Novel Predictors of Sepsis Outperform the American Burn Association Sepsis Criteria in the Burn Intensive Care Unit Patient:

Predictors of Sepsis and Sepsis-related Mortality in Critically Ill Burn Patients: A Single Tertiary Care Center Experience

Background

Clinical diagnosis of sepsis is challenging, emphasizing the importance of regular bacterial surveillance, and tailored antimicrobial therapy. This study aims to elucidate the predictors of sepsis in critically ill burn patients.

Methods

A retrospective analysis was conducted on patients admitted to the burn intensive care unit between 2016 and 2022. Demographics, type of burn, total body surface area (TBSA), presence of inhalation injury, mortality, sepsis, deep vein thrombosis, pulmonary embolism, pneumonia, cultures, and laboratory findings were collected. Descriptive statistics and survival analysis were used to analyze trends during the 7-year period.

Results

The study encompassed 196 participants. Among patient factors, men constituted 73.4% (n = 102) of those without sepsis and 86.0% (n = 49) with sepsis, with an association between sepsis and lower age (34 versus 41 years) as well as larger TBSA (41.1% versus 17.3%). Inhalation injury was a significant predictor of sepsis [35.1% (n = 20) versus 11.6% (n = 16)]. Mortality was higher in sepsis cases [17.5% (n = 10) versus 2.9% (n = 4)], as well as positive blood cultures [47.4% (n = 27) versus 2.2% (n = 3)], positive wound cultures [71.9% (n = 41) versus 12.2% (n = 17)], and positive fungal cultures [12.3% (n = 7) versus 0% (n = 0)]. Multivariable analysis identified age and TBSA as significant predictors of sepsis (P = 0.025, P < 0.001).

Conclusions

Age, TBSA affected emerge as a strong risk factor for sepsis among critically ill burn patients. It underscores the need for vigilant monitoring to improve outcomes and reduce sepsis-related mortality.

Plasma-derived extracellular vesicles (EVs) as biomarkers of sepsis in burn patients via label-free Raman spectroscopy

Sepsis following burn trauma is a global complication with high mortality, with ∼60% of burn patient deaths resulting from infectious complications. Diagnosing sepsis is complicated by confounding clinical manifestations of the burn injury, and current biomarkers lack the sensitivity and specificity required for prompt treatment. There is a strong rationale to assess circulating extracellular vesicles (EVs) from patient liquid biopsy as sepsis biomarkers due to their release by pathogens from bacterial biofilms and roles in the subsequent immune response. This study applies Raman spectroscopy to patient plasma-derived EVs for rapid, sensitive, and specific detection of sepsis in burn patients, achieving 97.5% sensitivity and 90.0% specificity. Furthermore, spectral differences between septic and non-septic burn patient EVs could be traced to specific glycoconjugates of bacterial strains associated with sepsis morbidity. This work illustrates the potential application of EVs as biomarkers in clinical burn trauma care and establishes Raman analysis as a fast, label-free method to specifically identify features of bacterial EVs relevant to infection amongst the host background.

Evaluation of White Blood Cell Count, Lymphocyte Percentage, Neutrophil Percentage, and Elevated Temperature as Predictors of Wound Infection in Burn Patients

INTRODUCTION

Infection remains a chief cause of morbidity and mortality among burn patients. The burn wound surface is initially sterile after a thermal injury but eventually gets colonized by microorganisms. A burn wound is considered infected upon the presence of high concentrations of microorganisms in the wound and scab. Burn wound infections can lead to a delay in epidermal maturation, higher scar formation, and sepsis. However, burn patients are commonly misclassified as septic due to the manifestation of systemic inflammatory response syndrome (SIRS) after their injury, despite the presence or absence of an infection.

METHODS

This is a retrospective review of medical records of patients admitted to the burn unit in Salmaniya Medical Complex in Manama, Bahrain, between the years 2018 and 2020. Demographic data, total body surface area (TBSA), initial temperature, white blood cell count, lymphocyte percentage, neutrophil percentage, and wound cultures were obtained for all subjects. Logistic regression analysis was performed to compare the presence or absence of wound infection by the aforementioned parameters.

RESULTS

Of 412 cases, 68.2% were male patients, with a mean age for the studied population of 25.1 years (standard deviation (SD)=20.7). Staphylococcus aureus was the most prevalent organism across all of the study population (n=31)(34.4%). Staphylococcus aureus was the most prevalent organism in patients under the age of five, while Pseudomonas aeruginosa was the most common organism among adults older than 65 years of age. TBSA was not found to be a good predictor of wound infection. There was no statistically significant relation between initial temperature and wound culture (p-value=0.056). However, logistic regression revealed that the initial temperature increases the likelihood of positive wound culture by almost three times.

CONCLUSION

White blood cell count, lymphocyte percentage, and neutrophil percentage were not clinically reliable in predicting burn wound infection. However, initial temperature might be a helpful predictor. Further research is needed to identify reliable clinical parameters of burn wound infections.

Plasma-derived Extracellular Vesicles (EVs) as Biomarkers of Sepsis in Burn Patients via Label-free Raman Spectroscopy

Sepsis following burn trauma is a global complication with high mortality, with ~60% of burn patient deaths resulting from infectious complications. Sepsis diagnosis is complicated by confounding clinical manifestations of the burn injury, and current biomarkers markers lack the sensitivity and specificity required for prompt treatment. Circulating extracellular vesicles (EVs) from patient liquid biopsy as biomarkers of sepsis due to their release by pathogens from bacterial biofilms and roles in subsequent immune response. This study applies Raman spectroscopy to patient plasma derived EVs for rapid, sensitive, and specific detection of sepsis in burn patients, achieving 97.5% sensitivity and 90.0% specificity. Furthermore, spectral differences between septic and non-septic burn patient EVs could be traced to specific glycoconjugates of bacterial strains associated with sepsis morbidity. This work illustrates the potential application of EVs as biomarkers in clinical burn trauma care, and establishes Raman analysis as a fast, label-free method to specifically identify features of bacterial EVs relevant to infection amongst the host background.

The Role of the Insulin/Glucose Ratio in the Regulation of Pathogen Biofilm Formation

During the management of patients in acute trauma the resulting transient hyperglycemia is treated by administration of insulin. Since the effect of insulin, a quorum sensing compound, together with glucose affects biofilm formation in a concentration-specific manner, we hypothesize that the insulin/glucose ratio over the physiologic range modulates biofilm formation potentially influencing the establishment of infection through biofilm formation.

METHODS

A variety of Gram-positive and Gram-negative bacteria were grown in peptone (1%) yeast nitrogen base broth overnight in 96-well plates with various concentrations of glucose and insulin. Biofilm formation was determined by the crystal violet staining procedure. Expression of insulin binding was determined by fluorescent microscopy (FITC-insulin). Controls were buffer alone, insulin alone, and glucose alone.

RESULTS

Overall, maximal biofilm levels were measured at 220 mg/dL of glucose, regardless of insulin concentration (10, 100, 200 µU/mL) of the organism tested. In general, insulin with glucose over the range of 160-180 mg/dL exhibited a pattern of biofilm suppression. However, either above or below this range, the presence of insulin in combination with glucose significantly modulated (increase or decrease) biofilm formation in a microbe-specific pattern. This modulation appears for some organisms to be reflective of the glucose-regulated intrinsic expression of bacterial insulin receptor expression.

CONCLUSION

Insulin at physiologic levels (normal and hyperinsulinemic) in combination with glucose can affect biofilm formation in a concentration-specific and microbe-specific manner. These findings may provide insight into the importance of co-regulation of the insulin/glucose ratio in patient management.

Surviving Sepsis After Burn Campaign

INTRODUCTION

The Surviving Sepsis Campaign was developed to improve outcomes for all patients with sepsis. Despite sepsis being the primary cause of death after thermal injury, burns have always been excluded from the Surviving Sepsis efforts. To improve sepsis outcomes in burn patients, an international group of burn experts developed the Surviving Sepsis After Burn Campaign (SSABC) as a testable guideline to improve burn sepsis outcomes.

