Acute respiratory distress syndrome is as important as inhalation injury for the development of respiratory dysfunction in major burns

The impact and validity of the Berlin criteria on burn-induced ARDS: Examining mortality rates, and inhalation injury influences. A single center observational cohort study

BACKGROUND

As several recent studies have shown low mortality rates in burn injury induced ARDS early (≤7 days) after the burn, the Berlin criteria for the ARDS diagnosis in this setting may be disputed. Related to this issue, the present study investigated the incidence, trajectory and risk factors of early Acute Respiratory Distress Syndrome (ARDS) and outcome in burn patients, as per the Berlin criteria, along with the concurrent prevalence and influence of inhalation injury, and ventilator-acquired pneumonia (VAP).

METHODS

Over a 2.5-year period, burn patients with Total Burn Surface Area (TBSA) exceeding 10% admitted to a national burn center were included. The subgroup of interest comprised patients with more than 48 h of ventilatory support. This group was assessed for ARDS, inhalation injury, and VAP.

RESULTS

Out of 292 admissions, 62 sustained burns > 10% TBSA. Of these, 28 (45%) underwent ventilatory support for over 48 h, almost all, 24 out of 28, meeting the criteria for ARDS early, within 7 days post-injury and with a PaO2/FiO2 (PF) ratio nadir at day 5. The mortality rate for this early ARDS group was under 10%, regardless of PF ratios (mean TBSA% 34,8%). Patients with concurrent inhalation injury and early ARDS showed significantly lower PF ratios (p < 0.001), and higher SOFA scores (p = 0.004) but without impact on mortality. Organ failure, indicated by SOFA scores, peaked early (day 3) and declined in the first week, mirroring PF ratio trends (p < 0.001).

CONCLUSIONS

The low mortality associated with early ARDS in burn patients in this study challenges the Berlin criteria's for the early ARDS diagnosis, which for its validity relies on that higher mortality is linked to worsening PF ratios. The finding suggests alternative mechanisms, leading to the early ARDS diagnosis, such as the significant impact of inhalation injury on early PF ratios and organ failure, as seen in this study. The concurrence of early organ failure with declining PF ratios, supports, as expected, the hypothesis of trauma-induced inflammation/multi-organ failure mechanisms contributing to early ARDS. The study highlights the complexity in differentiating between the contributions of inhalation injury to early ARDS and the related organ dysfunction early in the burn care trajectory. The Berlin criteria for the ARDS diagnosis may not be fully applicable in the burn care setting, where the low mortality significantly deviates from that described in the original Berlin ARDS criteria publication but is as expected when considering the actual not very extensive burn injury sizes/Baux scores as in the present study.

Risk Factors of Mortality and Long-Term Survival in Burn Patients With/Without Extracorporeal Membrane Oxygenation: A 16 Year Real-World Study

Burn patients face cardiopulmonary failure risks, with recent observational studies suggesting promising outcomes for extracorporeal membrane oxygenation (ECMO). However, the effectiveness and long-term survival remain unclear. Our study aims to assess mortality risk factors and long-term survival in burn patients with and without ECMO. This study used Taiwan's National Health Insurance Research Database and designed a case-control with onefold propensity score matching across variables including sex, age, total body surface area (TBSA) burned, and index date. We analyzed mortality and survival risk factors in each stratified group with/without ECMO. Finally, we analyze the mortality according to ECMO and TBSA burned, and the cause of death and long-term survival. From 2000 to 2015, 4,556 burn patients with ECMO compared to an equivalent number without ECMO. Primary mortality include male, age >65, TBSA ≥30%, escharotomy, hemodialysis, and bacteremia. The ECMO group showed lower survival across all stratified risk factors, with the primary cause of death being burn-related issues, followed by respiratory and heart failure. The overall mortality rate was 54.41% with ECMO and 40.94% without ECMO (p < 0.001). Additionally, long-term survival is lower in the group with ECMO. This research provides a valuable real-world gross report about ECMO efficacy and long-term survival among burn patients with/without ECMO.

Lung Protection After Severe Thermal Burns With Adenosine, Lidocaine, and Magnesium (ALM) Resuscitation and Importance of Shams in a Rat Model

The management of severe burns remains a complex challenge. Adenosine, lidocaine, and magnesium (ALM) resuscitation therapy has been shown to protect against hemorrhagic shock and traumatic injury. The aim of the present study was to investigate the early protective effects of small-volume ALM fluid resuscitation in a rat model of 30% total body surface area (TBSA) thermal injury. Male Sprague-Dawley rats (320-340 g; n = 25) were randomly assigned to: 1) Sham (surgical instrumentation and saline infusion, without burn, n = 5), 2) Saline resuscitation group (n = 10), or 3) ALM resuscitation group (n = 10). Treatments were initiated 15-min after burn trauma, including 0.7 mL/kg 3% NaCl ± ALM bolus and 0.25-0.5 mL/kg/h 0.9% NaCl ± ALM drip, with animals monitored to 8.25-hr post-burn. Hemodynamics, cardiac function, blood chemistry, hematology, endothelial injury markers and histopathology were assessed. Survival was 100% for Shams and 90% for both ALM and Saline groups. Shams underwent significant physiological, immune and hematological changes over time as a result of surgical traums. ALM significantly reduced malondialdehyde levels in the lungs compared to Saline (P = .023), and showed minimal alveolar destruction and inflammatory cell infiltration (P < .001). ALM also improved cardiac function and oxygen delivery (21%, P = .418 vs Saline), reduced gut injury (P < .001 vs Saline), and increased plasma adiponectin (P < .001 vs baseline). Circulating levels of the acute phase protein alpha 1-acid glycoprotein (AGP) increased 1.6-times (P < .001), which may have impacted ALM's therapeutic efficacy. We conclude that small-volume ALM therapy significantly reduced lung oxidative stress and preserved alveolar integrity following severe burn trauma. Further studies are required to assess higher ALM doses with longer monitoring periods.

Extracorporeal Life Support for Severely Burned Patients with Concurrent Inhalation Injury and Acute Respiratory Distress Syndrome: Experience from a Military Medical Burn Center

BACKGROUND

Both inhalation injury and acute respiratory distress syndrome (ARDS) are risk factors that predict mortality in severely burned patients. Extracorporeal life support (ECLS) is widely used to rescue these patients; however, its efficacy and safety in this critical population have not been well defined. We report our experience of using ECLS for the treatment of severely burned patients with concurrent inhalation injury and ARDS.

METHODS

This was a retrospective analysis of 14 patients collected from a single medical burn center from 2012 to 2019. All patients suffered from major burns with inhalation injury and ARDS, and were treated with ECLS.

RESULTS

The median total body surface area of deep dermal or full thickness burns was 94.5%, ranging 47.7-99.0 %. The median revised Baux score was 122.0, ranging 90.0-155.0. All patients developed ARDS with a median partial pressure of arterial oxygen to a fraction of inspired oxygen ratio of 61.5, ranging 49.0-99.0. Indications for ECLS included sustained hypoxemia and unstable hemodynamics. The median interval for initiating ECLS was 2.5 days, ranging 1.0-156.0 days. The median duration of ECLS was 2.9 days, ranging 0.3-16.7 days. The overall survival to discharge was 42.8%. Causes of death included sepsis and multiple organ failure. ECLS-related complications included cannulation bleeding, catheter-related infection, and hemolysis. The incidence of risk factors reported in literature were higher in non-survivors, including Baux>120, albumin < 3.0 g/dL, and lactate > 8 mmol/L.

CONCLUSIONS

For severely burned patients with concurrent inhalation injury and ARDS, ECLS could be a salvage treatment to improve sustained hypoxemia. However, the efficacy of hemodynamic support was limited. Identifying definite ECLS indications and rigorous patient selection would contribute to better clinical outcomes.

