Major burns in Cape Town: a modified burns score for patient triage

Better among the two for Burn Mortality Prediction in Developing Nations: Revised Baux or Modified Abbreviated Burn Severity Index?

Background

Burns is one of the leading causes of mortality in developing countries like India. Most of the major burns requiring hospital care are not triaged adequately for the use of medical resources. An efficient mortality predicting scale would not only help in better care to those who will benefit the most but also make it easy to explain to patient's attendants. Among the various tools, revised Baux (rBaux) and modified Abbreviated Burn Severity Index (ABSI) are two most commonly used scales in developed nations. We proposed this study to analyze the reliability of these two scoring scales in our burn population.

Aim

This study aimed to retrospectively study the two scoring systems and analyze them for their reliability in predicting mortality compared to actual observed mortality in each case.

Materials and Methods

This study was conducted on all burn patients admitted to the intensive care unit of our hospital. Data on their demographic profile, total burn surface area, thickness of burns, inhalational injury, and other comorbidities were collected from files. rBaux and modified ABSI (mABSI) were calculated. The end result in the form of survival or nonsurvival was also recorded. Appropriate statistical analysis using Mann-Whitney U-test, Chi-square test, and receiver operator characteristic curve was done to look for a better scoring system out of the two.

Results

A total of 504 patients were included in the study, out of which 337 were survivors. Female gender was not a risk factor for mortality in our study. The median rBaux score in the survivor group was 100 (80-110) and in nonsurvivor group was 111 (103-123). The median mABSI score in the survivor group was 8 (7-9) and in nonsurvivor group was 10 (9-11). The area under the receiver operating characteristic curve shows mABSI having better specificity for predicting mortality. rBAUX, though more sensitive, overestimates mortality than actual observed mortality.

Conclusion

mABSI predicts mortality better than rBaux. A multicentric prospective study is recommended for mABSI to be used as a standard mortality predictor in burns in India.

The BUrn Mortality Prediction (BUMP) Score - An improved mortality prediction score based on data of the German burn registry

BACKGROUND

Burn injuries constitute the fourth most common injuries globally. Patient outcomes must be currently assessed to provide appropriate patient care with high quality standards. However, existing mortality prediction scoring methods have been shown to lack accuracy in current burn patient populations. Therefore, this study aimed to validate existing scores using current patient data and assess whether new prediction parameters can provide better accuracy.

METHODS

A retrospective analysis of the patient data from the German Burn Registry between 2016 and 2019 was performed to evaluate all Abbreviated Burn Severity Index (ABSI) score parameters. All patients over 16 years of age who received intensive care were included. Descriptive statistics and logistic regression analysis were used to identify novel prediction parameters based on the parameters documented at admission and establish a new prediction score, the BUrn Mortality Prediction (BUMP) score. The quality of the new score was subsequently compared to that of the original ABSI, modified ABSI, Galeiras, Revised Baux score and TIMM. The new prediction score was then validated using patient data collected in the German Burn Registry in 2020.

RESULTS

In total, 7276 patients were included. Age; the presence of at least two comorbidities; burn injuries caused by work-related accidents, traffic accidents and suicide attempts; total burn surface area; inhalation trauma and full-thickness burns were identified as independent significant predictors of mortality (p < 0.001). Additionally, we evaluated new age groups to improve prediction accuracy. The number of comorbidities (p < 0.001) and the aetiology (burns occurring at work [p = 0.028], burns caused by traffic accidents [p < 0.001] or burns due to attempted suicide [p < 0.001]) had a significant influence on mortality. The BUMP score, which was developed based on these parameters, showed the best fitness and showed more accurate mortality prediction than all the above-mentioned scores (area under the receiver operating characteristic curve: 0.947 [0.939-0.954] compared to 0.926 [0.915-0.936], 0.928 [0.918-0.939], 0.937 [0.928-0.947], 0.939 [0.930-0.948], 0.940 [0.932-0.949] respectively).

CONCLUSIONS

A novel score (BUMP score) was developed for the purpose of external quality assessment of burn centres participating in the German burn registry, where observed and expected outcomes are compared on a hospital level, and for scientifically applications. The clinical impact of this score and its generalisability to other patient populations needs to be evaluated.