METHODS

The International Society for Burn Injuries (ISBI) reached out to regional or national burn organizations to recommend members to participate in the program. Two members of the ISBI developed specific "patient/population, intervention, comparison and outcome" (PICO) questions that paralleled the 2021 Surviving Sepsis Campaign [1]. SSABC participants were asked to search the current literature and rate its quality for each topic. At the Congress of the ISBI, in Guadalajara, Mexico, August 28, 2022, a majority of the participants met to create "statements" based on the literature. The "summary statements" were then sent to all members for comment with the hope of developing an 80% consensus. After four reviews, a consensus statement for each topic was created or "no consensus" was reported.

RESULTS

The committee developed sixty statements within fourteen topics that provide guidance for the early treatment of sepsis in burn patients. These statements should be used to improve the care of sepsis in burn patients. The statements should not be considered as "static" comments but should rather be used as guidelines for future testing of the best treatments for sepsis in burn patients. They should be updated on a regular basis.

CONCLUSION

Members of the burn community from the around the world have developed the Surviving Sepsis After Burn Campaign guidelines with the goal of improving the outcome of sepsis in burn patients.

Infections in Burn Patients

Infections are the leading cause of mortality in burn patients who survive their initial resuscitation. Burn injury leads to immunosuppression and a dysregulated inflammatory response which can have a prolonged impact. Early surgical excision along with support of the multidisciplinary burn team has improved mortality in burn patients. The authors review diagnostic and therapeutic challenges as well as strategies for management of burn related infections.

DIAGNOSTIC VALUE OF MITOCHONDRIAL DNA AND PERIPHERAL BLOOD MONONUCLEAR CELL RESPIROMETRY FOR BURN-RELATED SEPSIS

ABSTRACT

Background: Sepsis is the leading cause of mortality among burn patients that survive acute resuscitation. Clinical criteria have poor diagnostic value for burn-induced sepsis, making it difficult to diagnose. Protein biomarkers (e.g., procalcitonin) have been examined with limited success. We aimed to explore other biomarkers related to mitochondria (mitochondrial DNA [mtDNA]) and mitochondrial function of peripheral blood mononuclear cells (PBMCs) for sepsis diagnosis in burn patients. Methods: We conducted a follow-up analysis of a single center, prospective observational study of subjects (n = 10 healthy volunteers, n = 24 burn patients) to examine the diagnostic value of mtDNA and PBMC respirometry. Patients were enrolled regardless of sepsis status and followed longitudinally. Patient samples were classified as septic or not based on empiric clinical criteria. Isolated PBMCs were loaded into a high-resolution respirometer, and circulating mtDNA was measured with a PCR-based assay. Sequential Organ Failure Assessment (SOFA) criteria were also compared. Results: The SOFA criteria comparing septic versus before/nonseptic patients revealed significantly higher heart rate ( P = 0.012) and lower mean arterial pressure ( P = 0.039) in burn sepsis. MtDNA was significantly elevated in septic burn patients compared with healthy volunteers ( P < 0.0001) and nonseptic patients ( P < 0.0001), with no significant difference between healthy volunteers and nonseptic burn patients ( P = 0.187). The area under the ROC curve (AUC) for mtDNA was 0.685 (95% confidence interval = 0.50-0.86). For PBMC respirometry, burn patients exhibited increased routine and maximal respiration potential compared with healthy volunteers. However, no difference was found between nonseptic and septic patient samples. A subanalysis revealed a significant mortality difference in PBMC respirometry after sepsis diagnosis, wherein survivors had higher routine respiration ( P = 0.003) and maximal respiration ( P = 0.011) compared with nonsurvivors. Conclusion: Our findings reveal that mtDNA may have diagnostic value for burn sepsis, whereas PBMC respirometry is nonspecifically elevated in burns, but may have value in mortality prognosis. A larger, multisite study is warranted for further validity of the diagnostic value of mtDNA and PBMC respirometry as biomarkers for prognosis of sepsis and outcomes in burn patients.

The Complexity of the Post-Burn Immune Response: An Overview of the Associated Local and Systemic Complications

Burn injury induces a complex inflammatory response, both locally and systemically, and is not yet completely unravelled and understood. In order to enable the development of accurate treatment options, it is of paramount importance to fully understand post-burn immunology. Research in the last decades describes insights into the prolonged and excessive inflammatory response that could exist after both severe and milder burn trauma and that this response differs from that of none-burn acute trauma. Persistent activity of complement, acute phase proteins and pro- and anti-inflammatory mediators, changes in lymphocyte activity, activation of the stress response and infiltration of immune cells have all been related to post-burn local and systemic pathology. This "narrative" review explores the current state of knowledge, focusing on both the local and systemic immunology post-burn, and further questions how it is linked to the clinical outcome. Moreover, it illustrates the complexity of post-burn immunology and the existing gaps in knowledge on underlying mechanisms of burn pathology.

Validation of Sepsis-3 using survival analysis and clinical evaluation of quick SOFA, SIRS, and burn-specific SIRS for sepsis in burn patients with suspected infection

PURPOSE

Sepsis-3 is a life-threatening organ dysfunction caused by dysregulated host responses to infection; and defined using the Sepsis-3 criteria, introduced in 2016, however, the criteria need to be validated in specific clinical fields. We investigated mortality prediction and compared the diagnostic performance of quick Sequential Organ Failure Assessment (qSOFA), systemic inflammatory response syndrome (SIRS), and burn-specific SIRS (bSIRS) in burn patients.

METHODS

This single-center retrospective cohort study examined burn patients in Seoul, Korea during January 2010-December 2020. Overall, 1,391 patients with suspected infection were divided into four sepsis groups using SOFA, qSOFA, SIRS, and burn-specific SIRS.

RESULTS

Hazard ratios (HRs) of all unadjusted models were statistically significant; however, the HR (0.726, p = 0.0080.001) in the SIRS ≥2 group is below 1. In the adjusted model, HRs of the SOFA ≥2 (2.426, <0.001), qSOFA ≥2 (7.198, p<0.001), and SIRS ≥2 (0.575, p<0.001) groups were significant. The diagnostic performance of dichotomized qSOFA, SIRS, and bSIRS for sepsis was defined by the Sepsis-3 criteria. The mean onset day was 4.13±2.97 according to Sepsis-3. The sensitivity of SIRS (0.989, 95% confidence interval [CI]: 0.982-0.994) was higher than that of qSOFA (0.841, 95% CI: 0.819-0.861) and bSIRS (0.803, 95% CI: 0.779-0.825). Specificities of qSOFA (0.929, 95% CI: 0.876-0.964) and bSIRS (0.922, 95% CI: 0.868-0.959) were higher than those of SIRS (0.461, 95% CI: 0.381-0.543).

CONCLUSION

Sepsis-3 is a good alternative diagnostic tool because it reflects sepsis severity without delaying diagnosis. SIRS showed higher sensitivity than qSOFA and bSIRS and may therefore more adequately diagnose sepsis.

Recent advances in neutrophil chemotaxis abnormalities during sepsis

Sepsis remains one of the leading causes of death globally, in spite of advanced developments in intensive care and better understandings of pathophysiology related to sepsis. There is no special treatment or drug available for sepsis, currently. Under normal circumstances, neutrophil is a major player in acute infection control. However, during sepsis, the migration abilities and antimicrobial functions of neutrophils are impaired, resulting in a dysregulated immune response. Recent studies have indeed demonstrated that blocking or reversing neutrophil migration and impaired antibacterial function can improve the outcomes in septic animal models. This article systemically synthesized information regarding related factors and signaling involved in the functions of neutrophils in sepsis. This review also discussed the possibility that neutrophils be used as a marker for specific diagnosis and/or prediction of the outcomes of sepsis.

