The impact of risk factors and pre-existing conditions on the mortality of burn patients and the precision of predictive admission-scoring systems

Concordance between coding sources of burn size and depth across Australian and New Zealand specialist burn services

BACKGROUND

The percentage of total body surface area (%TBSA) burned and burn depth provide valuable information on burn injury severity.

OBJECTIVE

This study investigated the concordance between The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM) codes and expert burn clinicians in assessing burn injury severity.

METHOD

We conducted a retrospective population-based review of all patients who sustained a burn injury between July 1, 2009, and June 30, 2019, requiring admission into a specialist burn service across Australia and New Zealand. The %TBSA burned (including the percentage of full thickness burns) recorded by expert burn clinicians within the Burns Registry of Australia and New Zealand (BRANZ) were compared to ICD-10-AM coding.

RESULTS

20,642 cases (71.5%) with ICD-10-AM code data were recorded. Overall, kappa scores (95% confidence interval [CI]) for burn size ranged from 0.64 (95% CI 0.63-0.66) to 0.86 (95% CI 0.78-0.94) indicating substantial to almost perfect agreement across all %TBSA groups. When stratified by depth, the lowest agreement was observed for < 10% TBSA and < 10% full thickness (kappa 0.03; 95% CI 0.02-0.04) and the highest agreement was observed for burns of ≥ 90% TBSA and ≥ 90% full thickness (kappa 0.72; 95% CI 0.58-0.85).

CONCLUSION

Overall, there was substantial agreement between the BRANZ and ICD-10-AM coded data for %TBSA classification. When %TBSA classification was stratified by burn depth, greater agreement was observed for larger and deeper burns compared with smaller and superficial burns.

IMPLICATIONS

Greater consistency in the classification of burns is needed.

A comparative study of outcomes of burns across multiple levels of care

BACKGROUND

Burn injuries are a significant contributor to the burden of diseases. The management of burns at specialised burn centres has been shown to improve survival. However, in low- and middle-income countries (LMICs) major burns are managed at non-specialised burn centres due to resource constraints. There is insufficient data on survival from treatment at non-specialised burn centres in LMICs. This study aimed to compare the outcomes of burns treatment between a specialised burn centre and five non-specialised centres.

METHODS

A prospective cohort study was conducted on patients aged 18 years or above from January 1, 2021 to September 30, 2021. Participants were selected from the admission register at the emergency department. All burns irrespective of the mechanism of injury or %TBSA were included. Data were entered into REDCap. Statistical analysis of outcomes such as positive blood culture, length of hospital stay (LOHS) and 90-day mortality between specialised burn versus non-specialised centres was performed. Furthermore, an analysis of risk factors for mortality was performed and survival data computed.

RESULTS

Of the 488 study participants, 36% were admitted to a specialised burn centre compared to 64% admitted to non-specialised centres. The demographic characteristics were similar between centres. Patients at the specialised burn centre compared to non-specialised centres had a significantly higher inhalation injury of 30.9% vs 7.7% (p < 0.001), > 10%TBSA at 83.4% vs 45.7% (p < 0.001), > 20%TBSA at 46.9% vs 16.6% (p < 0.001), and a median (IQR) ABSI score of 6 (5-7) vs 5 (4-6) (p < 0.0001). Furthermore, patients from specialised burn vs non-specialised centres had a longer median (IQR) time from injury to first burn excision at 7 (4-11) vs 5 (2-10) days, higher rate of burn sepsis 69% vs 35%, increased LOHS 17 (11-27) vs 12 (6-22) days, and 90-day mortality rates at 19.4% vs 6.4%. After adjusting for cofounding variables, survival data showed no difference between specialised burn and non-specialised centres (HR 1.8 95% CI 1.0-3.2, p = 0.05).

CONCLUSION

Although it appears that the survival of burn patients managed at non-specialised centres in a middle-income country is comparable to those managed at specialised burn centres, there is uncounted bias in our survival data. Hence, a change in practice is not advocated. However, due to resource constraint specialised burn centres in addition to managing major burns should provide training and support to the non-specialised centres.

Impact of diabetes on clinical outcome in severely burned patients

INTRODUCTION

According to the International Diabetes Federation, approximately 425 million people worldwide suffer from diabetes mellitus, a figure that will double in the next 20 years. Data on the ratio of treated diabetics in burn intensive care units remain scarce and the effects on the mortality rate are poorly defined.

METHODS

Our retrospective, single-centre study aimed to evaluate differences in the risk factors due to diabetes mellitus, the clinical outcome and the patient population of diabetic patients after severe burn injuries over a time period of 21 years.

RESULTS

Despite increasing numbers of diabetic patients, the ratio of burn patients suffering from diabetes remained stable during the study period. The risk factors for mortality were higher age (OR 1.03, 95% confidence interval (CI), 1.02-1.04, p < 0.0001), female sex (OR 1.56, 95% CI, 1.06-2.29, p = 0.025), higher % total body surface area (TBSA) (OR 3.88, 95% CI, 2.81-5.46, p < 0.0001), full thickness burns (OR 8.58, 95% CI, 3.84 - 23.60, p < 0.0001) and the presence of inhalation injuries (OR 4.68, 95% CI, 3.15-7.02, p < 0.0001) Patients with diabetes had a smaller extent of burned areas with a median TBSA of 30% (quartiles: 22-50%, p = 0.036) compared to non-diabetic patients (35% (25-55%)) but had a similar length of stay with a median of 29 (quartiles: 13-44) days vs. 23 (10-48) days. Outcome analysis showed an overall mortality of 35.6%. Diabetes was not associated with higher mortality rate after burn injury in a univariate model (OR 1.80, 95% CI 0.92-3.51). After correction for %TBSA, the effect of diabetes on mortality was significant (OR 2.80, 95% CI, 1.33-5.90).

CONCLUSION

Our data indicate higher mortality rates (50-100%) of diabetic patients with TBSA greater than 40% in severely burned patients compared to non-diabetic patients without a significant outcome due to the low number of cases in the subgroup analyses.

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.

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.

Outcomes following traumatic inhalational airway injury - Predictors of mortality and effect of procedural intervention

OBJECTIVE

Study outcomes, predictors of mortality, and effects of procedural interventions on patients following traumatic inhalational airway injury.

STUDY

Design: Retrospective study.

SETTING

National Trauma Data Bank METHODS: Patients over the age of eighteen admitted between 2008 and 2016 to NTDB-participating sites were included. In-hospital mortality and length of stay were the primary outcomes.