Validation of four burn-specific prognostic models in a cohort of 9625 cases, and a novel model for prediction of mortality in burn patients

BACKGROUND

Survival after burn injury has steadily improved in recent decades. The models for assessing the severity of burn injury and predicting burn-associated mortality have been used for over 20 years. The predictive accuracy of these models should be reconsidered now.

METHOD

In this retrospective study on all burn patients (n = 9625) admitted to the Burn Department, Southwest Hospital between 2008 and 2017, we compared the predictive performance of the four burn-severity models (Abbreviated Burn Severity Index, Ryan score, revised Baux score and Belgian Outcome of Burn Injury) by area under the receiver operating curve (AUC) and Hosmer-Lemeshow test. We developed a new model with the data from 2008 to 2012 (5006 patients) by logistic regression, data from 2013 to 2017 (4619 patients) were used for validation.

RESULT

The overall mortality rate of the burn patients was 1.14%. The four previously validated burn models showed good discrimination power of death risk (AUC > 0.890) but poor fitness to the observed mortality rate (p < 0.001). Risk factors associated with mortality included sex, age, total burn area, full thickness burn area, and inhalation injury. The new logistic model was devised with high sensitivity and specificity (0.913 and 0.806, respectively) and an AUC of 0.940. The new model also had good fitness to the observed mortality of burn patients (p = 0.588).

CONCLUSION

The four widely used burn models have poor accuracy in predicting burn-associated mortality, and an accurate new model was developed based on simple and objective clinical characteristics of burn patients at admission.

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.

A competing risk analysis for hospital length of stay in patients with burns

IMPORTANCE

Current outcome predictors for illness and injury are measured at a single time point-admission. However, patient prognosis often changes during hospitalization, limiting the usefulness of those predictions. Accurate depiction of the dynamic interaction between competing events during hospitalization may enable real-time outcome assessment.

OBJECTIVE

To determine how the effects of burn outcome predictors (ie, age, total body surface area burn, and inhalation injury) and the outcomes of interest (ie, mortality and length of stay) vary as a function of time throughout hospitalization.

DESIGN, SETTING, AND PARTICIPANTS

In this retrospective study, we used the American Burn Association's National Burn Repository, containing outcomes and patient and injury characteristics, to identify 95 579 patients admitted with an acute burn injury to 80 tertiary American Burn Association burn centers from 2000 through 2009. We applied competing risk statistical methods to analyze patient outcomes.

MAIN OUTCOMES AND MEASURES

We estimated the cause-specific hazard rates for death and discharge to assess how the instantaneous risk of these events changed across time. We further evaluated the varying effects of patient age, total body surface area burn, and inhalation injury on the probability of discharge and death across time.

RESULTS

Maximum length of stay among patients who died was 270 days and 731 days among those discharged. Total body surface area, age, and inhalation injury had significant effects on the subdistribution hazard for discharge (P < .001); these effects varied across time (P < .002). Burn size (coefficient -0.046) determined early outcomes, while age (coefficient -0.034) determined outcomes later in the hospitalization. Inhalation injury (coefficient -0.622) played a variable role in survival and hospital length of stay.

CONCLUSIONS AND RELEVANCE

Real-time measurement of dynamic interrelationships among burn outcome predictors using competing risk analysis demonstrated that the key factors influencing outcomes differed throughout hospitalization. Further application of this analytic technique to other injury or illness types may improve assessment of outcomes.

Revised Baux Score and updated Charlson comorbidity index are independently associated with mortality in burns intensive care patients

PURPOSE

The purpose of the current study was to utilise established scoring systems to analyse the association of (i) burn injury severity, (ii) comorbid status and (iii) associated systemic physiological disturbance with inpatient mortality in patients with severe burn injuries admitted to intensive care.

METHODS

Case notes of all patients with acute thermal injuries affecting ≥15% total body surface area (TBSA) admitted to the Burns Intensive Care Unit (BICU) at Chelsea and Westminster Hospital during a 10-year period were retrospectively reviewed. Revised Baux Score, Belgian Outcome in Burn Injury (BOBI) Score, Abbreviated Burn Severity Index (ABSI), APACHE II Score, Sequential Organ Failure Assessment (SOFA) Score and Updated Charlson Comorbidity Index (CCI) were computed for each patient and analysed for association with inpatient mortality.