EVALUATING SEPSIS CRITERIA IN DETECTING ALTERATIONS IN CLINICAL, METABOLIC, AND INFLAMMATORY PARAMETERS IN BURN PATIENTS

ABSTRACT

Sepsis has become the leading cause of death in burn patients. Furthermore, sepsis and septic complications result in significant morbidities and longer hospitalization, which has profound impacts on the healthcare system. Despite this, sepsis in burn patients is surprisingly poorly understood and characterized. This retrospective, single-institution cohort study aimed to increase our understanding of the septic response after burns. We hypothesized that different sepsis definitions will results in distinctive septic trajectories and biochemical patterns after injury. Sepsis was defined by our burn center-specific prospective definition, the American Burn Association criteria, Sepsis-3 criteria, and the Mann-Salinas criteria. Applying these definitions, we compared clinical, metabolic, and inflammatory markers in septic and nonseptic burn patients. We found that the Sepsis-3 criteria are the most reliable screening tool used before clinical diagnoses for detecting sepsis trajectories and biochemical patterns. Moreover, we characterized distinct temporal alterations in biomarkers during the pre- and post-septic periods in burn patients, which may be incorporated into future sepsis definitions to improve the accuracy of a sepsis diagnosis in burn patients.

Specific patterns of vital sign fluctuations predict infection and enable sepsis diagnosis in pediatric burn patients

Early recognition of the clinical signs of bloodstream infection in pediatric burn patients is key to improving survival rates in the burn unit. The objective of this study was to propose a simple scoring criteria that used readily available temperature, heart rate (HR) and mean arterial pressure (MAP) data to accurately predict bloodstream infection in pediatric burn patients. A retrospective chart review included 100 patients admitted to the pediatric burn unit for >20% total body surface area (TBSA) burn injuries. Each patient had multiple blood culture tests, and each test was treated as a separate and independent “infection event” for analysis. The time at each blood culture draw was time 0 for that event, and temperature, HR and MAP data was collected for 24 hours after the blood culture was drawn. “Infection events” included in this study had at least six complete sets of temperature, HR and MAP data entries. Median temperature, HR and MAP, as well as mean fever spikes, HR spikes and MAP dips, were compared between infection group (positive blood cultures) and control group (negative blood cultures). These vital sign fluctuations were evaluated individually and as a combination of all three as timely predictors of bloodstream infection. In addition, we tested the prediction of Gram-negative bacteria versus Gram-positive or fungi present in blood cultures. Patients in the infection group had significantly higher median temperatures (p<0.001), mean fever spikes (p<0.001) and mean HR spikes (p<0.001), compared to the control group. Using the combination scoring criteria to predict bloodstream infection, the strongest predictive values in the 24-hour timeframe had high sensitivity (93%) and specificity (81%). The predictive test metric based on vital sign spikes predicted Gram-negative bacteria, but with limited sensitivity (57%) and specificity (44%). A simple scoring criteria using a combination of fever spikes, HR spikes and MAP dips predicted bloodstream infection in pediatric burn patients, and can be feasibly implemented in routine clinical care. There is also potential to use the predictive metric to detect a few select organisms based on vital signs, however further work is necessary to enhance accuracy to levels that would allow consideration for clinical use.

Burn Wound Healing: Clinical Complications, Medical Care, Treatment, and Dressing Types: The Current State of Knowledge for Clinical Practice

According to the World Health Organization (WHO), it is estimated that each year approximately 11 million people suffer from burn wounds, 180,000 of whom die because of such injuries. Regardless of the factors causing burns, these are complicated wounds that are difficult to heal and are associated with high mortality rates. Medical care of a burn patient requires a lot of commitment, experience, and multidirectional management, including surgical activities and widely understood pharmacological approaches. This paper aims to comprehensively review the current literature concerning burn wounds, including classification of burns, complications, medical care, and pharmacological treatment. We also overviewed the dressings (with an emphasis on the newest innovations in this field) that are currently used in medical practice to heal wounds.

A Prospective Observational Study Comparing Clinical Sepsis Criteria to Protein Biomarkers Reveals a Role for Vascular Dysfunction in Burn Sepsis

OBJECTIVES

To compare the diagnostic value of clinical sepsis criteria to novel protein biomarkers in the burn patient.

DESIGN

Prospective observational study.

SETTING

American Burn Association verified Burn Center ICU.

PATIENTS

Burn patients (n = 24) and healthy volunteers (n = 10).

INTERVENTIONS

Enrolled burn patients (n = 24) were stratified based on whether or not they met a clinical definition of sepsis. Four separate clinical criteria for sepsis were analyzed for their diagnostic sensitivity and specificity, which were compared to a panel of protein biomarkers. The most significant protein biomarkers were further analyzed via the area under the receiver operating characteristic curves (AUROCs).

MEASUREMENTS AND MAIN RESULTS

Of the clinical criteria, SEPSIS-2 criteria led to the highest AUROC (0.781; p < 0.001), followed by the quick Sequential Organ Failure Assessment score (AUROC = 0.670; p = 0.022). Multiplexing revealed a number of inflammatory proteins (complement C5) and matrix metalloproteinases (MMP1, MMP7) that were significantly elevated in septic samples compared with both healthy controls and nonseptic burn samples. Furthermore, three proteins associated with endothelial dysfunction and glycocalyx shedding revealed diagnostic potential. Specifically, syndecan-1, p-selectin, and galectin-1 were all significantly elevated in sepsis, and all resulted in an AUROC greater than 0.7; analyzing the sum of these three markers led to an AUROC of 0.808.

CONCLUSIONS

These data reveal several potential biomarkers that may help with sepsis diagnosis in the burn patient. Furthermore, the role of endotheliopathy as a mechanistic etiology for sepsis after burns warrants further investigation.

Evolving Applications of Artificial Intelligence and Machine Learning in Infectious Diseases Testing

Background

Artificial intelligence (AI) and machine learning (ML) are poised to transform infectious disease testing. Uniquely, infectious disease testing is technologically diverse spaces in laboratory medicine, where multiple platforms and approaches may be required to support clinical decision-making. Despite advances in laboratory informatics, the vast array of infectious disease data is constrained by human analytical limitations. Machine learning can exploit multiple data streams, including but not limited to laboratory information and overcome human limitations to provide physicians with predictive and actionable results. As a quickly evolving area of computer science, laboratory professionals should become aware of AI/ML applications for infectious disease testing as more platforms are become commercially available.

Content

In this review we: (a) define both AI/ML, (b) provide an overview of common ML approaches used in laboratory medicine, (c) describe the current AI/ML landscape as it relates infectious disease testing, and (d) discuss the future evolution AI/ML for infectious disease testing in both laboratory and point-of-care applications.

Summary

The review provides an important educational overview of AI/ML technique in the context of infectious disease testing. This includes supervised ML approaches, which are frequently used in laboratory medicine applications including infectious diseases, such as COVID-19, sepsis, hepatitis, malaria, meningitis, Lyme disease, and tuberculosis. We also apply the concept of “data fusion” describing the future of laboratory testing where multiple data streams are integrated by AI/ML to provide actionable clinical knowledge.

Sepsis in Burns-Lessons Learnt from Developments in the Management of Septic Shock

After surviving the acute phase of resuscitation, septic shock is the cause of death in the majority of burn patients. Therefore, the management of septic shock is a cornerstone in modern burn care. Whereas sepsis therapy in general has undergone remarkable developments in the past decade, the management of septic shock in burn patients still has a long way to go. Instead, the differences of burn patients with septic shock versus general patients have been emphasized and thus, burn patients were excluded in every sepsis study which are the basis for modern sepsis therapy. However, due to the lack of evidence in burn patients, the standards of procedure for general sepsis therapy have been adopted in burn care. This review identifies the differences of burn patients with sepsis versus other septic patients and summarizes the scientific basis for modern sepsis therapy in general ICU patients and burn patients. Consequently, the results in general sepsis research should be transferred to burn care, which means the implementation of effective screening, early resuscitation, and efficient antimicrobial treatment. Therefore, on the basis of past developments and in the light of the current update of the Surviving Sepsis Campaign guidelines, this review introduces the "Burn SOFA score" and the "3 H's of burn sepsis" as a screening tool for early sepsis recognition in burn patients.

Application of mNGS to describe the clinical and microbial characteristics of severe burn a tanker explosion at a tertiary medical center: a retrospective study patients following

Background

Multiple organ dysfunction syndrome secondary to infection is the leading cause of death in burn patients. Bloodstream infection (BSI) and the prognosis of burn patients are negatively correlated. Metagenomic next-generation sequencing (mNGS) can detect many potential pathogens and may be more valuable for patients with severe burns.

