Assessment of mortality prediction models in a Ghanaian burn population

The Revised Baux Score as a Predictor of Burn Mortality: A Systematic Review and Meta-Analysis

Mortality following a severe burn is influenced by both patient- and injury-factors, and a number of predictive models have been developed or applied. As there is no consensus on the optimal formula to use, we aimed to investigate the predictive value of the revised Baux score in comparison to other models when determining mortality risk in patients with burn injuries. A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The review yielded 21 relevant studies. The Prediction model Risk Of Bias ASsessment Tool quality appraisal checklist was used with many studies classified as "high" quality. All studies assessed the utility of the revised Baux score in comparison to other scoring systems such as the original Baux, Belgian Outcome in Burn Injury, Abbreviated Burn Severity Index, Acute Physiology and Chronic Health Evaluation II, Sequential Organ Failure Assessment, Boston Group/Ryan scores, the Fatality by Longevity, APACHE II score, Measured Extent of burn, and Sex model, and the Prognostic Burn Index. There was a range of 48 to 15975 participants per study, with a mean age range of 16 to 52 years old. The area under the curve (AUC) values of the rBaux score ranged from 0.682 to 0.99, with a summary AUC of 0.93 for all included studies (CI 0.91-0.95). This summary value demonstrates that the rBaux equation is a reliable predictor for mortality risk in heterogeneous populations. However, this study also identified that the rBaux equation has a diminished ability to predict mortality risk when applied to patients at both extremes of age, highlighting an important area for future research. Overall, the rBaux equation offers a relatively easy means to quickly assess the mortality risk from burn injury in a broad range of patient populations.

External Validation of Three Burn-Specific Mortality Prediction Models in Adult Burn Patients at a Tertiary Care Hospital in India

Background Several burn-specific mortality prediction models have been formulated and validated in the developed countries. There is a dearth of studies validating these models in the Indian population. Our objective was to validate three such models in the Indian burn patients.

Methods A prospective observational study was performed after ethical clearance on consecutive eligible consenting burn patients. Patient demographics, vitals, and results of hematological workup were collected. Using these. the Abbreviated Burn Severity Index (ABSI), the revised Baux score (rBaux), and the Fatality by Longevity, APACHE II score, Measured extent of burn, and Sex score (FLAMES) were calculated. The discriminative ability of the ABSI, rBaux, and the FLAMES was tested using the receiver operating characteristic (ROC) curve at 30 days and the area under the ROC curve (AUROC) compared. A p-value ≤ 0.05 was considered significant. Probability of death was calculated using these models. Hosmer–Lemeshow goodness of fit test was run.

Results The ABSI (AUROC 0.7497, 95% CI 0.67796–0.82141), rBaux (AUROC 0.7456, 95% CI 0.67059–0.82068) and FLAMES (AUROC 0.7119, 95% CI 0.63209–0.79172), had fair discriminative ability. The Hosmer–Lemeshow test reported that ABSI and rBaux were a good fit for the Indian population, while FLAMES was not a good fit.

Conclusion The ABSI and rBaux had a fair discriminative ability and were a good fit for the adult patients with 30 to 60% thermal and scald burn patients. FLAMES despite having fair discriminative ability was not a good fit for the study population.

Clinical decision-support for acute burn referral and triage at specialized centres - Contribution from routine and digital health tools

BACKGROUND

Specialized care is crucial for severe burn injuries whereas minor burns should be handled at point-of-care. Misdiagnosis is common which leads to overburdening the system and to a lack of treatment for others due to resources shortage.

OBJECTIVES

The overarching aim was to evaluate four decision-support tools for diagnosis, referral, and triage of acute burns injuries in South Africa and Sweden: referral criteria, mortality prediction scores, image-based remote consultation and automated diagnosis.

METHODS

Study I retrospectively assessed adherence to referral criteria of 1165 patients admitted to the paediatric burns centre of the Western Cape of South Africa. Study II assessed mortality prediction of 372 patients admitted to the adults burns centre by evaluating an existing score (ABSI), and by using logistic regression. In study III, an online survey was used to assess the diagnostic accuracy of burn experts' image-based estimations using their smartphone or tablet. In study IV, two deep-learning algorithms were developed using 1105 acute burn images in order to identify the burn, and to classify burn depth.