RESULTS

Ninety mechanically ventilated patients (median age 45.7 years, median % TBSA burned 36.5%) were included. 72 patients had full thickness burns and 35 patients had inhalational injuries. Forty-four patients died in hospital while 46 survived to discharge. In a multivariate logistic regression model, only the Revised Baux Score (p<0.001) and updated CCI (p=0.014) were independently associated with mortality. This gave a ROC curve with area under the curve of 0.920. On multivariate cox regression survival analysis, only the Revised Baux Score (p<0.001) and the updated CCI (p=0.004) were independently associated with shorter time to death.

CONCLUSION

Our data suggest that the Revised Baux Score and the updated CCI are independently associated with inpatient mortality in patients admitted to intensive care with burn injuries affecting ≥15% TBSA. This emphasises the importance of comorbidities in the prognosis of patients with severe burn injuries.

Validation of the prognostic burn index: a nationwide retrospective study

BACKGROUND

The burn index (BI=full thickness total burn surface area [TBSA]+1/2 partial thickness TBSA) and prognostic burn index (PBI=BI+age) are clinically used particularly in Japan. However, few studies evaluated the validation of PBI with large sample size. We retrospectively investigated the relationships between PBI and mortality among burn patients using data from a nationwide database.

METHODS

Data of all burn patients with burn index ≥1 were extracted from the Japanese Diagnosis Procedure Combination (DPC) inpatient database from 1 July 2010 to 31 March 2013 (17,185 patients in 1044 hospitals). The primary endpoint was all-cause in-hospital mortality.

RESULTS

Overall in-hospital mortality was 5.9% (1011/17,185). Mortality increased significantly as the PBI increased (Mantel-Haenszel trend test, P<0.001). The area under the receiver operating characteristic curve for PBI was 0.90 (95%CI, 0.90-0.91), and a PBI above a threshold of 85 showed the highest association with in-hospital mortality. Logistic regression analysis showed that PBI≥85 (odds ratio (OR), 14.6; 95%CI, 12.1-17.6), inhalation injury with mechanical ventilation (OR, 13.0; 95%CI, 10.8-15.7), Charlson Comorbidity Index≥2 (OR, 1.8; 95%CI, 1.5-2.3), and male gender (OR, 1.5; 95%CI, 1.3-1.8) were significant independent risk factors for death.

CONCLUSIONS

Our study suggested that a PBI above a threshold of 85 was significantly associated with mortality. The PBI and mechanical ventilation were the most significant factors predicting in-hospital mortality, after adjustment for inhalation injury, comorbidity, and gender.

Predicting mortality from burns: the need for age-group specific models

Traditional burn mortality models are derived using all age groups. We hypothesized that age variably impacts mortality after burn and that age-specific models for children, adults, and seniors will more accurately predict mortality than an all-ages model. We audited data from the American Burn Association (ABA) National Burn Repository (NBR) from 2000 to 2009 and used mixed effect logistic regression models to assess the influence of age, total body surface area (TBSA) burn, and inhalation injury on mortality. Mortality models were constructed for all ages and age-specific models: children (<18 years), adults (18-60 years), and seniors (>60 years). Model performance was assessed by area under the receiver operating curve (AUC). Main effect and two-way interactions were used to construct age-group specific mortality models. Each age-specific model was compared to the All Ages model. Of 286,293 records 100,051 had complete data. Overall mortality was 4% but varied by age (17% seniors, <1% children). Age, TBSA, and inhalation injury were significant mortality predictors for all models (p<0.05). Differences in predicted mortality between the All Ages model and the age-specific models occurred in children and seniors. In the age-specific pediatric model, predicted mortality decreased with age; inhalation injury had greater effect on mortality than in the All Ages model. In the senior model mortality increased with age. Seniors had greater increase in mortality per 1% increment in burn size and 1 year increase in age than other ages. The predicted mortality in seniors using the senior-specific model was higher than in the All Ages model. "One size fits all" models for predicting burn outcomes do not accurately reflect the outcomes for seniors and children. Age-specific models for children and seniors may be advisable.