ABO blood group and effects on ventilatory time, length of stay and mortality in major burns a retrospective observational outcome study

Blood group has been found to be important in the development of many diseases and the outcome of several disease processes, especially cardiovascular morbidity and mortality, such as caused by trauma and sepsis. The main reason is claimed to be related to glycobiology and effects mediated through the endothelium. This study investigated the possible effect of blood group (ABO) on burn care outcome. Burn outcome prediction models are extremely accurate and as such can be used to identify outcome effects even in single centre settings. In this retrospective risk adjusted observational study, we investigated the effect of ABO blood group on ventilatory time, length of hospital stay (LOS), and 90 day mortality among patients with burns. RESULTS: A total of 225 patients were included (2008-2019) with median TBSA of 26%; interquartile range (IQR) of 20-37%; median age 45 years (IQR 22-65 years); median Baux score (age + TBSA%); 76 (IQR 53- 97); 168 (75%) were male; median duration of hospital stay was 31 days (IQR 19-56); a total of 138 (61%) received treatment with mechanical ventilation; and 29 (13%) died. In a multivariable regression model, we were unable to isolate any significant effect of any blood group (O, A, B, AB) on the outcome measures studied (ventilatory time, LOS, and mortality). IN SUMMARY: contrary to many other major areas of disease in which ABO blood groups affect outcome, we were unable to find any such effect on patients with burns. Given the precision of the outcome models presented (AUC 0.93) any such an effect, if missed due to the limited study cohort, may be considered limited and to have only a minor clinical impact.

Positive signs on physical examination are not always indications for endotracheal tube intubation in patients with facial burn

Background

After clinical evaluation in the emergency department (ED), facial burn patients are usually intubated to protect their airways. However, the possibility of unnecessary intubation or delayed intubation after admission exists. Objective criteria for the evaluation of inhalation injury and the need for airway protection in facial burn patients are needed.

Methods

Facial burn patients between January 2013 and May 2016 were reviewed. Patients who were and were not intubated in the ED were compared. All the intubated patients received routine bronchoscopy and laboratory tests to evaluate whether they had inhalation injuries. The patients with and without confirmed inhalation injuries were compared. Multivariate logistic regression analysis was used to identify the independent risk factors for inhalation injuries in the facial burn patients. The reasons for intubation in the patients without inhalation injuries were also investigated.

Results

During the study period, 121 patients were intubated in the ED among a total of 335 facial burn patients. Only 73 (60.3%) patients were later confirmed to have inhalation injuries on bronchoscopy. The comparison between the patients with and without inhalation injuries showed that shortness of breath (odds ratio = 3.376, p = 0.027) and high total body surface area (TBSA) (odds ratio = 1.038, p = 0.001) were independent risk factors for inhalation injury. Other physical signs (e.g., hoarseness, burned nostril hair, etc.), laboratory examinations and chest X-ray findings were not predictive of inhalation injury in facial burn patients. All the patients with a TBSA over 60% were intubated in the ED even if they did not have inhalation injuries.

Conclusions

In the management of facial burn patients, positive signs on conventional physical examinations may not always be predictive of inhalation injury and the need for endotracheal tube intubation in the ED. More attention should be given to facial burn patients with shortness of breath and a high TBSA. Airway protection is needed in facial burn patients without inhalation injuries because of their associated injuries and treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-022-00594-9.

Environmental Factors

The acute respiratory distress syndrome (ARDS) remains a major cause of morbidity and mortality in the intensive care unit. Improving outcomes depends on not only evidence-based care once ARDS has already developed but also preventing ARDS incidence. Several environmental exposures have now been shown to increase the risk of ARDS and related adverse outcomes. How environmental factors impact the risk of developing ARDS is a growing and important field of research that should inform the care of individual patients as well as public health policy.

Addition of admission lactate levels to Baux score improves mortality prediction in severe burns

Risk adjustment and mortality prediction models are central in optimising care and for benchmarking purposes. In the burn setting, the Baux score and its derivatives have been the mainstay for predictions of mortality from burns. Other well-known measures to predict mortality stem from the ICU setting, where, for example, the Simplified Acute Physiology Score (SAPS 3) models have been found to be instrumental. Other attempts to further improve the prediction of outcome have been based on the following variables at admission: Sequential Organ Failure Assessment (_aSOFA) score, determinations of _aLactate or Neutrophil to Lymphocyte Ratio (_aNLR). The aim of the present study was to examine if estimated mortality rate (EMR, SAPS 3), _aSOFA, _aLactate, and _aNLR can, either alone or in conjunction with the others, improve the mortality prediction beyond that of the effects of age and percentage total body surface area (TBSA%) burned among patients with severe burns who need critical care. This is a retrospective, explorative, single centre, registry study based on prospectively gathered data. The study included 222 patients with median (25th–75th centiles) age of 55.0 (38.0 to 69.0) years, TBSA% burned was 24.5 (13.0 to 37.2) and crude mortality was 17%. As anticipated highest predicting power was obtained with age and TBSA% with an AUC at 0.906 (95% CI 0.857 to 0.955) as compared with EMR, _aSOFA, _aLactate and _aNLR. The largest effect was seen thereafter by adding _aLactate to the model, increasing AUC to 0.938 (0.898 to 0.979) (p < 0.001). Whereafter, adding EMR, _aSOFA, and _aNLR, separately or in combinations, only marginally improved the prediction power. This study shows that the prediction model with age and TBSA% may be improved by adding _aLactate, despite the fact that _aLactate levels were only moderately increased. Thereafter, adding EMR, _aSOFA or _aNLR only marginally affected the mortality prediction.

Characteristics of burn casualties treated at role 2 in Afghanistan

BACKGROUND

Role 2 medical treatment facilities (MTFs) are frequently located in austere settings and have limited resources. A dedicated assessment of burn casualties treated at this level of care has not been performed. Therefore, the objective of this study was to characterize burn casualties presenting to role 2 MTFs in Afghanistan, along with the procedures they required, complications, and mortality to begin understanding the resources consumed by their care.

METHODS

We identified burn casualties from the Department of Defense Trauma Registry (DODTR). The inclusion criteria were (1) experienced burn injuries in Afghanistan between October 2005 and April 2018 and (2) had documentation of treatment at role 2 in the DODTR. We excluded casualties with only first-degree burns, not otherwise specified burns, or only corneal burns. Casualty demographics, injury characteristics, procedures, and outcomes were reported.

RESULTS

We identified 453 burn casualties with a median (interquartile range) Injury Severity Score of 10 (4-22) and percent total body surface area burned of 11 (5-30). There were 123 casualties (27.2%) with inhalation injury, and the casualties experienced 3,343 additional traumatic injuries and needed 2,530 procedures. Casualties with documentation of resuscitation information received a median (interquartile range) of 1.9 (0.7-3.7) L of crystalloid fluids. Complications were documented in 53 casualties (11.7%). Final mortality was reported in 36 casualties (8.0%), and mortality at role 2 MTFs was reported in 7 casualties (1.5%).

CONCLUSION

Burn casualties had many injuries and needed many procedures, including those related to airway management, resuscitation, and wound care. Given the urgency of these procedures, ensuring that there is enough equipment and supplies will be important in the future. Although infrequent, some casualties experienced complications. Factors that may influence resuscitation include injury severity, concomitant traumatic injuries, and available supplies. Obtaining more contextual information on the patient care environment will be useful going forward.

LEVEL OF EVIDENCE

Epidemiological, level III.

Long-term survival among elderly after burns compared with national mean remaining life expectancy

INTRODUCTION

As compared to younger adults, older people have a greater risk of domestic accidents, such as burns, and their prognosis is worsened by a diminished physiological ability to face a thermal trauma. The in-hospital mortality is adversely affected by old age and burn size, whereas less is known about the long-term-survival in elderly patients who survive a burn injury. The aim of this study was to investigate if elderly burn patients after discharge from a Swedish National Burn Centre have a shorter remaining life compared to the national population, by using calculated remaining Life Expectancy (rLE).