Methods

We retrospectively explored the utility of mNGS in describing the clinical and microbial characteristics of severely burned patients with BSI. We compared mNGS with blood culture.

Results

Fourteen patients (127 blood samples) developed 71 episodes of BSIs with 102 unique causative pathogens. The median total body surface area was 93%. The overall 90-day mortality was 43%. In total, 17 (23.9%) episodes were polymicrobial, and 61 (86.1%) episodes originated from the wound. In total, 62/71 cases (87%) showed positive findings by mNGS, while 42/71 cases (59%) showed positive findings using blood culture. We found that mNGS outperformed culture, especially in terms of fungi (27% vs. 6%, p < 0.0001).

Conclusions

The incidence of BSI and polymicrobial in patients with large-area severe burns is high. mNGS has potential value in the diagnosis of fungal infections and coinfections in such patients. In addition, mNGS may provide unique guidance for antibiotic therapy in complicated BSI.

Incidence and Time Point of Sepsis Detection as Related to Different Sepsis Definitions in Severely Burned Patients and Their Accompanying Time Course of Pro-Inflammatory Biomarkers

Background: Diagnosis of sepsis in burn patients remains difficult for various reasons. One major problem is the definition of sepsis itself. Therefore, previous and current sepsis definitions are a matter of ongoing validation, but a well-defined consensus on which clinical and laboratory parameters to incorporate in such a definition is lacking. The aim of the present study was to compare the incidence and time-related occurrence of septic events according to different definitions as well as their accompanying time course of pro-inflammatory biomarkers. Methods: Across the first 14 days after admission, the incidence and time point of sepsis according to three different definitions (Sepsis-3, Sepsis American Burns Association [ABA] 2007, Sepsis Zurich Burn Center) were assessed on a daily basis in adult burn patients with total body surface area (TBSA) ≥15% admitted to the Zurich Burn Center between May 2015 and October 2018. In order to investigate how well daily drawn proinflammatory biomarkers (white blood cells (WBCs), C-reactive protein (CRP), procalcitonin (PCT), and novel pancreatic stone protein (PSP)) reflect the progression of sepsis depending on its type of definition, a longitudinal mixed model analysis was performed across the first 14 days for septic and non-septic patients. Additionally, the relative increase of biomarker levels 24, 48, and 72 h prior to a septic event was analyzed for each definition used. Results: In our cohort of 90 severely burned patients, Sepsis-3 identified 46 patients (51.1%) as septic, while ABA 2007 and the Zurich Burn Center definition counted 33 patients (36.7%) and 24 patients (26.6%), respectively. Sepsis-3 detected sepsis about 1 day earlier than Sepsis ABA 2007 (p < 0.001) and about 0.5 days earlier than Sepsis Zurich Burn Center (p = 0.04). The course of pro-inflammatory biomarkers was largely unaffected by the type of sepsis definition. Irrespective of the sepsis definition, PSP was the only marker to demonstrate a highly significant interaction between time and group (sepsis versus no sepsis) (p < 0.001) with a 3.3–5.5-fold increase within 72 h before the event of sepsis, whereas CRP, PCT, and WBC showed only mild undulations. Conclusions: Despite the ongoing dilemma of how to define sepsis in burn patients, a continually calculated SOFA score as used in Sepsis-3 is advantageous to early identify a patient’s detrimental progression to sepsis. Inclusion of biomarkers, such as PSP, may help support the burn specialist’s diagnosis of sepsis and could improve the diagnostic performance of current and future definitions in burn patients.

Development and validation of a screening tool for early identification of bloodstream infection in acute burn injury patients

BACKGROUND

Standard diagnostic criteria are not useful for identifying bloodstream infection in patients with an acute burn injury patients. The study objective was to develop and validate a tool using common laboratory, clinical, and patient parameters for early identification of bloodstream infection after acute burn injury (within 10 days after a burn).

METHODS

We retrospectively and prospectively reviewed for tool development the hospital course of patients with an acute burn injury (n = 156) and validated the tool in different cohorts (retrospective [n = 26] and prospective [n = 90]). The Pearson correlation identified independent variables associated with bloodstream infection (P < .1) in the development cohort that were then analyzed using binary logistic regression to identify the simplest model (P < .05; adjusted odds ratio >1). Classification and regression tree analysis was used to identify tool parameter breakpoints. Performance metrics were completed to evaluate and validate the tool.

RESULTS

The best model (P < .05) was: Ln [odds of bloodstream infection] = -96.749 + 3.230 (platelet volatility) + 2.235 (max temperature [°C]) + 0.339 (% full burn) + 0.242 (% partial burn) + 0.045 (max heart rate [bpm]), with a threshold probability categorizing bloodstream infection of >48%. The sensitivity, specificity, accuracy, false positive rate, false negative rate, and positive (+) and negative (-) likelihood ratios of the tool in the developmental cohort (n = 156) were 89%, 98%, 96%, 2%, 11%, 53, and 0·11, respectively; and in the prospective validation cohort (n = 90 were 91%, 90%, 90%, 10%, 9%, 9, and 0·1, respectively (n = 90).

CONCLUSION

The validated bloodstream infection screening tool in patients with acute burn injury has excellent predictive ability to assist in the identification of patients for whom blood cultures should be requested.

Outcomes prediction in longitudinal data: Study designs evaluation, use case in ICU acquired sepsis

Outcomes' prediction in Electronic Health Records (EHR) and specifically in Critical Care is increasingly attracting more exploration and research. In this study, we used clinical data from the Intensive Care Unit (ICU), focusing on ICU acquired sepsis. Looking at the current literature, several evaluation approaches are reported, inspired by epidemiological designs, in which some do not always reflect real-life application's conditions. This problem seems relevant generally to outcomes' prediction in longitudinal EHR data, or generally longitudinal data, while in this study we focused on ICU data. Unlike in most previous studies that investigated all sepsis admissions, we focused specifically on ICU-Acquired Sepsis. Due to the sparse nature of the longitudinal data, we employed the use of Temporal Abstraction and Time Interval-Related Patterns discovery, which are further used as classification features. Two experiments were designed using three different outcomes prediction study designs from the literature, implementing various levels of real-life conditions to evaluate the prediction models. The first experiment focused on predicting whether a patient would suffer from ICU-acquired sepsis and when during her admission, given a sliding observation time window, and the comparison of the three study designs behavior. The second experiment focused only on predicting whether the patient will suffer from ICU-acquired sepsis, based on data taken relatively to his admission start time. Our results show that using Temporal Discretization for Classification (TD4C) led to better performance than using the Equal-Width Discretization, Knowledge-Based, or SAX. Also, using two states abstraction was better than three or four. Using the default Binary TIRP representation method performed better than Mean Duration, Horizontal Support, and horizontally normalized horizontal support. Using XGBoost as a classifier performed better than Logistic Regression, Neural Net, or Random Forest. Additionally, it is demonstrated why the use of case-crossover-control is most appropriate for real life application conditions evaluation, unlike other incomplete designs that may even result in "better performance".

Variations in insulin requirements can be an early indicator of sepsis in burn patients

INTRODUCTION

A >25% increase in daily insulin dosing is suggestive of possible sepsis in burn patients, however, no conclusive evidence is available regarding the time point at which insulin dosing begins to increase. The purpose of this study is to determine the exact time point at which the insulin requirement increases among non-diabetic burn patients with sepsis.

METHODS

A retrospective chart review in non-diabetic burn patients with ≥20% total body surface area burned (TBSA) during 2010-2018 who received a blood culture for suspected sepsis. Absolute insulin dosing at intervals (0, 24, 48, 72, and 96 h prior to blood culture) were Box-Cox transformed and compared vs.-96 h reference using mixed-effects models accounting for within-patient dependencies.

RESULTS

Fifty-eight patients (84% males, age 44 ± 17 years, TBSA% 49 ± 17.5) were included. When cube root of daily insulin dosing was regressed on each time point in a mixed-effects model, statistically significant increase in insulin dosing compared to baseline was observed for -48 (p = 0.018), -24 (p = 0.011), and 0 h (p = 0.008).