Medical futility and the burns patient

Since its inception in the 1980s 'futility' has been a controversial concept. The history of this concept, its definition and application to burns care are discussed from the perspective of a burn surgeon. Although introduced as an objective (value-free) criterion, futility proves impossible to objectivate and judgements about the value of human life always play a role. The roles of the patient, the doctor, the 'politician' and society at large in futility-decisions are discussed.

Assessment of mortality prediction models in a Ghanaian burn population

PURPOSE

Over 40 new or modified outcome prediction models have been developed for severe burns; with age, total burned surface area (TBSA) and inhalation area as major determinants of mortality. The objective of this study was to assess their applicability in a developing country.

PROCEDURES

Data were collected retrospectively of a consecutive series of 261 patients (2009-2011) admitted to a Burns Intensive Care. Five outcome prediction models based on admission criteria were evaluated: Bull grid, Abbreviated Burn Severity Index--ABSI, Ryan-model, Belgian Outcome in Burn Injury--BOBI and revised Baux. Discriminative power and goodness-of-fit were assessed by receiver operating characteristic analyses (area under the curve--AUC) and Hosmer-Lemeshow tests.

FINDINGS

Median age was 10.5 years (IQR: 2.5-27 years), median TBSA 21% (IQR: 11-34%); 55.2% were male, 28 patients died (10.7%). Only 2 patients were intubated (0.8%). The AUC were between 77 and 86%. The ABSI model showed the best calibration (28.7 expected deaths). Ryan, BOBI and rBaux significantly underestimated mortality, whereas Bull showed an overestimation.

CONCLUSION

This study on a young group of burn patients showed moderate to good discriminative power using all five prediction models. The expected number of deaths tended to be underestimated in the three most recent prediction models.

Prognostic scoring systems in burns: a review

Survival after burn has steadily improved over the last few decades. Patient mortality is, however, still the primary outcome measure for burn care. Scoring systems aim to use the most predictive premorbid and injury factors to yield an expected likelihood of death for a given patient. Age, burn surface area and inhalational injury remain the mainstays of burn prognostication, but their relative weighting varies between scoring systems. Biochemical markers may hold the key to predicting outcomes in burns. Alternatively, the incorporation of global scales such as those used in the general intensive care unit may have relevance in burn patients. Outcomes other than mortality are increasingly relevant, especially as mortality after burns continues to improve. The evolution of prognostic scoring in burns is reviewed with specific reference to the more widely regarded measures. Alternative approaches to burn prognostication are reviewed along with evidence for the use of outcomes other than mortality. The purpose and utility of prognostic scoring in general is discussed with relevance to its potential uses in audit, research and at the bedside.

Comfort care in burns: the Burn Modified Liverpool Care Pathway (BM-LCP)

INTRODUCTION

Despite advances in burn care some injuries remain non survivable. Good end of life care for these patients is arguably as important as life prolonging care. The Liverpool Care Pathway is a useful tool for providing good quality end of life care. It has previously been modified for the acute setting. We modified it further specifically for use in burn care in 2007 and would like to share our experience of using it.

METHODS

A retrospective case series of deaths occurring between 01/01/08 and 31/12/09 is presented and adherence to the Burn Modified Liverpool Care Pathway (BM-LCP) is assessed.

RESULTS

There were 22 deaths over the study period with a mean TBSA of 55%. Mean Acute Burn Severity Index score (ABSI) 12.5. A decision of futility was made in 14 cases, 11 of these were started on the BM-LCP. 7 were started on the pathway at the time of admission. Mean time from decision to start the pathway to death 11 h (range 3-48). There were no variances from the pathway.

CONCLUSION

The BM-LCP appears to be an appropriate tool for assisting in end of life care in burns and when used appears to improve end of life care. We recommend its use and would encourage others to implement its use.

[Inhalation injury--epidemiology, diagnosis and therapy]

OBJECTIVE

Inhalation injury is a vitally threatening medical syndrome, which might appear in patients with or without burn injuries. Thus, knowledge about development, diagnosis and treatment of inhalation injury should be available for each physician working in an intensive care unit.