RESULTS

Adherence to referral criteria was of 93.4%, and the age and severity criteria were associated with patient care. In adults, the ABSI score was a good predictor of mortality which affected a fifth of the patients and which was associated with gender, burn size and referral status. Experts were able to diagnose burn size, and burn depth using handheld devices. Finally, both a wound identifier and a depth classifier algorithm could be developed with relatively high accuracy.

CONCLUSIONS

Altogether the findings inform on the use of four tools along the care trajectory of patients with acute burns by assisting with the diagnosis, referral and triage from point-of-care to burns centres. This will assist with reducing inequities by improving access to the most appropriate care for patients.

Comparative Analysis of Composite Mortality Prediction Scores in Intensive Care Burn Patients

Multiple outcome scoring models have been used in predicting mortality in burn patients. In this study, we compared the accuracy of five established models in predicting outcomes in burn patients admitted to the intensive care unit and assessed risk factors associated with mortality. Intensive care burn patients admitted between March 2007 and December 2020 with total body surface area (TBSA) affected ≥ 10% were analyzed. Multivariate analysis was conducted to examine variables associated with mortality. The ABSI, Ryan, BOBI, revised Baux and BUMP scores were analyzed by receiver operating characteristics. A total of 617 patients were included. Morality was 14.4%, with non-survivors being significantly older, male, and having experienced domestic burns. Multivariate analysis identified age, TBSA, full-thickness burns and renal insufficiency as independent mortality predictors. The BUMP score presented the highest mortality prognostication rate, followed by ABSI, revised Baux, BOBI and Ryan scores. BUMP, ABSI and revised Baux scores displayed AUC values exceeding 90%, indicating excellent prognostic capabilities. The BUMP score showed the highest accuracy of predicting mortality in intensive care burn patients and outperformed the most commonly used ABSI score in our cohort. The older models displayed adequate predictive performance and accuracy compared with the newest model.

Predicting and Estimating Burn Outcomes: An Institutional Analysis of 4622 cases

Advances in burn care have improved patient outcomes, and independently validated indices and predictors of burn outcomes warrant re-evaluation. The purpose of this study is to consolidate predictors of burn outcomes and determine the factors that significantly contribute to length-of-stay (LOS) and mortality. A retrospective review was conducted of all burn patients (n=5778) admitted to a quaternary provincial burn unit from 1973 to 2017. Our inclusion criteria yielded 4622 independent cases. Multivariate linear and logistic regression models were generated, and area-under-receiver-operator-curve (AUROC) analysis was performed. Burn predictors included %TBSA, Baux (classic and revised) index, Abbreviated Burn Severity Index (ABSI), and Ryan score. Primary outcomes were mortality and LOS. Multivariate logistic regression for mortality showed the Baux index to be the best predictor for mortality (OR=1.11, p<0.001). The AUROC for Baux index was 0.95. With regards to LOS, ABSI was the best predictor for LOS (p<0.001). ICU stay, ventilator use, alcoholism, age, significantly associated with increased LOS. Interestingly, hypertension had a protective effect for LOS (p<0.01) and trended towards a protective effect in mortality. Lethal score 50% (LS50) improved over the study period. The regressions show that burn mortality and LOS are best predicted with the Baux index and ABSI, respectively. Hypertension may have a protective effect on burn outcomes and may be attributed to increased perfusion to the periphery. These predictive scores are useful in determining institutional outcomes in burn surgery. Objective benchmarking of improvement in burn care outcomes can be established using LS50 trends.

Estimates of Total Burned Surface Area by Emergency Department Clinicians and Burn Specialists

Introduction

Correctly assessing burn size is extremely important since it is directly associated with a patient’s subsequent management. Further, an accurate assessment of the total body surface area (TBSA) involved is crucial to decide if specialty care in a burn unit is necessary, whereby overestimation has the potential to lead to unnecessary patient transfers and undesirable burdens on the healthcare system and inconvenience to patients. The goal of this study was to identify whether burn injury estimates of TBSA percentage correlate between emergency department (ED) clinician and burn specialists.

