A comparative study of a preclinical survival model of smoke inhalation injury in mice and rats.

Smoke inhalation injury increases morbidity and mortality. Clinically relevant animal models are necessary for the continued investigation of the pathophysiology of inhalation injury and the development of therapeutics. The goal of our research was threefold: 1) to develop a reproducible survival model of smoke inhalation injury in rats that closely resembled our previous mouse model, 2) to validate the rat smoke inhalation injury model using a variety of laboratory techniques, and 3) to compare and contrast our rat model with both the well-established mouse model and previously published rat models to highlight our improvements on smoke delivery and lung injury. Mice and rats were anesthetized, intubated, and placed in custom-built smoke chambers to passively inhale woodchip-generated smoke. Bronchoalveolar lavage fluid (BALF) and lung tissue were collected for confirmatory tests. Lung sections were hematoxylin and eosin stained, lung edema was assessed with wet-to-dry (W/D) ratio, and inflammatory cell infiltration and cytokine elevation were evaluated using flow cytometry, immunohistochemistry, and ELISA. We confirmed that our mouse and rat models of smoke inhalation injury mimic the injury seen after human burn inhalation injury with evidence of pulmonary edema, neutrophil infiltration, and inflammatory cytokine elevation. Interestingly, rats mounted a more severe immunological response compared with mice. In summary, we successfully validated a reliable and clinically translatable survival model of lung injury and immune response in rats and mice and characterized the extent of this injury. These animal models allow for the continued study of smoke inhalation pathophysiology to ultimately develop a better therapeutic.

Association between hydroxocobalamin administration and acute kidney injury after smoke inhalation: a multicenter retrospective study.

BACKGROUND: The use of hydroxocobalamin has long been advocated for treating suspected cyanide poisoning after smoke inhalation. Intravenous hydroxocobalamin has however been shown to cause oxalate nephropathy in a single-center study. The impact of hydroxocobalamin on the risk of acute kidney injury (AKI) and survival after smoke inhalation in a multicenter setting remains unexplored. METHODS: We conducted a multicenter retrospective study in 21 intensive care units (ICUs) in France. We included patients admitted to an ICU for smoke inhalation between January 2011 and December 2017. We excluded patients discharged at home alive within 24 h of admission. We assessed the risk of AKI (primary endpoint), severe AKI, major adverse kidney (MAKE) events, and survival (secondary endpoints) after administration of hydroxocobalamin using logistic regression models. RESULTS: Among 854 patients screened, 739 patients were included. Three hundred six and 386 (55.2%) patients received hydroxocobalamin. Mortality in ICU was 32.9% (n = 243). Two hundred eighty-eight (39%) patients developed AKI, including 186 (25.2%) who developed severe AKI during the first week. Patients who received hydroxocobalamin were more severe and had higher mortality (38.1% vs 27.2%, p = 0.0022). The adjusted odds ratio (95% confidence interval) of AKI after intravenous hydroxocobalamin was 1.597 (1.055, 2.419) and 1.772 (1.137, 2.762) for severe AKI; intravenous hydroxocobalamin was not associated with survival or MAKE with an adjusted odds ratio (95% confidence interval) of 1.114 (0.691, 1.797) and 0.784 (0.456, 1.349) respectively. CONCLUSION: Hydroxocobalamin was associated with an increased risk of AKI and severe AKI but was not associated with survival after smoke inhalation. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03558646.

High-Frequency Ventilation Modalities as Salvage Therapy for Smoke Inhalation-Associated Acute Lung Injury: A Systematic Review.

