Identification of predictors of early infection in acute burn patients

Routinely collected burn clinical data in Canada: Determining the knowledge gap

Unlike other developed countries that hold national burn registries to monitor burn injury and care, Canada relies on single-centre secondary datasets and administrative databases as surveillance mechanisms. The objective of this study was to determine the knowledge gap faced in Canada for not having a dedicated burn registry. A comprehensive scoping review was conducted to identify the burn literature that has arisen from secondary datasets in Canada. Literature of all study designs was included with the exception of case reports and cases series. Once data extraction was concluded, a thematic framework was constructed based on the information that arose from nations that hold national burn registries. Eighty-eight studies were included. Twelve studies arose from national datasets, and 18 from provincial databases, most of which were from Ontario and British Columbia. Only seven studies were conducted using a combination of Canadian units' single-centre datasets. The majority of included studies (58%) resulted from non-collaborative use of single-centre secondary datasets. Research efforts were predominantly conducted by burn units in Ontario, British Columbia, Manitoba and Alberta. A significant number of the included studies were outdated and several provinces/territories had no published burn data whatsoever. Efforts should be made towards the development of systems to surveil burn injury and care in Canada. This study supports the development of a nation-wide burn registry to bridge this knowledge gap.

The impact of infection on length of stay in adult burns: A scoping review

BACKGROUND

The disruption to the immune system and profound metabolic response to burn injury gives rise to a unique susceptibility to infection. Indeed, infection is one of the most frequently encountered post-burns complications placing significant burden on patients and healthcare system. Advancements in burn care have led to marked improvements in burn-related mortality and morbidity; however, scarce hospital resources hamper adequate burn-related care, and patient length of stay (LOS) in hospital is an important drain on such resources. The aim of this review was to assess and evaluate the existing literature relating to the impact of infections on LOS in hospitalised, adult burn patients.

METHODS

Electronic searches were performed in Medline and Embase. Eligible studies were those reporting on LOS and infection in adult burn populations. Articles published before 2000 were excluded to ensure that the analysis was focused on contemporary literature that reflects current, clinical management of burn patients.

RESULTS

Nineteen studies (54,397 burn patients) were included in the review. All studies were retrospective, with the majority undertaken in North America (14 studies). The mean age range was 38-67 years and the majority of patients were male. Inhalation injury was recorded in eleven studies. The most common types of infection included pneumonia, blood stream infections (BSI) and burn wound infections. Overall, there was a trend towards a positive association between infection and LOS.

CONCLUSION

The results of this scoping review provide an overview of the existing literature on the relationship between infection and LOS in adult burn populations. However, significant gaps remain in knowledge which call for further high-quality research. Standardised definitions for the collection of infection data and the use of burns specific infection control guidelines are also critical to understanding and improving patient outcomes.

Bacterial fluorescence imaging as a predictor of skin graft integration in burn wounds

BACKGROUND

Split-thickness skin graft (STSG)1 integration rates are susceptible to improvement. Infection and/or biofilm should be appropriately addressed prior to grafting to improve the likelihood of graft-take. Incorporating technological aids such as fluorescence (FL)2 imaging (MolecuLight®), which accurately locates areas of bacterial loads above 104 CFU/gr, for graft site assessment and preparation could yield better outcomes.

METHODS

This single-center, prospective observational study included adult burn patients with previously infected wounds that had been deemed clinically and microbiologically clean and were therefore candidates for grafting. Prior to grafting, a FL imaging assessment (blinded to the surgical team) localized areas positive for moderate-high bacterial loads (>104 CFU/gr). Intra-operatively, a standard swab sample from the recipient site was collected by the surgical team. Postoperatively, areas positive/negative for FL and areas of graft take and failure were overlapped and measured (cm2) over a 2D schematic. The performance and accuracy of FL imaging and swab sampling in relation to graft outcomes were assessed.

RESULTS

38 patients were enrolled in the study. The mean total body surface area (TBSA)3 involvement was 14.5 ± 12.4 % [range 0.8 - 40.2 %]. 25/38 of the subjects enrolled had complete graft take while 13 had partial graft losses. There were no total losses. FL-imaging was positive in 100 % of losses versus 31 % (4/13) of the swab microbiology. FL-imaging was found to have a sensitivity of 86 %, specificity of 98 %, PPV of 72 %, NPV of 99 %, and an accuracy of 94 % for predicting any type or range of graft loss in the entire cohort. Meanwhile, the sensitivity of microbiology from swab samples was 30 %, with a specificity of 76 %.

CONCLUSIONS

FL imaging is an accurate method for assessing recipient sites and predicting the outcome of a skin graft among burn patients. These findings suggest that FL imaging can inform better decision-making surrounding grafts that may lead to better outcomes.

LEVEL OF EVIDENCE

Level IIA, Therapeutic study.