CONCLUSION

Daily insulin dosing increases 48 h prior to development of other clinical signs of sepsis and can be used as a sensitive early marker.

The pathogenesis and diagnosis of sepsis post burn injury

Burn is an under-appreciated trauma that is associated with unacceptably high morbidity and mortality. Although the survival rate after devastating burn injuries has continued to increase in previous decades due to medical advances in burn wound care, nutritional and fluid resuscitation and improved infection control practices, there are still large numbers of patients at a high risk of death. One of the most common complications of burn is sepsis, which is defined as “severe organ dysfunction attributed to host's disordered response to infection” and is the primary cause of death in burn patients. Indeed, burn injuries are accompanied by a series of events that lead to sepsis and multiple organ dysfunction syndrome, such as a hypovolaemic state, immune and inflammatory responses and metabolic changes. Therefore, clear diagnostic criteria and predictive biomarkers are especially important in the prevention and treatment of sepsis and septic shock. In this review, we focus on the pathogenesis of burn wound infection and the post-burn events leading to sepsis. Moreover, the clinical and promising biomarkers of burn sepsis will also be summarized.

Review of Sepsis in Burn Patients in 2020

Background: Severe burn injury results in substantial damage to the skin, inhibiting its ability to perform as the primary barrier to infection. Additionally, severe burn injury can lead to critical illness and extensive time in the intensive care unit (ICU). These two factors work to increase the risk of sepsis in the burn patient compared with other hospitalized patients. The increased risk of sepsis is compounded by the difficulty of diagnosing sepsis in severely burned patients because the pathophysiology of large burns mimics sepsis, leading to possible delay in diagnosis and initiation of treatment. Methods: A literature review was performed to discuss and review the diagnostic difficulties and criteria used to identify patients with sepsis. Additionally, the most current management of sepsis was reviewed and described in caring for burn patients with sepsis. Results: The incidence of sepsis in patients with more than 20% total body surface area (TBSA) burns is between 3% and 30% and is the most common cause of death in the burn patient, with pneumonia being the most common etiology. Several different diagnostic criteria for diagnosing sepsis in burn patients exist, however, none of these criteria have proven to be superior to clinical diagnosis by an experienced burn surgeon. As with sepsis in other patient populations, prompt diagnosis, initiation of antibiotic agents, and source control remain the standard management of sepsis in the burn patient. Conclusions: Because of the loss of the primary infection barrier function of the skin after a substantial burn injury, this patient population is at increased risk for sepsis. Because of the pathophysiology of burn injuries, diagnosing sepsis in the burn population remains challenging. Understanding the most common etiologies of sepsis in burn patients may help with more expedient diagnosis and initiation of treatment.

Burn Wound Colonization, Infection, and Sepsis

Background: Infection is a major cause of morbidity and mortality among burn patients, and it is important to understand the progression of wound colonization to wound infection to systemic sepsis. Methods: After a review of the literature we describe the clinical characteristics of burn wound colonization, infection, and sepsis, and conclude with best practices to decrease these complications. Results: Burn wounds are initially sterile after the thermal insult but become colonized by gram-positive organisms and subsequently by gram-negative organisms. Some populations are especially susceptible to initial or subsequent colonization by drug-resistant organisms. An increase in fungal colonization has been observed because of the widespread use of topical antibiotic agents. Male gender, older age, lower extremity burn, scald burn, full-thickness burn, delay in treatment, and pre-existing diabetes place patients at increased risk of infection. These infections range from cellulitis that requires systemic antibiotic agents, to invasive burn wound infection that requires prompt treatment with antibiotic agents and excision. Fungal wound infections pose a special challenge and cause substantial morbidity. Infection that leads to systemic sepsis is difficult to define in burn patients because of the body's compensatory hypermetabolic response to the burn injury. Potential sources of sepsis include wound infections and common nosocomial infections. The American Burn Association Sepsis criteria, defined in 2007, has demonstrated poor specificity for identifying sepsis and septic shock. The best approach to decrease wound infections is prevention. Practices that have been beneficial include isolation rooms, handwashing, appropriate wound care, early excision and grafting, antibiotic stewardship, and nutritional support. Conclusions: A burn patient remains at a substantial risk of wound infection despite advances in care. A burn care provider must understand the natural progression of colonization to infection to sepsis, and the multidisciplinary approach to wound care to limit the morbidity and mortality from these infectious.

Sepsis Definitions in Burns

Background: Sepsis is the leading cause of death in burns. Despite its importance, sepsis lacks a proper definition. An established definition will lead to early and accurate diagnosis, prompt treatment, and a reduced mortality rate. The aim of this work is to discuss current definitions and to look ahead at novel definitions with clinical implications. Method: A review of the current understanding of sepsis definitions in burns. Results: Adaptation of sepsis definitions in the general population and specific burn definitions have gotten better but still need improvements and, potentially, incorporation of molecular, laboratory, patient-specific, and clinical factors. This work includes the history, evolution, and predictive value of current definitions of sepsis in burns. A review of current and future markers of sepsis and potentially useful definitions are presented. Conclusions: Sepsis definitions have evolved over the last decades and will continue to do so. We believe the best definition in burn patients is the Sepsis-3 that was developed originally for critically ill patients. However, there are several studies investigating more specific definitions with better sensitivity and specificity.

Detection of Infection and Sepsis in Burns

Background: Infection is the most frequent complication after severe burns and has a propensity to progress into sepsis then septic shock and multiple organ dysfunction syndrome (MODS). Improving outcomes in acute burn care depends on early detection of infection to allow prompt interventions. Diagnosis of sepsis in severe burns is uniquely challenging because otherwise-typical clinical signs are masked by the hypermetabolic state and systemic inflammation induced by the burn itself. For this reason, burns have historically been excluded from high-impact studies on the diagnosis and treatment of sepsis. Methods: This article provides a comprehensive three-fold review of current findings and guidelines pertinent to the early detection of infection and sepsis in severe burns. Results: First, evidence-based detection of the most common infections encountered in the burn intensive care unit is reviewed. Second, we analyze the evolution of the diagnostic criteria for sepsis and the evidence regarding their utility in severe burns. Last, we examine the development of biomarkers, from procalcitonin to molecular genomics, for the detection of sepsis. Conclusions: Although gold standard methods of early detection of sepsis in burn patients have yet to be identified, improved understanding and appropriate application of the available diagnostic criteria and assays are paramount to providing effective care of patients with severe burns.

Outcomes in Burn-Injured Patients Who Develop Sepsis

This study examines health outcomes in burn patients with sepsis. We hypothesized that burn patients with sepsis would have an increased odds risk for in-hospital death and longer intensive care unit (ICU) stays. This was a retrospective cohort of consecutive patients admitted to the burn ICU with total BSA (TBSA) ≥10% and/or inhalation injury between January 2008 and March 2015. Overall 407 burn patients were included; the case-rate for sepsis was 39.1% (n = 159); 20.1% (n = 82) patients were septic and 18.9% (n = 77) patients experienced septic shock. Patients with septic shock had the highest mortality rate (13.31% no sepsis vs 3.7% sepsis vs 49.4% septic shock, P < .01). Median 28-day ICU-free days was higher in patients without sepsis (23 days [Interquartile range (IQR) 14-27] no sepsis vs 0 days [IQR 0-10] sepsis vs 0 days [IQR 0-0] septic shock, P < .01). Sepsis (with or without shock) increased odds of in-hospital death (odds ratio 7.04, 95% confidence interval 1.93-25.7) in reference to the no sepsis group. With each incremental Sequential Organ Failure Assessment (SOFA) score or 10% TBSA increase, the odds risk for in-hospital death increased by 56 and 75%, respectively. Our study characterized outcomes in patients with sepsis after severe burn injury. The odds risk for in-hospital death was greater in patients with sepsis, increasing burn severity according to TBSA and SOFA score.

