Hyperbaric oxygen does not improve outcome in patients with necrotizing soft tissue infection

Reactive Oxygen Species (ROS)-Mediated Antibacterial Oxidative Therapies: Available Methods to Generate ROS and a Novel Option Proposal

The increasing emergence of multidrug-resistant (MDR) pathogens causes difficult-to-treat infections with long-term hospitalizations and a high incidence of death, thus representing a global public health problem. To manage MDR bacteria bugs, new antimicrobial strategies are necessary, and their introduction in practice is a daily challenge for scientists in the field. An extensively studied approach to treating MDR infections consists of inducing high levels of reactive oxygen species (ROS) by several methods. Although further clinical investigations are mandatory on the possible toxic effects of ROS on mammalian cells, clinical evaluations are extremely promising, and their topical use to treat infected wounds and ulcers, also in presence of biofilm, is already clinically approved. Biochar (BC) is a carbonaceous material obtained by pyrolysis of different vegetable and animal biomass feedstocks at 200-1000 °C in the limited presence of O2. Recently, it has been demonstrated that BC's capability of removing organic and inorganic xenobiotics is mainly due to the presence of persistent free radicals (PFRs), which can activate oxygen, H2O2, or persulfate in the presence or absence of transition metals by electron transfer, thus generating ROS, which in turn degrade pollutants by advanced oxidation processes (AOPs). In this context, the antibacterial effects of BC-containing PFRs have been demonstrated by some authors against Escherichia coli and Staphylococcus aureus, thus giving birth to our idea of the possible use of BC-derived PFRs as a novel method capable of inducing ROS generation for antimicrobial oxidative therapy. Here, the general aspects concerning ROS physiological and pathological production and regulation and the mechanism by which they could exert antimicrobial effects have been reviewed. The methods currently adopted to induce ROS production for antimicrobial oxidative therapy have been discussed. Finally, for the first time, BC-related PFRs have been proposed as a new source of ROS for antimicrobial therapy via AOPs.

The effect of hyperbaric oxygen therapy on the clinical outcomes of necrotizing soft tissue infections: a systematic review and meta-analysis

BACKGROUND

To determine the efficacy of hyperbaric oxygen therapy (HBO) in the treatment of necrotizing soft tissue infections (NSTI), we conducted a meta-analysis of the available evidence.

METHODS

Data sources were PubMed, Embase, Web of Science, Cochrane Library, and reference lists. The study included observational trials that compared HBO with non-HBO, or standard care. The primary outcome was the mortality rate. Secondary outcomes were the number of debridement, amputation rate and complication rate. Relative risks or standardized mean differences with 95% confidence intervals were calculated for dichotomous and continuous outcomes, respectively.

RESULTS

A total of retrospective cohort and case-control studies were included, including 49,152 patients, 1448 who received HBO and 47,704 in control. The mortality rate in the HBO group was significantly lower than that in the non-HBO group [RR = 0.522, 95% CI (0.403, 0.677), p < 0.05]. However, the number of debridements performed in the HBO group was higher than in the non-HBO group [SMD = 0.611, 95% CI (0.012, 1.211), p < 0.05]. There was no significant difference in amputation rates between the two groups [RR = 0.836, 95% CI (0.619, 1.129), p > 0.05]. In terms of complications, the incidence of MODS was lower in the HBO group than in the non-HBO group [RR = 0.205, 95% CI (0.164, 0.256), p < 0.05]. There was no significant difference in the incidence of other complications, such as sepsis, shock, myocardial infarction, pulmonary embolism, and pneumonia, between the two groups (p > 0.05).

CONCLUSION

The current evidence suggests that the use of HBO in the treatment of NSTI can significantly reduce the mortality rates and the incidence rates of complications. However, due to the retrospective nature of the studies, the evidence is weak, and further research is needed to establish its efficacy. It is also important to note that HBO is not available in all hospitals, and its use should be carefully considered based on the patient's individual circumstances. Additionally, it is still worthwhile to stress the significance of promptly evaluating surgical risks to prevent missing the optimal treatment time.

Hyperbaric oxygen treatment in the management of necrotising soft-tissue infections: results from a Danish nationwide registry study

OBJECTIVES

Application of hyperbaric oxygen (HBO2) treatment in the multidisciplinary setting of necrotising soft-tissue infection (NSTI) is debated as a considerable number of studies are of low quality with marked prognostication bias due to inadequately addressing disease severity. The objective of this study was to associate HBO2 treatment with mortality in patients with NSTI including disease severity as a prognostic variable.

DESIGN

Nationwide population-based register study.

SETTING

Denmark.

PARTICIPANTS

Danish residents with NSTI patients between January 2011 and June 2016.

PRIMARY AND SECONDARY OUTCOME MEASURES

Thirty-day mortality was compared between patients receiving and patients not receiving HBO2 treatment using inverse probability of treatment weighting and propensity-score matching with predetermined variables (age, sex and weighted Charlson comorbidity score, presence of septic shock and Simplified Acute Physiology Score II (SAPS II)).