RESULTS

The final study cohort included 13,351 patients. History of active smoking was negatively associated with in-house mortality with an OR of 0.33 (0.25-0.44). History of alcohol use, and presence of significant medical co-morbidities were positively associated with in-house mortality with OR of 5.28 (4.32-6.46) 2.74 (19.4-3.86) respectively. There was little to no association between procedural interventions and in-house mortality. Intubation, laryngobronchoscopy, and tracheostomy had OR of 0.90 (0.67-1.20), 1.02 (0.79-1.30), and 0.94 (0.58-1.51), respectively. However, procedural intervention did affect both the median hospital and ICU lengths of stay of patients. Median hospital and ICU length of stay were shorter for patients receiving endotracheal intubation. Median hospital length of stay was longer for patients undergoing bronchoscopy and laryngoscopy, but median ICU length of stay was shorter for patients undergoing bronchoscopy and laryngoscopy. Patients receiving a tracheostomy have both significantly increased median hospital and ICU lengths of stay.

CONCLUSIONS

Active smoking was associated with decreased odds of in-hospital mortality, while presence of pre-existing medical comorbidities and history of alcohol use disorder was associated with increased odds of in-hospital mortality. Procedural intervention had little to no association with in-hospital mortality but did affect overall hospital and ICU LOS.

The Predictive Capacity of American Society of Anesthesiologists Physical Status (ASA PS) Score in Burn Patients

Advances in burn care continues to improve survival rates and patient outcomes. There are several burn prognostic tools used to predict mortality and outcomes; however, none include patient comorbidities. We used the American Society of Anesthesiologists physical status score as a surrogate measure for comorbidities, and evaluated its role in predicting mortality and outcomes in adult burn patients undergoing surgery. A retrospective analysis was performed on data collected from a single burn center in the United States, which was comprised of 183 patients. We evaluated the American Society of Anesthesiologists physical status score as an independent predictor of mortality and outcomes, including intensive care unit (ICU) length of stay (LOS), hospital LOS, mechanical ventilator (MV) days, and complications. We compared the American Society of Anesthesiologists physical status score to other prognostic models which included the revised Baux score, Belgian Outcome in Burn Injury, and the Abbreviated Burn Severity Index. Our results demonstrated that the revised Baux and American Society of Anesthesiologists physical status scores could be used to determine the mortality risk in adult burn patients. The revised Baux was the best predictor of mortality, ICU LOS, and MV days, while the Abbreviated Burn Severity Index was the best predictor of total LOS.

Sparsity of burn centers and prolonged length of hospital stay: A nationwide study

INTRODUCTION

The optimal distribution of burn centers remains unclear. We aimed to determine the appropriate number of burn centers per population (density) and examined a nationwide registry with the hypothesis that low-density burn centers would be associated with unfavorable outcomes.

PATIENTS AND METHODS

A retrospective study was conducted using the Japanese Society of Burn Injury registry (2011-2021). Burn center density was defined as the number of burn centers per one million population in each prefecture, and centers were trisected on the basis of density. Hospital-free days until day 30 were compared between patients at high-, middle-, and low-density centers. Inverse probability weighting was conducted to adjust baseline characteristics, including age, burn mechanism, and burn severity.

RESULTS

We included 6764, 6209, and 2200 patients at high-, middle-, and low-density burn centers, respectively. After adjusting for patient demographics and burn severity, patients at high- and middle-density centers (≥0.4 centers per one million population) had longer hospital-free days compared with those at low-density centers (11 [0-23] vs 11 [0-23] vs 8 [0-22] days; p < 0.001).

CONCLUSIONS

Low burn center density (<0.4 centers per one million population) was associated with longer hospital stay, whereas no higher limit was determined.

Predicting Burn Mortality Using a Simple Novel Prediction Model

Background  Prediction of outcome for burn patients allows appropriate allocation of resources and prognostication. There is a paucity of simple to use burn-specific mortality prediction models which consider both endogenous and exogenous factors. Our objective was to create such a model.

Methods  A prospective observational study was performed on consecutive eligible consenting burns patients. Demographic data, total burn surface area (TBSA), results of complete blood count, kidney function test, and arterial blood gas analysis were collected. The quantitative variables were compared using the unpaired student t -test/nonparametric Mann Whitney U-test. Qualitative variables were compared using the ⊠2-test/Fischer exact test. Binary logistic regression analysis was done and a logit score was derived and simplified. The discrimination of these models was tested using the receiver operating characteristic curve; calibration was checked using the Hosmer—Lemeshow goodness of fit statistic, and the probability of death calculated. Validation was done using the bootstrapping technique in 5,000 samples. A p -value of <0.05 was considered significant.

Results  On univariate analysis TBSA ( p <0.001) and Acute Physiology and Chronic Health Evaluation II (APACHE II) score ( p = 0.004) were found to be independent predictors of mortality. TBSA (odds ratio [OR] 1.094, 95% confidence interval [CI] 1.037–1.155, p = 0.001) and APACHE II (OR 1.166, 95% CI 1.034–1.313, p = 0.012) retained significance on binary logistic regression analysis. The prediction model devised performed well (area under the receiver operating characteristic 0.778, 95% CI 0.681–0.875).

Conclusion  The prediction of mortality can be done accurately at the bedside using TBSA and APACHE II score.

Chronic Neuropathic Pain Following Hand Burns: Etiology, Treatment, and Long-Term Outcomes

PURPOSE

Chronic neuropathic pain (CNP) after burn injury to the hand/upper extremity is relatively common, but not well described in the literature. This study characterizes patients with CNP after hand/upper extremity burns to help guide risk stratification and treatment strategies. We hypothesize that multiple risk factors contribute to the development of CNP and refractory responses to treatment.

METHODS

Patients older than 15 years admitted to the burn center after hand/upper extremity burns, from January 1, 2014, through January 1, 2019, were included. Chronic neuropathic pain was defined as self-described pain for longer than 6 months after burn injury, not including pain due to preexisting illness/medications. Two analyses were undertaken: (1) determining risk factors for developing CNP among patients with hand/upper extremity burns, and (2) determining risk factors for developing refractory pain (ie, nonresponsive to treatment) among hand/upper extremity burn patients with CNP.

RESULTS

Of the 914 patients who met the inclusion criteria, 55 (6%) developed CNP after hand/upper extremity burns. Twenty-nine of these patients (53%) had refractory CNP. Significant risk factors for developing CNP after hand/upper extremity burns included history of substance abuse and tobacco use. Among CNP patients, significant risk factors for developing refractory pain included symptoms of burning sensations. In all CNP patients, gabapentin and ascorbic acid were associated with significant decreases in pain scores on follow-up.

