Toward targeted early burn care: lessons from a European survey

A Deep Learning Image-to-Image Translation Approach for a More Accessible Estimator of the Healing Time of Burns

OBJECTIVE

An accurate and timely diagnosis of burn severity is critical to ensure a positive outcome. Laser Doppler imaging (LDI) has become a very useful tool for this task. It measures the perfusion of the burn and estimates its potential healing time. LDIs generate a 6-color palette image, with each color representing a healing time. This technique has very high costs associated. In resource-limited areas, such as low- and middle-income countries or remote locations like space, where access to specialized burn care is inadequate, more affordable and portable tools are required. This study proposes a novel image-to-image translation approach to estimate burn healing times, using a digital image to approximate the LDI.

METHODS

This approach consists of a U-net architecture with a VGG-based encoder and applies the concept of ordinal classification. Paired digital and LDI images of burns were collected. The performance was evaluated with 10-fold cross-validation, mean absolute error (MAE), and color distribution differences between the ground truth and the estimated LDI.

RESULTS

Results showed a satisfactory performance in terms of low MAE ( 0.2370 ±0.0086). However, the unbalanced distribution of colors in the data affects this performance.

SIGNIFICANCE

This novel and unique approach serves as a basis for developing more accessible support tools in the burn care environment in resource-limited areas.

Reliability and feasibility of skeletal muscle ultrasound in the acute burn setting

OBJECTIVES

Despite the impact of muscle wasting after burn, tools to quantify muscle wasting are lacking. This multi-centre study examined the utility of ultrasound to measure muscle mass in acute burn patients comparing different methodologies.

METHODS

B-mode ultrasound was used by two raters to determine feasibility and inter-rater reliability in twenty burned adults following admission. Quadriceps muscle layer thickness (QMLT) and rectus femoris cross-sectional area (RF-CSA) were measured, comparing the use of i) a single versus average measurements, ii) a proximal versus distal location for QMLT, and iii) a maximum- versus no-compression technique for QMLT.

RESULTS

Analysis of twenty burned adults (50 years [95%CI 42-57], 32%TBSA [95%CI 23-40]) yielded ICCs of> 0.97 for QMLT (for either location and compression technique) and> 0.95 for RF-CSA, using average measurements. Relative minimal detectable changes were smaller using no-compression than maximum-compression (6.5% vs. 15%). Using no-compression to measure QMLT was deemed feasible for both proximal and distal locations (94% and 96% of attempted measurements). In 9.5% of cases maximum-compression was not feasible. 95% of RF-CSA measurements were successfully completed.

CONCLUSION

Ultrasound provides feasible and reliable values of quadriceps muscle architecture that can be adapted to clinical scenarios commonly encountered in acute burn settings.

The Impact of Ambient Temperature Control Across Various Care Settings on Outcomes in Burn Patients: A Review Article

Ambient/room temperature settings in burn treatment areas vary greatly due to a lack of evidence-based guidelines to direct care. While it is generally understood that ambient/room temperature impacts patient body temperature and metabolism, the ideal settings for optimizing patient outcomes are unclear. The literature assessing this topic is scarce, with many of the articles having significant limitations. We aim to summarize the current evidence for ambient/room temperature control, to address gaps in current reviews addressing this topic, and to elucidate topics requiring further research. PubMed and Google Scholar databases were queried for studies which evaluated the effect of the ambient/room temperature on burn patient core body temperature, patient metabolism, and outcomes among those treated in trauma bays, burn ICUs, and operating rooms. Although existing literature lacks sufficient patient outcome data regarding specific ambient/room temperatures, we highlight physiological processes that are impacted by changes in room temperatures in an effort to describe strategies that can allow for improved patient core body temperature control and outcomes in burn care settings.

Evidence Based Burn Depth Assessment Using Laser-Based Technologies: Where Do We Stand?

