Effect of transfer status on outcomes for necrotizing soft tissue infections

Identifying patients with difficult-to-treat acute bacterial skin infections

PURPOSE OF REVIEW

The early recognition of acute bacterial skin infections (ABSIs) and their swift and adequate care are the major determinants of success. The features that can hamper or delay surgical and medical management can lead to 'difficult-to-treat' ABSIs.

RECENT FINDINGS

Delayed diagnosis and belated management are the key obstacles to be overcome. Clinicians should be careful about underestimating the severity of ABSIs and overlooking comorbidities, especially immunosuppression. Many conditions can lead to delayed source control, including a misdiagnosis, interhospital transfers, delayed re-exploration, or extensive injuries. Difficult therapeutic issues can occur, including rapidly destructive infections from highly pathogenic microorganisms (Group-A-streptococci, Vibrio spp., Clostridium spp. and Staphylococcus aureus ) or inadequate antibiotic therapy resulting from multidrug-resistant bacteria. Impaired pharmacokinetic capacities of antibiotic agents should also be considered as a source of clinical failure due to insufficient antimicrobial activity at the site of infection.

SUMMARY

Microbiological samples should be used for guiding antimicrobial therapy. Risk factors for multidrug-resistant bacteria should be considered, including local epidemiology and comorbidities. The optimization of antibiotic therapy should be achieved. Optimized care should be achieved through multidisciplinary management involving professionals with sufficient and appropriate training.

Severe skin infections

PURPOSE OF REVIEW

The incidence of necrotizing soft-tissue infections (NSTI) has increased during recent decades. These infections are still associated with high morbidity and mortality, underlining a need for continued education of the medical community. This review will focus on practical approaches to management of NSTI focusing on antibiotic therapies and optimizing the management of group A streptococcus (GAS)-associated NSTIs.

RECENT FINDINGS

Antibiotic therapy for NSTI patients faces several challenges as the rapid progression of NSTIs mandates broad-spectrum agents with bactericidal action. Current recommendations support using clindamycin in combination with penicillin in case of GAS-documented NSTIs. Linezolide could be an alternative in case of clindamycin resistance.

SUMMARY

Reducing the time to diagnosis and first surgical debridement, initiating early broad-spectrum antibiotics and early referral to specialized centres are the key modifiable factors that may impact the prognosis of NSTIs. Causative organisms vary widely according to the topography of the infection, underlying conditions, and geographic location. Approximately one third of NSTIs are monomicrobial, involving mainly GAS or Staphylococcus aureus . Data for antibiotic treatment specifically for necrotizing soft-tissue infections are scarce, with guidelines mainly based on expert consensus.

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.

Characterization of Necrotizing Soft Tissue Infections in Obese and Non-Obese Patients

Background: The impact of obesity on the pathogenesis and prognosis of necrotizing soft tissue infections (NSTIs) is unclear. The goal of this study was to characterize differences in NSTI presentation and outcomes by obesity status. Patients and Methods: A retrospective analysis of institutional data for patients diagnosed with NSTIs were identified (n = 619; 2011-2020). Patients were divided based on obesity (body mass index [BMI] ≥ 30 kg/m²) and non-obese (BMI <30 kg/m²). Primary outcomes included NSTI location, micro-organisms, and index hospitalization data. Multiple logistic regression was used to model predictors of in-hospital and 90-day mortality. Results: The obese cohort (n = 390; 63%) had higher rates of congestive heart failure and type 2 diabetes mellitus. There were no differences in length of stay, mortality, or discharge disposition between groups. A higher rate of respiratory failure was observed in the obese versus non-obese group (36.7% vs. 20.9%; p < 0.0005). The obese cohort was associated with perineal (40.8% vs. 27.0%) and torso NSTIs (20.9% vs. 15.8%; p < 0.005) but reduced staphylococcal (19.2% vs. 27.4%; p = 0.02) and group A streptococcal (2.6% vs. 6.5%; p = 0.03) infections, and increased polymicrobial infections. Class 2 obesity was a negative predictor for in-hospital mortality (odds ratio [OR], 0.1; 95% confidence interval [CI], 0.03-0.5) and 90-day mortality (OR, 0.3; 95% CI, 0.1-0.8), when adjusting for demographic data, type of infection, and baseline comorbidities. Conclusions: Necrotizing soft tissue infections in obesity may present with unique distributions and microbial characteristics. Class 2 obesity may exhibit a survival benefit compared with non-obese patients, suggestive of an obesity paradox.

