Burn Patient Population Research Articles

Utilizing the Heterogeneity of Clinical Data for Model Refinement and Rule Discovery Through the Application of Genetic Algorithms to Calibrate a High-Dimensional Agent-Based Model of Systemic Inflammation.

Introduction: Accounting for biological heterogeneity represents one of the greatest challenges in biomedical research. Dynamic computational and mathematical models can be used to enhance the study and understanding of biological systems, but traditional methods for calibration and validation commonly do not account for the heterogeneity of biological data, which may result in overfitting and brittleness of these models. Herein we propose a machine learning approach that utilizes genetic algorithms (GAs) to calibrate and refine an agent-based model (ABM) of acute systemic inflammation, with a focus on accounting for the heterogeneity seen in a clinical data set, thereby avoiding overfitting and increasing the robustness and potential generalizability of the underlying simulation model.Methods: Agent-based modeling is a frequently used modeling method for multi-scale mechanistic modeling. However, the same properties that make ABMs well suited to representing biological systems also present significant challenges with respect to their construction and calibration, particularly with respect to the selection of potential mechanistic rules and the large number of associated free parameters. We have proposed that machine learning approaches (such as GAs) can be used to more effectively and efficiently deal with rule selection and parameter space characterization; the current work applies GAs to the challenge of calibrating a complex ABM to a specific data set, while preserving biological heterogeneity reflected in the range and variance of the data. This project uses a GA to augment the rule-set for a previously validated ABM of acute systemic inflammation, the Innate Immune Response ABM (IIRABM) to clinical time series data of systemic cytokine levels from a population of burn patients. The genome for the GA is a vector generated from the IIRABM’s Model Rule Matrix (MRM), which is a matrix representation of not only the constants/parameters associated with the IIRABM’s cytokine interaction rules, but also the existence of rules themselves. Capturing heterogeneity is accomplished by a fitness function that incorporates the sample value range (“error bars”) of the clinical data.Results: The GA-enabled parameter space exploration resulted in a set of putative MRM rules and associated parameterizations which closely match the cytokine time course data used to design the fitness function. The number of non-zero elements in the MRM increases significantly as the model parameterizations evolve toward a fitness function minimum, transitioning from a sparse to a dense matrix. This results in a model structure that more closely resembles (at a superficial level) the structure of data generated by a standard differential gene expression experimental study.Conclusion: We present an HPC-enabled machine learning/evolutionary computing approach to calibrate a complex ABM to complex clinical data while preserving biological heterogeneity. The integration of machine learning, HPC, and multi-scale mechanistic modeling provides a pathway forward to more effectively representing the heterogeneity of clinical populations and their data.

573 A Novel Nursing Approach in Reducing Catheter-Associated Urinary Tract Infections in a Regional Burn Center

Abstract Introduction Catheter-associated urinary tract infections (CAUTI) adversely affect more than 30% of patients in critical care hospital settings. Considered one of the most prevalent of nosocomial infections, CAUTI are linked to extended hospital stays, rising health care costs, and increased morbidity and mortality. CAUTI are attributed to prolonged catheter use, contaminated catheter insertion, and improper care and maintenance. Adhering to infection control guidelines is essential in preventing CAUTI in healthcare institutions. To illustrate, nearly 380,000 CAUTIs could be prevented and 9,000 lives saved, annually, with the prevention of CAUTI (Centers for Disease Control and Prevention, 2019). Methods Over the last nine months, our burn team has been working to reduce the CAUTI Standardized Infection Ratio (SIR) and Standardized Utilization Ratio (SUR) in the Burn Center. Efforts to facilitate this reduction include the education of nurses and providers on the indications for placement, replacement, and removal of indwelling urinary catheters. We also developed and assigned a PowerPoint presentation and post-assessment to staff members to educate and measure their understanding of the proper care for patients with urinary catheters in place. The hospital facility’s protocol was revised to reflect the specific needs and alternatives for urinary catheters in our burn patient population. The new burn specific protocol now serves as a guideline for the multidisciplinary team during daily rounds to reduce the risk of CAUTI in the Burn Center. Charge Nurses continue regular audits. Results The SIR benchmark for 2019 was 0.774. The SIR for the Burn Center in the third quarter of 2019 was incalculable because the predicted number was less than one. The SIR for the fourth quarter of 2019 was 0.913. The SUR benchmark for 2019 was 1. The SUR for the Burn Center in the third and fourth quarters of 2019 were 1.035 and 1.150, respectively. This data indicated the need for a comprehensive plan for improvement. Following the implementation of our team’s comprehensive improvement plan, the SIR and number of infections for the first quarter of 2020 was zero, which is below the SIR benchmark 0.727 for 2020. The improvement plan we instituted also reduced the SUR to 0.897 for the first quarter of 2020, compared to the benchmark of one for 2020. The SUR rate for the second quarter was 1.118. Conclusions Instituting this simple nurse-driven protocol has resulted in a noteworthy improvement in patient outcomes. Achieving benchmark goals remains a significant priority to our burn center team as we continue to see the progress and health benefits of fostering the safest care environment for our patients, while remaining financially responsible to our institution.