Current Approaches to Wound Repair in Burns: How far Have we Come From Cover to Close? A Narrative Review

Burn injuries are a significant global health concern, with more than 11 million people requiring medical intervention each year and approximately 180,000 deaths annually. Despite progress in health and social care, burn injuries continue to result in socioeconomic burdens for victims and their families. The management of severe burn injuries involves preventing and treating burn shock and promoting skin repair through a two-step procedure of covering and closing the wound. Currently, split-thickness/full-thickness skin autografts are the gold standard for permanent skin substitution. However, deep burns treated with split-thickness skin autografts may contract, leading to functional and appearance issues. Conversely, defects treated with full-thickness skin autografts often result in more satisfactory function and appearance. The development of tissue-engineered dermal templates has further expanded the scope of wound repair, providing scar reductive and regenerative properties that have extended their use to reconstructive surgical interventions. Although their interactions with the wound microenvironment are not fully understood, these templates have shown potential in local infection control. This narrative review discusses the current state of wound repair in burn injuries, focusing on the progress made from wound cover to wound closure and local infection control. Advancements in technology and therapies hold promise for improving the outcomes for burn injury patients. Understanding the underlying mechanisms of wound repair and tissue regeneration may provide new insights for developing more effective treatments in the future.

Multidrug-Resistant Pathogens in Burn Wound, Prevention, Diagnosis, and Therapeutic Approaches (Conventional Antimicrobials and Nanoparticles)

Multidrug-resistant pathogens are one of the common causes of death in burn patients and have a high risk of nosocomial infections, especially pneumonia, urinary tract infections, and cellulitis. The role of prolonged hospitalization and empirical antibiotics administration in developing multidrug-resistant pathogens is undeniable. In the early days of admitting burn patients, Gram-positive bacteria were the dominant isolates with a more sensitive antibiotic pattern. However, the emergence of Gram-negative bacteria that are more resistant later occurs. Trustworthy guideline administration in burn wards is one of the strategies to prevent multidrug-resistant pathogens. Also, a multidisciplinary therapeutic approach is an effective way to avoid antibiotic resistance that involves infectious disease specialists, pharmacists, and burn surgeons. However, the emerging resistance to conventional antimicrobial approaches (such as systemic antibiotic exposure, traditional wound dressing, and topical antibiotic ointments) among burn patients has challenged the treatment of multidrug-resistant infections, and using nanoparticles is a suitable alternative. In this review article, we will discuss different aspects of multidrug-resistant pathogens in burn wounds, emphasizing the full role of these pathogens in burn wounds and discussing the application of nanotechnology in dealing with them. Also, some advances in various types of nanomaterials, including metallic nanoparticles, liposomes, hydrogels, carbon quantum dots, and solid lipid nanoparticles in burn wound healing, will be explained.

Prevalence of Multidrug-Resistant Organism in ICU Burns Patients at Tertiary Care Hospital

Burns carries a high-risk of mortality and morbidity. This with increased chances of drug-resistant infections makes the management complicated. Hence this study was conducted to find out the prevalence of multidrug-resistant organisms (MDRO) in burns patients admitted to the intensive care unit at a tertiary care hospital. A 2-year retrospective study was conducted where burn patients reporting MDRO were included. Statistical analysis was performed using SPSS version 26 where a P-value < .05 was considered statistically significant. Out of 97 patients, tissue cultures of 65 patients revealed the presence of MDRO in 27 (27.8%) patients. A male predominance (17, 63.0%) was noted with a mean age of 29.0-year-old. Fire burn (15, 55.6%) was reported to be the most common cause of burn with an average of 29.9% of Total Body Surface Area (TBSA) involved. MDR Pseudomonas aeruginosa was the commonest organism reported in 12 (44%) patients. The average length of stay (LOS) was noted to be 11.3 days with a mortality rate of 48.1% (overall, in all MDRO'S infections). Patients who reported MDRO showed a tendency for longer hospitalization with a higher risk of mortality as the TBSA increased. However, in presence of other factors in burns like higher TBSA, inhalation injury and lack of advanced skin substitute these mortality figures, and their association can be debated. Lastly, the implementation of control measures, as basic as hand hygiene, should be partaken to reduce the burden of MDR infections.

Outbreak of Carbapenemase-Producing Enterobacteriaceae in a Regional Burn Center

Antimicrobial resistance is an increasing problem in hospitals worldwide; however, the prevalence of carbapenemase-producing Enterobacteriaceae (CPE) in our region is low. Burn patients are vulnerable to infection because of the loss of the protective skin barrier, thus burn centers prioritize infection prevention and control (IP&C). This report describes a CPE outbreak in a regional burn center. In a period of 2.5 months, four nosocomial cases of CPE were identified, three containing the Klebsiella pneumoniae carbapenemase (KPC) gene and one Verona integrin-encoded metallo-β-lactamase (VIM) gene. The first two cases were identified while there was no CPE patient source on the unit. CPE KPC gene was then isolated in sink drains of three rooms. In addition to rigorous IP&C practices already in place, we implemented additional outbreak measures including restricting admissions to patients with complex burns or burns ≥10% TBSA, admitting patients to other in-patient units, and not permitting elective admissions. We began cohorting patients using nursing team separation for CPE-positive and -negative patients and geographical separation on the unit. Despite aggressive IP&C measures already in place, hospital-acquired CPE colonization/infection occurred. Given that CPE contaminated sinks of the same enzyme were identified, we believe hospital sink drains may the source. This highlights the importance of sink design and engineering solutions to prevent the formation of biofilm and reduce splashing. CPE infections are associated with poor outcomes in patients and significant health system costs due to a longer length of stay and additional institutional resources.