METHODS

In this retrospective study we included all patients who were admitted for burns to the Linköping Burn Centre during 1993-2016 and who were 60 years or older and alive, at the time of discharge. The control group was extracted from Statistics Sweden, the national statistics database, and consisted of all individuals from the Swedish population matched for each patient in the study group, by sex and age at the year of discharge. The proportion who died before reaching the rLE was compared between the study population and the control group by calculating risk ratio.

RESULTS

The study group consisted of 111 former patients and 77 of them (69%) died before reaching the rLE, with mean 4.7 years of life lost (YLL), which was 33% more than that (52%) of the control group (RR 1.33, 95% CI 1.18-1.51). Burn related factors, such as TBSA % or FTB % were not found to account for this effect.

CONCLUSION

We found that the long-time survival of elderly patients after burns is shorter than that of a national control, the magnitude of which is quantitatively important. The current study does not support that burn related factors account for this effect and the reason should therefore be sought in other factors, such as e.g., co-morbidity or psychosocial issues.

Ventilation practices in burn patients—an international prospective observational cohort study

Background

It is unknown whether lung-protective ventilation is applied in burn patients and whether they benefit from it. This study aimed to determine ventilation practices in burn intensive care units (ICUs) and investigate the association between lung-protective ventilation and the number of ventilator-free days and alive at day 28 (VFD-28).

Methods

This is an international prospective observational cohort study including adult burn patients requiring mechanical ventilation. Low tidal volume (VT) was defined as VT ≤ 8 mL/kg predicted body weight (PBW). Levels of positive end-expiratory pressure (PEEP) and maximum airway pressures were collected. The association between VT and VFD-28 was analyzed using a competing risk model. Ventilation settings were presented for all patients, focusing on the first day of ventilation. We also compared ventilation settings between patients with and without inhalation trauma.

Results

A total of 160 patients from 28 ICUs in 16 countries were included. Low VT was used in 74% of patients, median VT size was 7.3 [interquartile range (IQR) 6.2–8.3] mL/kg PBW and did not differ between patients with and without inhalation trauma (p = 0.58). Median VFD-28 was 17 (IQR 0–26), without a difference between ventilation with low or high VT (p = 0.98). All patients were ventilated with PEEP levels ≥5 cmH2O; 80% of patients had maximum airway pressures &lt;30 cmH2O.

Conclusion

In this international cohort study we found that lung-protective ventilation is used in the majority of burn patients, irrespective of the presence of inhalation trauma. Use of low VT was not associated with a reduction in VFD-28.

Trial registration

Clinicaltrials.gov NCT02312869. Date of registration: 9 December 2014.

Effects of Multiday Ethanol Intoxication on Postburn Inflammation, Lung Function, and Alveolar Macrophage Phenotype

Burn patients who consumed alcohol before injury have worse clinical outcomes, including longer hospital stays, increased ventilator days, and more respiratory infections. Most alcohol consumers are binge drinkers and not chronic alcoholics, and binge drinking patterns fluctuate over the week, with consecutive days of drinking over the weekend followed by relative abstinence during the week. We used a murine model simulating this drinking pattern in the context of burn injury. Mice were given ethanol for 3 days, rested for 4 days, given ethanol for 3 more days, followed by a sham or 15% total body surface area full-thickness burn. We previously demonstrated that mice exposed to the combined insult exhibited respiratory dysfunction and 50% mortality, with those that succumbed to injury dying between 24 and 72 h, thus identifying a therapeutic intervention window. Our goal herein is to characterize inflammatory and respiratory parameters during this critical time frame. We saw that mice exposed to the combined insult had the highest circulating and pulmonary cytokine levels at 24 h, which were normalized by 72 h in survivors. Alveolar macrophage activation was observed at 24 h in burned mice, regardless of intoxication (P < 0.05). However, at 72 h, alveolar macrophages from intoxicated burned mice had elevated CD206, relative to controls (P < 0.05), indicative of an anti-inflammatory phenotype. Taken together, these findings suggest that although lung function and inflammation are normalized by 72 h, the alterations in alveolar macrophage phenotype shed light on a potential mechanism underlying increased infection susceptibility in intoxicated burn patients.

Is Mitochondrial Oxidative Stress the Key Contributor to Diaphragm Atrophy and Dysfunction in Critically Ill Patients?

Diaphragm dysfunction is prevalent in the progress of respiratory dysfunction in various critical illnesses. Respiratory muscle weakness may result in insufficient ventilation, coughing reflection suppression, pulmonary infection, and difficulty in weaning off respirators. All of these further induce respiratory dysfunction and even threaten the patients' survival. The potential mechanisms of diaphragm atrophy and dysfunction include impairment of myofiber protein anabolism, enhancement of myofiber protein degradation, release of inflammatory mediators, imbalance of metabolic hormones, myonuclear apoptosis, autophagy, and oxidative stress. Among these contributors, mitochondrial oxidative stress is strongly implicated to play a key role in the process as it modulates diaphragm protein synthesis and degradation, induces protein oxidation and functional alteration, enhances apoptosis and autophagy, reduces mitochondrial energy supply, and is regulated by inflammatory cytokines via related signaling molecules. This review aims to provide a concise overview of pathological mechanisms of diaphragmatic dysfunction in critically ill patients, with special emphasis on the role and modulating mechanisms of mitochondrial oxidative stress.

Development of delirium: Association with old age, severe burns, and intensive care

BACKGROUND

Delirium is defined as a disturbance of attention and awareness that develops over a short period of time, is a change from the baseline, and typically fluctuates over time. Burn care involves a high prevalence of known risk factors for delirium such as sedation, inflammation, and prolonged stay in hospital. Our aim was to explore the extent of delirium and the impact of factors associated with it for adult patients who have been admitted to hospital with burns.

METHODS

In this retrospective study, all adult patients who had been admitted with burns during a four-year period were studied, including both those who were treated with intensive care and intermediate care only (no intensive care). Daily records of the assessment of delirium using the Nursing Delirium Screening Scale (Nu-DESC) were analysed together with age, sex, the percentage of total body surface area burned, operations, and numbers of wound care procedures under anaesthesia, concentrations of plasma C-reactive protein, and other clinical variables. Logistic regression was used to analyse factors that were associated with delirium and its effect on mortality, and linear regression was used to analyse its effect on the duration of hospital stay.

RESULTS

Fifty-one patients (19%) of the total 262 showed signs of delirium (Nu-DESC score of 2 or more) at least once during their stay in hospital. Signs of delirium were recorded in 42/89 patients (47%) who received intensive care, and in 9/173 (5%) who had intermediate care. Independent factors for delirium in the multivariable regression were: age over 74 years; number of operations and wound care procedures under anaesthesia; and the provision of intensive care (area under the curve 0.940, 95% CI 0.899-0.981). Duration of hospital stay, adjusted for age and burn size, was 13.2 (95% CI 7.4-18.9, p < 0.001) days longer in the group who had delirium. We found no independent effects of delirium on mortality.

CONCLUSION

We found a strong association between delirium and older age, provision ofr intensive care, and number of interventions under anaesthesia. A further 5% of patients who did not receive intensive care also showed signs of delirium, which is a finding that deserves to be thoroughly investigated in the future.

Survival analysis and mortality predictors of hospitalized severe burn victims in a Malaysian burns intensive care unit

Background

Prognostic measures to determine burn mortality are essential in evaluating the severity of individual burn victims. This is an important process of triaging patients with high risk of mortality that may be nursed in the acute care setting. Malaysian burn research is lacking with only one publication identified which describes the epidemiology of burn victims. Therefore, the objective of this study was to go one step further and identify the predictors of burn mortality from a Malaysian burns intensive care unit (BICU) which may be used to triage patients at higher risk of death.