614 Addressing Increasing Mental Health Needs in Burn Patient Population: Dedicated Burn Center Psychologist

Abstract Introduction During the past four years, mental health coverage at our burn center has evolved and become more robust. The emotional aspects of burn recovery are well documented; patients often present with co-morbid psychological conditions and develop psychological conditions as a result of the traumatic experience of their injury and subsequent hospitalization. To address this need, our burn center created a burn psychology fellowship and hired a dedicated full-time attending psychologist. Methods The burn center medical director has advocated for increased mental health support for several years. Mental health support was initially provided by the Psychiatry Consultation-Liaison team, and primarily focused on medication management for patients with severe mental illness. Recognizing the need for additional support, the burn center hired a part-time psychologist. After two years of part-time dedicated psychology coverage, a full-time position was approved. Through quantitative data review over the past several years, the number of patients with psychiatric diagnoses and the number of patients connected to mental health treatment during their hospitalization was analyzed. Results The overall patient census at the burn center has increased over the past several years (n=319 FY2016 vs n=506 FY2020). Burn patients with mental health diagnoses has increased along with and beyond the overall patient census growth; 34% (n=173) of patients admitted had a documented psych diagnosis in FY2020 compared to just 21% (n=68) of patients admitted in FY2016. Conclusions Integrating full-time psychology coverage dedicated to the burn center has allowed our patients to be evaluated and treated sooner, which has resulted in shortened time to psychotherapy and psychiatric medication management, and improved discharge planning to include outpatient mental health treatment. A full-time burn psychologist has improved holistic patient care of our burn patient population to positively aid in their overall recovery process.

527 Use of Bioelectrical Impedance Analysis for Assessing Phase Angle, Hydration Status, and Predicting Outcomes in Critically Ill Patients: A Systematic Review and Meta-Analysis

Abstract Introduction Bioelectrical impedance analysis (BIA) is a simple, noninvasive method of assessing body composition. BIA operates by sending a low-voltage electric current through the body and measuring the impedance to that current. Parameters obtained from BIA have been used to investigate a range of variables such as nutrition and hydration status in a variety of patient populations. Phase angle is also a unique parameter that is thought to reflect cellular health. BIA parameters can undergo further analysis by bioelectrical impedance vector analysis (BIVA) which can provide information about hydration status. Burn and critical care patients pose a unique challenge because they are particularly sensitive to fluid shifts and metabolic derangements which are associated with poorer outcomes. The utility of BIA and BIVA in this patient population has not been well studied. Thus, we have conducted a systematic review and meta-analysis of the ability of BIVA and BIA parameters to assess cellular health and hydration status in critically ill adults and whether they can be correlated with outcomes. Methods A search was performed on PubMed and Google Scholar in accordance with PRISMA guidelines between June 2020-August 2020 utilizing the keywords: bioelectrical impedance analysis, critical care, critical, body composition, phase angle, water, fluid. Inclusion criteria were articles investigating the relationship between BIA, BIVA and outcomes with regards to phase angle, hydration, and fluid status in critically ill adults. Reviews, non-English articles, and studies involving pediatric patients were excluded. A meta-analysis was conducted on the correlation between mean phase angle and mortality. Results The final analysis included 21 articles; 4 articles were included in the meta-analysis. Statistically significant correlations were found between phase angle and mortality in 9/13 articles, hospital length of stay in 4/7 articles, ICU length of stay in 5/7 articles, and mechanical ventilation duration in 1/4 articles. For meta-analysis, mean phase angle in survivors and non-survivors was 4.5 and 3.9 respectively, and this difference was statistically significant (Figure 1, p< 0.01). Significant correlations were found between ECW/TBW and mortality in 4/7 articles, and BIVA derived hydration status and mortality in 6/7 articles. Conclusions BIA and BIVA may be used as a prognostic indicator for outcomes in critical care patients. Further investigations are needed to explore this relationship in the burn patient population.