Risk factors for nosocomial infections and/or sepsis in adult burns patients: An integrative review

BACKGROUND

In comparison to general trauma patients, loss of skin barrier amongst the burns cohort predisposes them to a higher risk of nosocomial infections and sepsis, and this often leads to unfavourable morbidity and mortality outcomes.

PURPOSE

This integrative review aimed to explore existing literature to identify risk factors related to nosocomial infections and/or sepsis in adult burns patients following hospital admission.

METHODS

Electronic searches for journals published between 2007 and 2021 were performed in CINAHL, Scopus and Medline, and key journals were hand-searched. Inclusion criteria was: (1) peer-reviewed, primary studies; (2) qualitative, quantitative or mixed-methods studies; (3) study participants had sustained burns-related injury and developed nosocomial infections and/or sepsis during the course of hospitalisation. Studies were appraised using the Critical Appraisal Skill Program checklists.

RESULTS

15 studies ranging from 'poor' to 'fair' to 'moderate' quality were included in the final review. Patient factors that contributed to the development of nosocomial infections and/ or sepsis included: (1) Full thickness burns; (2) age; (3) % Total Burns Surface Area; and (4) Herpes Simplex Virus activation. Several provider-system risk factors were identified by 'poor' quality studies and further research is required to substantiate those findings.

DISCUSSION

Findings remained inconclusive due to the lack of 'good' quality studies however, there was an overemphasis on patient-related risk factors instead of healthcare workers or the system. Future research may focus on activation of the latest infection prevention strategies and early enforcement of care bundles. Through identification of related risk factors, it may reduce the incidence of nosocomial infection and/or sepsis post-burns.

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.

Disseminated Mycobacterium abscessus Infection in a Burn Patient

Disseminated infection caused by non-tuberculous mycobacteria (NTM) is very rare, with an incidence of 1.0 to 1.8 cases per 100,000 persons, and typically only occurs in severely immunocompromised hosts. Burn patients suffer loss of the natural cutaneous barrier as well as injury-induced immune dysfunction, and as a result, commonly develop infections, especially with multidrug-resistant organisms. However, very few NTM infections in burn patients have been reported in the literature. Disseminated NTM infection, in particular, can be a challenge to diagnose in burn patients due to burn related physiology such as hyperpyrexia and widespread skin injury. We present a case of disseminated infection leading to bacteremia caused by Mycobacterium abscessus in a critically ill burn patient with a 74% total body surface area burn. M. abscessus belongs to the subgroup of NTM known as rapidly growing mycobacteria (RGM), which are notable for their ability to form colonies in a matter of days, rather than weeks, and because they are often highly drug-resistant, which complicates antimicrobial therapy. This is the third reported case of bacteremia caused by NTM in a burn patient and the second case that was successfully transitioned from intravenous antimicrobials to an oral regimen.

Patient safety culture in burn care units from the perspectives of healthcare providers: across-sectional study

Creating a positive patient safety culture is a key step in the improvement of patient safety in healthcare settings. PSC is a set of shared attitudes, beliefs, and perceptions about PS among healthcare providers. This study aimed to assess PSC in burn care units from the perspectives of healthcare providers. This cross-sectional descriptive study was conducted in 2020 in the units of a specialty burn center. Participants were 213 healthcare providers recruited to the study through a census. A demographic questionnaire and the Hospital Survey on Patient Safety Culture were used for data collection. Data were managed using the SPSS16 software and were summarized using the measures of descriptive statistics. The mean of positive responses to PSC items was 51.22%, denoting a moderate-level PSC. The lowest and the highest dimensional mean scores were related to the no punitive response to error dimension (mean: 12.36%) and the teamwork within departments dimension (mean: 73.25%), respectively. Almost half of the participants (49.3%) reported acceptable PS level in their workplace and 69.5% of them had not reported any error during the past twelve months before the study. Given the great vulnerability of patients with burn injuries in clinical settings, improving PSC, particularly in the no punitive response to error dimension, is essential to encourage healthcare providers for reporting their errors and thereby, to enhance PS. For quality care delivery, healthcare providers in burn care units need a safe workplace, adequate managerial support, a blame-free PSC, and an incentive error reporting system to readily report their errors.