CONCLUSIONS

Substance abuse and tobacco use may contribute to the development of CNP after hand/upper extremity burns. Those who developed refractory CNP were more likely to use the pain descriptor, burning sensations. Pharmacological pain management with gabapentin or pregabalin and ascorbic acid may provide the most relief of CNP symptoms.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Self-inflicted Burn Injury Is Independently Associated With Increased Mortality in a More Economically Developed Country: A Propensity Score Matching Analysis

Self-inflicted burn accounts for considerable morbidity and mortality in more economically developed countries, and there is a substantial debate regarding the pathophysiological relevance between self-inflicted burns and unfavorable outcomes. To validate whether self-inflicted injury is an independent predictor of high mortality regardless of the severity of burn, they conducted a retrospective observational study using the Japan Trauma Data Bank, a nationwide database including over 200 major tertiary care centers. Among 2006 patients with burn who had arrived at collaborating centers between 2004 and 2016, they included patients aged ≥15 years, those who did not present with cardiopulmonary arrest upon arrival, and those who had ≥10 percent total body surface area burns. Patients with missing survival data or unknown mechanism of injury were excluded. In total, 1094 patients were eligible, of whom 222 (20.3 percent) had self-inflicted burns. The patients were divided into the self-inflicted and non-self-inflicted groups, and propensity score was calculated using the demographic information of the patients, injury variables, time from injury to hospital arrival, and other survival predictors. Via a propensity score matching, 98 pairs were selected, and the self-inflicted group had a higher mortality than the non-self-inflicted group (43.9 vs 28.6 percent, hazard ratio = 1.77; 95% confidence interval = 1.10-2.86; P = .02). Inverse probability weighting and multivariate logistic regression were performed as sensitivity analyses, and results validated that self-inflicted burn was independently associated with increased in-hospital mortality. Therefore, patients with self-inflicted burns should receive judicious management, regardless of burn injury severity.

Effect of comorbidities on clinical outcome of patients with burn injury - An analysis of the German Burn Registry

BACKGROUND

Severe burn injuries are associated with high morbidity and mortality. Well-implemented scoring systems for patients with major burns exist in the literature. A major disadvantage of these scores is the partial non-consideration of patient-related comorbidities. Published data on this matter is limited to small study cohorts and/or single center studies. Further, the effect of comorbidities on clinical outcome of patients with severe burn injuries has not yet been examined nationwide in a large cohort in Germany. Hence, the aim of this study was to examine the influence of comorbidities on clinical outcome of these patients based on data from the national registry.

METHODS

Anonymized data from a total of 3455 patients with documented burns of 1% or more Total Burn Surface Area (TBSA) and over 16 years of age included in the German Burn Registry between 2017 and 2018 were analyzed retrospectively. Data included burn extent, body weight, age, burn depth, inhalation injury, comorbidities, mortality, number of operations and length of hospital stay (LOS).

RESULTS

In the logistic regression analysis age (OR 1.07 [1.06-1.09], p < 0.001), TBSA (OR 1.09 [1.08-1.11], p < 0.001), IHT (OR 2.15 [1.44-3.20], p < 0001), third degree burn (OR 2.08 [1.39-3.11], p < 0.001), Chronic Obstructive Pulmonary Disease (COPD) (OR 2.45 [1.38-4.35], p = 0.002) and renal insufficiency (OR 2.02 [1.13-3.59], p = 0.017) influenced mortality significantly. If a patient had more than one comorbidity, mortality was higher and in-hospital length of stay (LOS) longer. Renal insufficiency was significantly (p < 0.001) associated with the most prolonged LOS by 11.44 days. TBSA (p < 0.001), Abbreviated Burn Severity Index (ABSI) > 3 (p < 0.001) and IHT (p = 0.001) correlated with the amount of required surgeries and significantly predicted the need for intubation. Patients with arrhythmia significantly required more surgeries (p = 0.041), whereas patients with COPD required significantly less surgical interventions (p = 0.013).

CONCLUSION

Preexisting comorbidities have a significant impact on the clinical outcome of patients with severe burn injuries. Further investigation is warranted in order to supplement existing prognostic scores with new mortality-associated parameters.

Length of hospital stay and mortality associated with burns from assault: a retrospective study with inverse probability weighting analysis

Background

Burns resulting from assaults account for considerable morbidity and mortality among patients with burn injuries around the world. However, it is still unclear whether unfavorable clinical outcomes are associated primarily with the severity of the injuries. To elucidate the direct relationship between burns resulting from assaults and mortality and/or length of hospital stays, we performed this study with the hypothesis that burns from assault would be independently associated with fewer hospital-free days than would burns from other causes, regardless of the severity of burn injuries.

Methods

We conducted a retrospective cohort study, using a city-wide burn registry (1996-2017) accounting for 14 burn centers in Tokyo, Japan. Patients who arrived within 24 hours after injury were included, and those with self-inflicted burn injuries were excluded. Patients were divided into two groups according to mechanism of burns (assault vs. accident), and the number of hospital-free days until day 30 after injury (a composite of in-hospital death and hospital length of stay) was compared between the groups. To estimate the probability that an injury would be classified as an assault, we calculated propensity scores, using multivariate logistic regression analyses adjusted for known outcome predictors. We also performed an inverse probability weighting (IPW) analysis to compare adjusted numbers of hospital-free days.

Results

Of 7419 patients in the registry with burn injuries during the study period, 5119 patients were included in this study. Of these, 113 (2.2%) were injured as a result of assault; they had significantly fewer hospital-free days than did those with burns caused by accident (18 [27] vs. 24 [20] days; coefficient = [Formula: see text]3.4 [[Formula: see text]5.5 to [Formula: see text]1.3] days; p = 0.001). IPW analyses similarly revealed the independent association between assault burn injury and fewer hospital-free days (adjusted coefficient = [Formula: see text]0.6 [[Formula: see text]1.0 to [Formula: see text]0.1] days; p = 0.009).

Conclusions

Burn from assault was independently associated with fewer hospital-free days, regardless of the severity of burn injuries. The pathophysiological mechanism underlying the relationship should be further studied in a prospective observational study.

Prevalence and prognostic impact of inhalation injury among burn patients: A systematic review and meta-analysis

BACKGROUND

The objective of our study was to perform a systematic review and meta-analysis aimed at assessing the prevalence of inhalation injury in burn patients and its prognostic value in relation to in-hospital mortality.

METHODS

We searched the PubMed and EMBASE databases for noninterventional studies published between 1990 and 2018 investigating in-hospital mortality predictors among burn patients.The primary meta-analysis evaluated the association between inhalation injury and mortality. A secondary meta-analysis determined the global estimate of the prevalence of inhalation injury and the rate of mortality. Random effects models were used, and univariate meta-regressions were used to assess sources of heterogeneity. This study is registered in the PROSPERO database with code CRD42019127356.

FINDINGS

Fifty-four studies including a total of 408,157 patients were selected for the analysis. A pooled inhalation prevalence of 15.7% (95% confidence interval, 13.4%-18.3%) was calculated.The summarized odds ratio of in-hospital mortality secondary to an inhalation injury was 3.2 (95% confidence interval, 2.5-4.3). A significantly higher odd of mortality was found among the studies that included all hospitalized burn patients, those that included a lower proportion of male patients, those with a lower mean total body surface area, and those with a lower prevalence of inhalation injury.