RESULTS

A total of 671 NSTI patients were included with a median age of 63 (52-71), 61% male sex, 30% had septic shock and a median SAPS II of 46 (34-58). Patients who received HBO2 treatment (n=266) were younger and had lower SAPS II, but a larger fraction had septic shock compared with patients not receiving HBO2 treatment. Overall, all-cause 30-day mortality was 19% (95% CI 17% to 23%). The statistical models were in general acceptably balanced with covariates reaching <0.1 absolute standardised mean differences and patients receiving HBO2 treatment were associated with lower 30-day mortality (OR 0.40, 95% CI 0.30 to 0.53, p<0.001).

CONCLUSIONS

In analyses using inverse probability of treatment weighting and propensity score analysis, patients treated with HBO2 treatment were associated with improved 30-day survival.

Outcome of necrotizing fasciitis and Fournier's gangrene with and without hyperbaric oxygen therapy: a retrospective analysis over 10 years

BACKGROUND

Necrotizing soft tissue infections (NSTI) require immediate radical debridement, broad-spectrum antibiotics and intensive care. Hyperbaric oxygen therapy (HBOT) may be performed adjunctively, but unequivocal evidence for its benefits is still lacking.

METHODS

We performed a retrospective single-center study including 192 patients with necrotizing fasciitis or Fournier's gangrene to assess in-hospital mortality and outcome dependent on patient, disease and treatment characteristics with or without HBOT.

RESULTS

The in-hospital mortality rate was 27.6%. Factors associated with increased mortality according to multivariate analysis were higher age, affection of multiple or problem localizations (odds ratio (OR) = 2.88, P = 0.003), ineligibility for HBOT despite clinical indication (OR = 8.59, P = 0.005), pathogens in blood cultures (OR = 3.36, P = 0.002), complications (OR = 10.35, P < 0.001) and sepsis/organ dysfunction (OR = 19.58, P < 0.001). Factors associated with better survival included vacuum-assisted wound closure (OR = 0.17, P < 0.001), larger number of debridements (OR = 0.83, P < 0.001) and defect closure with mesh graft (OR = 0.06, P < 0.001) or flap (OR = 0.09, P = 0.024). When participants were stratified into subgroups without requirement of HBOT (n = 98), treated with HBOT (n = 83) and ineligible for HBOT due to contraindications (n = 11), the first two groups had similar survival rates (75.5% vs. 73.5%) and comparable outcome, although patients with HBOT suffered from more severe NSTI, reflected by more frequent affection of multiple localizations (P < 0.001), sepsis at admission (P < 0.001) and intensive care treatment (P < 0.001), more debridements (P < 0.001) and a larger number of antibiotics (P = 0.001). In the subgroup ineligible for HBOT, survival was significantly worse (36.4%, P = 0.022).

CONCLUSION

These results point to a benefit from HBOT for treatment of NSTI in critically ill patients.

Severe Skin and Soft-Tissue Infections

Skin and soft-tissue infections (SSTIs) are a common reason for hospital admission. Severe SSTIs, particularly necrotizing infections, often require intensive care. Source control (often with surgical debridement) and broad-spectrum antimicrobials are paramount for minimizing significant morbidity and mortality. Rapid diagnostic tests may help in selection and de-escalation of antimicrobials for SSTIs. Besides early source control and early effective antimicrobial therapy, other patient-level factors such as comorbidities and immune status play a role in clinical outcomes. Intravenous immunoglobulin continues to be studied for severe SSTI, though recruitment in trials continues to be an issue. Severe SSTIs are complex to manage, due in part to regional variation in predominant pathogens and antimicrobial resistance patterns, as well as variations in host immune responses. This review includes descriptions of source control, antimicrobial therapies, intravenous immunoglobulin, and hyperbaric oxygen therapy, as well as host factors in severe SSTIs.

Necrotizing Soft Tissue Infections, the Challenge Remains

Background: Necrotizing Soft Tissue Infections (NSTIs) are uncommon rapidly spreading infection of the soft tissues for which prompt surgical treatment is vital for survival. Currently, even with sufficient awareness and facilities available, ambiguous symptoms frequently result in treatment delay.

Objectives: To illustrate the heterogeneity in presentation of NSTIs and the pitfalls entailing from this heterogeneity.

Discussion: NSTI symptoms appear on a spectrum with on one side the typical critically ill patient with fast onset and progression of symptoms combined with severe systemic toxicity resulting in severe physical derangement and sepsis. In these cases, the suspicion of a NSTI rises quickly. On the other far side of the spectrum is the less evident type of presentation of the patient with gradual but slow progression of non-specific symptoms over the past couple of days without clear signs of sepsis initially. This side of the spectrum is under represented in current literature and some physicians involved in the care for NSTI patients are still unaware of this heterogeneity in presentation.

Conclusion: The presentation of a critically ill patient with evident pain out of proportion, erythema, necrotic skin and bullae is the classical presentation of NSTIs. On the other hand, non-specific symptoms without systemic toxicity at presentation frequently result in a battery of diagnostics tests and imaging before the treatment strategy is determined. This may result in a delay in presentation, delay in diagnosis and delay in definitive treatment. This failure to perform an adequate exploration expeditiously can result in a preventable mortality.

Hyperbaric oxygen therapy as adjuvant therapy for odontogenic necrotizing myositis: A case report

In a young man affected by skin soft tissue infections complicated with myositis, the use of hyperbaric oxygen treatment as an adjuvant therapy to surgical debridement and antibiotic therapy could improve management and prognosis.