Microbiology and Infection Profile of Electric Burned Patients in a Referral Burn Hospital in Mexico City

Electrical burn injuries are one of the most severe forms of trauma. This study aims to investigate the infection complications in electrical burn patients in a referral hospital in Mexico City. A longitudinal retrospective study was conducted, involving electrical burn patients admitted from April 2011 to December 2016. Demographic and clinical data including type of electric burns, infection complications, and mortality was sought. Data were collected at admission and daily until discharge. Number and type of infections and microorganism isolations were sought. Risk factors for death were analyzed. A total of 111 patients were included, of which 96.4% were males, mean age of 31.6±16.22, most injuries were high voltage associated. The total body surface area average was 27.8% ± 19.63. The overall infection rate was 72.9 cases per 100 patients. Mortality was observed in 4 (3.6%) patients. About 59.1% (443/749) had growth for Gram-negative bacteria. Multidrug-resistant Pseudomonas aeruginosa was the most frequent microorganism isolated. Fungi were present in 4.9% of cases. Electrical burn injuries occurred in young males in our study. Infection was frequent, most of them caused by Gram-negative rods with an important rate of antimicrobial resistance; however, an important microbial diversity was present.

The Impact of Multidrug-Resistant Organisms Infection on Outcomes in Burn Injury Patients at Sanglah General Hospital, Bali

BACKGROUND: Research related to the impact of multidrug resistant organisms (MDRO) infection on clinical outcomes in burns is still limited. AIM: This study evaluated the effect of MDRO infection on morbidity and mortality of burn patients. METHODS: A single-center retrospective cohort study was conducted on burn patients admitted to the burn unit of Sanglah General Hospital, Bali, between 2018 and 2020. MDRO patients were described as those who had at least one positive MDRO culture. All other patients were included in the non-MDRO group. Measurement and analysis included mortality and five indicators of morbidity: length of stay, duration of antibiotic therapy, sepsis, pneumonia, and acute kidney injury (AKI). RESULTS: Significant associations of MDRO infection were found for duration of antibiotic therapy (0 vs. 7 days), sepsis (odds ratio [OR] 13.90 [95% Confidence interval (CI) 95% 2.88–67.10]), pneumonia (OR 12,67 [95% CI 3.26–49.23]), and mortality (OR 9.75 [95% CI 2.00–47.50]). No significant association was found for the length of stay and the incidence of AKI. Multivariate analysis found that MDRO infection increased risk of sepsis (OR 36.53 [95% CI 2.05–652.45], pneumonia (OR 10.75 [95% CI 1.87–61.86]) and mortality (OR 57.09 [95% CI 1.41–2318.87]). Multivariate analysis of MDRO infection with duration of antibiotic therapy found no independent variables that were significantly related. CONCLUSION: These research findings suggest that MDRO infections are associated with increasing length of antibiotic treatment, sepsis, pneumonia, and mortality in burn patients.

Eradication of vancomycin-resistant Staphylococcus aureus on a mouse model of third-degree burn infection by melittin: An antimicrobial peptide from bee venom

Third-degree burn infections caused by antibiotic-resistant bacteria are of high clinical concern. Chemical antibiotics are not promising in eradication of bacterial infections. In this challenging condition, antimicrobial peptides (AMPs) are recently introduced as novel promising agents to overcome the issue. Accordingly, our study aimed to evaluate the efficiency of 'melittin' as natural peptide in bee venom, in eradicating vancomycin resistant Staphylococcus aureus (VRSA) on a mouse model of third-degree burn infection. In vitro pharmacological value of melittin was determined by examining its inhibitory and killing activities on VRSA isolates at different doses and time periods. The action mechanism of 'melittin' was evaluated by fluorescent release assay and Field Emission Scanning Electron Microscopy (FE-SEM) analyses. In vivo activity and toxicity of melittin were also examined on a mouse model of third-degree burn infection. The Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) of melittin on all isolates ranged from '0.125-2 μg/mL' and '0.125-4 μg/mL', respectively. Rapid antibacterial activity of melittin on VRSA isolates was demonstrated by killing kinetics assays. Fluorometric and FE-SEM analyses indicated the membranolytic effects of melittin on VRSA isolates. The colonized VRSA bacteria were eradicated by melittin at 16 μg, in a single dose. No dermal toxicity and in vivo hemolysis were observed in the examined mice. The lack of in vivo toxicity of melittin along with its potent antibacterial activity indicated its promising therapeutic value as a topical drug against S. aureus associated third-degree burn infections.

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.

Multicentre observational study describing the systemic response to small-area burns in children

BACKGROUND AND OBJECTIVES

Burns of less than 10% total body surface area (TBSA) are common injuries in children under five years of age. The inflammatory response to burn injury is well recognised for burns greater than 20% TBSA but has not been described for smaller burns. The aim of this study was to describe the systemic response to burn injury in young children with small-area burns.

METHODS

The Morbidity In Small Thermal Injury in Children study (MISTIC) was a multicentre prospective observational cohort study that recruited 625 patients under five years of age with burns of less than 10% TBSA over eighteen months across three sites in England. Prospectively collected data included physical observations and laboratory blood tests taken in hospital as part of routine care. Additional information was sourced from temperature recordings taken at home following discharge.