CONCLUSION

Despite our study's limitations due to the high risk of bias and the interstudy heterogeneity of some of our analyses, our results revealed a wide range of prevalence rates of inhalation injury and a significant association between this entity and in-hospital mortality in burn patients. However, this association is not significant if adjusted for disease severity.

LEVEL OF EVIDENCE

Systematic review/meta-analysis, level III.

Influence of pre-existing medical condition and predicting value of modified Elixhauser comorbidity index on outcome of burn patients

OBJECTIVES

To evaluate the impact of comorbidity and predicting value of the modified Elixhauser comorbidity index score on the outcome of burn patients.

METHODS

A retrospective study was conducted on 5480 patients admitted during 24 h after burn to the National Burn Hospital from 1/1/2016 to 31/12/2018. Demographic data and pre-existing medical conditions were collected. Modified Elixhauser comorbidity index (ECI) score developed by Walravel et al. was calculated for each patient. The score was the weighted sum of comorbid conditions. Outcomes measured included hospitalization, complication and mortality.

RESULTS

Among 5480 patients, 345(6.3%) had at least one pre-existing medical condition. Most common comorbidities were neurological disorder, diabetes, hypertension and psychoses. Pre-existing medical conditions were more common in elderly (25% vs. 4.8%; p < .001) and female (7.5% vs. 5.8%; p < .05). Moreover, significantly larger burn extent, higher rate of inhalation injury (p < .01) and complication (12.8% vs. 6.1%; p < .001), longer time of hospitalization (21.4 vs. 17.1 days; p < .001) were recorded in comorbidity group. It is noted that higher ECI score was remarkably higher in patients who developed complication (.6 vs. .3 respectively, p < .05) and death (.5 vs. .3; p < .05). Multivariate analysis indicated that apart from presence of inhalation injury, increased burn extent, full thickness burn area, ECI score was an independently predicted factor for prolonging the time of staying, for the development of complication and death. Each score of ECI results in increased probability unit of complication to .13 and probability unit of death to .11.

CONCLUSION

Pre-existing medical conditions lead to more severe and worse outcomes among burn patients. Modified Elixhauser comorbidity index score should be used as a prognosis factor for outcomes of burn patients.

Effects of Diabetes Mellitus on the Mortality, Length of Hospital Stay and Number of Operations in Burn Patients

Background

The effects of diabetes mellitus (DM) on mortality and morbidities in burn patients have not been sufficiently elucidated.

Objective

The present study aimed to investigate the effects of DM on the mortality, length of hospital stay, and number of operations in burn patients.

Methods

A retrospective cohort study was performed using medical records of 3,220 burn patients. Multiple logistic regression, linear regression, and Poisson regression models were used to determine whether DM increases mortality in patients with burn injury, whether DM prolongs length of hospital stay in burn survivors, and whether DM increases the number of operations in burn survivors, respectively.

Results

After adjusting for potential confounding factors, DM significantly increased odds of death in burn patients (adjusted odds ratio 3.225 [95% confidence interval 1.405~7.400], p=0.006). DM also increased the mean length of hospital stay in burn survivors (adjusted mean ratio 1.312 [95% confidence interval 1.198~1.437], p<0.001). Furthermore, DM significantly increased the mean number of operations in burn survivors (adjusted mean ratio 1.576 [95% confidence interval 1.391~1.785], p<0.001).

Conclusion

DM increases mortality, elongates hospital stay and makes more operations required in patients with burn injury.

Predictors of withdrawal of life support after burn injury

INTRODUCTION

Discussions regarding withdrawal of life support after burn injury are challenging and complex. Often, providers may facilitate this discussion when the extent of injury makes survival highly unlikely or when the patient's condition deteriorates during resuscitation. Few papers have evaluated withdrawal of life support in burn patients. We therefore sought to determine the predictor of withdrawal of life support (WLS) in a regional burn center.

METHODS

We conducted a retrospective analysis of all burn patients from 2002 to 2012. Patient characteristics included age, gender, burn mechanism, percentage total body surface area (%TBSA) burned, presence of inhalation injury, hospital length of stay, and pre-existing comorbidities. Patients <17years of age and patients with unknown disposition were excluded. Patients were categorized into three cohorts: Alive till discharge (Alive), death by withdrawal of life support (WLS), or death despite ongoing life support (DLS). DLS patients were then excluded from the study population. Multivariate logistic regression was used to estimate predictors of WLS.

RESULTS

8,371 patients were included for analysis: 8134 Alive, 237 WLS. Females had an increased odd of WLS compared to males (OR 2.03, 95% CI 1.18-3.48; p=0.010). Based on higher CCI, patients with pre-existing comorbidities had an increased odd of WLS (OR 1.28, 95% CI 1.08-1.52; p=0.005). There was a significantly increased odds for WLS (OR 1.09, 95% CI 1.06-1.12; p<0.001) with increasing age. Similarly, there was an increased odd for WLS (OR 1.08, 95% CI 1.07-1.51; p<0.001) with increasing %TBSA. An increased odd of WLS (OR 2.47, 95% CI 1.05-5.78; p=0.038) was also found in patients with inhalation injury.

CONCLUSION

The decision to withdraw life support is a complex and difficult decision. Our current understanding of predictors of withdrawal of life support suggests that they mirror those factors which increase a patient's risk of mortality. Further research is needed to fully explore end-of-life decision making in regards to burn patients. The role of patient's sex, particularly women, in WLS decision making needs to be further explored.

Poverty, population density, and the epidemiology of burns in young children from Mexico treated at a U.S. pediatric burn facility

INTRODUCTION

Children 5 and younger are at risk for sustaining serious burn injuries. The causes of burns vary depending on demographic, cultural and socioeconomic variables. At this pediatric burn center we provided medical care to children from Mexico with severe injuries. The purpose of this study was to understand the impact of demographic distribution and modifiable risk factors of burns in young children to help guide prevention.

METHODS

A retrospective chart review was performed with children 5 and younger from Mexico who were injured from 2000-2013. The medical records of 447 acute patients were reviewed. Frequency counts and percentages were used to identify geographic distribution and calculate incidence of burns. Microsoft Powermap software was used to create a geographical map of Mexico based on types of burns. A binomial logistic regression was used to model the incidence of flame burns as opposed to scald burns in each state with relation to population density and poverty percentage. In all statistical tests, alpha=0.05 for a 95% level of confidence.