Novel application of an automated-machine learning development tool for predicting burn sepsis: proof of concept

Sepsis is the primary cause of burn-related mortality and morbidity. Traditional indicators of sepsis exhibit poor performance when used in this unique population due to their underlying hypermetabolic and inflammatory response following burn injury. To address this challenge, we developed the Machine Intelligence Learning Optimizer (MILO), an automated machine learning (ML) platform, to automatically produce ML models for predicting burn sepsis. We conducted a retrospective analysis of 211 adult patients (age ≥ 18 years) with severe burn injury (≥ 20% total body surface area) to generate training and test datasets for ML applications. The MILO approach was compared against an exhaustive “non-automated” ML approach as well as standard statistical methods. For this study, traditional multivariate logistic regression (LR) identified seven predictors of burn sepsis when controlled for age and burn size (OR 2.8, 95% CI 1.99–4.04, P = 0.032). The area under the ROC (ROC-AUC) when using these seven predictors was 0.88. Next, the non-automated ML approach produced an optimal model based on LR using 16 out of the 23 features from the study dataset. Model accuracy was 86% with ROC-AUC of 0.96. In contrast, MILO identified a k-nearest neighbor-based model using only five features to be the best performer with an accuracy of 90% and a ROC-AUC of 0.96. Machine learning augments burn sepsis prediction. MILO identified models more quickly, with less required features, and found to be analytically superior to traditional ML approaches. Future studies are needed to clinically validate the performance of MILO-derived ML models for sepsis prediction.

Burn Infection and Burn Sepsis

Background: Infection is the most common complication and cause of death in patients suffering burn injuries. These patients are susceptible to infection and burn wound sepsis secondary to the alterations in their physiology. Diagnosis and management of infections rely on physical examination, cultures, and the pathology of the burn wound. Method: We performed an electronic search for articles in the Google Scholar and PubMed databases using the search terms "burn sepsis," "burn infection," and "burn critical care." Results: Multiple factors increase burn patients' risk of invasive infection and sepsis, including underlying factors and co-morbidities, the percent total body surface area of the burn, delays in burn wound excision, and microbial virulence/bacterial count. Organisms causing burn wound infection differ, depending on the time since injury and its location; and diagnosis is multi-factorial. The most common pathogens remain Staphylococcus and Pseudomonas spp. Conclusion: Overall, the recognition of burn sepsis is based on clinical findings. Treatment consists of a combination of local dressings, early burn excision, and systemic antimicrobial therapy. The mortality rate has decreased significantly over the past 10 years, but continued efforts at timely management and infection prevention are essential.

Predictive value of quick SOFA and revised Baux scores in burn patients

Several scoring systems, such as the Baux score, help predict outcomes in burn patients. The quick Sequential Organ Failure Assessment (qSOFA) score (composed of a respiratory rate of 22/min or greater, systolic blood pressure of 100 mmHg or less, and altered mental status) is a new bedside index proposed to help identify patients with suspected infection at risk of complications. We hypothesized that qSOFA scores would be associated with in-hospital mortality, ICU admission, and length of stay (LOS) in patients with burns. We performed a retrospective review of all burn patients admitted between January 2010-March 2017 at an academic, suburban, hospital with a regional burn center. qSOFA scores were calculated as 1 point each for GCS<15, RR≥22, and SBP≤100. A qSOFA value of>2 was considered high risk. Revised Baux (rBaux) scores were calculated as age +%TBSA burned +17 (if inhalation injury). A rBaux score >140 was considered high risk. Univariate, multivariate and receiver operating characteristics analyses were performed to compare qSOFA and rBaux scores. There were 1039 burn admissions during the study period. Mean age was 30 ± 24 years, 66% were male. Mean TBSA was 10 ± 12%, mean injury severity score was 5 ± 8. Mean hospital LOS was 8 ± 24 days, 22 patients (2.1%) died. qSOFA scores were associated with mortality and ICU admission. Of all patients, 80 were high risk by qSOFA and 7 by Baux scores. ROC characteristics of qSOFA and Baux scores for predicting death were sensitivity 36% vs. 32%, specificity 94% vs. 100%, PPV 13% vs. 100%, and NPV 98% vs. 99% respectively. The AUC for qSOFA (0.68 [95% CI, 0.54-0.81]) was lower than for Baux (0.99 [95%CI, 0.99-1.00]). Youden's index identified an optimal cutoff of 85 on the Baux score yielding sensitivity 100%, specificity 94%, PPV 27%, and NPV 100% for mortality. Our results indicate that while qSOFA scores were associated with outcomes, a rBaux score had greater predictive value. The optimal rBaux score for predicting all mortality and ICU admission was 85.

Impact of insufficient admission vitamin D serum concentrations on sepsis incidence and clinical outcomes in patients with thermal injury

INTRODUCTION

In burn patients, vitamin D has been studied primarily in the pediatric population and focused mainly on the correlation with bone marker measurements and incidence of fractures. There is an association between vitamin D deficiency and the development of sepsis in non-burn critically-ill patients. However, there is limited data on vitamin D concentrations and clinical outcomes in burn patients, such as sepsis. The objective of this study is to evaluate the impact of vitamin D concentrations on the incidence of sepsis in adult burn patients.

METHODS

This was a retrospective cohort of patients 18 years of age and older admitted between February 1, 2016 and February 28, 2018 to an American Burn Association (ABA) verified burn center with diagnosis of burn injury. The primary endpoint was incidence of sepsis using the ABA 2007 Sepsis Consensus Criteria between patients with adequate vitamin D concentrations (25[OH]D > 20 ng/mL) and insufficient vitamin D (25[OH]D < 20 ng/mL) concentrations measured on admission. Descriptive statistics were used for baseline demographics. Univariate analysis was conducted using Chi-square, Fisher's exact test or Mann-Whitney U test, as appropriate.

RESULTS

A total of 115 patients were screened and 107 patients were included in this study. Sixty three patients (58.9%) had insufficient vitamin D concentrations. Patient demographics were overall similar between groups. The median total body surface area burned was 14.6% in the insufficient vitamin D group, and 12.1% in the adequate vitamin D group (p = 0.2). There was a trend towards greater incidence of sepsis in the insufficient vitamin D group in the univariate analysis (15.9% vs. 4.5%, p = 0.07). The multivariable logistic regression analysis found that adequate vitamin D concentrations was associated with a reduction in the incidence of sepsis (OR 0.10, 95% CI 0.01-0.88). The insufficient vitamin D group had a longer median hospital LOS (19 [IQR 11-37] vs 11.5 [IQR 7-20] days, p < 0.05), longer intensive care unit LOS (17 [IQR 10-37] vs 5 [IQR 2-19.5] days, p < 0.05) and fewer ventilator free days (26 [IQR 18-28] vs 28 [IQR 27-28] days, p < 0.05). There was no difference in mortality between groups (p = 0.69).

CONCLUSIONS

Patients with adequate vitamin D concentrations on admission had a reduction in the incidence of sepsis as compared to patients with insufficient vitamin D concentrations. Insufficient vitamin D concentrations may contribute to other worsened clinical outcomes in burn patients. Our findings set the stage for future, multicenter studies to determine the role of vitamin D supplementation in burn patients.

Management and prevention of drug resistant infections in burn patients

Introduction: Despite modern advances, the primary cause of death after burns remains infection and sepsis. A key factor in determining outcomes is colonization with multi-drug resistant (MDR) organisms. Infections secondary to MDR organisms are challenging due to lack of adequate antibiotic treatment, subsequently prolonging hospital stay and increasing risk of adverse outcomes. Areas covered: This review highlights the most frequent organisms colonizing burn wounds as well as the most common MDR bacterial infections. Additionally, we discuss different treatment modalities and MDR infection prevention strategies as their appropriate management would minimize morbidity and mortality in this population. We conducted a search for articles on PubMed, Web of Science, Embase, Cochrane, Scopus and UpToDate with applied search strategies including a combination of: "burns, 'thermal injury,' 'infections,' 'sepsis,' 'drug resistance,' and 'antimicrobials.' Expert opinion: Management and prevention of MDR infections in burns is an ongoing challenge. We highlight the importance of preventative over therapeutic strategies, which are easy to implement and cost-effective. Additionally, targeted, limited use of antimicrobials can be beneficial in burn patients. A promising future area of investigation within this field is post-trauma microbiome profiling. Currently, the best treatment strategy for MDR in burn patients is prevention.