Methods

This is a retrospective cohort study of all admissions to Hospital Sultan Ismail’s BICU from January 2010 till October 2015. Admission criteria were in accordance with the American Burn Association guidelines, and risk factors of interest were recorded. Data was analyzed using simple logistic regression to determine significant predictors of mortality. Survival analysis with time to death event was performed using the Kaplan-Meier survival curve with log-rank test.

Results

Through the 6-year period, 393 patients were admitted with a male preponderance of 73.8%. The mean age and length of stay were 35.6 (±15.72) years and 15.3 (±18.91) days. There were 48 mortalities with an overall mortality rate of 12.2%. Significant risk factors identified on simple logistic regression were total body surface area (TBSA) > 20% (p < 0.001), inhalation injury (p < 0.001) and presence of early systemic inflammatory response syndrome (SIRS) (p < 0.001). Survival analysis using Kaplan-Meier survival curve showed similar results with TBSA > 20%, presence of SIRS, mechanical ventilation and inhalation injury which were associated with poorer survival (p < 0.001).

Conclusion

The predictors of mortality identified in a Malaysian BICU were TBSA > 20%, early SIRS, mechanical ventilation and inhalation injury which were associated with poorer survival outcome. The immunological response differs from individual patients and influenced by the severity of burn injury. Early SIRS on admission is an important predictor of death and may represent the severity of burn injury. Patients who required mechanical ventilation were associated with mortality and it is likely related to the severity of pulmonary insults sustained by individual patients. This data is important for outcome prognostication and mortality risk counselling in severely burned patients.

Use of the burn intervention score to calculate the charges of the care of burns

BACKGROUND

To our knowledge this is the first published estimate of the charges of the care of burns in Sweden. The Linköping Burn Interventional Score has been used to calculate the charges for each burned patient since 1993. The treatment of burns is versatile, and depends on the depth and extension of the burn. This requires a flexible system to detect the actual differences in the care provided. We aimed to describe the model of burn care that we used to calculate the charges incurred during the acute phase until discharge, so it could be reproduced and applied in other burn centres, which would facilitate a future objective comparison of the expenses in burn care.

METHODS

All patients admitted with burns during the period 2010-15 were included. We analysed clinical and economic data from the daily burn scores during the acute phase of the burn until discharge from the burn centre.

RESULTS

Total median charge/patient was US$ 28 199 (10th-90th centiles 4668-197 781) for 696 patients admitted. Burns caused by hot objects and electricity resulted in the highest charges/TBSA%, while charges/day were similar for the different causes of injury. Flame burns resulted in the highest mean charges/admission, probably because they had the longest duration of stay. Mean charges/patient increased in a linear fashion among the different age groups.

CONCLUSION

Our intervention-based estimate of charges has proved to be a valid tool that is sensitive to the procedures that drive the costs of the care of burns such as large TBSA%, intensive care, and operations. The burn score system could be reproduced easily in other burn centres worldwide and facilitate the comparison regardless of the differences in the currency and the economic circumstances.

Risk of pneumonia in patients with burn injury: a population-based cohort study

Background

Burns are the main cause of accidental injury, and pneumonia is a common respiratory disease in humans.

Aim

The purpose of this study was to investigate the relationship between burn injury and pneumonia.

Patients and methods

A nationwide population-based cohort study was conducted using data from the National Health Insurance Research Database in Taiwan. We identified and enrolled 2,893 subjects with burn injury, who were individually matched to 2,893 subjects in the comparison group by using the propensity score. Furthermore, we used a self-controlled case-series design to estimate the temporal association between burn injury and pneumonia.

Results

Exposure to burn injury revealed a higher risk of pneumonia than that to non-burn injury within 1 year. The Cox proportional hazards model revealed that, compared with the non-burn injury, burn injury yielded a 2.39-fold (95% CI=1.44-3.96) increase in risk of pneumonia. The exposure period of burn injury within 30 days showed 2.76-fold increase in risk of pneumonia (95% CI=1.44-3.96) compared with that in the baseline period.

Conclusion

Burn injury was associated with a significant increased risk of pneumonia, especially occurring within 30 days.

Are there any differences in the provided burn care between men and women? A retrospective study

Background

Disparity between medical treatment for men and women has been recorded worldwide. However, it is difficult to find out if the disparities in both the use of resources and outcome depend entirely on sex-related discrimination. Our aim was to investigate if there are differences in burn treatments between the sexes.

Methods

All patients admitted with burns to Linköping University Hospital during the 16-year period 2000–2015 were included. Interventions were prospectively recorded using the validated Burn SCoring system (BSC). Data were analysed using a multivariable panel regression model adjusted for age, percentage total body surface area (%TBSA), and in-hospital mortality.

Results

A total of 1363 patients were included, who generated a total of 22,301 daily recordings while they were inpatients. Males were 70% (930/1363). Sex was not an independent factor for daily scores after adjustment for age, %TBSA, and mortality in hospital (model R²=0.60, p < 0.001).

Conclusion

We found no evidence of inequity between the sexes in treatments given in our burn centre when we had adjusted for size of burn, age, and mortality. BSC seems to be an appropriate model in which to evaluate sex-related differences in the delivery of treatments.

The Use of Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome in Severe Burns Without Inhalation Injury

Burn injury results in a severe systemic inflammatory response which is associated with the development of acute respiratory distress syndrome (ARDS), even without associated inhalation injury. Venous-venous extracorporeal membrane oxygenation (VV-ECMO) has been implemented in various cases of ARDS to provide support and allow for protective lung ventilation strategies. We report the case of a 27-year-old man presenting with a 60% total body surface area partial thickness burn who developed refractory ARDS with Murray Score of 3.75. ECMO was initiated on hospital day 9 for a total of 10 days with concurrent lung-protective ventilation. He subsequently recovered and was discharged on hospital day 48. ECMO should be considered as an adjunctive strategy in burn patients without inhalation injury to minimize ventilator-induced lung injury when high levels of support are needed to achieve adequate ventilation in patients with ARDS.

Inhalation Injury in the Burned Patient

Inhalation injury causes a heterogeneous cascade of insults that increase morbidity and mortality among the burn population. Despite major advancements in burn care for the past several decades, there remains a significant burden of disease attributable to inhalation injury. For this reason, effort has been devoted to finding new therapeutic approaches to improve outcomes for patients who sustain inhalation injuries.The three major injury classes are the following: supraglottic, subglottic, and systemic. Treatment options for these three subtypes differ based on the pathophysiologic changes that each one elicits.Currently, no consensus exists for diagnosis or grading of the injury, and there are large variations in treatment worldwide, ranging from observation and conservative management to advanced therapies with nebulization of different pharmacologic agents.The main pathophysiologic change after a subglottic inhalation injury is an increase in the bronchial blood flow. An induced mucosal hyperemia leads to edema, increases mucus secretion and plasma transudation into the airways, disables the mucociliary escalator, and inactivates hypoxic vasocontriction. Collectively, these insults potentiate airway obstruction with casts formed from epithelial debris, fibrin clots, and inspissated mucus, resulting in impaired ventilation. Prompt bronchoscopic diagnosis and multimodal treatment improve outcomes. Despite the lack of globally accepted standard treatments, data exist to support the use of bronchoscopy and suctioning to remove debris, nebulized heparin for fibrin casts, nebulized N-acetylcysteine for mucus casts, and bronchodilators.Systemic effects of inhalation injury occur both indirectly from hypoxia or hypercapnia resulting from loss of pulmonary function and systemic effects of proinflammatory cytokines, as well as directly from metabolic poisons such as carbon monoxide and cyanide. Both present with nonspecific clinical symptoms including cardiovascular collapse. Carbon monoxide intoxication should be treated with oxygen and cyanide with hydroxocobalamin.Inhalation injury remains a great challenge for clinicians and an area of opportunity for scientists. Management of this concomitant injury lags behind other aspects of burn care. More clinical research is required to improve the outcome of inhalation injury.The goal of this review is to comprehensively summarize the diagnoses, treatment options, and current research.