Methods

This was a retrospective study conducted between February 1, 2018 and July 31, 2019 of patients with a burn injury who were evaluated by both an ED clinician and a burn specialist during the same ED visit. Charts were reviewed to identify the documentation of TBSA by pre-hospital personnel, ED nursing staff, ED mid-level providers (MLP), ED attending physicians, burn consultant MLPs, and burn consultant attending physicians.

Results

During the study period, 189 subjects with both an ED and burn consultant. The median age was 11 years [interquartile range (IQR) 1-49], and 103 (54%) were males. More than half of the subjects (n=106, 56%) were under the age of 18. There was a statistically significant correlation between estimates of TBSA between ED and burn consultants overall (p<0.0001). Furthermore, there was a statistically significant correlation between ED and burn MLPs (p<0.0001) as well as ED and burn attending physicians (p<0.0001). When adjusted for MLP and attending sex, there was still a correlation among all groups (p<0.0001).

Conclusions

In this study, there was a statistically significant correlation between estimates of TBSA between ED and burn consultants

Palliation, end-of-life care and burns; concepts, decision-making and communication - A narrative review

Palliative care is the turn from cure as the priority of care to symptom relief and comfort care. Although very little is published in the burn literature on palliative care, guidelines can be gleaned from the general literature on palliative care, particularly for acute surgical and critical care patients. Palliative care may be started because of futility, on request of the patient, or because of limited resources. The SPIKES acronym is a useful guide to avoid errors in communication with terminal patients and their relatives.

Admission factors associated with the in-hospital mortality of burns patients in resource-constrained settings: A two-year retrospective investigation in a South African adult burns centre

OBJECTIVE

Little is known concerning the factors associated with in-hospital mortality of trauma patients in resource-constrained settings, not least in burns centres. We investigated this question in the adult burns centre at Tygerberg Hospital in Cape Town. We further assessed whether the Abbreviated Burn Severity Index (ABSI) is an accurate predictive score of mortality in this setting.

METHODS

Medical records of all patients admitted with fresh burns over a two-year period (2015 and 2016) were scrutinized to obtain data on patient, injury and admission-related characteristics. Association with in-hospital mortality was investigated for flame burns using logistic regressions and expressed as odds ratios (ORs). The mortality prediction of the ABSI score was assessed using sensitivity and specificity analyses.

RESULTS

Overall the in-hospital mortality was 20.4%. For the 263 flame burns, while crude ORs suggested gender, burn depth, burn size, inhalation injury, and referral status were all individually significantly associated with mortality, only the association with female gender, not being referred and burn size remained significant after adjustments (adjusted ORs = 3.79, 2.86 and 1.11 (per percentage increase in size) respectively). For the ABSI score, sensitivity and specificity were 84% and 86% respectively.

CONCLUSION

In this specialised centre, mortality occurs in one in five patients. It is associated with a few clinical parameters, and can be predicted using the ABSI score.

Factors associated with acute kidney injury in the Helsinki Burn Centre in 2006-2015

BACKGROUND

Acute kidney injury (AKI) is a common complication in severe burns and can lead to significantly poorer outcomes. Although the prognosis has improved in recent decades, the mortality of AKI remains considerable. We investigated the factors that increase the risk of AKI and death after severe burn injury.

METHODS

Intensive care patients with ≥20% burned total body surface area (TBSA%) between January 2006 and December 2015 treated in Helsinki Burn Centre were enrolled retrospectively. Patients who arrived > 36 h after burn injury or died < 48 h from arrival were excluded. A total of 187 patients were included in the final analysis. Serum creatinine ≥120 μmol/l (1.4 mg/dl) was the criterion for AKI.