652 Burns and Incidence of Operative Treatment

Abstract Introduction Over the past three decades, it has been repeatedly demonstrated that early surgical intervention is associated with improved outcomes in burns, however, large-scale studies regarding the incidence of operative treatment in burn patients are lacking. We conducted a retrospective study using the TriNetX database, a global, real-time electronic medical record driven index of patient populations, analyzing the incidence of grafting procedures in burned patients related to age and % total body surface area (TBSA) burned. Methods The population of burn patients and operative treatments were indexed using ICD-10 codes T31.0-T31.9 and 1013913, respectively. Queries were structured as sequential events allowing analysis of burn diagnosis to be followed by a subsequent operation. The patient population was partitioned by TBSA burned, and the number of grafting procedures were assessed. All patients were included and stratified by ages of 0–17, 18–34, 35–64, and 65–89. The data includes information collected between 2000–2020 from over 35 healthcare organizations comprising the Research network in TriNetX. Extracted data were analyzed using chi-square statistical analysis with p< 0.05 considered significant. Results Of 116,325 burn patients identified, 11.14% underwent at least one grafting procedure. Of surgeries performed, the majority occurred in the 35–64 years age group (45.3% p = < 0.001). Additionally, the incidence of grafting procedures was directly proportional to patient age: age groups of 0–17, 18–34, 35–64, and 65–89 years received grafting procedures in 6.5% (p = < 0.001), 9.8% (p = < 0.001), 12.9% (p = < 0.001), and 15.9% (p = < 0.001) of cases, respectively. When stratified by TBSA burned, those with 40–49% TBSA burns had the highest incidence of operations (50.7% p = < 0.001). Large TBSA burns correlated with increasing incidence of grafting procedures until 50–59% TBSA burned, where incidence begins to decrease, likely related to referral patterns which did not capture grafting procedures performed at specialized burn treatment centers or institution of palliative care. Conclusions This study reveals that the incidence of operational treatment increases with both age and percent TBSA burned. The data corroborate a referral pattern for burns that demonstrates a decline in operative treatments beginning with 50–59% TBSA, inconsistent with referral guidelines to specialized burn care centers published by the ABA.

22 Acute Kidney Injury in Burn Patients Following Combination Antibiotic Therapy: A Large Database Analysis

Abstract Introduction Burn patients are prone to infections, which often warrants broad-spectrum antibiotic coverage. Vancomycin is a common antibiotic used at burn centers and is administered alone, or in combination with other agents such as piperacillin-tazobactam (Pip/Tazo). A recent study showed that this combination therapy was associated with increased rates of acute kidney injury (AKI) in adult and pediatric burn patients when compared to vancomycin in combination with other antibiotics. However, other studies failed to demonstrate these findings. The degree of nephrotoxic effect of the combination therapy relative to its drug components has not been demonstrated in burn patients. Using a large national database encompassing 41 health care organizations, we sought to determine whether a combination of vancomycin and Pip/Tazo exacerbates AKI in burn patients. Methods Using the TriNetX Global Health Research Network, we identified the population of burn patients with ICD-10 codes T20-T25 and T30-T32 between 2000–2020. We then grouped this population into 4 cohorts based on the administration of broad-spectrum antibiotics they received after the burn incident: vancomycin, Pip/Tazo alone, combination, and neither vancomycin nor Pip/Tazo. All cohorts were balanced for age, gender, and race. We explored the distribution of these cohorts and conducted comparative outcome analysis to determine the relative risk of developing AKI using the ICD10 code N17. Results Comparative analysis showed burn patients who received vancomycin had a 4.81% increased associated risk with AKI compared to those who did not receive either vancomycin or Pip/Tazo (p< 0.0001, RR =3.35, 95%CI= 2.63–4.26). Patients who received Pip/Tazo monotherapy had a 5.1% increased association with AKI compared to those who did not receive either drug (p< 0.0001, RR =3.57, 95%CI: 2.33–5.45). The combination of vancomycin with Pip/Tazo increased the association with AKI by 9.49% compared to patients who did not receive either drug (p< 0.00001, RR=5.65, 95%CI: 4.40–7.26). Combination therapy also increased the risk of AKI when compared to the vancomycin monotherapy (5.01%, p< 0.00001, RR= 1.69, 95%CI: 1.42–2.00) and Pip/Tazo monotherapy (4.85%, p< 0.00002, RR= 1.62, 95%CI: 4.40–7.26). Conclusions The use of broad-spectrum antibiotics in burn patients is associated with a higher risk of AKI. The combination of these drugs affords an increased relative risk of AKI when compared to monotherapy with the respective component drugs. Whether this is associated with selection bias or drug-effect warrants further investigation.