Optimizing Safety for Surgical Patients Undergoing Interhospital Transfer

Interhospital transfers play a key role in ensuring that patients receive necessary care. However, patients who are transferred between hospitals are a vulnerable population, and outcomes of transferred patients are suboptimal. Despite the critical nature of interhospital transfers, only limited effort has been dedicated to standardization and improvement of the transfer process. Studying and adapting quality improvement efforts directed at other transitions of care, particularly those that cross between different facilities and care teams "such as the transition from hospital to home or extended care facilities" may improve the care of surgical patients transferred between acute care institutions.

Impact of interhospital transfer on patient outcomes in emergency general surgery

BACKGROUND

Emergency general surgery patients are at an increased risk for morbidity and mortality compared to their elective surgery counterparts. The complex nature of emergency general surgery conditions can challenge community hospitals, which may lack appropriate systems and personnel. Outcomes related to transfer have not been well-established. We aimed to compare postoperative outcomes of patients who were transferred from another hospital to a center with dedicated acute care surgery services with patients admitted directly to the acute care surgery centers.

METHODS

We performed a secondary analysis of a national, multicenter review of emergency general surgery patients undergoing complex emergency general surgery at 5 centers across Canada. The primary outcome was the development of any complication. The adjusted odds of postoperative complication was assessed using logistic regression, controlling for age, comorbidities, duration of stay before transfer, American Society of Anesthesiologists classification, and booking priority.

RESULTS

A total of 1,846 patients were included in the study, and 176 (9.5%) were transferred. Of these 21% (n = 37) underwent an operative procedure, and 15% (n = 27) underwent an operation at the transferring center. Transferred patients were more likely to have at least 1 comorbidity (68% vs 57%; P = .004), were classified as greater urgency on arrival (<2 hours booking priority, 43% vs 17%; P < .001), had a greater American Society of Anesthesiologists classification (American Society of Anesthesiologists ≥3 = 81% vs 65%; P < .001), a greater duration of operation (119 vs 110 minutes; P = .004), and were more likely to undergo a second operation (28% vs 14%; P < .001) compared to patients directly admitted to an acute care surgery center. On univariate analysis, transferred patients had greater rates of complications (48% vs 31%; P < .001), mortality (14% vs 7%; P = .005), and admission to the intensive care unit (22% vs 12%; P < .001). Transfer status remained an independent predictor of complication (odds ratio 1.9 [95% confidence interval 1.3-2.7]; P < .001) and intensive care unit admission (odds ratio 1.9 [95% confidence interval 1.2-3.0]; P = .007), but not mortality (odds ratio 1.1 [95% confidence interval 0.6-1.9]; P = .79) on regression analysis.

CONCLUSION

Complex emergency general surgery patients transferred to acute care surgery centers may have worse outcomes and greater use of resources compared to those admitted directly. This finding has clinically and financially important implications for the design and regionalization of acute care surgery services as well as resource allocation at acute care surgery centers.

Incidence, comorbidity and mortality in patients with necrotising soft-tissue infections, 2005-2018: a Danish nationwide register-based cohort study

OBJECTIVE

To assess the incidence, comorbidities, treatment modalities and mortality in patients with necrotising soft-tissue infections (NSTIs) in Denmark.

DESIGN

Nationwide population-based registry study.

SETTING

Denmark.

PARTICIPANTS

Danish residents with NSTI between 1 January 2005 and 31 August 2018.

MAIN OUTCOME MEASURE

Incidence of disease per 100 000 person/year and all-cause mortality at day 90 obtained from Danish National Patient Registry and the Danish Civil Registration System.

RESULTS

1527 patients with NSTI were identified, yielding an incidence of 1.99 per 100 000 person/year. All-cause 30-day, 90-day and 1-year mortality were 19.4% (95% CI 17.4% to 21.5%), 25.2% (95% CI 23.1% to 27.5%) and 30.4% (95% CI 28.0% to 32.8%), respectively. Amputation occurred in 7% of the individuals. Diabetes was the most predominant comorbidity affecting 43% of the cohort, while 26% had no comorbidities. Higher age, female sex and increasing comorbidity index were found to be independent risk factors of mortality. Admission to high-volume hospitals was associated with improved survival (OR 0.59, 95% CI 0.45 to 0.77). Thirty-six per cent received hyperbaric oxygen therapy (HBOT) as an adjunctive therapy. No change in overall mortality was found over the studied time period.

CONCLUSION

The present study found that in Denmark, the incidence of NSTI increased; mortality rates remained high and largely unaltered. Diabetes was the most common comorbidity, while higher age, female sex and increasing comorbidity index were associated to increased mortality. Survival was improved in those admitted to hospitals with more expertise in treating NSTI. In high-volume hospital, HBOT was associated with decreased odds for mortality.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Prognostic, Level III.