RESULTS

Burns were primarily caused by flame and scald injuries. Admissions from flame injuries were mainly from explosions of propane tanks and gas lines and house fires. Flame injuries were predominantly from the states of Jalisco, Chihuahua, and Distrito Federal. Scalds were attributed to falling in large containers of hot water or food on the ground, and spills of hot liquids. Scald injuries were largely from the states of Oaxaca, Distrito Federal, and Hidalgo. The odds of a patient having flame burns were significantly associated with poverty percentage (p<0.0001) and population density (p=0.0085). Increasing levels of poverty led to decrease in odds of a flame burn, but an increase in the odds of scald burns. Similarly, we found that increasing population density led to a decrease in the odds of a flame burn, but an increase in the odds of a scald burn.

CONCLUSIONS

Burns in young children from Mexico who received medical care at this pediatric burn center were attributed to flame and scalds. Potential demographic associations have been identified. Different states in Mexico have diverse cultural and socioeconomic variables that may influence the etiology of burns in young children and this information may help efficiently tailor burn prevention campaigns for burn prevention efforts in each region.

APPLICABILITY OF RESEARCH TO PRACTICE

This information will be used to develop and help modify existing prevention campaigns.

The measured effect magnitude of co-morbidities on burn injury mortality

INTRODUCTION

The ability to better prognosticate burn injury outcome is challenging and historically, most center use the Baux or revised Baux score to help prognosticate burn outcome, however, the weighted contribution of comorbidity on burn mortality has traditionally not been accounted for nor adequately studied. We therefore sought to determine the effect of comorbidities, using the Charlson comorbidity index (CCI) on burn mortality.

METHODS

The purpose of this study was to determine the effect of comorbidities on burn injury mortality as determined by the LA50 (lethal TBSA burn at which 50% of the cohort will succumb from the burn injury) in a retrospective analysis of patients admitted to a regional burn center from 2002 to 2012. Independent variables analyzed included basic demographics, burn mechanism, presence of inhalation injury, TBSA (total body surface area), length of hospital stay, and pre-existing comorbidities. Bivariate analysis was performed and logistic regression modeling using significant variables was utilized to estimate odds of death.

RESULTS

7640 patients were included in this study. Overall survival rate was 96%. 40% of our burn cohort had at least one comorbidity. There was a linear increase in the likelihood of death with an increase in CCI. The logistic regression model for mortality outcomes identified four statistically significant variables: age, TBSA, inhalational injury and the presence of comorbidities (OR=1.59 for each 1 point increase in CCI; 95% CI 1.44-1.77). The unadjusted LA50 was 53% for the entire cohort. Partial adjustment multivariate regression controlling for burn mechanism and inhalation injury only, produced a slight reduction in LA50 for the 0-18 and 19-64 age categories to 76% and 48% TBSA, respectively, but a significant decrease occurred in the ≥65 years age group with a reduced LA50 to 20% TBSA (p<0.001). After full adjustment for all significant covariates, including comorbidities, the independent magnitude of effect of comorbidities on the LA50 was evident in the <65 cohort. The full adjustment showed a LA50 decreased to 61% and 43% TBSA, respectively in the 0-18 and >18-65 age groups respectively (p<0.001), however, in the >65 years age cohort there was no change in the LA50.

CONCLUSION

Preexisting comorbidities have a significant effect on burn injury mortality in all age groups, particularly the younger burn population. The measured effect of comorbidities in the >65 yr age cohort was mitigated by the co-linearity between age and comorbidities. The inclusion of CCI is imperative so as to better prognosticate burn outcome and help guide expectations and resource utilization, particularly in the younger burn cohort.

Central Nervous System Depressants Poisoning and Ventilator Associated Pneumonia: An Underrated Risk Factor at the Toxicological Intensive Care Unit

BACKGROUND

Ventilator-Associated Pneumonia (VAP) is the main cause of nosocomial infection at intensive care units (ICUs), which causes high mortality and morbidity.

OBJECTIVES

The objective of the present survey was to identify the VAP risk and prognostic factors among poisoned patients, who were admitted to the toxicological ICU (TICU), especially central nervous system (CNS) depressants due to their prevalence and importance.

PATIENTS AND METHODS

A case-control study was conducted at the Loghman Hakim hospital between March 2013 and March 2014. Among 300 poisoned patients with mechanical ventilator ≥ 48 hours, 150 patients, who had developed microbiologically-confirmed VAP were considered as the VAP group and 150 without VAP were defined as the control group. The following data were collected; age, gender, type of poisoning, glasgow coma score, Acute physiology and chronic health evaluation (APACHE) II score, length of hospital stay, previous antibiotic use, microbial culture of the trachea, body temperature, leukocyte count, and patients' outcome. Based on the type of poisoning, patients were divided into three groups including: opioid, CNS depressants and others. All data were expressed as means (SD) for continuous variables and frequencies for categorical variables. Logistic regression was used to determine the relationship between risk factors and VAP.

RESULTS

The mean age of the patients was 33.9 ± 14.3 years. The probable VAP incidence and mortality were 22% and 18.6%, respectively. The rate of CNS depressant versus opioid use (odds ratio, 3.74; P < 0.027), APACHE II (odds ratio, 1.28; P < 0.000) and length of hospital stay (odds ratio, 2.15; P < 0.000) were the independent risk factors for VAP. While, the APACHE II score (odds ratio, 1.12; P < 0.044) and length of hospital stay (odds ratio, 2.15; P < 0.000) were the independent predictors of VAP mortality among these patients. The most common microorganisms in VAP cases were Methicillin-Resistant Staphylococcus aureus (MRSA) and Acinetobacter sp. (56.7% and 12.7%, respectively).

CONCLUSIONS

Central nervous system depressant was an important risk factor for VAP among poisoned patients. Hypoventilation due to CNS depression can lead to VAP. The APACHE II and length of hospital stay were shown as independent predictors of VAP and mortality among these patients.

A novel mathematical model to predict prognosis of burnt patients based on logistic regression and support vector machine

OBJECTIVE

To develop a mathematical model of predicting mortality based on the admission characteristics of 6220 burn cases.

METHODS

Data on all the burn patients presenting to Institute of Burn Research, Southwest Hospital, Third Military Medical University from January of 1999 to December of 2008 were extracted from the departmental registry. The distributions of burn cases were scattered by principal component analysis. Univariate associations with mortality were identified and independent associations were derived from multivariate logistic regression analysis. Using variables independently and significantly associated with mortality, a mathematical model to predict mortality was developed using the support vector machine (SVM) model. The predicting ability of this model was evaluated and verified.

RESULTS

The overall mortality in this study was 1.8%. Univariate associations with mortality were identified and independent associations were derived from multivariate logistic regression analysis. Variables at admission independently associated with mortality were gender, age, total burn area, full thickness burn area, inhalation injury, shock, period before admission and others. The sensitivity and specificity of logistic model were 99.75% and 85.84% respectively, with an area under the receiver operating curve of 0.989 (95% CI: 0.979-1.000; p<0.01). The model correctly classified 99.50% of cases. The subsequently developed support vector machine (SVM) model correctly classified nearly 100% of test cases, which could not only predict adult group but also pediatric group, with pretty high robustness (92%-100%).