523 Retrospective Outcomes Analysis of Tracheostomy in Paediatric Burn Population

Abstract Introduction For decades, controversy has raged regarding the placement of tracheostomy in severe paediatric burns. Numerous variables including extent of smoke inhalation injury, % TBSA burned, age of the patient, and co-morbidities among others complicate reaching consensus. Furthermore, paediatric patients are particularly susceptible to complications including inadvertent loss of airway and long-term swallowing and other anatomic issues. Additionally, previous analysis of the efficacy of tracheostomy in paediatric burn patients appears to be hindered by a lack of nationwide analysis. The aim of this study was to explore the efficacy of tracheostomy in the general paediatric burn patient population. Methods De-identified patient data was obtained from the TriNetX Research Network database. Two cohorts were identified: paediatric burn patients with tracheostomy (cohort A) and paediatric burn patients without tracheostomy (cohort B). Burn patients were identified using the ICD-10 codes T20-T25 & T30-T32. Tracheostomy was identified using the ICD-10 codes 1005887, 1014613, 31600, 31601, 31603, 31604, 31610, and Z93.0. A total of 132 patients were identified in cohort A in 23 HCOs and 83,117 patients were identified in cohort B in 38 HCOs. Infection, hypovolemia, pulmonary injury, laryngeal injury, pneumonia, and death were compared between the cohorts. Results Cohort A had a mean age of 11 (SD=5) and Cohort B had a mean age of 9 (SD=5). Paediatric burn patients with tracheostomy had a higher risk for death, infection, hypovolemia, pulmonary injury, laryngeal injury, and pneumonia when compared to their non-tracheostomy counterparts. The risk ratios for these outcomes were 62.452, 4.713, 9.267, 26.483, 116.163, and 18.154, respectively. Conclusions The analysis of the longitudinal outcomes of pediatric burn patients with tracheostomy as compared to those without tracheostomy demonstrated the tracheostomy cohort suffered much worse mortality and morbidity across several metrics. The potential benefits of tracheostomy placement in pediatric burn patients should be weighed against these outcomes.

Single-center Experience with Venous Thromboembolism Prophylaxis for Obese Burn Patients.

Burn injured patients are at high risk of thromboembolic complications. Morbid obesity further increases this risk. Our objective was to evaluate the efficacy of enoxaparin dosed 40 mg twice daily in achieving prophylactic plasma anti-Xa levels in obese burn patients. A retrospective chart review from November 2018 until September 2019 identified patients who were either ≥100 kg or had a body mass index ≥30 kg/m2 and initiated on enoxaparin 40 mg twice daily for venous thromboembolism prophylaxis. Patients were ≥18 yr of age and received ≥3 sequential doses of enoxaparin with appropriately timed peak plasma anti-Xa levels to monitor efficacy. One hundred forty-eight patients were screened with 43 patients included for analysis. Forty-two percent of the patients did not reach target peak plasma anti-Xa levels (0.2-0.5 IU/ml) on enoxaparin 40 mg twice daily. Patients who did not meet prophylactic target levels were more likely to be male (P < 0.05) and have an increased mean body weight (129 ± 24 kg vs 110 ± 16 kg, P < 0.05). Thirteen out of 18 patients received dosage adjustments with subsequent anti-Xa levels available for follow-up assessment, of which an additional six patients required further dosage adjustment to meet prophylactic goals. Current utilization of a fixed 40 mg twice daily regimen of enoxaparin for venous thromboembolism (VTE) is inadequate to meet target prophylactic peak plasma anti-Xa levels in the obese burn patient population. Dose adjusting enoxaparin to target anti-Xa levels to reduce VTE rates in obese burn patients should be further evaluated.

Upper Airway Burn Injury

Airway burn injury continues to be a significant cause of morbidity and mortality in the burn patient population. It is essential to identify patients with potential airway obstruction and also to avoid potential complications of airway manipulation in those with less severe injury. In this review, the initial evaluation and management of airway burn injuries will be discussed, including indications for observation versus intubation versus tracheotomy. Additionally, the long term sequelae of upper airway burn injury and management of these consequences will be reviewed.

Observed concentrations of amikacin and gentamycin in the setting of burn patients with gram-negative bacterial infections: Preliminary data from a prospective study

Critically ill populations often have shown subtherapeutic aminoglycosides' concentrations mostly because of unavoidable changes in drug volume distribution and clearance. We present a real life prospective study evaluating plasma concentrations for once-daily dosing for amikacin and gentamycin among a population of severe burn adults. We conducted a real life prospective study on the plasma observed concentrations of amikacin and gentamycin among severe burn patients, using aminoglycoside as combination therapy. Antibiotics were prescribed at the standard doses of 15-20mg/kg/day for amikacin and 3-5mg/kg/day for gentamycin. Eight patients (4 in amikacin and 4 in gentamycin groups, respectively) were enrolled in the study. All subjects were admitted for severe burns. The most common site of infection was bloodstream (5; 62.5%) and pneumonia (4; 50%). Pseudomonas aeruginosa, followed by Klebsiella pneumoniae and multi-drug resistant Acinetobacter baumannii were the most prevalent agents isolated. Amikacin and gentamycin never achieved the target peak concentration of 60mg/L and 30mg/L: in our study Cmax, for amikacin, was 33.1±15.6mg/L (SD), while for gentamycin was 14.3mg/L±9. Cmax and total body surface area have shown a strong negative correlation with borderline statistical significance (amikacin: ρ=0.922, P=0.078; gentamycin: ρ=0.937, P=0.063). At the standard dosage, the pharmacokinetic/pharmacodynamic (PK/PD) target of Cmax>8×highest MIC was reached for 8 (53.3%) out of 15 isolated pathogens. The present study found that, in a population of septic burn patients, standard doses of gentamycin and amikacin most often lead to plasma concentrations under the PK/PD target.