Validation of the burn intervention score in a National Burn Centre

The Linköping burn score has been used for two decades to calculate the cost to the hospital of each burned patient. Our aim was to validate the Burn Score in a dedicated Burn Centre by analysing the associations with burn-specific factors: percentage of total body surface area burned (TBSA%), cause of injury, patients referred from other (non-specialist) centres, and survival, to find out which of these factors resulted in higher scores. Our second aim was to analyse the variation in scores of each category of care (surveillance, respiration, circulation, wound care, mobilisation, laboratory tests, infusions, and operation). We made a retrospective analysis of all burned patients admitted during the period 2000-15. Multivariable regression models were used to analyse predictive factors for an increased daily burn score, the cumulative burn score (the sum of the daily burn scores for each patient) and the total burn score (total sum of burn scores for the whole group throughout the study period) in addition to sub-analysis of the different categories of care that make up the burn score. We retrieved 22301 daily recordings for inpatients. Mobilisation and care of the wound accounted for more than half of the total burn score during the study. Increased TBSA% and age over 45 years were associated with increased cumulative (model R² 0.43, p<0.001) and daily (model R² 0.61, p<0.001) burn scores. Patients who died had higher daily burn scores, while the cumulative burn score decreased with shorter duration of hospital stay (p<0.001). To our knowledge this is the first long term analysis and validation of a system for scoring burn interventions in patients with burns that explores its association with the factors important for outcome. Calculations of costs are based on the score, and it provides an indicator of the nurses' workload. It also gives important information about the different dimensions of the care provided from thorough investigation of the scores for each category.

Inhalation Injury: State of the Science 2016

This article summarizes research conducted over the last decade in the field of inhalation injury in thermally injured patients. This includes brief summaries of the findings of the 2006 State of the Science meeting with regard to inhalation injury, and of the subsequent 2007 Inhalation Injury Consensus Conference. The reviewed studies are categorized in to five general areas: diagnosis and grading; mechanical ventilation; systemic and inhalation therapy; mechanistic alterations; and outcomes.

ECMO in major burn patients: feasibility and considerations when multiple modes of mechanical ventilation fail

BACKGROUND

We report two cases of acute respiratory distress syndrome in burn patients who were successfully managed with good outcomes with extra corporeal membrane oxygenation (ECMO) after failing multiple conventional modes of ventilation, and review the relevant literature.

CASE PRESENTATION

The two patients were a 39-year-old male and 53-year-old male with modified Baux Scores of 79 and 78, respectively, with no known inhalation injury. After the initial modified Parkland-based fluid resuscitation and partial escharotomy, both patients developed worsening hypoxemia and acute respiratory distress syndrome. The hypoxemia continued to worsen on multiple modes of ventilation including volume control, pressure regulated volume control, pressure control, airway pressure release ventilation and volumetric diffusive ventilation. In both cases, the PaO₂ ≤ 50 mm Hg on a FiO₂ 100% during the trial of mechanical ventilation. The deterioration was rapid (<12 h since onset of worsening oxygenation) in both cases. A decision was made to trial the patients on ECMO. Veno-Venous ECMO (V-V ECMO) was successfully initiated following cannulation-under transesophgeal echo guidance-with the dual lumen Avalon® (Maquet, NJ, USA) cannula. ECMO support was maintained for 4 and 24 days, respectively. Both patients were successfully weaned off ECMO and were discharged to rehabilitation following their complex hospital course.

CONCLUSION

Early ECMO for isolated respiratory failure in the setting on maintained hemodynamics resulted in a positive outcome in our two burn patients suffered from acute respiratory distress syndrome.

Improvement in mortality at a National Burn Centre since 2000: Was it the result of increased resources?

The aim of this study was to find out whether the charging costs (calculated using interventional burn score) increased as mortality decreased.During the last 2 decades, mortality has declined significantly in the Linköping Burn Centre. The burn score that we use has been validated as a measure of workload and is used to calculate the charging costs of each burned patient.We compared the charging costs and mortality in 2 time periods (2000-2007 and 2008-2015). A total of 1363 admissions were included. We investigated the change in the burn score, as a surrogate for total costs per patient. Multivariable regression was used to analyze risk-adjusted mortality and burn score.The median total body surface area % (TBSA%) was 6.5% (10-90 centile 1.0-31.0), age 33 years (1.3-72.2), duration of stay/ TBSA% was 1.4 days (0.3-5.3), and 960 (70%) were males. Crude mortality declined from 7.5% in 2000-2007 to 3.4% in 2008-2015, whereas the cumulative burn score was not increased (P  =  .08). Regression analysis showed that risk-adjusted mortality decreased (odds ratio 0.42, P  =  .02), whereas the adjusted burn score did not change (P  =  .14, model R 0.86).Mortality decreased but there was no increase in the daily use of resources as measured by the interventional burn score. The data suggest that the improvements in quality obtained have been achieved within present routines for care of patients (multidisciplinary/orientated to patients' safety).

Kupffer Cell p38 Mitogen-Activated Protein Kinase Signaling Drives Postburn Hepatic Damage and Pulmonary Inflammation When Alcohol Intoxication Precedes Burn Injury

OBJECTIVES

Clinical and animal studies demonstrate that alcohol intoxication at the time of injury worsens postburn outcome. The purpose of this study was to determine the role and mechanism of Kupffer cell derangement in exacerbating postburn end organ damage in alcohol-exposed mice.

DESIGN

Interventional study.

SETTING

Research Institute.

SUBJECTS

Male C57BL/6 mice.

INTERVENTIONS

Alcohol administered 30 minutes before a 15% scald burn injury. Antecedent Kupffer cell depletion with clodronate liposomes (0.5 mg/kg). p38 mitogen-activated protein kinase inhibition via SB203580 (10 mg/kg).

MEASUREMENTS AND MAIN RESULTS

Kupffer cells were isolated 24 hours after injury and analyzed for p38 activity and interleukin-6 production. Intoxicated burned mice demonstrated a two-fold (p < 0.05) elevation of Kupffer cell p38 activation relative to either insult alone, and this corresponded to a 43% (p < 0.05) increase in interleukin-6 production. Depletion of Kupffer cells attenuated hepatic damage as seen by decreases of 53% (p < 0.05) in serum alanine aminotransferase and 74% (p < 0.05) in hepatic triglycerides, as well as a 77% reduction (p < 0.05) in serum interleukin-6 levels compared to matched controls. This mitigation of hepatic damage was associated with a 54% decrease (p < 0.05) in pulmonary neutrophil infiltration and reduced alveolar wall thickening by 45% (p < 0.05). In vivo p38 inhibition conferred nearly identical hepatic and pulmonary protection after the combined injury as mice depleted of Kupffer cells.

CONCLUSIONS

Intoxication exacerbates postburn hepatic damage through p38-dependent interleukin-6 production in Kupffer cells.

Division of overall duration of stay into operative stay and postoperative stay improves the overall estimate as a measure of quality of outcome in burn care

Total duration of stay adjusted for percentage of the total body surface area burned (TBSA%) is a commonly used outcome measure in burn care. However, it has been criticised as it is affected by many factors, some of which are not strictly part of burn care. A division into operative stay and postoperative stay may improve this measure. The aim was to evaluate if operative stay can serve as a more standardised measure by: comparing the variation in operative stay/TBSA% with the variation in total stay/TBSA%, and to study different factors associated with operative stay and postoperative stay.

Pathophysiology, research challenges, and clinical management of smoke inhalation injury

Smoke inhalation injury is a serious medical problem that increases morbidity and mortality after severe burns. However, relatively little attention has been paid to this devastating condition, and the bulk of research is limited to preclinical basic science studies. Moreover, no worldwide consensus criteria exist for its diagnosis, severity grading, and prognosis. Therapeutic approaches are highly variable depending on the country and burn centre or hospital. In this Series paper, we discuss understanding of the pathophysiology of smoke inhalation injury, the best evidence-based treatments, and challenges and future directions in diagnostics and management.