Risk Prediction Accuracy Differs for Transferred and Nontransferred Emergency General Surgery Cases in the ACS-NSQIP

BACKGROUND

Risk prediction accuracy of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) Surgical Risk Calculator has been shown to differ between emergency and elective surgery. Benchmarking methods of clinical performance require accurate risk estimation, and current methods rarely account for admission source; therefore, our goal was to assess whether the ACS-NSQIP predicts mortality comparably between transferred and nontransferred emergency general surgery (EGS) cases.

MATERIALS AND METHODS

This is a retrospective study using the ACS-NSQIP database from 2005 to 2014including all inpatients who underwent one of seven previously described EGS procedures. The admission source was classified as directly admitted versus transferred from an outside emergency room or an acute care facility. We compared the accuracy of ACS-NSQIP-predicted mortality probabilities using the observed-to-expected (O:E) ratio and Brier score. A subgroup analysis was performed to compare accuracy of high-risk and low-risk procedures.

RESULTS

A total of 206,103 EGS admissions were identified, of which 6.97% were transfers. Overall mortality was 3.26% for the entire cohort and 10.24% within the transfer group. The O:E ratios generated by ACS-NSQIP models differed between transferred patients (O:E = 1.0, 95% confidence interval = 0.97-1.02) and nontransferred patients (O:E = 1.12, 95% confidence interval = 1.09-1.14). The Brier score for transferred patients was greater than that for nontransferred patients (0.063 versus 0.018, respectively) showing higher accuracy for nontransferred patients.

CONCLUSIONS

The ACS-NSQIP risk estimates used for benchmarking differ between transferred and nontransferred EGS cases. Analyses of the Brier score by the ACS-NSQIP risk calculator demonstrated inferior prediction for transferred patients. This increased burden on accepting institutions will have an impact on quality metrics and should be considered for benchmarking of clinical performance.

Impact of a multidisciplinary care bundle for necrotizing skin and soft tissue infections: a retrospective cohort study

BACKGROUND

Necrotizing skin and soft tissue infections (NSTIs) require both prompt medical and surgical treatment. The coordination of multiple urgent interventions by care bundles has improved outcome in other settings. This study aimed to assess the impact of a multidisciplinary care bundle on management and outcome of patients with NSTIs.

METHODS

Patients with NSTIs admitted between 2006 and 2017 were compared according to admission before or after bundle implementation (2012-2013). This bundle consisted mainly in (1) the creation of a multidisciplinary task force; (2) management guidelines on empirical antibiotics, intensive care unit admission criteria, a triage algorithm to accelerate operating room access; and (3) an active communication policy. Patient recruitment and management were compared between pre- and post-implementation periods. Main outcome was day 60-censored hospital survival.

RESULTS

Overall, 224 patients were admitted: 60 before, 35 during, and 129 after bundle implementation. Admission after implementation was associated with increased yearly admissions (10 [8-13] vs 30 [24-43] patients/year, p = 0.014) and decreased mortality (30 vs 15%, HR = 0.49 [0.26-0.92]; p = 0.026) but was no longer a protective factor for mortality after adjustment on confounding factors (adjusted HR = 0.90 [0.43-1.88], p = 0.780). There was no significant difference regarding time to surgery (0 [0-1] vs 0 [0-1] days, p = 0.192) or rate of antibiotic treatment within 24 h (98% vs 99%, p > 0.99).

CONCLUSIONS

Implementation of a multidisciplinary care bundle for NSTIs was feasible, but in a retrospective study from an already experienced center was not associated with significantly increased survival after adjustment.

Fournier Gangrene: A Review for Emergency Clinicians

BACKGROUND

Fournier gangrene (FG) is a rare, life-threatening infection that can result in significant morbidity and mortality, with many patients requiring emergency department (ED) management for complications and stabilization.

OBJECTIVE

This narrative review provides an evidence-based summary of the current data for the emergency medicine evaluation and management of FG.

DISCUSSION

Although originally thought to be an idiopathic process, FG has been shown to have a strong association for male patients with advanced age and comorbidities affecting microvascular circulation and immune system function, most commonly those with diabetes or alcohol use disorder. However, it can also affect patients without risk factors. The initial infectious nidus is usually located in the genitourinary tract, gastrointestinal tract, or perineum. FG is a mixed infection of aerobic and anaerobic bacterial flora. The development and progression of gangrene is often fulminant and can rapidly cause multiple organ failure and death, although patients may present subacutely with findings similar to cellulitis. Laboratory studies, as well as imaging including point-of-care ultrasound, conventional radiography, and computed tomography are important diagnostic adjuncts, though negative results cannot exclude diagnosis. Treatment includes emergent surgical debridement of all necrotic tissue, broad-spectrum antibiotics, and resuscitation with intravenous fluids and vasoactive medications.