Adjunctive hyperbaric oxygen treatment for necrotising soft-tissue infections: A systematic review and meta-analysis

INTRODUCTION

Surgical intervention, broad-spectrum antibiotics and intensive care support are the standard of care in the treatment of necrotising soft-tissue infections (NSTI). Hyperbaric oxygen treatment (HBOT) may be a useful adjunctive treatment and has been used for almost 60 years, but its efficacy remains unknown and has not been systematically appraised. The aim was to systematically review and synthesise the highest level of clinical evidence available to support or refute the use of HBOT in the treatment of NSTI.

METHODS

The review was prospectively registered (PROSPERO; CRD42020148706). MEDLINE, EMBASE, CENTRAL and CINAHL were searched for eligible studies that reported outcomes in both HBOT treated and non-HBOT treated individuals with NSTI. In-hospital mortality was the primary outcome. Odds ratio (ORs) were pooled using random-effects models.

RESULTS

The search identified 486 papers of which 31 were included in the qualitative synthesis and 21 in the meta-analyses. Meta-analysis on 48,744 patients with NSTI (1,237 (2.5%) HBOT versus 47,507 (97.5%) non-HBOT) showed in-hospital mortality was 4,770 of 48,744 patients overall (9.8%) and the pooled OR was 0.44 (95% CI 0.33-0.58) in favour of HBOT. For major amputation the pooled OR was 0.60 (95% CI 0.28-1.28) in favour of HBOT. The dose of oxygen in these studies was incompletely reported.

CONCLUSIONS

Meta-analysis of the non-random comparative data indicates patients with NSTI treated with HBOT have reduced odds of dying during the sentinel event and may be less likely to require a major amputation. The most effective dose of oxygen remains unclear.

Necrotizing myositis case report and brief literature study

Necrotizing myositis is an extremely rare soft tissue infection, mainly caused by Group A Streptococci. Although its presentation is nonspecific and seems harmless, it quickly leads to death in almost all cases. Therefore, diagnosis and treatment of necrotizing myositis are considered as medical emergencies. The 27 years old patient we report benefited from early diagnosis and care. Necrotic tissues were surgically removed 24 hours after the appearance of the first clinical signs. Intravenous antibiotherapy as well as immunoglobulin therapy were also given on the first day. Starting from this clinical case, we present a brief explanation of the pathogenesis, the key clinical features and appropriate tools for diagnosis. Then, adequate antibiotherapy, role of immunoglobulin therapy and interest of hyperbaric oxygenotherapy will be discussed.

Clostridial Gas Gangrene - A Rare but Deadly Infection: Case series and Comparison to Other Necrotizing Soft Tissue Infections

Objective

Clostridial gas gangrene (GG) or clostridial myonecrosis is a very rare but life‐threatening necrotizing soft tissue infection (NSTI) caused by anaerobic, spore‐forming, and gas‐producing clostridium subspecies. It is the most rapidly spreading and lethal infection in humans, also affecting muscle tissue. The high mortality, of up to 100%, in clostridial GG is mediated by potent bacterial exotoxins. Necrotizing fasciitis (NF) is an important differential diagnosis, most often caused by group A streptococci, primarily not affecting musculature but the subcutaneous tissue and fascia. In the early stages of the infection, it is difficult to distinguish between GG and NF. Therefore, we compare both infection types, identify relevant differences in initial clinical presentation and later course, and present the results of our patients in a retrospective review.

Methods

Patients diagnosed with GG from 2008 to 2018 in our level one trauma center were identified. Their charts were reviewed retrospectively and data analyzed in terms of demographic information, microbiological and histological results, therapeutic course, outcome, and mortality rates. The laboratory risk indicator for NF (LRINEC) score was applied on the first blood work acquired. Results were compared to those of a second group diagnosed with NF.

Results

Five patients with GG and nine patients with NF were included in the present study. Patients with GG had a mortality rate of 80% compared to 0% in patients with NF. In eight patients with NF, affected limbs could be salvaged; one NF underwent amputation. LRINEC did not show significant differences between the groups; however, C‐reactive protein was significantly increased (P = 0.009) and hemoglobin (Hb) was significantly decreased (P = 0.02) in patients with GG. Interleukin‐6 and procalcitonin levels did not show significant difference. Patients with GG were older (70.2 vs 50 years). Of the isolated bacteria, 86% were sensitive to the initial calculated antibiotic treatment with ampicillin‐sulbactam or imipenem plus metronidazole plus clindamycin.

Conclusion

Both GG and NF need full‐scale surgical, antibiotic, and intensive care treatment, especially within the first days. Among patients with NSTI, those with clostridial GG have a significantly increased mortality risk due to early septic shock caused by clostridial toxins. In the initial stages, clinical differences are hardly detectable. Immediate surgical debridement is the key to successful therapy for NSTI and needs to be performed as early as possible. However, patients should be treated in a center with an experienced interdisciplinary intensive care team based on a predetermined treatment plan.

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.

Time is of the essence when treating necrotizing soft tissue infections: a systematic review and meta-analysis

Background

Although the phrase “time is fascia” is well acknowledged in the case of necrotizing soft tissue infections (NSTIs), solid evidence is lacking. The aim of this study is to review the current literature concerning the timing of surgery in relation to mortality and amputation in patients with NSTIs.