784 Automated SIRS Alert Systems Are Ineffective at Predicting Sepsis in Burn Patients

Abstract Introduction Burn injury patients represent a population at particularly high risk for sepsis and sepsis mortality due to the severe immunological insult. Because of the unique nature of burn injury, this population has largely been excluded from studies developing protocols for identification and treatment of sepsis. In our institution, the protocolized approach to sepsis starts with an alert if two SIRS criteria are met, regardless of the patient’s diagnosis. We examined whether the SIRS alert was an effective way to identify and treat sepsis in burn patients. Methods Patients admitted to the burn surgery service at an academic regional burn center were identified by querying the “SIRS alert” dashboard from the hospital’s quality and safety department. The dashboard is a record of every patient whose clinical status triggered a SIRS alert during hospital admission, and whether a screening order set was opened. The SIRS alert and order set usage data were analyzed directly from the dashboard. Each patient’s chart was then reviewed to decide whether there was clinical suspicion of sepsis at the time an order set was released. We determined that there was clinical suspicion of sepsis if antibiotics were initiated or escalated within 6 hours of a SIRS screening order set being opened. Results From January 1, 2019 until September 14, 2019 there were 225 patients admitted to the burn surgery service at an academic regional burn center. 70 patients, specifically receiving treatment in the burn ICU, met the criteria to trigger a SIRS alert at least once in that time. Across those 70 patients, a total of 1381 SIRS alerts were acknowledged by the nursing staff. Due to a lack of clinical suspicion for sepsis, the SIRS screening order set was opened 8.5% of the time an alert was acknowledged. Only two times in the 1381 alerts was an order set opened and then followed by the initiation or escalation of antibiotics within 6 hours. Conclusions SIRS criteria appear to be ineffective at helping clinicians to identify and treat sepsis in the burn patient population. This is consistent with the fact that burn patients are in a virtually constant state of inflammation, making SIRS alerts futile at picking up subtle changes that could indicate early sepsis. Applicability of Research to Practice Hospitals should abandon the use of the standard SIRS criteria as a starting point for sepsis protocols when treating burn patients. There does not yet exist a validated criteria set to replace the standard SIRS criteria. In the meantime, the Burn Sepsis Consensus Conference definitions could be used as a guideline to modify the criteria, and future research should continue seeking to identify early predictors of sepsis in the burn population.

774 Examination of the Religious and Spiritual Needs of Acutely Injured Burn Patients

Abstract Introduction Despite advances in burn care that dramatically increase survivability for severe burn injuries, individuals who suffer such injuries will likely experience long recovery periods complicated by declines in psychological, social, behavioral, occupational, and sexual functioning. We compared the self-importance of spirituality in a patient’s life with select demographic data in order to better understand the role of spirituality in the treatment and recovery of patients in the Burn Intensive Care Unit (BICU). Methods In this survey study and subsequent retrospective review, we explored the importance of spiritual beliefs and practices to the burn patient population within the BICU. We utilized the Belief into Action Scale (BIAC), which is a validated survey tool designed to quantify the full range of an individual’s religious involvement. Each participant completed one BIAC survey during his or her inpatient stay. We then collected patient demographics, including religious affiliation and the number of pastoral visits received. Injury characteristics and outcome measures were examined including, Total Body Surface Area (TBSA) burn, length of stay (LOS), and Charlson Comorbidity Index (CCI). Results Between April and June of 2019, surveys were administered to 32 adult participants. The participants ranged in age from 21 to 83 (mean 52.5), 59% (19/32) were male and 41% (13/32) were female. Of the 32 participants, 69% were Caucasian, 25% were African American, 3% were Hispanic/Latino, and 3% were other. Sixty-six percent (21/32) had no religious affiliation identified within their medical record and 31% (10/32) of patients had at least 1 pastoral visit (range 0–5 visits). TBSA ranged from 0% (10/32) to 35%, seven (22%) participants had an inhalation injury, the most common mechanism of burn injury was flame (43.75%), and the average length of stay was 16 days (range 1–75 days). Mean BIAC score was 44.8 (out of 100), with a median of 46.5 and a standard deviation of 22.6, indicating a moderate degree of spiritual and religious beliefs. Conclusions Acutely injured burn patients, admitted to an urban burn center, report a moderate degree of spiritual and religious beliefs, strongly supporting the need for pastoral care in this population. Applicability of Research to Practice The increased likelihood of survival for severely burn injured patients has led to the need for a greater emphasis on the potential psychological and social morbidity for these individuals. This research highlights the importance of addressing the spiritual needs of burn patients.