RESULTS

Elevated temperatures were observed in children with scald or contact burns between 2-10% TBSA, with a peak on day one after burn followed by a fall over days four to seven after burn. No temperature rise was seen in children with burns of <2% TBSA. Higher temperature readings were associated with larger burn size, age under two years and male sex. Heart rate and C-Reactive Protein levels showed a peak on day three after burn.

CONCLUSIONS

An identifiable systemic inflammatory response to small-area burns in young children is reported. This knowledge can be used to aid in the diagnosis of children with a burn injury who re-present with a pyrexia, and no other symptoms to indicate clinical infection.

Bacterial infection profile and predictors among patients admitted to a burn care center: A retrospective study

BACKGROUND

Infection is the main cause of mortality and complications in burn patients. The present study was the first to examine the local profile and antecedents of bacterial infections among patients admitted to a Lebanese burn care center.

METHODS

The present study was a retrospective analysis of the occurrence and recurrence of infection, its characteristics as well as antimicrobial susceptibility among 475 patients admitted to the Burn Centre at the Lebanese Geitaoui Hospital between January 2014 and December 2018.

RESULTS

55% of patients contracted at least one infection during their hospitalization. Length of stay (LOS), sepsis, wound dressing under anesthesia, blood transfusion and female sex independently and positively predicted infection in burn patients. Infection was predominately caused by Staphylococcus aureus (48.7%), followed by Pseudomonas aeruginosa (22.6%) and Acinetobacter baumannii (15.7%). Bacterial isolates were predominately multi-drug or extensively drug resistant and showed variable antimicrobial susceptibility patterns. Recurrent infections occurred in 44.1% of infected burn patients, and were independently predicted by LOS (p = 0.004), sepsis (p = 0.001), surgery (p = 0.003), burn excision and skin grafting (p = 0.019), and central line insertion (p = 0.004).

CONCLUSION

Existing burn management and infection control measures must be revised in order to reduce the incidence and improve the treatment of infections 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.

Procalcitonin kinetics after burn injury and burn surgery in septic and non-septic patients - a retrospective observational study

BACKGROUND

Early sepsis diagnosis is crucial for the correct management of burn patients, and it clearly influences outcomes. The systemic inflammatory response triggered by burns mimics sepsis presentation and complicates early sepsis diagnosis. Biomarkers were advocated to aid the diagnosis of early sepsis. Serum procalcitonin (PCT) exhibits fair accuracy and good correlation with sepsis severity, being used in diverse clinical settings. However, few studies have evaluated perioperative changes in PCT levels in burn patients. The present study evaluated PCT kinetics during the first days after burn injury and subsequent surgical interventions to assess PCT utility in distinguishing septic from non-septic inflammatory responses.

METHODS

This study was a retrospective observational study of all burn patients admitted to the Coimbra Burns Unit (Portugal) between January 2011 and December 2014 who presented with a total burn surface area ≥ 15% and who underwent subsequent surgery. PCT kinetics were investigated a) during the first five days after burn injury and b) preoperatively during the five days after surgery in three subsets of patients, including those with no preoperative and no postoperative sepsis (NN), no preoperative but postoperative sepsis (NS), and preoperative and postoperative sepsis (SS). A total of 145 patients met the selection criteria and were included in the analysis.

RESULTS

PCT levels in the first five days after burn injury were significantly higher in patients who developed at least one sepsis episode (n = 85) compared with patients who did not develop sepsis (n = 60). PCT values > 1.00 ng/mL were clearly associated with sepsis. Study participants (n = 145) underwent a total of 283 surgical interventions. Their distribution by preoperative/postoperative sepsis status was 142 (50.2%) in NN; 62 (21.9%) in NS; and 79 (27.9%) in SS. PCT values exhibited a parallel course in the three groups that peaked on the second postoperative day and returned to preoperative levels on the third day or later. The lowest PCT values were found in NN, and the highest values were observed in SS; the NS values were intermediate.

CONCLUSIONS

PCT kinetics coupled with a clinical examination may be helpful for sepsis diagnosis during the first days after burn injury and burn surgery.

Bacterial Infections After Burn Injuries: Impact of Multidrug Resistance

Patients who are admitted to the hospital after sustaining a large burn injury are at high risk for developing hospital-associated infections. If patients survive the initial 72 hours after a burn injury, infections are the most common cause of death. Ventilator-associated pneumonia is the most important infection in this patient population. The risk of infections caused by multidrug-resistant bacterial pathogens increases with hospital length of stay in burn patients. In the first days of the postburn hospitalization, more susceptible, Gram-positive organisms predominate, whereas later more resistant Gram-negative organisms are found. These findings impact the choice of empiric antibiotics in critically ill burn patients. A proactive infection control approach is essential in burn units. Furthermore, a multidisciplinary approach to burn patients with a team that includes an infectious disease specialist and a pharmacist in addition to the burn surgeon is highly recommended.