CONCLUSION

A mathematical model based on logistic regression and SVM could be used to predict the survival prognosis according to the admission characteristics.

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.

Inclusion of coexisting morbidity in a TBSA% and age based model for the prediction of mortality after burns does not increase its predictive power

INTRODUCTION

Several models for predicting mortality have been developed for patients with burns, and the most commonly used are based on age and total body surface area (TBSA%). They often show good predictive precision as depicted by high values for area under the receiver operating characteristic curves (AUC). However the effect of coexisting morbidity on such prediction models has not to our knowledge been thoroughly examined. We hypothesised that adding it to a previously published model (based on age, TBSA%, full thickness burns, gender, and need for mechanical ventilation) would further improve its predictive power.

METHODS

We studied 772 patients admitted during the period 1997-2008 to the Linköping University Hospital, National Burn Centre with any type of burns. We defined coexisting morbidity as any of the medical conditions listed in the Charlson list, as well as psychiatric disorders or drug or alcohol misuse. We added coexisting medical conditions to the model for predicting mortality (age, TBSA%, and need for mechanical ventilation) to determine whether it improved the model as assessed by changes in deviances between the models.

RESULTS

Mean (SD) age and TBSA% was 35 (26) years and 13 (17) %, respectively. Among 725 patients who survived, 105 (14%) had one or more coexisting condition, compared with 28 (60%) among those 47 who died. The presence of coexisting conditions increased with age (p<0.001) among patients with burns. The AUC of the mortality prediction model in this study, based on the variables age, TBSA%, and need for mechanical ventilation was 0.980 (n=772); after inclusion of coexisting morbidity in the model, the AUC improved only marginally, to 0.986. The model was not significantly better either.

CONCLUSION

Adding coexisting morbidity to a model for prediction of mortality after a burn based on age, TBSA%, and the need for mechanical ventilation did not significantly improve its predictive value. This is probably because coexisting morbidity is automatically adjusted for by age in the original model.

Morbidity and survival probability in burn patients in modern burn care

OBJECTIVE

Characterizing burn sizes that are associated with an increased risk of mortality and morbidity is critical because it would allow identifying patients who might derive the greatest benefit from individualized, experimental, or innovative therapies. Although scores have been established to predict mortality, few data addressing other outcomes exist. The objective of this study was to determine burn sizes that are associated with increased mortality and morbidity after burn.

DESIGN AND PATIENTS

Burn patients were prospectively enrolled as part of the multicenter prospective cohort study, Inflammation and the Host Response to Injury Glue Grant, with the following inclusion criteria: 0-99 years old, admission within 96 hours after injury, and more than 20% total body surface area burns requiring at least one surgical intervention.

SETTING

Six major burn centers in North America.

MEASUREMENTS AND MAIN RESULTS

Burn size cutoff values were determined for mortality, burn wound infection (at least two infections), sepsis (as defined by American Burn Association sepsis criteria), pneumonia, acute respiratory distress syndrome, and multiple organ failure (Denver 2 score>3) for both children (<16 yr) and adults (16-65 yr). Five hundred seventy-three patients were enrolled, of which 226 patients were children. Twenty-three patients were older than 65 years and were excluded from the cutoff analysis. In children, the cutoff burn size for mortality, sepsis, infection, and multiple organ failure was approximately 60% total body surface area burned. In adults, the cutoff for these outcomes was lower, at approximately 40% total body surface area burned.

CONCLUSIONS

In the modern burn care setting, adults with over 40% total body surface area burned and children with over 60% total body surface area burned are at high risk for morbidity and mortality, even in highly specialized centers.

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.

Comparison of mortality prediction models in burns ICU patients in Pinderfields Hospital over 3 years

BACKGROUND

Many different burns mortality prediction models exist; however most agree that important factors that can be weighted include the age of the patient, the total percentage of body surface area burned and the presence or absence of smoke inhalation.

METHODS

A retrospective review of all burns primarily admitted to Pinderfields Burns ICU under joint care of burns surgeons and intensivists for the past 3 years was completed. Predicted mortality was calculated using the revised Baux score (2010), the Belgian Outcome in Burn Injury score (2009) and the Boston group score by Ryan et al. (1998). Additionally 28 of the 48 patients had APACHE II scores recorded on admission and the predicted and actual mortality of this group were compared.

RESULTS

The Belgian score had the highest sensitivity and negative predictive value (72%/85%); followed by the Boston score (66%/78%) and then the revised Baux score (53%/70%). APACHE II scores had higher sensitivity (81%) and NPV (92%) than any of the burns scores.

DISCUSSION

In our group of burns ICU patients the Belgian model was the most sensitive and specific predictor of mortality. In our subgroup of patients with APACHE II data, this score more accurately predicted survival and mortality.

A 10-year experience with major burns from a non-burn intensive care unit

OBJECTIVE

The aim of this study was to review clinical data and outcomes of patients with burns in a Mexican non-burn intensive care unit (ICU).

METHODS

We did a retrospective analysis of our single-centre database of burn patients admitted to the ICU in the Hospital Civil Fray Antonio Alcalde (University Hospital). The sample was divided for analysis into two groups according to the outcome 'death' or 'discharge' from ICU.

RESULTS

Overall mortality was 58.2%, without a decreasing trend in mortality rates through the years. We identified the presence of third-degree burns (odds ratio (OR) 1.5, p=0.003), and >49% total burned surface area (TBSA; OR 3.3, p≤0.001) was associated with mortality. Mean age was higher in deceased patients (38.2 years vs. 31.3 years, p=0.003) as was the TBSA (62.8% vs. 36.4%, p≤0.001). At multivariate analysis, inhalation injury was not associated with increased mortality, but it was with more mechanical ventilation days. Early surgical debridement/cleansing was performed in most patients; however, the mean of the procedures was 1.7 per patient in both groups.

CONCLUSION

We identified significant factors associated with mortality. These variables and prognosis from non-burn ICUs differ broadly compared with burn intensive care units (BICUs); thus, more structured, multidisciplinary and specialised treatment strategies are still needed.

Prognostic factors for failure of nonoperative management in adults with blunt splenic injury: a systematic review

BACKGROUND

Contradictory findings are reported in the literature concerning prognostic factors for failure of nonoperative management (NOM) in the treatment of adults with blunt splenic injury. The objective of this systematic review was to identify prognostic factors for failure of NOM, with or without angiography and embolization.

METHODS

MEDLINE, Embase, and the Cochrane Library databases were searched. Prospective or retrospective cohort studies addressing failure of nonoperative treatment, with and/or without angiography and embolization, of blunt abdominal injuries were included. Methodological quality of the studies was assessed.