Surgical Evaluation of Flame Burn Injuries in Syrian Civilians

The aim of the current study was to evaluate the severity and location of flame burns and the mortality rate of civilians affected by these in the Syrian Civil War and to present the surgical treatment outcomes of the injured civilians to be able to provide recommendations. This was a prospective hospital-based observational cohort study involving 573 patients with data collected from 2011 to 2018. All of these patients were Syrian civilians, and their flame burn injuries were related to the Syrian conflict. All burns were divided into four subgroups according to TBSA and compared. The groups of TBSA were compared as 0 to 25% (n = 97), 25 to 50% (n = 257), 50 to 75% (n = 135), and >75% (n = 84) (P = .413). Almost all had a second (n = 331; 57.7%) and third (n = 189; 32.9%) degree deep burns. The median burn size was 47% TBSA in the patients. The burn mechanism was mostly the flame type of burn (n = 467; 81.5%) as a result of fuel oil explosions, followed by bomb-related burns (n = 106; 18.5%) (P < .001). Mortality was seen in 223 (39%) due to the high surface area and reaching hospital too late at 1 to 8 days (P = .187). The findings of this study indicate that war-related flame burns result in an extremely high mortality rate and time is lost, which could protect against life-threatening outcomes.

Survival analysis and mortality predictors of hospitalized severe burn victims in a Malaysian burns intensive care unit

Background

Prognostic measures to determine burn mortality are essential in evaluating the severity of individual burn victims. This is an important process of triaging patients with high risk of mortality that may be nursed in the acute care setting. Malaysian burn research is lacking with only one publication identified which describes the epidemiology of burn victims. Therefore, the objective of this study was to go one step further and identify the predictors of burn mortality from a Malaysian burns intensive care unit (BICU) which may be used to triage patients at higher risk of death.

Methods

This is a retrospective cohort study of all admissions to Hospital Sultan Ismail’s BICU from January 2010 till October 2015. Admission criteria were in accordance with the American Burn Association guidelines, and risk factors of interest were recorded. Data was analyzed using simple logistic regression to determine significant predictors of mortality. Survival analysis with time to death event was performed using the Kaplan-Meier survival curve with log-rank test.

Results

Through the 6-year period, 393 patients were admitted with a male preponderance of 73.8%. The mean age and length of stay were 35.6 (±15.72) years and 15.3 (±18.91) days. There were 48 mortalities with an overall mortality rate of 12.2%. Significant risk factors identified on simple logistic regression were total body surface area (TBSA) > 20% (p < 0.001), inhalation injury (p < 0.001) and presence of early systemic inflammatory response syndrome (SIRS) (p < 0.001). Survival analysis using Kaplan-Meier survival curve showed similar results with TBSA > 20%, presence of SIRS, mechanical ventilation and inhalation injury which were associated with poorer survival (p < 0.001).

Conclusion

The predictors of mortality identified in a Malaysian BICU were TBSA > 20%, early SIRS, mechanical ventilation and inhalation injury which were associated with poorer survival outcome. The immunological response differs from individual patients and influenced by the severity of burn injury. Early SIRS on admission is an important predictor of death and may represent the severity of burn injury. Patients who required mechanical ventilation were associated with mortality and it is likely related to the severity of pulmonary insults sustained by individual patients. This data is important for outcome prognostication and mortality risk counselling in severely burned patients.

Optimization of an empiric vancomycin dosing algorithm for improved target concentration attainment in patients with thermal injury

OBJECTIVE

Vancomycin empirical dosing studies in thermally injured patients have netted low successful target attainment and most excluded renal dysfunction, limiting applicability. In a previous study, the authors performed a retrospective analysis of 124 patients' measured pharmacokinetic parameters to calculate optimal dose and interval for intermittent infusion regimens and find predictors of clearance and total daily dose. The objective of this study was to improve the accuracy of attaining goal therapeutic targets with initial vancomycin regimens in patients with thermal injury through retrospective modeling.

METHODS

In this phase 2 study, variables collected and calculated regimens in phase 1 were utilized to try and create an improved empiric vancomycin dosing algorithm in patients with thermal injury. Logistic regression was utilized to determine best predictors of dosing vancomycin every 6 and 8h. The strongest models were built as individual algorithms and tested for accuracy of target attainment. Each algorithm produced a regimen for each patient that was then tested utilizing each patient's actual measured pharmacokinetic parameters.

RESULTS

Univariable logistic regression of 41 variables identified 27 and 23 to be predictive of dosing every 8 or 6h, respectively. The most predictive multivariable model for dosing every 8h consisted of creatinine clearance (CrCl)≥80ml/min, Acute Kidney Injury Network classification <1, and total body surface area burned≥10 percent. For dosing every 6h, CrCl≥80ml/min, age≤40years old, days since injury≤6, and serum creatinine (SCr)≤0.8 were most predictive. Based on the top 5 multivariable models for each dosing interval, 7 algorithms were built to produce recommended regimens. The highest performing algorithm resulted in trough concentrations of <10mg/L (23%), 10-20mg/L (65%), 15-20mg/L (26%), and >20mg/L (11%); area under the concentration curve (AUC)>400mghr/L (83%); and AUC >400mghr/L without having a trough >20mg/L (72%).

CONCLUSIONS

The algorithm that resulted in the highest target attainment without overdosing recommended 15mg/kg dosed every 24h for CrCl≥30, every 12h for CrCl 31-79, every 8h for patients with CrCl≥80ml/min, and every 6h only if the patient with a CrCl≥80ml/min is also≤40 years old and has a SCr≤0.8. Caution is warranted for groups underrepresented in this study, such as those with very low CrCl, a low BMI, or receiving renal replacement therapy. This algorithm should be validated in other centers for patients with thermal injuries.

Sepsis criteria versus clinical diagnosis of sepsis in burn patients: A validation of current sepsis scores

BACKGROUND

Sepsis remains an ongoing diagnostic challenge in burns, especially with the signs of sepsis being ubiquitously present during the acute period after injury. We aimed to determine the predictive validity of 3 current sepsis criteria in the burn population. The criteria of interest included the American Burn Association sepsis criteria, Mann-Salinas et al predictors of sepsis, and the Sepsis-3 consensus definition.

METHODS

Adult patients with an acute burn injury who were diagnosed prospectively with sepsis by the burn team using specific clinical markers were included in this cohort study. Sepsis predictors were collected from patient charts and used to calculate the results of the 3 criteria, then subsequently compared to the clinical diagnosis.

RESULTS

Of the 418 patients in the study, which took place from 2000 until 2016, 88 (21%) were septic; the mean age was 50 ± 18 years with a mean percent total body surface area burn of 30% ± 17%. Inhalation injury was present in 50%, median length of stay was 49 (29-71) days, and mortality was 19%. The American Burn Association, Mann-Salinas, and Sepsis-3 criteria were positive in 59%, 28%, and 85% respectively, P < .05. The most reliable predictors included increased oxygen requirements, altered mental status, hypothermia, hyperthermia, tachycardia, and hypotension.

CONCLUSION

The Sepsis-3 criteria was the most predictive, followed by the American Burn Association and Mann-Salinas criteria. However, no criterion alone had the accuracy to be a diagnostic standard within this burn population. We recommend sepsis is clinically assessed, diagnosed, and documented prospectively by the burn team, and not by the application of retrospective criteria.

Sepsis in the Burn Patient

Sepsis is the leading cause of death in burn patients. Interventions are challenging owing to a lack of specific guidelines. All burn types involve a risk for complications. Interventions should include care of the burn, medication administration, continuous monitoring for infection development, infection prevention measures, and (if necessary) treatment of sepsis. Sepsis in burn patients is different from the unburned population. Efforts are needed to develop more accurate diagnostic strategies and guidelines to trigger rapid treatment via specific sepsis bundles.

