This rare condition has been reported in literature but still early diagnosis, which is a key for successful treatment, remains a challenge.

Life-threatening cervical necrotizing fasciitis after a common dental extraction

We report a case of cervical necrotizing fasciitis (NF) with severe sepsis occurring 8 hours after a banal dental extraction in a healthy adult. A 44-year-old man was admitted for cervical NF and severe sepsis in the emergency department. An early diagnosis was based on clinical examination (violent pain, swelling of face, and crepitation), confirmed by computed tomography scan, which showed subcutaneous gas and a fracture of the maxillary sinus in regard of the extracted tooth. Broad spectrum antibiotherapy was started quickly followed by surgical debridement. Operative and sinus pus cultures were positive for polymicrobial strains (aerobes and anaerobe). Ventilatory and hemodynamic supports (large fluid infusion and catecholamine) were mandatory during a week. Successful outcome occurred within 2 weeks. Cervical NF is a rare but life-threatening disease with fulminant course. The mortality rate is high if the diagnosis and treatment are not begun promptly and vigorously. Therefore, the emergency medicine community must be aware of its initial symptoms.

The epidemiology of necrotizing fasciitis including factors associated with death and amputation

The high morbidity and mortality of necrotizing fasciitis (NF) supports the need for epidemiological studies to characterize the disease and identify patient factors associated with adverse outcomes. A multi-site medical record review of patients diagnosed with NF was performed (n=80, mortality 15%). Variables collected were hypothesized to have association with adverse outcomes from NF, and multivariable analysis was used to detect any such association in this population. Select factors associated with mortality included evidence of underlying conditions (P=0.002), advanced age (P=0.04), young age (P=0.03), and evidence of sepsis (P=0.006). Select factors associated with amputation included diabetes mellitus (P=0.006), evidence of underlying conditions (P=0.03), and cutaneous gangrene noted on admission (P=0.006). These findings demonstrate the important association of NF and extremes of age with mortality and morbidity and support the value of early suspicion with prompt diagnosis and treatment in order to prevent adverse outcomes since the associated risk factors are not immediately modifiable.

Necrotizing fasciitis: microbiological characteristics and predictors of postoperative outcome

OBJECTIVE

Necrotizing fasciitis is a life threatening soft-tissue infection with a high morbidity and mortality. Prompt treatment based on extensive surgical debridement and antibiotic therapies are the therapeutic principles.

METHODS

The medical records of patients with necrotizing fasciitis (n = 26) from 1996 to 2005 were retrospectively analyzed.

RESULTS

The localization of necrotizing fasciitis was most commonly the trunk (42.3 %). Type I polymicrobial infection was the dominating infection. The involvement of anaerobic bacteria was associated with an increase in the number of surgical revisions (p = 0.005). Length of postoperative intensive care unit stay, duration of postoperative ventilation and mortality were significantly increased in the ASA IV-V group. Computed tomography displayed only a limited significance as diagnostic tool for initial diagnosis.

CONCLUSIONS

In severe cases the combination of necrotic skin and soft tissue gas facilitates the correct diagnosis, which should than be followed by immediate - and most often - repeated debridement. If anaerobes are isolated an early and aggressive second look is necessary.

MR imaging of urgent inflammatory and infectious conditions affecting the soft tissues of the musculoskeletal system

Soft tissue infections and inflammatory conditions of the musculoskeletal system are a group of disorders commonly seen by emergency room physicians and radiologists. Many of these entities can either be limb- or life-threatening. Magnetic resonance imaging is currently the best imaging modality to evaluate these conditions. In this review, the characteristic imaging findings of cellulitis, abscess formation, necrotizing fasciitis, pyomyositis, diabetic ischemic infarction, acute and exertional compartment syndromes, and rhabdomyolysis will be emphasized as well as imaging factors that can help to differentiate these disorders.

Low sensitivity of physical examination findings in necrotizing soft tissue infection is improved with laboratory values: a prospective study

BACKGROUND

When clinical "hard signs" of necrotizing soft tissue infection (NSTI) are present, establishing the diagnosis of NSTI is not difficult. However, hard signs of NSTIs are often absent on presentation, thus potentially delaying diagnosis and surgical intervention. A prior retrospective study performed at our institution demonstrated that admission white blood cell (WBC) count >15,400/microL x 10(9)/L and/or serum sodium (Na) <135 mEq/L could help differentiate NSTI from non-NSTI. The purpose of this study was to prospectively determine how often "hard signs" of NSTI are present and to evaluate how knowledge of laboratory parameters influence our surgeons' abilities to diagnose and manage NSTI.

METHODS

Prospective observational data collection to determine the sensitivity of NSTI "hard signs" and administration of a questionnaire in which the surgeon was asked whether he believed the patient had an NSTI based on physical examination (PE) alone, and then after being informed of the Na level and WBC count.

RESULTS

Twenty-one patients with a mean age of 41 years had NSTI. Mean admission WBC count and Na level were 31,500/microL and 127 mEq/L, respectively. Only 9 (43%) had hard signs of NSTI. Suspicion for NSTI increased from 9 to 18 (86%) after evaluating laboratory criteria (P = .008).

CONCLUSIONS

Fewer than half of the patients presented with hard clinical signs of NSTI. Admission WBC count >15,400/microL or serum Na <135 mEq/L significantly increased suspicion for NSTI and aided early diagnosis.