Ethanol intoxication prolongs post-burn pulmonary inflammation: role of alveolar macrophages

In this study, the role and fate of AMs were examined in pulmonary inflammation after intoxication and injury. Clinical evidence has revealed that half of all burn patients brought to the emergency department are intoxicated at the time of injury. This combined insult results in amplified neutrophil accumulation and pulmonary edema, with an increased risk of lung failure and mortality, relative to either insult alone. We believe that this excessive pulmonary inflammation, which also parallels decreased lung function, is mediated in part by AMs. Restoration of lung tissue homeostasis is dependent on the eradication of neutrophils and removal of apoptotic cells, both major functions of AMs. Thirty minutes after binge ethanol intoxication, mice were anesthetized and given a 15% total body surface area dorsal scald injury. At 24 h, we found a 50% decrease in the total number of AMs (P < 0.05) and observed a proinflammatory phenotype on the remaining lung AMs. Loss of AMs paralleled a 6-fold increase in the number of TUNEL⁺ lung apoptotic cells (P < 0.05) and a 3.5-fold increase in the percentage of annexin V⁺ apoptotic cells in BAL (P < 0.05), after intoxication and injury, relative to controls. In contrast to the reduction in the number of cells, AMs from intoxicated and injured mice had a 4-fold increase in efferocytosis (P < 0.05). In summary, these data suggest that loss of AMs may delay resolution of inflammation, resulting in the pulmonary complications and elevated mortality rates observed in intoxicated and burn-injured patients.

Nebulized Epinephrine Limits Pulmonary Vascular Hyperpermeability to Water and Protein in Ovine With Burn and Smoke Inhalation Injury

OBJECTIVES

To test the hypothesis that nebulized epinephrine ameliorates pulmonary dysfunction by dual action-bronchodilation (β2-adrenergic receptor agonism) and attenuation of airway hyperemia (α1-adrenergic receptor agonism) with minimal systemic effects.

DESIGN

Randomized, controlled, prospective, and large animal translational studies.

SETTING

University large animal ICU.

SUBJECTS

Twelve chronically instrumented sheep.

INTERVENTIONS

The animals were exposed to 40% total body surface area third degree skin flame burn and 48 breaths of cooled cotton smoke inhalation under deep anesthesia and analgesia. The animals were then placed on a mechanical ventilator, fluid resuscitated, and monitored for 48 hours in a conscious state. After the injury, sheep were randomized into two groups: 1) epinephrine, nebulized with 4 mg of epinephrine every 4 hours starting 1 hour post injury, n = 6; or 2) saline, nebulized with saline in the same manner, n = 6.

MEASUREMENTS AND MAIN RESULTS

Treatment with epinephrine had a significant reduction of the pulmonary transvascular fluid flux to water (p < 0.001) and protein (p < 0.05) when compared with saline treatment from 12 to 48 hours and 36 to 48 hours, respectively. Treatment with epinephrine also reduced the systemic accumulation of body fluids (p < 0.001) with a mean of 1,410 ± 560 mL at 48 hours compared with 3,284 ± 422 mL of the saline group. Hemoglobin levels were comparable between the groups. Changes in respiratory system dynamic compliance, mean airway pressure, PaO2/FiO2 ratio, and oxygenation index were also attenuated with epinephrine treatment. No considerable systemic effects were observed with epinephrine treatment.

CONCLUSIONS

Nebulized epinephrine should be considered for use in future clinical studies of patients with burns and smoke inhalation injury.

Alteration of Leukocyte Count Correlates With Increased Pulmonary Vascular Permeability and Decreased PaO2:FiO2 Ratio Early After Major Burns

Leukocytes are activated systemically and their numbers increase soon after a burn followed by a rapid decline to low normal or subnormal levels, possibly by increased extravasation. Experimental data support that an important target for such extravasation is the lungs and that leukocytes when they adhere to endothelial cells cause an increase in vascular permeability. The authors investigated a possible relation between early increased pulmonary vascular permeability or a decreased PaO2:FiO2 ratio and the dynamic change in concentration of blood leukocytes after a burn. This is a prospective, exploratory, single-center study. The authors measured the dynamic changes of leukocytes in blood starting early after the burn, pulmonary vascular permeability index by thermodilution, and PaO2:FiO2-ratios in 20 patients during the first 21 days after a major burn (>20% TBSA%). Median TBSA was 40% interquartile range (IQR, 25-52) and full thickness burn 28% (IQR, 2-39). There was a correlation between the early (<24 hours) alteration in white blood cell count and both early increased pulmonary vascular permeability (r = .63, P = .004) and the decreased oxygenation index defined as PaO2:FiO2 < 27 kPa (P = .004). The authors have documented a correlation between dynamic change of blood leukocytes and pulmonary failure early after burns.

Impaired respiratory function and heightened pulmonary inflammation in episodic binge ethanol intoxication and burn injury

Clinical data indicate that cutaneous burn injuries covering greater than 10% of the total body surface area are associated with significant morbidity and mortality, in which pulmonary complications, including acute respiratory distress syndrome (ARDS), contribute to nearly half of all patient deaths. Approximately 50% of burn patients are intoxicated at the time of hospital admission, which increases days on ventilators by 3-fold, and doubles the length of hospitalization, compared to non-intoxicated burn patients. The most common drinking pattern in the United States is binge drinking, where an individual rapidly consumes alcoholic beverages (4 for women, 5 for men) in 2 h. An estimated 38 million Americans binge drink, often several times per month. Experimental data demonstrate that a single binge-ethanol exposure, prior to scald injury, impairs innate and adaptive immune responses, thereby enhancing infection susceptibility and amplifying pulmonary inflammation, neutrophil infiltration, and edema, and is associated with increased mortality. Since these characteristics are similar to those observed in ARDS burn patients, our study objective was to determine whether ethanol intoxication and burn injury and the subsequent pulmonary congestion affect physiological parameters of lung function, using non-invasive and unrestrained plethysmography in a murine model system. Furthermore, to mirror young adult binge-drinking patterns, and to determine the effect of multiple ethanol exposures on pulmonary inflammation, we utilized an episodic binge-ethanol exposure regimen, where mice were exposed to ethanol for a total of 6 days (3 days ethanol, 4 days rest, 3 days ethanol) prior to burn injury. Our analyses demonstrate mice exposed to episodic binge ethanol and burn injury have higher mortality, increased pulmonary congestion and neutrophil infiltration, elevated neutrophil chemoattractants, and respiratory dysfunction, compared to burn or ethanol intoxication alone. Overall, our study identifies plethysmography as a useful tool for characterizing respiratory function in a murine burn model and for future identification of therapeutic compounds capable of restoring pulmonary functionality.

Alcohol potentiates postburn remote organ damage through shifts in fluid compartments mediated by bradykinin

Of the 450,000 burn patients each year, 50% have a positive blood alcohol content, and this predisposes them to worsened clinical outcomes. Despite high prevalence and established consequences, the mechanisms responsible for alcohol-mediated complications of postburn remote organ damage are currently unknown. To this end, mice received a single dose of alcohol (1.12 g/kg) or water by oral gavage and were subjected to a 15% total body surface area burn. Animals with a burn alone lost ∼5% of their body weight in 24 h, whereas intoxicated and burned mice lost only 1% body weight (P < 0.05) despite a 17% increase in hematocrit (P < 0.05) and a 57% increase in serum creatinine (P < 0.05) over burn injury alone. This retention of water weight despite increased dehydration suggests that intoxication at the time of a burn causes a shift in fluid compartments that may exacerbate end-organ ischemia and damage as evidenced by a 3-fold increase in intestinal bacterial translocation (P < 0.05), a 30% increase (P < 0.05) in liver weight-to-body weight ratio, and an increase in alveolar wall thickness over a burn alone. Furthermore, administration of the bradykinin antagonist HOE140 30 min after intoxication and burn restored fluid balance and alleviated end-organ damage. These findings suggest that alcohol potentiates postburn remote organ damage through shifts in fluid compartments mediated by bradykinin.