RESULTS

Fifty-one patients (27.3%) developed AKI during hospital stay and 21 (11.2%) required renal replacement therapy (RRT); 37 patients (19.8%) died during hospital stay. Mortality was significantly higher in the AKI group (52.9%) than in the AKI-negative group (7.4%). The Abbreviated Burn Severity Index (ABSI), Baux, and the modified Baux score were nearly equivalent in predicting mortality during ICU stay (AUC: 0.83-0.84). The risk of death and AKI were minimal with Baux scores < 80. LD₅₀ was 112 for Baux score in all patients. In flame burns, the risk of death increased rapidly after Baux score > 80. Multivariate logistic regression model detected age, TBSA%, sepsis, and rhabdomyolysis as independent risk factors for AKI. Age (per 10 yrs. OR 1.99), TBSA% (per 10% OR 1.64), and AKI predicted mortality during hospital stay; AKI had an odds ratio of (OR) of 5.97 (95% confidence interval [CI] 2.2-16.2).

CONCLUSIONS

Age, TBSA%, and AKI were the strongest independent factors in predicting outcome in severe burns. Even a major burn (> 50% TBSA) has a relatively good prognosis without simultaneous AKI. Prognosis is poorer even in minor burns for patients with AKI.

Epidemiologic shifts for burn injury in Ethiopia from 2001 to 2016: Implications for public health measures

BACKGROUND

The last generation has seen Ethiopia, a low income country with a population of 100 million people, undergo a marked increase in urbanization and development. The effects of these demographic changes on the epidemiology of burn risk and thermal injury in Ethiopia are unknown. This gap constitutes a major barrier to the creation of effective burn prevention programs.

METHODS

Yekatit 12 Hospital in Addis Ababa is the only burn unit in Ethiopia. In this cross sectional retrospective study, we identified and reviewed all admissions due to burn injury at that facility between 1/1/2016 and 12/31/2016. We then compared them to a previously published burn cohort treated at the same facility between 7/1/2001 and 9/31/2002. Chi square was used to compare proportions between the two samples. Continuous covariates are reported as descriptive data due to missing variance data in the 2001-02 publication.

RESULTS

There were a total of 121 subjects in the 2001-02 sample and 176 subjects in the 2016 sample. The 2016 sample was found to have a significantly larger proportion of males (57%) as compared to the 2001-02 sample (36%) (p=0.0003) and a significantly higher proportion of electrical injuries (27%) than the previous cohort (5%) (p<0.0001). No significant differences were seen in mortality rates between the 2016 and 2001-02 cohorts (8% vs 12%, respectively, p=0.29) or in the regions of origin (44% outside Addis Ababa vs 54%, p=0.09) For the 2016 sample, the highest surviving Baux score was 76 while the mean Baux score for survivors was 29.6±20.11.

CONCLUSION

As Ethiopia has become more industrialized over the last 15 years, the demographic pattern of burn injury has changed accordingly as electrical injuries have increased five-fold with males now constituting a majority of burn cases.

Important Developments in Burn Care

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Explain the epidemiology of severe burn injury in the context of socioeconomic status, gender, age, and burn cause. 2. Describe challenges with burn depth evaluation and novel methods of adjunctive assessment. 3. Summarize the survival and functional outcomes of severe burn injury. 4. State strategies of fluid resuscitation, endpoints to guide fluid titration, and sequelae of overresuscitation. 5. Recognize preventative measures of sepsis. 6. Explain intraoperative strategies to improve patient outcomes, including hemostasis, restrictive transfusion, temperature regulation, skin substitutes, and Meek skin grafting. 7. Translate updates in the pathophysiology of hypertrophic scarring into novel methods of clinical management. 8. Discuss the potential role of free tissue transfer in primary and secondary burn reconstruction.

SUMMARY

Management of burn-injured patients is a challenging and unique field for plastic surgeons. Significant advances over the past decade have occurred in resuscitation, burn wound management, sepsis, and reconstruction that have improved outcomes and quality of life after thermal injury. However, as patients with larger burns are resuscitated, an increased risk of nosocomial infections, sepsis, compartment syndromes, and venous thromboembolic phenomena have required adjustments in care to maintain quality of life after injury. This article outlines a number of recent developments in burn care that illustrate the evolution of the field to assist plastic surgeons involved in burn care.