Methods

A systematic search in PubMed/MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and the Cochrane Controlled Register of Trials (CENTRAL) was performed. The primary outcomes were mortality and amputation. These outcomes were related to the following time-related variables: (1) time from onset symptoms to presentation; (2) time from onset symptoms to surgery; (3) time from presentation to surgery; (4) duration of the initial surgical procedure. For the meta-analysis, the effects were estimated using random-effects meta-analysis models.

Result

A total of 109 studies, with combined 6051 NSTI patients, were included. Of these 6051 NSTI patients, 1277 patients died (21.1%). A total of 33 studies, with combined 2123 NSTI patients, were included for quantitative analysis. Mortality was significantly lower for patients with surgery within 6 h after presentation compared to when treatment was delayed more than 6 h (OR 0.43; 95% CI 0.26–0.70; 10 studies included). Surgical treatment within 6 h resulted in a 19% mortality rate compared to 32% when surgical treatment was delayed over 6 h. Also, surgery within 12 h reduced the mortality compared to surgery after 12 h from presentation (OR 0.41; 95% CI 0.27–0.61; 16 studies included). Patient delay (time from onset of symptoms to presentation or surgery) did not significantly affect the mortality in this study. None of the time-related variables assessed significantly reduced the amputation rate. Three studies reported on the duration of the first surgery. They reported a mean operating time of 78, 81, and 102 min with associated mortality rates of 4, 11.4, and 60%, respectively.

Conclusion

Average mortality rates reported remained constant (around 20%) over the past 20 years. Early surgical debridement lowers the mortality rate for NSTI with almost 50%. Thus, a sense of urgency is essential in the treatment of NSTI.

Treatment of severe skin and soft tissue infections: a review

PURPOSE OF REVIEW

To review the salient features of the management of severe skin and soft tissue infections (SSTIs), including toxic shock syndrome, myonecrosis/gas gangrene, and necrotizing fasciitis.

RECENT FINDINGS

For severe SSTIs, intensive care, source control, and broad-spectrum antimicrobials are required for the initial phase of illness. There is an increasing focus on the utility of rapid diagnostic tests to help in selection and de-escalation of antimicrobials for SSTIs. In addition, clinical prediction scores have shown promise in helping predict patients who do not require antimicrobials directed against methicillin-resistant Staphylococcus aureus. Immune status has been shown to be important in clinical outcomes of some, but not all types of SSTIs. The debate for benefits of intravenous immunoglobulin continues to be waged in the recent literature.

SUMMARY

Severe SSTIs are common and their management complex due to regional variation in predominant pathogens and antimicrobial resistance patterns, as well variations in host immune responses. Unique aspects of care for severe SSTIs are discussed including the role of surgical consultation and source control. The unique features of SSTIs in immunocompromised hosts are also described.

Scarce evidence of efficacy of hyperbaric oxygen therapy in necrotizing soft tissue infection: a systematic review

Background: Necrotizing soft tissue infection (NSTI) is a rare and potentially life-threatening disease. Rapid surgical intervention, antibiotics and intensive care are the mainstay of treatment. Hyperbaric oxygen therapy (HBOT) is used as adjuvant therapy in some centres but there is a lack of research-based evidence of efficacy. Methods: Following the PRISMA guideline we conducted a systematic review on the efficacy of HBOT on NSTI with mortality as primary outcome. Through January 2019 major databases were searched and relevant literature assessed. The criteria for study inclusion were research of any design and any period of time comparing HBOT vs. non-HBOT in a population of NSTI-patients. Studies were analysed using the modified Delphi method and risk of bias in non-randomized studies - of interventions tool. Relative risk (RR) on mortality was calculated for each study individually. Results: A number of 1733 studies were identified through database search. Ultimately, 21 studies were included of which 19 were case series with a control group. The majority of the studies performed poor in quality assessment and all featured a high to critical risk of bias. The association of HBOT on mortality was generally reported as positive, however, the results should be considered with great scepticism. Conclusions: The evidence of HBOT in NSTI is poor and biased. There is a strong need for randomized controlled trials (RCTs) to shed light on a potential life-saving treatment.

Hyperbaric oxygen therapy: Antimicrobial mechanisms and clinical application for infections

Hyperbaric oxygen therapy (HBOT) is a treatment procedure that involves breathing 100% O₂ for a certain time and under a certain pressure. HBOT is commonly administrated as a primary or alternative therapy for different diseases such as infections. In this paper, we reviewed the general aspect of HBOT procedures, the mechanisms of antimicrobial effects and the application in the treatment of infections. Parts of the antimicrobial effects of HBOT are believed to result of reactive from the formation of reactive oxygen species (ROS). It is also said that HBOT enhances the antimicrobial effects of the immune system and has an additive or synergistic effect with certain antimicrobial agents. HBOT has been described as a useful procedure for different infections, particularly in deep and chronic infections such as necrotizing fasciitis, osteomyelitis, chronic soft tissue infections, and infective endocarditis. The anti-inflammation property of HBOT has demonstrated that it may play a significant role in decreasing tissue damage and infection expansion. Patients treated by HBOT need carful pre-examination and monitoring. If safety standards are strictly tracked, HBOT can be considered a suitable procedure with an apt rate of complication.