Influence of surgical treatment timing on mortality from necrotizing soft tissue infections requiring intensive care management

PURPOSE

Surgical treatment is crucial in the management of necrotizing soft tissue infections (NSTIs). The aim of this study was to determine the influence of surgical procedure timing on hospital mortality in severe NSTI.

METHODS

A retrospective study including 106 patients was conducted in a medical intensive care unit equipped with a hyperbaric chamber. Data regarding pre-existing conditions, intensive care and surgical management were included in a logistic regression model to determine independent factors associated with hospital mortality.

RESULTS

Overall hospital mortality was 40.6%. In multivariate analysis, underlying cardiovascular disease, SAPS II, abdominoperineal compared to limb localization, time from the first signs to diagnosis <72 h, and time from diagnosis to surgical treatment >14 h in patients with septic shock were independently associated with hospital mortality.

CONCLUSION

In patients with NSTI and septic shock, hospital mortality is influenced by the timing of surgical treatment.

Laboratory risk indicator for necrotizing fasciitis score and the outcomes

BACKGROUND

Laboratory risk indicator for necrotizing fasciitis (LRINEC score) is a simple laboratory tool used to distinguish between necrotizing soft-tissue infections (NSTI) and other soft-tissue infections. A LRINEC score of > or =6 is considered as denoting a high risk of necrotizing fasciitis. A certain LRINEC score might also be associated with mortality and other outcomes of patients with NSTI.

METHODS

A review of the medical charts of patients was carried out. The study sites were one tertiary academic centre and one community, university-affiliated hospital. All adult patients with necrotizing soft-tissue infections from 2002 to 2005 were selected then LRINEC scores were calculated for each patient. We enrolled patients where there was sufficient information to determine that the LRINEC score was either <6 or > or =6.

RESULTS

A total of two hundred and nine patients were enrolled and analysed. The overall mortality rate was 33 of 209 (15.8%) and amputation rate was 55 of 209 (26.3%). The amputation rates were defined as numbers of patients who received amputation divided by numbers of total patients. Enrolled patients were divided into two groups. Group I was those whose LRINEC score was <6 and group II was those whose LRINEC score was > or =6. Significant differences in mortality rate (P = 0.04) and amputation rate (P = 0.002) were noted between two groups.

CONCLUSION

The LRINEC score is associated with the outcomes of patients with NSTI. Patients with a LRINEC score of > or =6 have a higher rate of both mortality and amputation.

Necrotizing fasciitis in southeast Taiwan: clinical features, microbiology, and prognosis

OBJECTIVES

To determine the spectrum of microorganisms, clinical features, and risk factors of necrotizing fasciitis in southeast Taiwan.

METHODS

We retrospectively studied patients diagnosed with necrotizing fasciitis and fully treated in our hospital for the period January 1995 to December 2006.

RESULTS

The mean age of the patients was 58.2+/-14.2 years. The affected anatomical sites were primarily peripheral (91 patients, 85.8%). Sixty patients (56.6%) had a type 1 infection, 17 patients (16.0%) had type 2, and eight patients (7.5%) had type 3. Diabetes mellitus was the most common comorbidity. A single pathogen was identified as the infectious agent in 64 patients (60.4%), multiple pathogens were identified in 21 patients (19.8%), and no organism was identified in 21 patients (19.8%). Streptococcus pyogenes was the most common pathogen. The average hospital stay was 28.0+/-23.1 days. Patients received a mean of 2.3+/-1.2 debridements, and five patients (4.7%) eventually underwent an amputation. The overall mortality was 17.0%. Predictors of mortality included advanced age, class C liver cirrhosis, ascites, higher serum creatinine, and lower hemoglobin and platelet levels.

CONCLUSIONS

Monobacterial infections are more common in our patients. Accurate early diagnosis and extensive surgical debridement are essential for a favorable outcome.

[Soft-tissue infections]

One of the soft-tissue infections with a large clinical relevance is necrotizing fascitis produced by Streptococcus pyogenes and skin infections produced by Staphylococcus aureus, particularly due to the evermore frequent methylcillin (MRSA) resistant varieties. In necrotizing fascitis the diagnostic delay as well as the delay in the indication for surgical debridement influence both the prognosis and a high mortality related to these infections. Two clinical forms have been described: Type I caused by at least one anaerobic species in combination with facultative anaerobes, more frequent in diabetics or patients with peripheral vascular disease; type II, monomicrobial, produced by group A beta hemolytic Streptococcus and with a lesser frequency by Staphylococcus aureus. Among the recognized risk factors diabetes mellitus, peripheral vascular disease, chronic renal failure, alcoholism, cancer, malnutrition, steroid and/or immunosuppressant treatment and the use of intravenous parenteral drugs are widely recognized. Therapeutics is based on hemodynamic support, antibiotic therapy and an early surgical approach with the elimination of all of the necrotic and devitalized tissue. Infections frequently associated to community-acquired MRSA are those present in skin and soft-tissue. Some population groups have been described as at-risk, but there is also an increase in the number of patients with no risk factors. Also, national and international registries of anti-TNF therapies have demonstrated the increase of soft-tissue infections in patients with rheumatoid arthritis treated with these agents. Other biologic drugs such as rituximab, abatacept or anakinra do not seem to be associated to an increase in these infections.