Assessing inhalation injury in the emergency room

Respiratory tract injuries caused by inhalation of smoke or chemical products are related to significant morbidity and mortality. While many strategies have been built up to manage cutaneous burn injuries, few logical diagnostic strategies for patients with inhalation injuries exist and almost all treatment is supportive. The goals of initial management are to ensure that the airway allows adequate oxygenation and ventilation and to avoid ventilator-induced lung injury and substances that may complicate subsequent care. Intubation should be considered if any of the following signs exist: respiratory distress, stridor, hypoventilation, use of accessory respiratory muscles, blistering or edema of the oropharynx, or deep burns to the face or neck. Any patients suspected to have inhalation injuries should receive a high concentration of supplemental oxygen to quickly reverse hypoxia and to displace carbon monoxide from protein binding sites. Management of carbon monoxide and cyanide exposure in smoke inhalation patients remains controversial. Absolute indications for hyperbaric oxygen therapy do not exist because there is a low correlation between carboxyhemoglobin levels and the severity of the clinical state. A cyanide antidote should be administered when cyanide poisoning is clinically suspected. Although an ideal approach for respiratory support of patients with inhalation injuries do not exist, it is important that they are supported using techniques that do not further exacerbate respiratory failure. A well-organized strategy for patients with inhalation injury is critical to reduce morbidity and mortality.

An alteration of the gut-liver axis drives pulmonary inflammation after intoxication and burn injury in mice

Approximately half of all adult burn patients are intoxicated at the time of their injury and have worse clinical outcomes than those without prior alcohol exposure. This study tested the hypothesis that intoxication alters the gut-liver axis, leading to increased pulmonary inflammation mediated by burn-induced IL-6 in the liver. C57BL/6 mice were given 1.2 g/kg ethanol 30 min prior to a 15% total body surface area burn. To restore gut barrier function, the specific myosin light chain kinase inhibitor membrane-permeant inhibitor of kinase (PIK), which we have demonstrated to reduce bacterial translocation from the gut, was administered 30 min after injury. Limiting bacterial translocation with PIK attenuated hepatic damage as measured by a 47% reduction in serum alanine aminotransferase (P < 0.05), as well as a 33% reduction in hepatic IL-6 mRNA expression (P < 0.05), compared with intoxicated and burn-injured mice without PIK. This mitigation of hepatic damage was associated with a 49% decline in pulmonary neutrophil infiltration (P < 0.05) and decreased alveolar wall thickening compared with matched controls. These results were reproduced by prophylactic reduction of the bacterial load in the intestines with oral antibiotics before intoxication and burn injury. Overall, these data suggest that the gut-liver axis is deranged when intoxication precedes burn injury and that limiting bacterial translocation in this setting attenuates hepatic damage and pulmonary inflammation.

Clinical review: the critical care management of the burn patient

Between 4 and 22% of burn patients presenting to the emergency department are admitted to critical care. Burn injury is characterised by a hypermetabolic response with physiologic, catabolic and immune effects. Burn care has seen renewed interest in colloid resuscitation, a change in transfusion practice and the development of anti-catabolic therapies. A literature search was conducted with priority given to review articles, meta-analyses and well-designed large trials; paediatric studies were included where adult studies were lacking with the aim to review the advances in adult intensive care burn management and place them in the general context of day-to-day practical burn management.

Characteristics of burn deaths from 2003 to 2009 in a burn center: A retrospective study

Mortality remains one of the most important end-point quality control parameters to evaluate a burn care system. We retrospectively reviewed the characteristics and multiple organ dysfunction syndrome (MODS) patterns of burn deaths in our center from January 2003 to December 2009. The mortality rate during this time period was 2.3%. Fifty-six patients died, including 49 males and 7 females. The mean survival time was 28.45 ± 24.60 days. The burn percentage was (76.70 ± 26.86) % total burn surface area (TBSA), with (27.74 ± 24.95) % deep-partial thickness burns and (46.88 ± 33.84) % full-thickness burns. Inhalation injury was diagnosed in 36 (64.29%) patients. Patients who had undergone an operation, particularly in the first week post-burn, had a significantly longer survival time. An average of 5.50 ± 1.35 malfunctioning organs per patient and a mean sequential organ failure assessment (SOFA) score of 13.91 ± 3.65 were observed. The most frequently malfunctioning organs were involved in the respiratory, hematologic, circulatory, and central nervous systems. Most of the organ damage occurred during the first week post-burn, followed by 4 weeks later, with relatively less organ damage observed in the third week. Among patients with a TBSA over 50%, non-survivors had larger burn sizes (particularly larger full-thickness burns) and a higher incidence of inhalation injury compared with survivors; non-survivors were also more likely to have microorganism-positive blood and sputum cultures. In conclusion, burn deaths are related to a higher burn percentage, inhalation injury, MODS, and infection. Early operation may help improve survival duration.

Heparin-binding protein (HBP): an early marker of respiratory failure after trauma?

BACKGROUND

Trauma and its complications contribute to morbidity and mortality in the general population. Trauma victims are susceptible to acute respiratory distress syndrome (ARDS) and sepsis. Polymorphonuclear leucocytes (PMNs) are activated after trauma and there is substantial evidence of their involvement in the development of ARDS. Activated PMNs release heparin-binding protein (HBP), a granule protein previously shown to be involved in acute inflammatory reactions. We hypothesised that there is an increase in plasma HBP content after trauma and that the increased levels are related to the severity of the trauma or later development of severe sepsis and organ failure (ARDS).

METHODS AND MATERIAL

We investigated HBP in plasma samples within 36 h from trauma in 47 patients admitted to a level one trauma centre with a mean injury severity score (ISS) of 26 (21-34). ISS, admission sequential organ failure assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were recorded at admission. ARDS and presence of severe sepsis were determined daily during intensive care.

RESULTS

We found no correlation between individual maximal plasma HBP levels at admission and ISS, admission SOFA or APACHE II. We found, however, a correlation between HBP levels and development of ARDS (P = 0.026, n = 47), but not to severe sepsis.

CONCLUSION

HBP is a potential biomarker candidate for early detection of ARDS development after trauma. Further research is required to confirm a casual relationship between plasma HBP and the development of ARDS.

Natriuretic peptide proANP (1-98), a biomarker of ALI/ARDS in burns

INTRODUCTION

Plasma atrial natriuretic peptide levels (proANP (1-98)), a parameter of myocardial dysfunction, have been reported to be increased in critically ill patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS). The aim of the study was to examine if proANP is a biomarker of ALI/ARDS as assessed by the Sequential Organ Failure Assessment score (SOFA Lung ≥2) in burn patients, and how it compares to the corresponding values for age, total body surface area percent (TBSA%) and inhalation injury for mortality prediction.

METHODS

A group of 22 burn patients with a mean TBSA of 30% (10-75%) and a mean age of 52 years (25-84 years) was investigated during 2010. Organ dysfunction/failure was classified according to the SOFA score. The criteria for ALI/ARDS were based on SOFA Lung ≥2. ProANP (1-98) concentrations (nmoll(-1)) were measured by commercially available enzyme linked immunosorbent assay (ELISA) immunoassays (Biomedica Austria) on post-burn days 2 and 7.

RESULTS

ProANP levels on day 7 post-burn positively correlated with a SOFA score day 7 post-burn, c=0.91. The receiver operating curve (ROC) analysis proved a sensitivity of 75% and a specificity of 75% for ALI/ARDS at cut-off values >3.35 nmoll(-1). The ROC value of proANP for ALI/ARDS (SOFA Lung ≥2) was significantly larger than that of age, TBSA% and inhalation injury: 0.90, 0.71, 0.74, and 0.69 (p<0.001).