Validation of a clinical trial composite endpoint for patients with necrotizing soft tissue infections

OBJECTIVE

Our objective was to develop and validate a composite endpoint for patients with necrotizing soft tissue infections that incorporates: local tissue injury, systemic organ dysfunction, and mortality.

METHODS

The Necrotizing Infection Clinical Composite Endpoint (NICCE) was defined as follows:(i) alive at day 28, (ii) three or less debridements before day 14, (iii) no amputation beyond first debridement, (iv) modified sequential organ failure assessment score score (mSOFA) at day 14 ≤ 1. To be considered a success, all individual criteria must be met. Several data sets were used to assess validity: (i) a retrospective data set of 198 patients treated during 2013 at 12 US trauma centers; (ii) a subset with high disease acuity, admission mSOFA score of 3 or higher (n = 69); and (iii) 40 patients from a multicenter, phase 2 randomized trial of a CD28 immunomodulator (AB103). Clinical success based on each parameter and the composite score was assessed.

RESULTS

Using the retrospective data set for all patients and those with high disease severity (respectively), survival rates were 92% and 84%; day 14 mSOFA 1 or lower score was 69% and 51%; three or less debridements was 84% and 77%; and no subsequent amputations were 96% and 94%. Overall, the percent meeting all success criteria for NICCE was 58% (all patients) and 33% (mSOFA > 3). NICCE success was also associated with reduced utilization of health care resources, intensive care unit-free days were median (interquartile range) of 25.3 (21.9-28) and 19.6 (4.3-25.1) days (one-sided Wilcoxon p < 0.001) and ventilator-free days were 28 (26-28) versus 25 (14-28) (p < 0.001) for NICCE success versus failure, respectively. Using the phase 2 data set, the treated group (0.5 mg/kg, n = 15) demonstrated a NICCE success rate of 73.3% versus 40% for placebo (n = 10).

CONCLUSION

These data demonstrate internal consistency of the components and face and criterion validity of the NICCE endpoint. NICCE offers an opportunity to demonstrate a clinically relevant treatment effect for patients enrolled in clinical trials for necrotizing soft tissue infection.

LEVEL OF EVIDENCE

Prognostic/Epidemiological, level III; Therapeutic, level IV.

Management and Novel Adjuncts of Necrotizing Soft Tissue Infections

Necrotizing soft tissue infections (NSTI) have been recognized for millennia and continue to impose considerable burden on both patient and society in terms of morbidity, death, and the allocation of resources. With improvements in the delivery of critical care, outcomes have improved, although disease-specific therapies are lacking. The basic principles of early diagnosis, of prompt and broad antimicrobial therapy, and of aggressive debridement have remained unchanged. Clearly novel and new therapeutics are needed to combat this persistently lethal disease. This review emphasizes the pillars of NSTI management and then summarizes the contemporary evidence supporting the incorporation of novel adjuncts to the pharmacologic and operative foundations of managing this disease.

Zoonotic necrotizing myositis caused by Streptococcus equi subsp. zooepidemicus in a farmer

BACKGROUND

Streptococcus equi subsp. zooepidemicus is a beta-hemolytic group C streptococcus mainly causing infections in domesticated animals. Here we describe the first case of zoonotic necrotizing myositis caused by this bacterium.

CASE PRESENTATION

The patient was a 73-year-old, previously healthy farmer with two asymptomatic Shetland ponies in his stable. After close contact with the ponies while feeding them, he rapidly developed erythema of his left thigh and sepsis with multiple organ failure. The clinical course was severe and complicated, requiring repetitive surgical excision of necrotic muscle, treatment with vasopressors, mechanical ventilation and continuous venovenous hemofiltration, along with adjunctive hyperbaric oxygen therapy. The patient was discharged from hospital at day 30, without obvious sequelae. The streptococcal isolate was identified as Streptococcus equi by MALDI-ToF MS, and was later assigned subspecies identification as S. equi subsp. zooepidemicus. Multilocus sequence typing identified the strain as a novel sequence type (ST 364), closely related to types previously identified in horses and cattle. A focused proteomic analysis revealed that the ST 364 expressed putative virulence factors similar to that of Streptococcus pyogenes, including homologues of the M protein, streptodornases, interleukin 8-protease and proteins involved in the biosynthesis of streptolysin S.

CONCLUSION

This case illustrates the zoonotic potential of S. equi subsp. zooepidemicus and the importance of early clinical recognition, rapid and radical surgical therapy, appropriate antibiotics and adequate supportive measures when necrotizing soft tissue infection is suspected. The expression of Streptococcus pyogenes-like putative virulence determinants in ST 364 might partially explain the fulminant clinical picture.

Early surgical intervention and its impact on patients presenting with necrotizing soft tissue infections: A single academic center experience

OBJECTIVES

Early diagnosis and emergent surgical debridement of necrotizing soft tissue infections (NSTIs) remains the cornerstone of care. We aimed to study the effect of early surgery on patients' outcomes and, in particular, on hospital length of stay (LOS) and Intensive Care Unit (ICU) LOS.