RESULTS

A total of 335 titles and abstracts were screened, of which 31 fulfilled the inclusion criteria. No randomized controlled trials were found. Ten articles were qualified as high-quality articles and used for data extraction (best-evidence synthesis). A total of 25 prognostic factors were investigated, of which 14 were statistically significant in one or more studies. Strong evidence exists that age of 40 years or above, Injury Severity Score (ISS) of 25 or greater, and splenic injury grade of 3 or greater are prognostic factors for failure of NOM. Moderate evidence was found for a splenic Abbreviated Injury Scale score of 3 or greater, trauma and ISS of less than 0.80, the presence of an intraparenchymal contrast blush, as well as transfusion of 1 unit of packed red blood cells or more. Limited evidence was found for large hemoperitoneum, lower Revised Trauma Score, lower Glasgow Coma Scale score, lower systolic blood pressure, male sex, the presence of traumatic brain injury, and splenic embolization as protective factor for failure of NOM.

CONCLUSION

Awareness for failure of NOM is required in patients aged 40 years or older, in patients with an ISS of 25 or higher or those with splenic injury grade 3 or higher. The prognostic factors for failure that we identified should be confirmed in future prospective cohort studies or meta-analyses using individual patient data.

LEVEL OF EVIDENCE

Systematic review, level III.

Attempted suicide by self-immolation is a powerful predictive variable for survival of burn injuries

Up to 9% of all burn victims in western countries are reported to have been caused by self-immolation with suicidal intent and usually involve extensive injuries. The authors sought to identify differences between suicide burn victims as opposed to those who sustained their injuries accidentally with regard to injury severity and mortality and determine the possible impact of suicide as a prognostic variable in the context of a scoring system such as the Abbreviated Burns Severity Index (ABSI). The data of all burns patients treated at the Specialist Burns Intensive Care Unit, University Hospital Zürich, between 1968 and 2008 were analyzed retrospectively. Of the 2813 patients included in the study, 191 were identified as attempted suicides, most commonly involving the use of accelerants. Thirty percent of all suicide victims had preexisting psychiatric diagnoses. Suicide victims presented with significantly more extensive burns (53.7%, ±0.98 SEM vs 21.4 %, ±0.36 SEM, P < .0001), had higher total ABSI scores (8.4, ±0.23 SEM vs 6.6, ±0.05 SEM, P < .0001), and had higher mortality rates (42.9% [83/191] vs 16.3% [426/2622]) than accident victims. Furthermore, logistic regression revealed suicide to be a significant predictor of mortality as inhalation injury (odds ratio 2.2, 95% confidence interval 1.4-3.5, P < .0003 and odds ratio 2.4, 95% confidence interval 1.4-4.0, P < .0009, respectively). The odds of dying from an attempted suicide are twice as high compared with those of accident patients in the same ABSI category, making suicide a powerful predictor of mortality. The authors therefore suggest including it as a fixed variable in scoring systems for estimating a patient's mortality after burn injuries such as the widely used ABSI.

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.

Activation of toll-like receptor 2 prevents suppression of T-cell interferon γ production by modulating p38/extracellular signal-regulated kinase pathways following alcohol and burn injury

Recent studies indicate that toll-like receptors (TLRs) are expressed on T cells and that these receptors directly or indirectly activate the adaptive immune system. We have shown previously that acute alcohol/ethanol (EtOH) intoxication combined with burn injury suppresses mesenteric lymph node (MLN) T-cell interleukin-2 (IL-2) and interferon γ (IFN-γ) production. We examined whether direct stimulation of T cells with TLR2, 4, 5 and 7 agonists modulates CD3-mediated T-cell IL-2/IFN-γ release following EtOH and burn injury. Male mice were gavaged with EtOH (2.9 gm/kg) 4 h prior to receiving an ~12.5% total body surface area sham or full-thickness burn injury. Animals were killed on d 1 after injury and T cells were purified from MLN and spleens. T cells were cultured with plate-bound anti-CD3 in the presence or absence of various TLR ligands. Although TLR2, 4 and 5 agonists potentiate anti-CD3-dependent IFN-γ by T cells, the TLR2 agonist alone induced IFN-γ production independent of CD3 stimulation. Furthermore, T cells were treated with inhibitors of myeloid differentiation primary response protein 88 (MyD88), TIR domain-containing adaptor protein (TIRAP), p38 and/or extracellular signal-regulated kinase (ERK) to determine the mechanism by which TLR2 mediates IL-2/IFN-γ production. IL-2 was not influenced by TLR agonists. MyD88 and TIRAP inhibitory peptides dose-dependently diminished the ability of T cells to release IFN-γ. p38 and ERK inhibitors also abolished TLR2-mediated T-cell IFN-γ. Together, our findings suggest that TLR2 directly modulates T-cell IFN-γ production following EtOH and burn injury, independent of antigen-presenting cells. Furthermore, we demonstrated that MyD88/TIRAP-dependent p38/ERK activation is critical to TLR2-mediated T-cell IFN-γ release following EtOH and burn injury.

Gram-negative bacterial infection in thigh abscess can migrate to distant burn depending on burn depth

Sepsis remains the major cause of death in patients with major burn injuries. In the present investigation we evaluated the interaction between burn injuries of varying severity and preexisting distant infection. We used Gram-negative bacteria (Pseudomonas aeruginosa and Proteus mirabilis) that were genetically engineered to be bioluminescent, which allowed for noninvasive, sequential optical imaging of the extent and severity of the infection. The bioluminescent bacteria migrated from subcutaneous abscesses in the leg to distant burn wounds on the back depending on the severity of the burn injury, and this migration led to increased mortality of the mice. Treatment with ciprofloxacin, injected either in the leg with the bacterial infection or into the burn eschar, prevented this colonization of the wound and decreased mortality. The present data suggest that burn wounds can readily become colonized by infections distant from the wound itself.

Ethanol exposure suppresses bone marrow-derived dendritic cell inflammatory responses independent of TLR4 expression

Acute alcohol (ethanol) exposure is linked with increased susceptibility to infection and increased mortality in trauma and burn patients. Dendritic cells (DCs) are central mediators in innate and adaptive immune responses, and they play a role in the presentation of pathogens to adaptive immune cells. We investigated the effects of acute ethanol exposure on bone marrow-derived DC (BM-DC) responses. Total bone marrow cells, obtained from 8 to 10 week old C57BL/6 male mice, were cultured in the presence of granulocyte/monocyte-colony stimulating factor and interleukin (IL)-4 for 7 days. BM-DCs were harvested and treated with increasing doses of ethanol (50, 100, and 250 mM) at the time of, or 3 h before, lipopolysaccharide (LPS). After LPS, supernatants were collected for cytokine measurement, and cells were harvested for flow cytometry. Concurrent acute ethanol exposure and LPS treatment resulted in a dose-dependent suppression of IL-6, IL-12p40, IL-23, and IL-10. In addition, ethanol exposure before LPS dysregulated the IL-12p40/IL-23 balance and more profoundly suppressed IL-6 and IL-10 secretion by BM-DCs, as compared with cells concurrently treated with ethanol and LPS. Ethanol treatment did not affect either toll-like receptor (TLR)4 or TLR2 expression. In summary, our study demonstrates that acute ethanol exposure suppresses BM-DC LPS-induced responses, irrespective of affecting TLR4 or TLR2 expression.