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.

Checking procalcitonin suitability for prognosis and antimicrobial therapy monitoring in burn patients

Background

Due to greater infection susceptibility, sepsis is the main cause of death in burn patients. Quick diagnosis and patient stratification, early and appropriated antimicrobial therapy, and focus control are crucial for patients' survival. On the other hand, superfluous extension of therapy is associated with adverse events and arousal of microbial resistance. The use of biomarkers, necessarily coupled with close clinical examination, may predict outcomes, stratifying patients who need more intensive care, and monitor the efficacy of antimicrobial therapy, allowing faster de-escalation or stop, reducing the development of resistance and possibly the financial burden, without increasing mortality. The aim of this work is to check the suitability of procalcitonin (PCT) to fulfill these goals in a large sample of septic burn patients.

Methods

One hundred and one patients, with 15% or more of total body surface area (TBSA) burned, admitted from January 2011 to December 2014 at Coimbra Burns Unit (CBU), in Portugal were included in the sample. All patients had a diagnosis of sepsis, according to the American Burn Association (ABA) criteria. The sample was factored by survival (68 survivors and 33 non-survivors). The maximum value of PCT in each day was used for statistical analysis. Data were summarized by location measures (mean, median, minimum, maximum, quartiles) and dispersion measures (standard error and range measures). Statistical analysis was performed with SPSS© 23.0 IBM© for Windows©.

Results

There were statistically significant differences between PCT levels of patients from the survivor and non-survivor groups during the first and the last weeks of hospitalization as well as during the first week after sepsis suspicion, being slightly higher during this period. During the first 7 days of antimicrobial therapy, PCT was always higher in the non-survivor, still without reaching statistical significance, but when the analysis was extended till the 15th day, PCT increased significantly, rapidly, and steadily, denouncing therapy failure.

Conclusion

Despite being not an ideal biomarker, PCT proved to have good prognostic power in septic burn patients, paralleling the evolution of the infectious process and reflecting the efficacy of antimicrobial therapy, and the inclusion of its serial dosing may be advised to reinforce antimicrobial stewardship programs at burn units; meanwhile, more accurate approaches are not available.

Risk Factors for Healthcare-Associated Infections in Adult Burn Patients

OBJECTIVE Burn patients are particularly vulnerable to infection, and an estimated half of all burn deaths are due to infections. This study explored risk factors for healthcare-associated infections (HAIs) in adult burn patients. DESIGN Retrospective cohort study. SETTING Tertiary-care burn center. PATIENTS Adults (≥18 years old) admitted with burn injury for at least 2 days between 2004 and 2013. METHODS HAIs were determined in real-time by infection preventionists using Centers for Disease Control and Prevention criteria. Multivariable Cox proportional hazards regression was used to estimate the direct effect of each risk factor on time to HAI, with inverse probability of censor weights to address potentially informative censoring. Effect measure modification by burn size was also assessed. RESULTS Overall, 4,426 patients met inclusion criteria, and 349 (7.9%) patients had at least 1 HAI within 60 days of admission. Compared to 6 times as likely to acquire an HAI (HR, 6.38; 95% CI, 3.64-11.17); and patients with >20% TBSA were >10 times as likely to acquire an HAI (HR, 10.33; 95% CI, 5.74-18.60). Patients with inhalational injury were 1.5 times as likely to acquire an HAI (HR, 1.61; 95% CI, 1.17-2.22). The effect of inhalational injury (P=.09) appeared to be larger among patients with ≤20% TBSA. CONCLUSIONS Larger burns and inhalational injury were associated with increased incidence of HAIs. Future research should use these risk factors to identify potential interventions. Infect Control Hosp Epidemiol 2017;38:1441-1448.

Hyperosmolar metabolic acidosis in burn patients exposed to glycol based topical antimicrobials-A systematic review

BACKGROUND

The well documented susceptibility of burn patients to acquired infections via damaged skin mandates application of antimicrobial agents. These agents are dissolved in various vehicles that augment skin absorption thus allowing greater efficacy. Polyethylene glycol (PEG) and Propylene glycol (PropG) are among the most commonly used vehicles, and both have been used in numerous medications and cosmetic products over the past few decades. Rarely, burn patients treated with agents containing these glycols present with a life threatening systemic toxidrome of hyperosmolar metabolic acidosis. We present a systematic review of outcomes in burn patients treated with similar agents.

METHODS

Relevant studies were identified through systematic searches conducted in MEDLINE (Ovid), Embase (Ovid), CENTRAL (Ovid), and Web of Science (Thomson Reuters), from database inception to August 4th, 2016. All publications of clinical burn patient studies included at least one arm receiving a glycol based topical therapy.

RESULTS

A total of 61 studies involving 10,282 patients and 4 different antimicrobial medications fulfilled the inclusion criteria. Nine burn patients (0.09%) were documented to present with hyperosmolar metabolic acidosis during topical silver sulfadiazine treatment. Propylene glycol isolated from their blood accounted for the high osmole gap.