90 Efficacy of Topical Antimicrobial Agents Against Bacterial Isolates from Burn Wounds

Abstract Introduction Topical antimicrobials are key to prevention of infection and mortality in the acute burn patient population. The purpose of this study was to determine the effectiveness of commercially available and in-house compounded topical preparations. Methods One hundred isolates from 15 different microorganisms were used to evaluate topical antimicrobial effectiveness. The isolates included 40 Gram-positive and 60 Gram-negative microorganisms. Sixteen multidrug-resistant organisms were included in the study. The study was conducted using the Nathan Topical Well Assay method to assess in-vitro activity. Twenty-two various irrigation solutions and ointments were tested. Since there are no standardized zones to determine susceptibility for topical antimicrobials, any zone of inhibition (&amp;gt;8 mm) was considered to show effectiveness. Results The compounds 1:1:1 + DAB (1 part bacitracin: 1 part silver sulfadiazine: 100,000 units per gram nystatin + 5mg/gram neomycin sulfate + 500 units/gram polymyxin B) and 3:1 + DAB (3 part bacitracin: 1 part silver sulfadiazine + 5mg/gram neomycin sulfate + 500 units/gram polymyxin B) in both irrigation and ointment dosage form demonstrated 100% effectiveness against all isolates. Sodium hypochlorite 0.5% solution appeared to be very effective against gram-negative organisms, but moderately effective against gram-positive organisms. Double antibiotic solution was highly effective against all gram-negative bacteria. 3:1 ointment and 1:1:1 ointment were highly effective against gram-positive organisms and moderately effective against gram-negative organisms. The data indicates that many of the topical antimicrobials target certain bacteria more readily than others. Besides 1:1:1 + DAB and 3:1 + DAB, it shows that more than one drug product is necessary to demonstrate adequate killing ability of a broad spectrum of organisms. Multidrug resistant organisms also indicate more resistance against topical antimicrobials. The only compounds that showed a high degree of effectiveness against MDROs were sodium hypochlorite 0.5% solution, 1:1:1 + DAB ointment and solution, and 3:1 + DAB ointment and solution. Conclusions The bacitracin and silver sulfadiazine component of 3:1 and 1:1:1 has a high degree of effectiveness against Gram-positive organisms. Double antibiotic ointment was moderately effective against Gram-negative organisms. However, when the two were combined into one ointment it created a synergistic effect, which killed all the organisms tested. Applicability of Research to Practice Antimicrobial effectiveness and adverse effects must be considered when selecting the appropriate topical agent to be used on wounds. Further research is needed to determine the production of resistant bacteria and topical antimicrobials and the clinical usefulness of topical antimicrobial susceptibilities.

512 Single Center Experience with Venous Thromboembolism Prophylaxis for Obese Burn Patients

Abstract Introduction Burn injured patients are at high risk of thromboembolic complications. Morbid obesity further increases risk for thromboembolic complications. Recent evidence supports the use of anti-Xa guided enoxaparin dosing for the prevention of venous thromboembolism (VTE) in high risk populations. Our objective was to evaluate the efficacy of enoxaparin 40mg twice daily in achieving prophylactic plasma anti-Xa levels in obese burn patients. Methods A retrospective chart review of an ABA-verified burn center from November 2018 until September 2019 identified patients who were either ≥100 kilograms (kg) or had a body mass index (BMI) ≥ 30 kg/m2 and were initiated on enoxaparin 40 mg twice daily for VTE prophylaxis. Patients were included if they were at least 18 years of age and received at least three sequential doses of enoxaparin with appropriately timed peak plasma anti-Xa levels to monitor efficacy. Patient demographics were analyzed, as well as body weight, BMI, and total body surface area (TBSA) burn. Statistical analysis was performed with student’s t-test for continuous data and Fischer’s exact test for categorical data. Results During the study period, 148 patients were screened with 44 patients included for analysis. Forty-one percent of the patients evaluated did not reach target peak plasma anti-Xa levels (0.2–0.5 IU/mL) on enoxaparin 40 mg twice daily. Patients who did not meet prophylactic target levels were more likely to be male (p&amp;lt; 0.05) and have an increased body weight (129 +/- 24 kg versus 112 +/- 17 kg, p&amp;lt; 0.05). Eleven out of 18 patients received dosage adjustments with subsequent anti-Xa levels available for follow-up assessment, of which an additional four patients required further dosage adjustment to meet goal peak plasma levels. Conclusions Current utilization of a fixed 40 mg twice daily regimen of enoxaparin for VTE prophylaxis is inadequate to meet target prophylactic peak plasma anti-Xa levels in the obese burn patient population. Dose adjusting enoxaparin to target peak plasma anti-Xa levels to reduce VTE rates in obese burn patients should be further evaluated. Applicability of Research to Practice This study demonstrates the need for more accurate dosing and evaluation of our dosing practices for VTE prevention. It also demonstrates the importance of having a Burn dedicated pharmacist in facilitating appropriate care.