MATERIALS AND METHODS

Over a 6-year period (January 2003 through December 2008), we analyzed the records of patients with NSTIs. We divided patients into two groups based on the time of surgery (i.e., the interval from being diagnosed and surgical intervention): Early (<6 h) and late (≥6 h) intervention groups. For these two groups, we compared baseline demographic characteristics, symptoms, and outcomes. For our statistical analysis, we used the Student's t-test and Pearson Chi-square (χ(2)) test. To evaluate the clinical predictors of early diagnosis of NSTIs, we performed multivariate logistic regression analysis.

RESULTS

In the study population (n = 87; 62% males and 38% females), age, gender, wound locations, and comorbidities were comparable in the two groups. Except for higher proportion of crepitus, the clinical presentations showed no significant differences between the two groups. There were significantly shorter hospital LOS and ICU LOS in the early than late intervention group. The overall mortality rate in our study patients with NSTIs was 12.5%, but early intervention group had a mortality of 7.5%, but this did not reach statistical significance.

CONCLUSIONS

Our findings show that early surgery, within the first 6 h after being diagnosed, improves in-hospital outcomes in patients with NSTIs.

Interventions for treating gas gangrene

BACKGROUND

Gas gangrene is a rapidly progressive and severe disease that results from bacterial infection, usually as the result of an injury; it has a high incidence of amputation and a poor prognosis. It requires early diagnosis and comprehensive treatments, which may involve immediate wound debridement, antibiotic treatment, hyperbaric oxygen therapy, Chinese herbal medicine, systemic support, and other interventions. The efficacy and safety of many of the available therapies have not been confirmed.

OBJECTIVES

To evaluate the efficacy and safety of potential interventions in the treatment of gas gangrene compared with alternative interventions or no interventions.

SEARCH METHODS

In March 2015 we searched: The Cochrane Wounds Group Specialized Register, The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), Ovid MEDLINE, Ovid EMBASE, EBSCO CINAHL, Science Citation Index, the China Biological Medicine Database (CBM-disc), the China National Knowledge Infrastructure (CNKI), and the Chinese scientific periodical database of VIP INFORMATION (VIP) for relevant trials. We also searched reference lists of all identified trials and relevant reviews and four trials registries for eligible research. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) and quasi-RCTs that compared one treatment for gas gangrene with another treatment, or with no treatment.

DATA COLLECTION AND ANALYSIS

Independently, two review authors selected potentially eligible studies by reviewing their titles, abstracts and full-texts. The two review authors extracted data using a pre-designed extraction form and assessed the risk of bias of each included study. Any disagreement in this process was solved by the third reviewer via consensus. We could not perform a meta-analysis due to the small number of studies included in the review and the substantial clinical heterogeneity between them, so we produced a narrative review instead.

MAIN RESULTS

We included two RCTs with a total of 90 participants. Both RCTs assessed the effect of interventions on the 'cure rate' of gas gangrene; 'cure rate' was defined differently in each study, and differently to the way we defined it in this review.One trial compared the addition of Chinese herbs to standard treatment (debridement and antibiotic treatment; 26 participants) against standard treatment alone (20 participants). At the end of the trial the estimated risk ratio (RR) of 3.08 (95% confidence intervals (CI) 1.00 to 9.46) favoured Chinese herbs. The other trial compared standard treatment (debridement and antibiotic treatment) plus topical hyperbaric oxygen therapy (HBOT; 21 participants) with standard treatment plus systemic HBOT (23 participants). There was no evidence of difference between the two groups; RR of 1.10 (95% CI 0.25 to 4.84). For both comparisons the GRADE assessment was very low quality evidence due to risk of bias and imprecision so further trials are needed to confirm these results.Neither trial reported on this review's primary outcomes of quality of life, and amputation and death due to gas gangrene, or on adverse events. Trials that addressed other therapies such as immediate debridement, antibiotic treatment, systemic support, and other possible treatments were not available.

AUTHORS' CONCLUSIONS

Re-analysis of the cure rate based on the definition used in our review did not show beneficial effects of additional use of Chinese herbs or topical HBOT on treating gas gangrene. The absence of robust evidence meant we could not determine which interventions are safe and effective for treating gas gangrene. Further rigorous RCTs with appropriate randomisation, allocation concealment and blinding, which focus on cornerstone treatments and the most important clinical outcomes, are required to provide useful evidence in this area.

Necrotising Soft Tissue Infections: The Effect of Hyperbaric Oxygen on Mortality

In a single-centre, retrospective, case-controlled study of patients attending the Alfred Hospital in Prahran, Victoria, we assessed the effect of hyperbaric oxygen therapy (HBOT) in reducing mortality or morbidity in patients with necrotising fasciitis (NF) over a 13-year period from 2002 to 2014. A total of three hundred and forty-one patients with NF were included in the study, of whom 275 received HBOT and 66 did not. The most commonly involved sites were the perineum (33.7%), lower limb (29.9%) and trunk (18.2%). The commonest predisposing factor was diabetes mellitus (34.8%). Polymicrobial NF (type 1 NF) occurred in 50.7% and Group A streptococcal fasciitis (type 2 NF) occurred in 25.8% of patients. Mortality was 14.4% overall, 12% in those treated with, and 24.3% in those not treated with, HBOT. ICU support was required in 248 (72.7%) patients. Independent factors impacting on mortality included HBOT (odds ratio [OR] 0.42 [0.22 to 0.83], P=0.01), increased age (OR 1.06 [1.03 to 1.08], P=0.001) and immunosuppression (OR 2.6 [1.23 to 5.51], P=0.01). Mortality was linked to illness severity at presentation, however when adjusted for severity score and need for intensive care management, HBOT was associated with significant reduction in mortality.