CONCLUSIONS

FG requires a high clinical level of suspicion, combined with knowledge of anatomy, risk factors, and etiology for an accurate diagnosis. Although FG remains a clinical diagnosis, relevant laboratory and radiography investigations can serve as useful adjuncts to expedite surgical management, hemodynamic resuscitation, and antibiotic administration.

Transfer Is Associated with a Higher Mortality Rate in Necrotizing Soft Tissue Infections

Background: Necrotizing soft tissue infections (NSTI) are a surgical emergency with significant morbidity and mortality rates. It has been thought that NSTIs are best treated in large tertiary centers. However, the effect of transfer has been under-studied. We examined whether transfer status is associated with a higher mortality rate in NSTIs. Methods: We conducted a retrospective review of patients with an International Classification of Disease (ICD) code associated with NSTI seen from 2012-2015 at two tertiary care institutions. Patients transferred to a tertiary center (T-NSTI) were compared with those who were treated initially at a tertiary center (P-NSTI). The primary endpoint was in-hospital death. Results: A total of 138 patients with NSTI met our study criteria, 39 transfer patients (28.0%) and 99 (72.0%) who were treated primarily at our institutions. The mortality rate was significantly higher for T-NSTI patients than P-NSTI patients (35.9% versus 14.1%; p < 0.01) with an adjusted odds ratio of 5.33 (95% confidence interval 1.02-28.30; p = 0.04). The need for hemodialysis was an independent predictor of in-hospital death. Treatment at a Level 1 trauma center and current smoking status were independent protectors???? of in-hospital death. For the transfer patients, the timing of transfer and debridement status were not different in survivors and non-survivors. However, there was a trend toward a lower in-hospital mortality rate if patients were transferred early without prior debridement than in all other transfers (21.4% versus 40.0%; p = 0.21). The in-hospital mortality rate was significantly lower at the Level 1 trauma center than at the non-trauma tertiary center (15.5% versus 34.3%; p = 0.02). Conclusion: Transfer status is an independent predictor of in-hospital death in patients with NSTI. Larger, multi-institutional studies are needed to elucidate further what factors contribute to the higher mortality rate in these patients.

Urgences dermatologiques en réanimation : infections nécrosantes de la peau et des parties molles et toxidermies graves

Les urgences dermatologiques nécessitant une admission en réanimation sont rares mais associées à une mortalité élevée et à de lourdes séquelles à long terme. Elles sont essentiellement représentées par les infections nécrosantes des tissus mous (également appelées : dermohypodermites bactériennes nécrosantes-fasciites nécrosantes [DHBN-FN]) et par les toxidermies graves que sont les nécrolyses épidermiques (comprenant le syndrome de Lyell ou nécrolyse épidermique toxique [NET], le syndrome de Stevens-Johnson [SJS] et le DRESS (drug reaction with eosinophilia and systemic symptoms)). Elles ont pour caractéristiques communes un diagnostic souvent difficile, la nécessité d’une approche multidisciplinaire et de soins paramédicaux lourds et spécifiques, imposant fréquemment le transfert dans un centre expert. Le traitement des DHBN-FN est médicochirurgical, associant un débridement chirurgical précoce et une antibiothérapie probabiliste à large spectre. La présence de signes de gravité locaux (nécrose, crépitation, douleur intense) ou généraux (sepsis, choc septique) est une indication d’urgence à l’exploration chirurgicale. Sa précocité est le principal facteur pronostique modifiable, les recommandations de thérapeutiques complémentaires (immunoglobulines intraveineuses, oxygénothérapie hyperbare, pansement à pressions négatives, ...) reposant à ce jour sur un faible niveau de preuve. L’élément essentiel de la prise en charge des toxidermies graves est la recherche et l’arrêt du médicament imputable, facteur essentiel du pronostic. Le SJS et le NET, en général associés à une ou plusieurs atteintes muqueuses, entraînent dans les formes les plus graves une défaillance cutanée aiguë. La prise en charge repose sur les soins de support (correction des troubles hydroélectrolytiques, prévention de l’hypothermie, prévention et traitement des épisodes infectieux, analgésie et anxiolyse, soins locaux). Les complications infectieuses et respiratoires sont les principales causes de décès à la phase aiguë. Aucun traitement spécifique n’a fait la preuve de son efficacité à ce jour. Le diagnostic de DRESS est difficile, et la prise en charge doit être multidisciplinaire. Sa gravité tient aux possibles atteintes viscérales associées (hépatique, rénale et cardiaque) qui justifient dans les formes graves d’une corticothérapie urgente.