Comparison of Automated Methods Versus the American Burn Association Sepsis Definition to Identify Sepsis and Sepsis With Organ Dysfunction/Septic Shock in Burn-Injured Adults

To develop an algorithm to identify sepsis and sepsis with organ dysfunction/septic shock in burn-injured patients incorporating criteria from the American Burn Association sepsis definition that possesses good test characteristics compared with International Classification of Diseases, Ninth Revision-Clinical Modification (ICD-9) codes and an algorithm previously validated in nonburn-injured septic patients (Martin et al method). This was a retrospective cohort study of consecutive patients admitted to the burn intensive care unit between January 2008 and March 2015. Of the 4761 admitted, 8.6% (n = 407) met inclusion criteria, of which the case rate for sepsis was 34.2% (n = 139; n = 48 sepsis; n = 91 sepsis with organ dysfunction/septic shock). For sepsis identification, the novel algorithm had an accuracy of 86.0% (95% CI: 82.2-89.2%), sensitivity of 66.9% (95% CI: 59.1-74.7%), and specificity of 95.9% (95% CI: 93.5-98.3%). The novel algorithm had better discrimination (0.81, 95% CI: 0.77-0.86) than the ICD-9 method (0.77, 95% CI: 0.73-0.81), although this was not significant (P = .08). For sepsis with organ dysfunction/septic shock, the novel algorithm plus vasopressors (0.67, 95% CI: 0.63-0.72) and the ICD-9 method (0.63, 95% CI: 0.58-0.68) performed equivocal (P = 0.15) but the Martin method (0.76, 95% CI: 0.71-0.81) had superior discrimination than other methods (P < .01). The novel algorithm is an accurate and simple tool to identify sepsis in the burn cohort with good sensitivity and specificity and equivocal discriminative ability to ICD-9 coding. The Martin method had superior discriminative ability for identifying sepsis with organ dysfunction/septic shock in burn-injured patients than either the novel algorithm plus vasopressors or ICD-9 coding.

Determinants of Outcome in Burn ICU Patients with Septic Shock

Infectious complications remain one of the most challenging concerns for the burn team. The goal of this study was to evaluate the diagnostic and therapeutic approaches and prognosis in burn patients with septic shock. This retrospective study included patients with severe burn injury who were admitted to a burn intensive care unit (ICU). Demographic and clinical data were recorded for each patient. The diagnostic and prognostic value of a number of clinical and laboratory parameters and various treatment options were evaluated. Sixty-four of the 378 patients (16.9%) were identified as having experienced a septic shock during ICU stay. The mortality rate of patients with septic shock was 46.9%. The main bacterial strains responsible for infection were Gram-negative bacteria (78.1%). Factors associated with outcome of septic shock on logistic regression analysis were presence of stage III of acute kidney injury (odds ratio [95% confidence interval] 2.03 [1.06-3.84]; P = 0.019), and lactate levels > 4 mmol/L during the first 48 hours of shock (odds ratio 1.92; 95% confidence interval: 1.02-3.62; P = 0.043). Prognosis of septic shock remains poor in burn patients with septic shock. The main causative pathogens of septic shock identified in our burn ICU were Gram-negative species. The main prognostic factors identified in this study were the presence of AKI, stage III, and high lactate levels early after the onset of septic shock.

Status and Challenges of Predicting and Diagnosing Sepsis in Burn Patients

Burns are a common form of trauma that account for more than 300,000 deaths each year worldwide. Survival rates have improved over the past decades because of improvements in nutritional and fluid support, burn wound care, and infection control practices. Death, however, remains unacceptably high. The primary cause of death has changed over the last decades from anoxic causes to now predominantly infections and sepsis. Sepsis and septic complications are not only major contributors to poor outcomes, but they further result in longer hospital stay and higher healthcare costs. Despite the importance of infections and sepsis, the diagnosis and prediction remain a major challenge. To date, no clear diagnostic criteria or predictive formula exist that can predict reliably the occurrence of sepsis and infections. This review will highlight and discuss current definitions and criteria for diagnosis as well as predictive biomarkers of sepsis in patients with burns. It will also present the diagnostic tools employed, such as procalcitonin, C-reactive protein, and cytokines. We will discuss the benefits and shortcomings of different treatment modalities in the context of sepsis prevention. Last, we identify new therapeutic strategies for sepsis prediction and present future considerations to prevent sepsis in patients with burns. Minimizing and preventing septic complications through early detection would significantly benefit patients and necessitate continued research to unravel new biomarkers and mechanisms. Subsequent studies need to take a fresh perspective and consider the implementation of patient-centered therapeutic strategies.

Utility of Sequential Organ Failure Assessment score in predicting bacteremia in critically ill burn patients

BACKGROUND

We evaluated whether qSOFA ≥2 and an increase in SOFA (ΔSOFA) ≥2 can help predict bacteremia in a critically ill burn population.

METHODS

Patients age ≥15 and TBSA ≥15% admitted between 2009 and 2015 were included. All blood cultures were recorded, and positive and negative blood culture days were defined based on the culture results. SOFA and qSOFA scores were compared between positive and negative blood culture days.

RESULTS

There were 50 patients in our study with a mean age of 47yrs and mean TBSA burn of 37%. Bacteremic patients had larger TBSA and full thickness burns, higher revised Baux score, and longer hospital LOS, without a difference in mortality, compared to non-bacteremic patients. There was no difference in qSOFA and SOFA scores between positive and negative blood culture days. A ΔSOFA ≥5 was highly specific for positive blood culture days.

CONCLUSIONS

SOFA and qSOFA have limited ability to predict bacteremia in critically ill burn patients.

Sepsis in the burn patient: a different problem than sepsis in the general population

Sepsis has recently been defined as "life-threatening organ dysfunction caused by a dysregulated host response to infection". A great amount of effort has been made to develop early treatments for sepsis through the Surviving Sepsis Campaign. There are similar but slightly different recommendations for the treatment of sepsis in the pediatric population. These international efforts have led to earlier diagnosis and treatments for sepsis that have led to improvements in survival. Sepsis is also the leading cause of death in the burn patient but most clinical sepsis studies have excluded burns. The reason for the exclusion is that the sepsis found in burn patients is different than that of the general population. The early treatment strategies, such as those directed by the Surviving Sepsis Campaign, focus on patients presenting to hospitals with recent signs of infection. Burn patients lose their primary barrier to infection, the skin, and thus the risk of infection persists as long as that barrier is absent. Efforts have been made to define sepsis, septic shock and infection in the burn population but there is constant need for revisions. One focus of this review is to discuss the differences in burn sepsis versus sepsis of the general population. Children often have profound responses to sepsis but can also make remarkable recoveries. This review will also explore problems specific to pediatric burns. The treatment of burns requires a continuous vigilance to watch for the subtle early signs of sepsis and then expeditious initiation of aggressive therapy. Strategies covering optimal management of pediatric burn sepsis will also be summarized.

A systematic review of quantitative burn wound microbiology in the management of burns patients

BACKGROUND

The early diagnosis of infection or sepsis in burns are important for patient care. Globally, a large number of burn centres advocate quantitative cultures of wound biopsies for patient management, since there is assumed to be a direct link between the bioburden of a burn wound and the risk of microbial invasion. Given the conflicting study findings in this area, a systematic review was warranted.

METHODS

Bibliographic databases were searched with no language restrictions to August 2015. Study selection, data extraction and risk of bias assessment were performed in duplicate using pre-defined criteria. Substantial heterogeneity precluded quantitative synthesis, and findings were described narratively, sub-grouped by clinical question.

RESULTS

Twenty six laboratory and/or clinical studies were included. Substantial heterogeneity hampered comparisons across studies and interpretation of findings. Limited evidence suggests that (i) more than one quantitative microbiology sample is required to obtain reliable estimates of bacterial load; (ii) biopsies are more sensitive than swabs in diagnosing or predicting sepsis; (iii) high bacterial loads may predict worse clinical outcomes, and (iv) both quantitative and semi-quantitative culture reports need to be interpreted with caution and in the context of other clinical risk factors.

CONCLUSION

The evidence base for the utility and reliability of quantitative microbiology for diagnosing or predicting clinical outcomes in burns patients is limited and often poorly reported. Consequently future research is warranted.