A systematic review of burn injuries in low- and middle-income countries: Epidemiology in the WHO-defined African Region

INTRODUCTION

According to the World Health Organization (WHO), burns result in the loss of approximately 18 million disability adjusted life years (DALYs) and more than 250,000 deaths each year, more than 90% of which are in low- and middle-income countries (LMICs). The epidemiology of these injuries, especially in the WHO-defined African Region, has yet to be adequately defined.

METHODS

We performed a systematic review of the literature regarding the epidemiology of thermal, chemical, and electrical burns in the WHO-defined African Region. All articles indexed in PubMed, EMBASE, Web of Science, Global Health, and the Cochrane Library databases as of October 2015 were included.

RESULTS

The search resulted in 12,568 potential abstracts. Through multiple rounds of screening using criteria determined a priori, 81 manuscripts with hospital-based epidemiology as well as eleven manuscripts that included population-based epidemiology were identified. Although the studies varied in methodology, several trends were noted: young children appear to be at most risk; most individuals were burned at home; and hot liquids and flame are the most common aetiologies.

DISCUSSION

While more population-based research is essential to identifying specific risk factors for targeted prevention strategies, our review identifies consistent trends for initial efforts at eliminating these often devastating and avoidable injuries.

Standardised mortality ratio based on the sum of age and percentage total body surface area burned is an adequate quality indicator in burn care: An exploratory review

Standardised Mortality Ratio (SMR) based on generic mortality predicting models is an established quality indicator in critical care. Burn-specific mortality models are preferred for the comparison among patients with burns as their predictive value is better. The aim was to assess whether the sum of age (years) and percentage total body surface area burned (which constitutes the Baux score) is acceptable in comparison to other more complex models, and to find out if data collected from a separate burn centre are sufficient for SMR based quality assessment. The predictive value of nine burn-specific models was tested by comparing values from the area under the receiver-operating characteristic curve (AUC) and a non-inferiority analysis using 1% as the limit (delta). SMR was analysed by comparing data from seven reference sources, including the North American National Burn Repository (NBR), with the observed mortality (years 1993-2012, n=1613, 80 deaths). The AUC values ranged between 0.934 and 0.976. The AUC 0.970 (95% CI 0.96-0.98) for the Baux score was non-inferior to the other models. SMR was 0.52 (95% CI 0.28-0.88) for the most recent five-year period compared with NBR based data. The analysis suggests that SMR based on the Baux score is eligible as an indicator of quality for setting standards of mortality in burn care. More advanced modelling only marginally improves the predictive value. The SMR can detect mortality differences in data from a single centre.

Do standard burn mortality formulae work on a population of severely burned children and adults?

Accurate prediction of mortality following burns is useful as an audit tool, and for providing treatment plan and resource allocation criteria. Common burn formulae (Ryan Score, Abbreviated Burn Severity Index (ABSI), classic and revised Baux) have not been compared with the standard Acute Physiology and Chronic Health Evaluation II (APACHEII) or re-validated in a severely (≥20% total burn surface area) burned population. Furthermore, the revised Baux (R-Baux) has been externally validated thoroughly only once and the pediatric Baux (P-Baux) has yet to be. Using 522 severely burned patients, we show that burn formulae (ABSI, Baux, revised Baux) outperform APACHEII among adults (AUROC increase p<0.001 adults; p>0.5 children). The Ryan Score performs well especially among the most at-risk populations (estimated mortality [90% CI] original versus current study: 33% [26-41%] versus 30.18% [24.25-36.86%] for Ryan Score 2; 87% [78-93%] versus 66.48% [51.31-78.87%] for Ryan Score 3). The R-Baux shows accurate discrimination (AUROC 0.908 [0.869-0.947]) and is well-calibrated. However, the ABSI and P-Baux, although showing high measures of discrimination (AUROC 0.826 [0.737-0.916] and 0.848 [0.758-0.938]) in children), exceedingly overestimates mortality, indicating poor calibration. We highlight challenges in designing and employing scores that are applicable to a wide range of populations.

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.