BACKGROUND: Smoke inhalation-associated acute lung injury (SI-ALI) is a major cause of morbidity and mortality in victims of fire tragedies. To date, there are no evidence-based guidelines on ventilation strategies in acute respiratory distress syndrome (ARDS) after smoke inhalation. We reviewed the existing literature for clinical studies of salvage mechanical ventilation (MV) strategies in patients with SI-ALI, focusing on mortality and pneumonia as outcomes. METHODS: A systematic search was designed in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Risk of bias assessment was performed using the Newcastle-Ottawa Quality Assessment Scale (NOS; 0 to 9 stars), with a score ≥7 being the threshold for inclusion in the meta-analysis. A systematic search strategy was used to search 10 databases. Clinical studies were included in which patients: (1) experienced smoke inhalation, (2) treated with MV, and (3) described a concurrent or historical control group. RESULTS: A total of 226 potentially relevant studies were identified, of which 7 studies on high-frequency percussive ventilation (HFPV) met inclusion criteria. No studies met inclusion for meta-analysis (NOS ≥ 7). In studies comparing HFPV to conventional mechanical ventilation (CMV), mortality and pneumonia incidence improved in 3 studies and remained unchanged in 3 others. No change in ventilator days or ICU length of stay was observed; however, oxygenation and work of breathing improved with HFPV. CONCLUSIONS: Mechanical ventilation in patients with SI-ALI has not been well studied. High-frequency percussive ventilation may decrease in-hospital mortality and pneumonia incidence when compared to CMV. The absence of "good" quality evidence precluded meta-analysis. Based upon low-quality evidence, there was a very weak recommendation that HFPV use may be associated with lower mortality and pneumonia rates in patients with SI-ALI. Given SI-ALI's unique underlying pathophysiology, and its potential implications on therapy, randomized controlled studies are required to ensure that patients receive the safest and most effective care. TRIAL REGISTRATION: The study was registered with PROSPERO International prospective register of systematic reviews (#47015).

Cyanide poisoning is a possible cause of cardiac arrest among fire victims, and empiric antidote treatment may improve outcomes.

BACKGROUND: Carbon monoxide and cyanide poisoning are important causes of death due to fire. Carbon monoxide is more regularly assessed than cyanide at the site of burn or smoke inhalation treatment due to its ease in assessment and simplicity to treat. Although several forensic studies have demonstrated the significance of cyanide poisoning in fire victims using blood cyanide levels, the association between the cause of cardiac arrest and the concentration of cyanide among fire victims has not been sufficiently investigated. This study aimed to investigate the frequency of cyanide-induced cardiac arrest in fire victims and to assess the necessity of early empiric treatment for cyanide poisoning. METHODS: This study was a retrospective analysis of fire victims with cardiac arrest at the scene who were transported to a trauma and critical care center, Kyorin University Hospital, from January 2014 to June 2017. Patients whose concentration of cyanide was measured were included. RESULTS: Five patients were included in the study; all died despite cardiopulmonary resuscitation. Three of these victims were later found to have lethal cyanide levels (>3 µg/ml). Two of the patients had non-lethal carboxyhemoglobin levels under 50% and might have been saved if hydroxocobalamin had been administered during resuscitation. CONCLUSION: According to our results, cyanide-induced cardiac arrest may be more frequently present among fire victims than previously believed, and early empiric treatment with hydroxocobalamin may improve outcomes for these victims in cases where cardiac arrest is of short duration.

Health benefits and costs of filtration interventions that reduce indoor exposure to PM2.5 during wildfires.

Increases in hospital admissions and deaths are associated with increases in outdoor air particles during wildfires. This analysis estimates the health benefits expected if interventions had improved particle filtration in homes in Southern California during a 10-day period of wildfire smoke exposure. Economic benefits and intervention costs are also estimated. The six interventions implemented in all affected houses are projected to prevent 11% to 63% of the hospital admissions and 7% to 39% of the deaths attributable to wildfire particles. The fraction of the population with an admission attributable to wildfire smoke is small, thus, the costs of interventions in all homes far exceeds the economic benefits of reduced hospital admissions. However, the estimated economic value of the prevented deaths exceed or far exceed intervention costs for interventions that do not use portable air cleaners. For the interventions with portable air cleaner use, mortality-related economic benefits exceed intervention costs as long as the cost of the air cleaners, which have a multi-year life, are not attributed to the short wildfire period. Cost effectiveness is improved by intervening only in the homes of the elderly who experience most of the health effects of particles from wildfires.

Risk factors associated with unintentional house fire incidents, injuries and deaths in high-income countries: a systematic review.