Tunneled central venous catheterization, a viable option for long-term venous access in pediatric burn patients

Introduction: Pediatric patients with severe burns often require long-term venous access over the course of their recovery. The need for long-term venous access in these critically ill patients often necessitates the placement of a central venous catheter (CVC). Many techniques exist for the establishment of a CVC in pediatric burn patients, and each technique poses its own set of inherent risks. No studies to date have clearly delineated the risk associated with tunneled central venous catheterization in the pediatric burn patient population. The primary aim of this study was to evaluate the use of tunneled CVCs in pediatric burn patients at the University Medical Center Hospital in Lubbock, Texas.&#x0D; Methods: To evaluate this method of central venous catheterization, we retrospectively reviewed the charts of pediatric burn patients who received a tunneled CVC to determine the incidence of specific complications associated with this catheterization technique. We present our findings here in a case series format.&#x0D; Results: Our initial search of patient charts yielded 86 potential candidates for inclusion in the study. After reviewing each chart, 26 pediatric patients were found to have received a CVC. Of these 26 patients, five met all of the inclusion criteria of our study. In these five patients, eight tunneled CVCs were placed. The average age of the patients in this series at the time of their respective burn injuries was 3.9 years old. Mean percent TBSA involvement was 38% with an average length of stay totaling 64.6 days. The average dwell time of the tunneled CVCs in this series was 28 days, and our analysis of the data revealed one tunneled catheterrelated infection and one hemodynamic complication.&#x0D; Conclusions: Overall, our data show that placement of long-term tunneled CVCs in pediatric burn patients appears to be a relatively safe practice. However, our small sample size warrants more investigation into this topic.Keywords: pediatrics, burns, central vein catheters

Cost-effectiveness and value of information analysis of a low-friction environment following skin graft in patients with burn injury

BackgroundPatients with burn injuries may receive a skin graft to achieve healing in a timely manner. However, in around 7% of cases, the skin graft is lost (fails to attach to the wound site) and a re-grafting procedure is necessary. It has been hypothesised that low-friction (smooth, more slippery) bedding may reduce the risk of skin-graft loss. A before and after feasibility study comparing low-friction with standard bedding in skin-grafted patients was conducted in order to collect proof of concept data. The resulting relative risk on the primary outcome (number of patients with skin graft failure) for the non-randomised study provided no evidence of effect but had a large standard error. The aim of this study is to see if an appropriately powered randomised control trial would be worthwhile.MethodsA probabilistic decision-analytic model was constructed to compare low-friction bedding to standard care in a population of burn patients who have undergone skin grafting. Results from the before and after study were used as model inputs. The sensitivity of results to bias in the relative risk of graft loss was conducted. Low-friction bedding is considered optimal if expected incremental net benefit (INB) is positive. Uncertainty is assessed using cost-effectiveness acceptability curves. Expected Value of Perfect Partial Information (EVPPI) provides an upper bound for the potential net health benefits of new research for given model input.ResultsAt a willingness to pay threshold of £20,000 per QALY, INB = £151 (95% Credible Interval (CrI) −142 to 814), marginally favouring low-friction bedding but with high uncertainty (probability of being cost-effective 70.5%). Expected value of perfect information (EVPI) per patient was £20.29, which results in a population EVPI of £174,765 over a 10-year lifetime for the technology (based on 1000 patients per year who would benefit from the intervention). The parameter contributing most to the uncertainty was the inpatient care cost, i.e. information that could be obtained from the audit of practice and without an expensive trial. These findings were robust to a wide-range of assumptions about the potential bias due to the observational nature of the comparative evidence.ConclusionsOur study results suggest that an RCT (randomised controlled trial) is unlikely to be worthwhile, but there may be value in a study to estimate the re-graft rates and associated costs in this population.

Obesity Paradox in the Burn Patient.

Despite the fact that obesity is a known risk factor for comorbidities and complications, there is evidence suggesting a survival advantage for patients classified by body mass index (BMI) as overweight or obese. Investigated in various clinical areas, this "Obesity Paradox" has yet to be explored in the burn patient population. We sought to clarify whether this paradigm exists in burn patients. Data collected on 519 adult patients admitted to an American Burn Association Verified Burn Center between 2009 and 2017 was utilized. Univariable and multivariable logistic regression were used to determine the association between in-hospital mortality and BMI classifications (underweight <18.5 kg/m2, normal 18.5 to 24.9 kg/m2, overweight 25-29.9 kg/m2, obesity class I 30 to 34.9 kg/m2, obesity class II 35 to 39.9 kg/m2, and extreme obesity >40 kg/m2). For every kg/m2 increase in BMI, the odds of death decreased, with an adjusted odds ratio of 0.856 (95% confidence interval [CI] 0.767 to 0.956). When adjusted for total BSA (TBSA), being obesity class I was associated with an adjusted odds ratio of mortality of 0.0166 (95% CI 0.000332 to 0.833). The adjusted odds ratio for mortality for underweight patients was 4.13 (95% CI 0.416 to 41.055). There was no statistically significant difference in odds of mortality between the normal and overweight BMI categories. In conclusion, the obesity paradox exists in burn care: further investigation is needed to elucidate what specific phenotypic aspects confer this benefit and how these can enhance the care of burn patients.