CONCLUSION

This first systematic review found very few cases of documented hyperosmolar metabolic acidosis, all within one study that had set to specifically explore this toxidrome. High index of suspicion with frequent osmolar gap monitoring may help identify future toxicities in a timely manner.

A prospective study evaluating tobramycin pharmacokinetics and optimal once daily dosing in burn patients

BACKGROUND

Once-daily aminoglycoside dosing (ODA) is used in most patient populations to optimize antibacterial activity and reduce toxicity. Unfortunately, burn patients are excluded from ODA due to concerns over altered pharmacokinetics resulting in a shortened half-life and low peak aminoglycoside concentrations. Retrospective studies suggest that ODA may be appropriate if higher milligram/kilogram doses are used. However, no prospective clinical trials in burn patients exist to confirm these findings.

OBJECTIVE

To determine the adequacy of once daily tobramycin dosed at 10mg/kg in adult burn patients.

METHODS

This prospective single dose pharmacokinetic clinical trial was conducted at the Ross Tilley Burn Centre. Patients with a total burn surface area (TBSA) of <20% and creatinine clearance ≥50mL/min were eligible. A first-order one compartment model was used to determine the pharmacokinetic profile from 3 or 5 tobramycin levels over a 24h period per patient. Monte Carlo simulation (MCS) was performed to determine the probability of target level attainment.

RESULTS

The mean percent TBSA, partial, and full thickness burn were 10%, 6%, and 4%, respectively. Nine of the ten patients recruited achieved peak concentrations of ≥20mg/L (mean of 29.4±5.7mg/L) and all patients had a trough level ≤0.5mg/L. The mean half-life, volume of distribution, and clearance were 2.58h, 0.33L/kg, and 7.40L/h, respectively. The MCS determined probability of attaining target peak concentrations with the 10mg/kg dose was 97%, which almost doubled that predicted with the usual 7mg/kg dose.

CONCLUSION

Burn patients with adequate renal function and <20% TBSA are candidates for ODA. Tobramycin half-life was similar to healthy, non-burn patients. The larger than normal volume of distribution supports the use of the higher empiric dose of 10mg/kg total body or adjusted weight in non-obese and obese patients, respectively, with further dose adjustment based on therapeutic drug monitoring.

In vitro discrimination of wound-associated bacteria by volatile compound profiling using selected ion flow tube-mass spectrometry

AIMS

To determine if bacterial species responsible for clinically relevant wound infection produce specific volatile profiles that would allow their speciation.

METHODS AND RESULTS

Selected ion flow tube-mass spectrometry (SIFT-MS) in full mass scan mode was used to analyse headspace gases produced by wound-associated bacteria grown in vitro, so as to enable identification of bacterial volatile product ion profiles in the resulting mass spectra. Applying multivariate statistical analysis (hierarchical clustering and principal component analysis) to the resultant mass spectra enabled clear speciation. Moreover, bacterial volatile product ions could be detected from artificially contaminated wound dressing material, although the pattern of product ions detected was influenced by culture conditions.

CONCLUSIONS

Using selected product ions from the SIFT-MS mass spectra it is possible to discriminate wound-associated bacterial species grown under specific in vitro culture conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study have shown that wound-associated bacteria can be discriminated using volatile analysis in vitro and that bacterial volatiles can be detected from wound dressing material. This indicates that volatile analysis of wounds or dressing material to identify infecting microbes has potential and warrants further study.

Alterations in airway microbiota in patients with PaO2/FiO2 ratio ≤ 300 after burn and inhalation injury

BACKGROUND

Injury to the airways after smoke inhalation is a major mortality risk factor in victims of burn injuries, resulting in a 15-45% increase in patient deaths. Damage to the airways by smoke may induce acute respiratory distress syndrome (ARDS), which is partly characterized by hypoxemia in the airways. While ARDS has been associated with bacterial infection, the impact of hypoxemia on airway microbiota is unknown. Our objective was to identify differences in microbiota within the airways of burn patients who develop hypoxemia early after inhalation injury and those that do not using next-generation sequencing of bacterial 16S rRNA genes.

RESULTS

DNA was extracted from therapeutic bronchial washings of 48 patients performed within 72 hours of hospitalization for burn and inhalation injury at the North Carolina Jaycee Burn Center. DNA was prepared for sequencing using a novel molecule tagging method and sequenced on the Illumina MiSeq platform. Bacterial species were identified using the MTToolbox pipeline. Patients with hypoxemia, as indicated by a PaO2/FiO2 ratio ≤ 300, had a 30% increase in abundance of Streptococcaceae and Enterobacteriaceae and 84% increase in Staphylococcaceae as compared to patients with a PaO2/FiO2 ratio > 300. Wilcoxon rank-sum test identified significant enrichment in abundance of OTUs identified as Prevotella melaninogenica (p = 0.042), Corynebacterium (p = 0.037) and Mogibacterium (p = 0.048). Linear discriminant effect size analysis (LefSe) confirmed significant enrichment of Prevotella melaninognica among patients with a PaO2/FiO2 ratio ≤ 300 (p<0.05). These results could not be explained by differences in antibiotic treatment.