Early clinical assessment of burn depth and associated healing potential (HP) remains extremely challenging, even for experienced surgeons. Inaccurate diagnosis often leads to prolonged healing times and unnecessary surgical procedures, resulting in incremental costs, and unfavorable outcomes. Laser Doppler imaging (LDI) is currently the most objective and accurate diagnostic tool to measure blood flow and its associated HP, the main predictor for a patient's long-term functional and aesthetic outcome. A systematic review was performed on non-invasive, laser-based methods for burn depth assessment using skin microcirculation measurements to determine time to healing: Laser Doppler flowmetry (LDF), LDI and laser speckle contrast imaging (LSCI). Important drawbacks of single point LDF measurements are direct contact with numerous small points on the wound bed and the need to carry out serial measurements over several days. LDI is a fast, "non-contact," single measurement tool allowing to scan large burned areas with a 96% accuracy. LDI reduces the number of surgeries, improves the functional and aesthetic outcome and is cost-effective. There is only limited evidence for the use of LSCI in burn depth assessment. LSCI still needs technical improvements and scientific validation, before it can be approved for reliable burn assessment. LDI has proven to be invaluable in determining the optimal treatment of a burn patient. For unclear reasons, LDI is still not routinely used in burn centers worldwide. Additional research is required to identify potential "barriers" for universal implementation of this evidence-based burn depth assessment tool.

The LDI Enigma, Part I: So much proof, so little use

INTRODUCTION

Laser Doppler imaging (LDI) is still not an ubiquitous part of burn care worldwide despite reported accuracy rates of more than 95%, which is significantly higher than clinical assessment alone (50-75%). The aims of Part I of this survey study are: to identify the most important barriers for the use of LDI and to provide useful recommendations for efficient implementation in routine burn care. The actual interpretation and use of LDI measurements is discussed in the Enigma Part II article.

MATERIAL AND METHODS

1. Informative interviews with 15 representatives of burn centers without LDI. 2. A survey among 51 burn centers with LDI by means of an extensive questionnaire. 3. In-depth interviews with 21 of the participating centers.

RESULTS

1. All 15 centers without LDI indicated that cost of purchase in combination with maintenance of the LDI device, as well as personnel costs were the reason for not buying, while 12 (80%) also rated the current scientific evidence as insufficient. 2. Twenty-seven burn centers with an LDI (53%) participated and filled in almost the entire questionnaire. In 5 centers, cost delayed the purchase of LDI. The hospital/department paid for the LDI device in 62% of the burn centers and in 88% also for maintenance and salaries. The LDI operators were mainly surgeons (47%) or nurses (42%). In more than half of the burn centers (52%), between 2 and 5 people were trained and certified to use an LDI. In 50% of burn centers, the interpretation of the LDI scan was done by the same person doing the actual measurements. Eighty-nine percent of the burn centers considered the accuracy of the LDI scan as mainly to almost completely accurate. In case of real discrepancy between clinical diagnosis and LDI, in 48% of the burn centers (13/27) the surgeon still relied more on the clinical diagnosis despite reporting this high or almost complete accuracy rate of the LDI.

CONCLUSIONS

Barriers for the routine implementation of LDI were: 1. cost of purchasing and using an LDI combined with health care systems that inadequately reimburse non-surgical management; 2. lack of awareness of or ongoing skepticism towards the scientific evidence supporting LDI use; and 3. organizational constraints combined with logistical limitations. Our recommendations for wider use of LDI technology include: 1. a cost-effective reimbursement of LDI use combined with a more appropriate valuation of expert conservative management compared to surgical therapy; 2. increased use of LDI for every mixed depth burn and; 3. specialized LDI teams to improve burn procedural flexibility and to enable embedding LDI use in the burn care routine. Implementing these measures would promote the highest standards for LDI measurements and interpretation resulting in optimal care with mutual benefits for the hospital, for burn care teams and, most importantly, for the patients.

Status of adult inpatient burn rehabilitation in Europe: Are we neglecting metabolic outcomes?

BACKGROUND

Hypermetabolism, muscle wasting and insulin resistance are challenging yet important rehabilitation targets in the management of burns. In the absence of concrete practice guidelines, however, it remains unclear how these metabolic targets are currently managed. This study aimed to describe the current practice of inpatient rehabilitation across Europe.

METHODS

An electronic survey was distributed by the European Burn Association to burn centres throughout Europe, comprising generic and profession-specific questions directed at therapists, medical doctors and dieticians. Questions concerned exercise prescription, metabolic management and treatment priorities, motivation and knowledge of burn-induced metabolic sequelae. Odds ratios were computed to analyse associations between data derived from the responses of treatment priorities and knowledge of burn-induced metabolic sequelae.