Modifiable risk factors for multidrug-resistant Gram-negative infection in critically ill burn patients: a systematic review and meta-analysis.

We conducted a systematic review and meta-analysis to identify potentially modifiable risk factors for multidrug-resistant Gram-negative colonization or infection in critically ill burn patients. A systematic search was conducted of PubMed, Embase, CINAHL, Web of Science and Central (Cochrane). Risk factors including antibiotic use and hospital interventions were summarized in a random-effects meta-analysis. Risk of publication bias was assessed using the Grading of Recommendations Assessment, Development and Evaluation method and funnel plots. A total of 11 studies met the inclusion criteria. We identified several potentially modifiable risk factors and were able to grade their importance based on effect size. Related to prior antibiotic exposure, extended-spectrum cephalosporins (pooled odds ratio (OR) 7.00, 95% confidence interval (CI) 2.77-17.67), carbapenems (pooled OR 6.65, 95% CI 3.49-12.69), anti-pseudomonal penicillins (pooled OR 4.23, 95% CI 1.23-14.61) and aminoglycosides (pooled OR 4.20, 95% CI 2.10-8.39) were most significant. Related to hospital intervention, urinary catheters (pooled OR 11.76, 95% CI 5.03-27.51), arterial catheters (pooled OR 8.99, 95% CI 3.84-21.04), mechanical ventilation (pooled OR 5.49, 95% CI 2.59-11.63), central venous catheters (pooled OR 4.26, 95% CI 1.03-17.59), transfusion or blood product administration (pooled OR 4.19, 95% CI 1.48-11.89) and hydrotherapy (pooled OR 3.29, 95% CI 1.64-6.63) were most significant. Prior exposure to extended-spectrum cephalosporins and carbapenems, as well as the use of urinary catheters and arterial catheters pose the greatest threat for infection or colonization with multidrug-resistant Gram-negative organisms in the critically ill burn patient population.

Pharmacokinetics of meropenem in burn patients with infections caused by Gram-negative bacteria: Are we getting close to the right treatment?

Infections caused by multidrug-resistant Gram-negative bacteria are associated with high mortality. A relevant concern is the efficacy of antibiotic therapy in burn patients in whom pathophysiological changes strongly influence pharmacokinetic (PK) parameters. This study aimed to describe the PK parameters of meropenem in a population of burn patients. Blood samples were collected immediately before and 2 h and 5 h after the start of intravenous drug administration. Plasma meropenem concentrations were determined using an ultra-performance liquid chromatography-photodiode array method. Seventeen burn patients were enrolled in the study. Thirteen patients (76%) were treated with meropenem for infections byPseudomonas aeruginosa or Acinetobacter baumannii isolated from blood or wounds. Mean Cmax, Cmin, AUC0-24, half-life, drug clearance and volume of distribution were 28.9 mg/L, 3.7 mg/L, 280.2 mg h/L, 2.0 h, 19.0 L/h and 44.4 L, respectively. Six patients (35%) achieved a Cmin ≥3.3 mg/L and seven patients (41%) achieved a Cmax ≥ 28.4 mg/L, whilst nine patients (53%) achieved an AUC0-24 of >226 mg h/L. Given a minimum inhibitory concentration (MIC) of 0.5 mg/L, all patients satisfied the target AUC/MIC of >125, but when the MIC rises to 2 mg/L (the ECOFF), only five patients reached the desired AUC/MIC. Regarding fT>MIC at an MIC of 2 mg/L with a 2-h infusion time, 13 patients (76%) achieved the PK target (>75%). These data suggest that a combined 2-h infusion with a higher dosage of meropenem, including a loading dose, may be successful to achieve effective PK parameters.

ECMO in the Burn Patient: the Time Has Come

The use of extracorporeal life support in the intensive care unit has exponentially increased in the last decade. Initially, its use in the burn population lagged behind the dramatic growth in other patient populations; however, in the last 2–3 years, there has been an increase in the number of publications related to its use in this population. In this article, we review the use of contemporary ECMO in the burn patient population and discuss future trends. Level 1 evidence for the use of ECMO in any patient population is scarce, and there is no level 1 evidence for the use of ECMO in burn patients. Recently, there has been an increase in case series and case reports describing the use of contemporary ECMO in burn patients. In addition, there are two large retrospective reviews of large registries utilizing ECMO in burn patients. The results from these studies all indicate that outcomes using ECMO in this critically ill patient population has survival rates at least comparable to the survival found in other patient populations. There are still many unanswered questions, and future focus needs to address patient selection, timing of initiation, management, and the duration of ECMO therapy.