CONCLUSIONS

ProANP levels, as a biomarker of ALI/ARDS, in critically burn patients correlated with SOFA scoring. The inhalation injury did not lead to increase in proANP values.

Ulinastatin improves pulmonary function in severe burn-induced acute lung injury by attenuating inflammatory response

BACKGROUND

Acute systemic inflammatory response to severe skin burn injury mediates burn-induced acute lung injury. Ulinastatin is potentially an effective intervention, because it attenuates the systemic inflammatory response induced by endotoxin and improves myocardial function during ischemic shock and reperfusion.

METHODS

Rats received full-thickness burn wounds to 30% total body surface area followed by delayed resuscitation. The treatment group received 50,000 U/kg of ulinastatin and the burn group was given vehicle only. A sham group was not burned but otherwise was treated identically. After killing, blood and lung samples were harvested for histology and measurement of inflammatory mediators.

RESULTS

Administration of ulinastatin significantly decreased the mRNA and protein levels of tumor necrosis factor-alpha, interleukin-1β, -6, and -8 both locally and systemically in burn-injured rats. The secretion of neutrophil elastase and myeloperoxidase in the lung and the expression of intercellular adhesion molecule-1 on the surface of lung epithelium were inhibited by ulinastatin. Ulinastatin also reduced the increase in pulmonary microvascular permeability. Consistent with these findings, ulinastatin ameliorated the lung edema and pulmonary oxygenation in burn-injured rats.

CONCLUSIONS

These results indicate that the inhibitory effects of ulinastatin on inflammatory mediator production, neutrophil activation, and microvascular permeability are associated with the recovery of pulmonary functions in severe burn-induced acute lung injury and suggest that ulinastatin may serve as a potential therapeutic administration in critical burn care.

Update on the critical care management of severe burns

Care of the severely injured patient with burn requires correct diagnosis, appropriately tailored resuscitation, and definitive surgical management to reduce morbidity and mortality. Currently, mortality rates related to severe burn injuries continue to steadily decline due to the standardization of a multidisciplinary approach instituted at tertiary health care centers. Prompt and accurate diagnoses of burn wounds utilizing Lund-Browder diagrams allow for appropriate operative and nonoperative management. Coupled with diagnostic improvements, advances in resuscitation strategies involving rates, volumes, and fluid types have yielded demonstrable benefits related to all aspects of burn care. More recently, identification of comorbid conditions such as inhalation injury and malnutrition have produced appropriate protocols that aid the healing process in severely injured patients with burn. As more patients survive larger burn injuries, the early diagnosis and successful treatment of secondary and tertiary complications are becoming commonplace. While advances in this area are exciting, much work to elucidate immune pathways, diagnostic tests, and effective treatment regimens still remain. This review will provide an update on the critical care management of severe burns, touching on accurate diagnosis, resuscitation, and acute management of this difficult patient population.

Severity score for predicting pneumonia in inhalation injury patients

Inhalation injuries contribute significantly to morbidity and mortality in both children and adults with burns. Pneumonia is a major compromising factor in these patients. The purpose of this article was to evaluate the characteristics, impact factors, incidence, morbidity, and mortality of pneumonia in inhalation injuries. Furthermore, a severity score has been formulated to help predict the probability of developing pneumonia following inhalation injuries. A retrospective study was performed of 214 patients, treated for inhalation injuries from 1999 to 2009 at the Burn Center in Chang Gung Memorial Hospital, Linkou, Taiwan. Patients' characteristics, length of hospitalization, total burn surface area, initial PaO2:FiO2 ratio, number of intubated days, bronchoscope grade, initial carboxyhemoglobin level (COHb) and mortality rate were recorded. A Student's t-test was used for comparison of inhalation injury patients with and without pneumonia and was also used for comparing a TBSA of >20% to those with a TBSA of ≤20% in patients with inhalation injury and pneumonia. Logistic regression analyses were utilized to create a severity score related to pneumonia. 129 patients with inhalation injury were included in the analysis. Overall, 38% (49/129) patients developed pneumonia. Pneumonia associated with inhalation injury occurred more often in patients with a TBSA>20% (P<0.05). The intubation days, bronchoscope grade and COHb level of pneumonia patients were significantly longer (P<0.05). Initial PaO2:FiO2 ratio (PaO2/FiO2) was significantly lower in patients with pneumonia (P<0.05). Mortality following pneumonia was increased sevenfold (P<0.05). Hospitalization days and intubation days were significantly longer in TBSA>20%. Logistic regression analysis was performed to find out the impact factors of pneumonia in inhalation injury patients and to set a severity score. Patients age >60 years, TBSA >20%, bronchoscope grade is 3 or 4, initial PaO2/FiO2≦300 and initial COHb level>10% showed a significant difference (P<0.05). The total severity scale was set at 5 points. Each impact factor was given one point and when the score ≥2 it means patients have high risk of development of pneumonia. This study had identified the significant risk factors for potential development of pneumonia in a group of inhalation injury patients. The impact of these risk factors should be validated in further prospective trials to improve outcome or at least reduce the incidence of the surrogate diagnosis of pneumonia.

Increase in early mechanical ventilation of burn patients: an effect of current emergency trauma management?

BACKGROUND

Data relating to patients admitted with extensive burn injuries in the Netherlands have revealed a marked increase in patients whose initial care included mechanical ventilation (MV). The increase was abrupt, dating from 1997, and has been sustained since. The aim of this study is to quantify this observation and to discuss possible causes.

METHODS

The study included 258 consecutive patients with burns >30% total body surface area admitted to the Beverwijk burns center. Patients were divided into two groups based on admission date: group 1 from 1987 to 1996 (n=135) and group 2 from 1997 to 2006 (n=123). Data were analyzed using χ or analysis of variance.

RESULTS

There were no differences between groups in demographics, facial burns, inhalation injury, and % total body surface area. However, the number of patients subjected to MV at admission increased from 38% to 76% (group 1 vs. 2; p<0.001). In 57% of patients who were intubated based on the suspicion of inhalation injury, this condition could not be confirmed (p<0.05 vs. 9% [1987-1996]).

CONCLUSIONS

This study has confirmed that a higher proportion of patients were treated with MV since 1997, whereas the severity of burn injury remained unchanged throughout the study period. In the absence of a clinical explanation, we surmise that there has been a change within Dutch casualty departments in the initial management of major burn injury. The change coincides with the implementation of the Advanced Life Trauma Support training course as the accepted standard of trauma care in Dutch hospitals.

Mortality after thermal injury: no sex-related difference

BACKGROUND

Young women have been reported to be more likely to survive than men after severe trauma. Girls also have less inflammation and hypermetabolism after major burns. Yet burned women have been found to have a twofold greater risk of death than men. Our aim was to find out if there is a sex-related difference in mortality after thermal injury, particularly in the age group between 16 years and 49 years, when hormonal differences would be most influential.

METHODS

All patients admitted to the Linköping University Hospital Burn Unit with thermal injuries during the years 1993-2008 were included and the variables percentage burned total body surface area (TBSA%), age, type of burn, mechanical ventilation, and year were included in a multiple regression (Poisson log) model.

RESULTS

Of 1,119 patients with thermal injury, 792 (71%) were men. Crude mortality was 5% among men, and 8% among women (p = 0.04). After adjustment for age and TBSA%, there was no correlation between mortality and sex, in any age group. Eight men and four women died in the group of young adults (16-49 years) in which TBSA% correlated with mortality (p < 0.01) but age did not. Mortality was 14% (32 of 221) among the men and 23% (23 of 102) of women in the group of older adults (50 years and older), and both age and TBSA% correlated with mortality (p < 0.001).

CONCLUSIONS

There is no relevant sex-related difference in survival after thermal injury. The conclusion is, however, tempered by the few deaths, particularly among younger adults.