METHODS

This review starts with the causal and formal pathogenesis of inhalation injuries. Furthermore, diagnosis and treatment in the critical care setting are presented, followed by the discussion of possible complications. Specific intoxications such as carbon monoxide are due to their importance separately discussed.

CONCLUSIONS

Inhalation injury present with an attributable excess mortality and thus worsen the prognosis of burned patients. New insights into the pathogenesis of inhalation injury, however, have led to improved therapeutic possibilities with improved outcome. Necessary prerequisites are a timely diagnosis and restrictive volume management, especially in patients with extensive burns. Prospective studies are needed to be able to answer the many emerging questions.

Evaluation of mortality following severe burns injury in Hungary: external validation of a prediction model developed on Belgian burn data

PURPOSE

To evaluate mortality in a group of Hungarian burn patients and, as such, to perform an external validation of a prediction model developed on Belgian burn data by which the mortality appraisal was executed.

BASIC PROCEDURES

In a historical cohort we analysed all burn patients admitted between 1998 and 2006 to the Debrecen University Hospital (n=2326). The prediction model, based on three criteria (age, burned surface area (BSA) and inhalation injury) was also used to evaluate several subpopulations based on gender and age.

MAIN FINDINGS

Mean age was 35.3 years, mean BSA was 10.7%, 54% of the population was male, inhalation injury was rare (n=7; 0.3%) and overall mortality was 1.4% (1.6% male, 1.1% female). The men were younger and more severely burned, which was significant in every age group above 2 years. The model gave an accurate prediction of mortality, with a small overestimation in the lower risk categories. The receiver operating characteristic analysis demonstrated an area under the curve of 0.94 (95% confidence interval: 0.89-0.98).

CONCLUSION

Overall burn mortality in Hungary was low. The mortality prediction model demonstrated a high discriminative value. As such, this model is a helpful tool for outcome prediction and risk stratification for research purposes in burn patients.

Development and validation of a model for prediction of mortality in patients with acute burn injury

BACKGROUND

The objective was to develop a user-friendly model to predict the probability of death from acute burns soon after injury, based on burned surface area, age and presence of inhalation injury.

METHODS

This population-based cohort study included all burned patients admitted to one of the six Belgian burn centres. Data from 1999 to 2003 (5246 patients) were used to develop a mortality prediction model, and data from 2004 (981 patients) were used for validation.

RESULTS

Mortality in the derivation cohort was 4.6 per cent. A mortality score (0-10 points) was devised: 0-4 points according to the percentage of burned surface area (less than 20, 20-39, 40-59, 60-79 or at least 80 per cent), 0-3 points according to age (under 50, 50-64, 65-79 or at least 80 years) and 3 points for the presence of an inhalation injury. Mortality in the validation cohort was 4.3 per cent. The model predicted 40 deaths, and 42 deaths were observed (P = 0.950). Receiver-operator characteristic curve analysis of the model for prediction of mortality demonstrated an area under the curve of 0.94 (95 per cent confidence interval 0.90 to 0.97).

CONCLUSION

An accurate model was developed to predict the probability of death from acute burn injury based on simple and objective clinical criteria.

Septicemia as a cause of death in burns: an autopsy study

In burn victims, invasion by the bacteria is not unexpected, despite advances in antibiotics, and it has been reported that in the absence of topical therapy, the superficial areas of burn wound contain up to 100 million organisms per gram of tissue within 48h following the injury. We examined the autopsy reports of 334 cases who died because of complicated burns and who underwent medico-legal autopsy during a period of 5 years to study the rate of infection/sepsis. It was observed that in 65% of fatal burn cases, septicemia was the cause of death. Pseudomonas aeuroginosa and Klebsiella sp. were the most common organism, isolated either singly or in combination in 29% and 28% cases, respectively. High mortality from burns in young married women has been recognized as an alarming and contentious problem in India, particularly among the low socio-economic groups. We found that the females aged 21-25 were the most common victims accounting for 37% of burn fatalities due to septicemia. It was concluded that to carry out periodic review of patterns of isolation and susceptibility profiles of microorganisms infecting burn wounds should be a routine in all burn units. In view of the limited resources of developing countries, we recommend the use of available scoring systems to estimate burn outcome so that the best care can be directed to those who have a better chance of improvement.