World Society of Emergency Surgery (WSES) guidelines for management of skin and soft tissue infections

Skin and soft tissue infections (SSTIs) encompass a variety of pathological conditions ranging from simple superficial infections to severe necrotizing soft tissue infections. Necrotizing soft tissue infections (NSTIs) are potentially life-threatening infections of any layer of the soft tissue compartment associated with widespread necrosis and systemic toxicity. Successful management of NSTIs involves prompt recognition, timely surgical debridement or drainage, resuscitation and appropriate antibiotic therapy. A worldwide international panel of experts developed evidence-based guidelines for management of soft tissue infections. The multifaceted nature of these infections has led to a collaboration among surgeons, intensive care and infectious diseases specialists, who have shared these guidelines, implementing clinical practice recommendations.

Management of necrotizing skin and soft tissue infections

Although rare, necrotizing skin and soft tissue infections can be devastating infections that are difficult to diagnose and challenging to manage. Clinical presentation is often insidious, and a low index of suspicion is critical. Various diagnostic tools, such as scoring systems or imaging techniques, have been introduced, but none is convincingly superior to sound clinical judgment. Early diagnosis allows early adequate therapy that includes antibiotic therapy, critical care support, specific interventions such as intravenous immunoglobulin in selected patients and, most importantly, early source control. Empirical antibiotic therapy should cover a broad range of both Gram-negative and Gram-positive aerobic and anaerobic microorganisms, and clindamycin is recommended when group A Streptococcus is a suspected pathogen.

Are we getting necrotizing soft tissue infections right? A 10-year review

BACKGROUND

The Alfred Hospital is a referral centre for necrotizing soft tissue infections (NSTIs) in the state of Victoria and receives around 20 such patients each year. We sought to compare our practice and outcomes against published data, and to examine management at referring hospitals to determine whether adjustments to current practices are required.

METHODS

A retrospective chart review of patients admitted to the Alfred Hospital between 1 January 2001 and 31 December 2010 with a diagnosis of necrotizing fasciitis was conducted. Demographic, etiologic, treatment and outcome data were collected and analysed.

RESULTS

Two hundred and nineteen patients were identified with a mean age of 54.76 years and a preponderance of men (63.47%). The overall mortality rate for the patient group was 15.98%. More than 80% of patients were transferred from another facility. Nearly 40% of patients did not undergo surgical debridement within 24 h of presentation to a hospital and 30.6% were not debrided prior to transfer. Patients underwent a median of three procedures at the Alfred Hospital and the majority of patients required admission to the intensive care unit (68.95%).

CONCLUSION

NSTIs remain a surgical emergency with high rates of mortality and resource requirements. The mortality rate at our institution compares well with other published series. Many patients experienced delays before undergoing debridement and in many cases were transferred without debridement. The trend towards transferring NSTI patients to centres accustomed to treating burns and major trauma seems logical, but should not delay life-saving surgical debridement. Timing of transfer does not seem to affect mortality.

[Necrotizing soft tissue infection of the upper limb]

Necrotizing soft tissue infections and necrotizing fasciitis are life-threatening infections affecting the hypodermis, muscular fascia, and dermis secondarily. Mortality is high, with an average of 30%. The early diagnosis of necrotizing soft tissue infection is challenging, but is key to successful management of these patients. The mainstay of therapy includes early and wide surgical debridement, antibiotics and supportive care. Adjunctive therapies may have a role, but their effectiveness remains unproven. A review of the literature allows us to highlight this multidisciplinary management.

Prognostic aspects, survival rate, and predisposing risk factors in patients with Fournier's gangrene and necrotizing soft tissue infections: evaluation of clinical outcome of 55 patients

OBJECTIVE

To determine predisposing or prognostic factors and mortality rates of patients with Fournier's gangrene compared to other necrotizing soft tissue infections (NSTI).

MATERIAL AND METHODS

Data of 55 intensive care patients (1981-2010) with NSTI were evaluated. Data were collected prospectively.

RESULTS

43.4% of the patients were in septic condition and 27.3% were hemodynamically unstable. Half of the patients showed predisposing factors (52.7%). The lower extremity (63.2%), abdomen (30.9%), and perineum (14.5%) were most affected. Polymicrobial infections were frequent (65.5%, mean 2.8, range: 1-4). The mortality rate was 16.4% (n = 9). An increase was shown for diabetes mellitus (20%), cardiac insufficiency (22.3%), septic condition at presentation (33.3%), abdominal affection (47.1%), and hemodynamic instability (46.7%). Comparing survivors and nonsurvivors, statistical significance was seen with age (p < 0.001), septic condition at admission (p < 0.001), hemodynamic instability (p < 0.001), low blood pressure (p < 0.001), and abdominal affection (p < 0.001). In laboratory findings, an increase of creatine kinase (p < 0.001) and lactate (p < 0.001) and a decrease of antithrombin III (p < 0.007) and the Quick value (p < 0.01) proved to be significant.

CONCLUSION

Patients with Fournier's gangrene do not differ in all aspects from those with other NSTI. Successful treatment consists of immediate surgical debridement, broad-spectrum antibiotic treatment, and critical care management. Supportive hyperbaric oxygen therapy should be considered.