RESULTS

Fifty-nine clinicians with 12.3 ± 9 years of professional experience in burns, representing 18 out of 91 burn centres (response rate, 19.8%) across eight European countries responded. Resistance and aerobic exercises were only provided by 42% and 38% of therapists to intubated patients, 87% and 65% once out-of-bed mobility was possible and 97% and 83% once patients were able to leave their hospital room, respectively. The assessment of resting energy expenditure by indirect calorimetry, muscle wasting and insulin resistance was carried out by only 40.7%, 15.3% and 7.4% respondents, respectively, with large variability in employed frequency and methods. Not all clinicians changed their care in cases of hypermetabolism (59.3%), muscle wasting (70.4%) or insulin resistance (44.4%), and large variations in management strategies were reported. Significant interdisciplinary variation was present in treatment goal importance ratings, motivation and knowledge of burn-induced metabolic sequelae. The prevention of metabolic sequelae was regarded as the least important treatment goal, while the restoration of functional status was rated as the most important. Knowledge of burn-induced metabolic sequelae was linked to higher importance ratings of metabolic sequelae as a therapy goal (odds ratio, 4.63; 95% CI, 1.50-14.25; p < 0.01).

CONCLUSION

This survey reveals considerable non-uniformity around multiple aspects of inpatient rehabilitation across European burn care, including, most notably, a potential neglect of metabolic outcomes. The results contribute to the necessary groundwork to formulate practice guidelines for inpatient burn rehabilitation.

An Assessment of Research Priorities to Dampen the Pendulum Swing of Burn Resuscitation

On June 17 to 18, 2019, the American Burn Association, in conjunction with Underwriters Laboratories, convened a group of experts on burn resuscitation in Washington, DC. The goal of the meeting was to identify and discuss novel research and strategies to optimize the process of burn resuscitation. Patients who sustain a large thermal injury (involving >20% of the total body surface area [TBSA]) face a sequence of challenges, beginning with burn shock. Over the last century, research has helped elucidate much of the underlying pathophysiology of burn shock, which places multiple organ systems at risk of damage or dysfunction. These studies advanced the understanding of the need for fluids for resuscitation. The resultant practice of judicious and timely infusion of crystalloids has improved mortality after major thermal injury. However, much remains unclear about how to further improve and customize resuscitation practice to limit the morbidities associated with edema and volume overload. Herein, we review the history and pathophysiology of shock following thermal injury, and propose some of the priorities for resuscitation research. Recommendations include: studying the utility of alternative endpoints to resuscitation, reexamining plasma as a primary or adjunctive resuscitation fluid, and applying information about inflammation and endotheliopathy to target the underlying causes of burn shock. Undoubtedly, these future research efforts will require a concerted effort from the burn and research communities.

Access to Operative Intervention Reduces Mortality in Adult Burn Patients in a Resource-Limited Setting in Sub-Saharan Africa

INTRODUCTION

Early excision and grafting remains the standard of care after burn injury. However, in a resource-limited setting, operative capacity often limits patient access to surgical intervention. This study sought to describe access to excision and grafting for adult burn patients in a sub-Saharan African burn unit and its relationship with burn-associated mortality.

METHODS

We analyzed patients recorded in the Kamuzu Central Hospital Burn Registry in Lilongwe, Malawi from 2011-2019. We examined patient characteristics, interventions, and outcomes for adults aged ≥16 years. Modified Poisson regression modeling was used to identify risk factors for mortality.

RESULTS

Five hundred and seventy-three patients were included. Median age was 30 years (IQR 23-40) with a male preponderance (63%). Median percent total body surface area burned (%TBSA) was 15% (IQR 8-26) and 68% of burns were caused by flame. 27% (n = 154) had burn excision with skin grafting, with a median time to operation of 18 days (IQR 9-38). When adjusted for age, %TBSA, and time to presentation, operative intervention conferred a survival benefit for patients with flame burns with a RR 0.16 (95% CI 0.06, 0.42).

CONCLUSIONS

In a resource-limiting setting, access to the operating room is inadequate, and burn patients are not prioritized. While many scald burn patients may be managed with wound care alone, patients with flame burn require surgical intervention to improve clinical outcomes. Burn injury in this region continues to confer a high risk of mortality, and more investment in operative capacity is imperative.