CONCLUSIONS

The airway microbiota following burn and inhalation injury is altered in patients with a PaO2/FiO2 ratio ≤ 300 early after injury. Enrichment of specific taxa in patients with a PaO2/FiO2 ratio ≤ 300 may indicate airway environment and patient changes that favor these microbes. Longitudinal studies are necessary to identify stably colonizing taxa that play roles in hypoxemia and ARDS pathogenesis.

Impact of hospital length of stay on the distribution of Gram negative bacteria and likelihood of isolating a resistant organism in a Canadian burn center

RATIONALE

The impact of hospital length of stay (LOS) on the distribution and susceptibility of Gram negative bacteria (GNB) causing infection in burn patients remains unexplored. Knowledge of causative pathogens is important in guiding empiric antibiotic therapy.

OBJECTIVES

To characterize the distribution of GNB causing infection and to identify changes in susceptibility with LOS in a tertiary care burn center.

METHODS

A retrospective review of all admissions to the Ross Tilley Burn Centre at Sunnybrook Health Sciences Centre with clinical cultures yielding GNB (duplicates excluded) between March 12, 2010 to July 17, 2013 was completed. Positive cultures were categorized into 5 clinically relevant time periods (in days) based on specimen collection date relative to the patient's date of admission: 0-7, 7-14, 14-21, 21-28, >28. Chi-square for proportions was used to compare the time periods.

RESULTS

The proportion of patients with clinical cultures for P. aeruginosa increased with hospital LOS (0-7 days: 8% vs. >28 days: 55%; p<0.05). Conversely, clinical cultures for H. influenzae occurred primarily within the first 7 days of hospitalization (0-7 days: 36% vs. >28 days: 0.7%; p<0.05). Enterobacteriaceae isolation was highest between 7 and 14 days of hospitalization (7-14 days: 62% vs. >28 days: 38%; p<0.05). Antibiotic resistance was directly proportional to hospital LOS (% patients with multidrug resistant GNB increased from 6% [LOS 0-7 days] to 44% [LOS>28 days]; p<0.05).

CONCLUSIONS

This study provides objective data documenting changes in species and resistance patterns of GNB causing infection in patients admitted to a burn center as a function of hospital LOS; which may support delaying the use of broad spectrum antibiotics (e.g. carbapenems and beta-lactam/beta-lactamase inhibitors) in clinically stable patients.

Prediction of multiple infections after severe burn trauma: a prospective cohort study

OBJECTIVE

To develop predictive models for early triage of burn patients based on hypersusceptibility to repeated infections.

BACKGROUND

Infection remains a major cause of mortality and morbidity after severe trauma, demanding new strategies to combat infections. Models for infection prediction are lacking.

METHODS

Secondary analysis of 459 burn patients (≥16 years old) with 20% or more total body surface area burns recruited from 6 US burn centers. We compared blood transcriptomes with a 180-hour cutoff on the injury-to-transcriptome interval of 47 patients (≤1 infection episode) to those of 66 hypersusceptible patients [multiple (≥2) infection episodes (MIE)]. We used LASSO regression to select biomarkers and multivariate logistic regression to built models, accuracy of which were assessed by area under receiver operating characteristic curve (AUROC) and cross-validation.

RESULTS

Three predictive models were developed using covariates of (1) clinical characteristics; (2) expression profiles of 14 genomic probes; (3) combining (1) and (2). The genomic and clinical models were highly predictive of MIE status [AUROCGenomic = 0.946 (95% CI: 0.906-0.986); AUROCClinical = 0.864 (CI: 0.794-0.933); AUROCGenomic/AUROCClinical P = 0.044]. Combined model has an increased AUROCCombined of 0.967 (CI: 0.940-0.993) compared with the individual models (AUROCCombined/AUROCClinical P = 0.0069). Hypersusceptible patients show early alterations in immune-related signaling pathways, epigenetic modulation, and chromatin remodeling.

CONCLUSIONS

Early triage of burn patients more susceptible to infections can be made using clinical characteristics and/or genomic signatures. Genomic signature suggests new insights into the pathophysiology of hypersusceptibility to infection may lead to novel potential therapeutic or prophylactic targets.

The year in burns 2013

Approximately 3415 research articles were published with burns in the title, abstract, and/or keyword in 2013. We have continued to see an increase in this number; the following reviews articles selected from these by the Editor of one of the major journals (Burns) and colleagues that in their opinion are most likely to have effects on burn care treatment and understanding. As we have done before, articles were found and divided into the following topic areas: epidemiology of injury and burn prevention, wound and scar characterization, acute care and critical care, inhalation injury, infection, psychological considerations, pain and itching management, rehabilitation and long-term outcomes, and burn reconstruction. The articles are mentioned briefly with notes from the authors; readers are referred to the full papers for details.