Hyperbaric oxygen therapy in necrotizing soft tissue infections

BACKGROUND

Surgical debridement and antibiotics are the mainstays of therapy for patients with necrotizing soft tissue infections (NSTIs), but hyperbaric oxygen therapy (HBO) is often used as an adjunctive measure. Despite this, the efficacy of HBO remains unclear. We hypothesized that HBO would have no effect on mortality or amputation rates.

METHODS

We performed a retrospective analysis of our institutional experience from 2005 to 2009. Inclusion criteria were age > 18 y and discharge diagnosis of NSTI. We abstracted baseline demographics, physiology, laboratory values, and operative course from the medical record. The primary endpoint was in-hospital mortality; the secondary endpoint was extremity amputation rate. We compared baseline variables using Mann-Whitney, chi-square, and Fisher's exact test, as appropriate. Significance was set at P < 0.05.

RESULTS

We identified 80 cases over the study period. The cohort was 54% male (n = 43) and 53% white (n = 43), and had a mean age of 55 ± 16 y. There were no significant differences in demographics, physiology, or comorbidities between groups. In-hospital mortality was not different between groups (16% in the HBO group versus 19% in the non-HBO group; P = 0.77). In patients with extremity NSTI, the amputation rate did not differ significantly between patients who did not receive HBO and those who did (17% versus 25%; P = 0.46).

CONCLUSIONS

Hyperbaric oxygen therapy does not appear to decrease in-hospital mortality or amputation rate after in patients with NSTI. There may be a role for HBO in treatment of NSTI; nevertheless, consideration of HBO should never delay operative therapy. Further evidence of efficacy is necessary before HBO can be considered the standard of care in NSTI.

Simultaneous necrotizing soft tissue infection and colonic necrosis caused by Clostridium septicum

BACKGROUND

Clostridial myonecrosis is an uncommon, highly lethal necrotizing soft tissue infection. The source may be occult at the time of clinical presentation. In cases caused by Clostridium septicum, there is an association with colorectal malignant disease, suggesting that underlying colonic pathology frequently is the source of the infection.

METHODS

Case report and literature review.

CASE REPORT

A 37-year old man with acquired immunodeficiency syndrome, end-stage renal disease, and C. difficile colitis presented to the Emergency Department (ED) with a primary complaint of abdominal pain and incidental right forearm pain. While undergoing evaluation in the ED, he developed progressive erythema, edema, and emergence of bullae over his right forearm. After rapid imaging of his abdomen, he underwent guillotine amputation of his right upper extremity because of extensive myonecrosis and total abdominal colectomy secondary to right colonic necrosis and C. difficile colitis. Blood cultures were positive for C. septicum. Microscopic examination of both the necrotic colon and the right forearm musculature demonstrated invasion of gram-positive bacilli throughout.

CONCLUSIONS

Myonecrosis caused by C. septicum frequently occurs in the presence of colonic pathology, typically malignant disease. This case report illustrates the development of this pathological process in an immunosuppressed patient who did not have colon cancer, but rather colonic mucosal inflammation produced by C. difficile.

Necrotizing soft-tissue infections

OBJECTIVE

To provide a contemporary review of the diagnosis and management of necrotizing soft-tissue infections.

DATA SOURCES

Scientific literature and internet sources.

STUDY SELECTION

Major articles of importance in this area.

CONCLUSIONS

The mortality for necrotizing soft-tissue infections appears to be decreasing, possibly due to improved recognition and earlier delivery of more effective therapy. Establishing a diagnosis and initiating treatment as soon as possible provides the best opportunity for a good outcome.

The pacific chapter annual meeting of the undersea & hyperbaric medical society

The following is the summary report on the UHMS Pacific Chapter Annual Meeting held in Long Beach in October 2010. The conference provided the latest updates on scientific, technical and organizational aspects of Hyperbaric and Diving Medicine. Invited speakers gave series of lectures dealing with current standards of clinical practice and presenting the results of laboratory investigations with particular emphasis on mechanisms of hyperbaric oxygen therapy. Scientific sessions were accompanied by vendor exhibits and social events.

Local variations in the epidemiology, microbiology, and outcome of necrotizing soft-tissue infections: a multicenter study

BACKGROUND

Necrotizing soft-tissue infections (NSTIs) are rare and highly lethal.

METHODS

A retrospective chart review of patients with NSTIs treated at 6 academic hospitals in Texas between January 1, 2004 and December 31, 2007. Patient demographics, presentation, microbiology, treatment, and outcome were recorded. Analysis of variance, chi-square test, and logistic regression analysis were performed.

RESULTS

Mortality rates varied between hospitals from 9% to 25% (n = 296). There was significant interhospital variation in patient characteristics, microbiology, and etiology of NSTIs. Despite hospital differences in treatment, primarily in critical care interventions, patient age and severity of disease (reflected by shock requiring vasopressors and renal failure postoperatively) were the main predictors of mortality.

CONCLUSIONS

Significant center differences occur in patient populations, etiology, and microbiology of NSTIs, even within a concentrated region. Management should be based on these characteristics given that adjunctive treatments are unproven and variations in outcome are likely because of patient disease at presentation.

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.

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.