The Added Benefit of Combining Laser Doppler Imaging With Clinical Evaluation in Determining the Need for Excision of Indeterminate-Depth Burn Wounds

Background Managing indeterminate-depth burn wounds remains challenging. Laser Doppler Imaging (LDI) has been validated for burn wound depth and can influence the clinical assessment. Our study investigated the value of LDI as an adjunct in determining the need for excision. Methods Seventy American Burn Association (ABA)-verified burn centers were surveyed. A controlled pre-test assessment without LDI and post-test assessment with LDI of 100 indeterminate-depth burn wounds was conducted to evaluate the influence on the clinical judgment among different health professionals. Relative risk, analysis of variance (ANOVA), paired t-test, and intention-to-treat were used for analysis. A p-value [Formula: see text] 0.05 was considered significant.  Results Among 32 burn centers, three confirmed using LDI. Six thousand grader-image interactions were analyzed. There was a significant difference in the predictive accuracy for pre-LDI and post-LDI assessments when all graders were considered (51.9% ± 7.0 vs. 72.9% ± 7.9; p < 0.0001). Post-LDI assessment added 20.9% more accuracy than the pre-LDI assessment. The post-LDI assessment was 1.4 times more likely to correctly predict the need for excision and skin-grafting than the pre-LDI assessment. All groups had an improved performance post-LDI: Group 1 (physicians), 51.9 ± 7.5 versus 76.4±5; Group 2 (nurses), 52.1 ± 6.1 versus 72.7±7.7; and Group 3 (others), 51.7 ± 9.2 versus 68.6 ± 10.1. No statistical difference was observed between groups (p = 0.92).  Conclusion LDI makes the clinical examination of indeterminate-depth burn wounds more accurate. For every five LDI evaluations performed, one assessor changed their treatment plan as a result of this imaging technique. LDI is cost-effective and increases the accuracy of determining the severity of indeterminate-depth burn wounds.

A new model for standardising and treating thermal injury in the rat

Thermal burn injury methodologies are inconsistently described within the current literature. To permit the advancement of new treatments there is an urgent need for the development and standardisation of an acute rat model. We describe a rat thermal burn model that involves: anaesthesia, chronic catheterisation, skin preparation, baseline hemodynamic and physiological monitoring, and a quantifiable method to reproduce a severe full-thickness burns injury affecting ∼30% percent of the total body surface area (%TBSA). Following a 15 min post-burn period, treatment commences with an acute monitoring phase lasting up to 8 h, which can be modified according to individual protocols. This model reflects the clinical continuum-of-care from point-of-injury, a 15 min ambulance response time, a 60 min prehospital phase and hospital treatment monitoring phase. The model is validated with histological evidence of full-thickness injury, evidence of the hypermetabolic response (K+, Base Excess, lactate) and changes in complete blood counts. •It has been 50 years since Walker and Mason published their widely popular "A Standard Animal Burn Model".•The model, however, lacks quantifiable methodology for the assessment of burn thickness, surface area burnt and physiological status.•We present a new standardised method for evaluation of drug and interventional therapies that mimic the clinical scenario including ambulance response, pre-hospital and hospital phases after burn.

Timing of early excision and grafting following burn in sub-Saharan Africa

BACKGROUND

This study sought to establish appropriate timing of burn wound excision and grafting in a resource-poor setting in sub-Saharan Africa.

METHODS

All burn patients (905 patients) admitted to Kamuzu Central Hospital (KCH) Burn Unit in Lilongwe, Malawi over three years (2011-2014) were studied.

RESULTS

275 patients (30%) had an operation during their admission. In patients who received an operation, median age was 5 years (IQR, 2.7-19) and median total body surface area burn was 15% (IQR, 8-25). 91 patients (33%) had early excision (≤5 days) and 184 patients (67%) had late excision (>5 days). Mortality was significantly greater in the early group (25.3% vs. 9.2%, p=0.001). Controlling for total body surface area burn and age, the adjusted predictive probability of mortality were 0.256 (CI 0.159-0.385) and 0.107 (CI 0.062-0.177) if operated ≤5 and >5 days, respectively (p=0.0114). The odds ratio for mortality if operated >5 days is 0.34 (CI 0.15-0.79, p<0.000).

CONCLUSIONS

Early excision and grafting in a resource-poor area in sub-Saharan Africa is associated with a significant increase in mortality. Delaying the timing of early excision and grafting of burn patients in a resource-poor setting past burn day 5 may confer a survival advantage.