Incidence and treatment of burns: a twenty-year experience from a single center in Germany

OBJECTIVE

To analyze trends in incidence and treatment of thermal injuries over the last two decades.

METHODS

We retrospectively reviewed our local single center database of patients with thermal injuries admitted to the burn intensive care unit (BICU) of the Cologne-Merheim Medical Center (University Hospital of Witten/Herdecke). The cohort was divided into two groups according to the decade of admission and the epidemiology and clinical course of the patient sample admitted during the period 1991-2000 (n=911) was compared to that of 2001-2010 (n=695).

RESULTS

The following variables were significantly different in the bivariate analysis: mean age (39.8 years vs. 44.0 years), burn size of total body surface area (23.2% vs. 18.0%) and size of 3rd degree burns (9.6% vs. 14.9%). The incidence of inhalation injury was significantly lower in the last decade (33.3% vs. 13.7%) and was associated with a shorter duration of mechanical ventilation (10.8 days vs. 8.5 days). The ABSI-score as an indicator of burn severity declined in the second period (6.3 vs. 6.0) contributing partially to the decline of BICU length of stay (19.1 days vs. 18.8 days) and to the mortality rate decrease (18.6% vs. 15.0%).

CONCLUSION

The severity of burn injuries during the last two decades declined, probably reflecting the success of prevention campaigns. Concerning mortality, the chance of dying for a given severity of injury has decreased.

Outcomes and predictors in burn rehabilitation

Advances in burn care in recent decades have resulted in a growing population of burn survivors and an increased need for inpatient rehabilitation. Burn survivors who require inpatient rehabilitation typically experience severe and complicated injuries. The purpose of this study is to examine burn rehabilitation outcomes and their predictor variables. Data are obtained from the Uniform Data System for Medical Rehabilitation from 2002 to 2007. Inclusion criterion is primary diagnosis of burn injury. Predictor variables include demographic, medical, and facility data. Outcome measures are length of stay efficiency, FIM® gain, community discharge, and FIM® discharge of at least 78. Linear and logistic regression analyses are used to determine significant predictors of outcomes. There are 2920 patients who meet inclusion criteria. The mean age of the population is 51 years, 33% of the population is female, 73% is Caucasian, and 40% are married. The median TBSA decile is 20 to 29%. The population exhibits a mean FIM® gain of 28 and length of stay efficiency of 2.1. A majority of the population is discharged to the community (76%) and has a FIM® discharge of at least 78 (81%). Significant predictors of outcomes in burn rehabilitation include age, FIM® admission, onset days, employment status, and marital status. Inpatient rehabilitation is critical to community reintegration of burn survivors. Survivors who are young, married, employed, and higher functioning at the time of admission to rehabilitation demonstrate the best outcomes. This research will help assess the rehabilitation potential of burn survivors and inform resource allocation.

Professional Practice and Innovation: Level of Agreement between Coding Sources of Percentage Total Body Surface Area Burnt (%TBSA)

The percentage of total body surface area burnt (%TBSA) is a critical measure of burn injury severity and a key predictor of burn injury outcome. This study evaluated the level of agreement between four sources of %TBSA using 120 cases identified through the Victorian State Trauma Registry. Expert clinician, ICD-10-AM, Abbreviated Injury Scale, and burns registry coding were compared using measures of agreement. There was near-perfect agreement (weighted Kappa statistic 0.81–1) between all sources of data, suggesting that ICD-10-AM is a valid source of %TBSA and use of ICD-10-AM codes could reduce the resource used by trauma and burns registries capturing this information.

Predicting prognosis in thermal burns with associated inhalational injury: a systematic review of prognostic factors in adult burn victims

Burn injuries are a significant problem with high associated morbidity and mortality. Those associated with inhalational trauma (IHT) may be associated with higher mortality, but studies on prognosis are small and underpowered. This study was designed to identify prognostic factors that increase the risk of death, to quantify this risk, and to identify existing prognostic models. An electronic search of English-language publications that identify prognostic risk factors in thermal burns including IHT was carried out. Each article was reviewed systematically, and data extraction, quality assessment, and summarization of the articles were performed. Thirteen articles that met the inclusion/exclusion criteria of this study were reviewed. Overall, the mortality rate among burn patients in this review was 13.9% (4-28.3%), with the mortality rate among those with IHT being 27.6% (7.8-28.3%). Those studies with multivariate analyses identified increasing %TBSA, presence of IHT, and increasing age as the strongest predictors for mortality in this patient population. It seems that %TBSA, presence of IHT, and age are the best predictors of mortality among the current published literature on burn prognosis.

Severe burn injury in Europe: a systematic review of the incidence, etiology, morbidity, and mortality

INTRODUCTION

Burn injury is a serious pathology, potentially leading to severe morbidity and significant mortality, but it also has a considerable health-economic impact. The aim of this study was to describe the European hospitalized population with severe burn injury, including the incidence, etiology, risk factors, mortality, and causes of death.

METHODS

The systematic literature search (1985 to 2009) involved PubMed, the Web of Science, and the search engine Google. The reference lists and the Science Citation Index were used for hand searching (snowballing). Only studies dealing with epidemiologic issues (for example, incidence and outcome) as their major topic, on hospitalized populations with severe burn injury (in secondary and tertiary care) in Europe were included. Language restrictions were set on English, French, and Dutch.

RESULTS

The search led to 76 eligible studies, including more than 186,500 patients in total. The annual incidence of severe burns was 0.2 to 2.9/10,000 inhabitants with a decreasing trend in time. Almost 50% of patients were younger than 16 years, and ~60% were male patients. Flames, scalds, and contact burns were the most prevalent causes in the total population, but in children, scalds clearly dominated. Mortality was usually between 1.4% and 18% and is decreasing in time. Major risk factors for death were older age and a higher total percentage of burned surface area, as well as chronic diseases. (Multi) organ failure and sepsis were the most frequently reported causes of death. The main causes of early death (< 48 hours) were burn shock and inhalation injury.

CONCLUSIONS

Despite the lack of a large-scale European registration of burn injury, more epidemiologic information is available about the hospitalized population with severe burn injury than is generally presumed. National and international registration systems nevertheless remain necessary to allow better targeting of prevention campaigns and further improvement of cost-effectiveness in total burn care.