OBJECTIVE: To identify the distinguishing risk factors associated with unintentional house fire incidents, injuries and deaths. STUDY DESIGN: Systematic review. METHODS: A range of bibliographical databases and grey literature were searched from their earliest records to January 2016. To ensure the magnitude of risk could be quantified, only those study types which contained a control group, and undertook appropriate statistical analyses were included. A best evidence synthesis was conducted instead of a meta-analysis due to study heterogeneity. RESULTS: Eleven studies investigating a variety of risk factors and outcomes were identified. Studies ranged from medium to low quality with no high quality studies identified. Characteristics commonly associated with increased risk of house fire incidents, injuries and fatalities included: higher numbers of residents, male, children under the age of 5 years, non-working households, smoking, low income, non-privately owned properties, apartments and buildings in poor condition. Several risk factors were only associated with one outcome (eg, living alone was only associated with increased risk of injurious fires), and households with older residents were at increased risk of injurious fires, but significantly less likely to experience a house fire in the first place. CONCLUSIONS: This best evidence synthesis indicates that several resident and property characteristics are associated with risk of experiencing house fire incidents, injuries or death. These findings should be considered by the Fire and Rescue Services and others with a role in fire prevention. Future research should adopt robust, standardised study designs to permit meta-analyses and enable stronger conclusions to be drawn.

A Coordinated Emergency Response: A Color Dust Explosion at a 2015 Concert in Taiwan.

In June 2015, nearly 500 concert attendees suffered injuries from smoke inhalation and severe burns following a color-dust explosion at a waterpark in Taiwan. We report on the progressions of the incident and government responses, share cross-departmental mobilization and case management lessons, and reflect on clinical and complex policy issues emerged. The timely and coordinated emergency responses, a high-quality universal health care system, and dedicated clinicians voluntarily working overtime resulted in an unprecedented 2.4% mortality rate (international statistics predicted 26.8%).

Burn center volume makes a difference for burned children.

OBJECTIVES: Determine the relationship between the volume of burn admissions and outcomes for children with burns. DESIGN: Retrospective review of the National Burn Repository from 2000-2009 using mixed effect logistic regression modeling. SETTING: Tertiary burn centers in the United States. PATIENTS: All children <18 years of age admitted with burn injury to a burn center submitting data to the National Burn Repository. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 210,683 records in the NBR from 2000-2009, 33,115 records for children ≤ 18 years of age met criteria for analysis; 26,280 had burn sizes smaller than 10%; only 32 of these children died. Volume of children treated varied greatly among facilities. Age, total body surface area burn, inhalation injury, and burn center volume influenced mortality (p < 0.05) An increase in the median yearly admissions of 100 decreased the odds of mortality by approximately 40%. High volume centers (admitting >200 pediatric patients/year) had the lowest mortality when adjusting for age and injury characteristics (p < 0.05). CONCLUSIONS: Higher volume pediatric burn centers had lower mortality, particularly at larger burn sizes. The lower mortality of children a high volume centers could reflect greater experience, resource, and specialized expertise in treating pediatric patients.

Mass-casualty Response to the Kiss Nightclub in Santa Maria, Brazil.

On January 27, 2013, a fire at the Kiss Nightclub in Santa Maria, Brazil led to a mass-casualty incident affecting hundreds of college students. A total of 234 people died on scene, 145 were hospitalized, and another 623 people received treatment throughout the first week following the incident.1 Eight of the hospitalized people later died.1 The Military Police were the first on scene, followed by the state fire department, and then the municipal Mobile Prehospital Assistance (SAMU) ambulances. The number of victims was not communicated clearly to the various units arriving on scene, leading to insufficient rescue personnel and equipment. Incident command was established on scene, but the rescuers and police were still unable to control the chaos of multiple bystanders attempting to assist in the rescue efforts. The Municipal Sports Center (CDM) was designated as the location for dead bodies, where victim identification and communication with families occurred, as well as forensic evaluation, which determined the primary cause of death to be asphyxia. A command center was established at the Hospital de Caridade Astrogildo de Azevedo (HCAA) in Santa Maria to direct where patients should be admitted, recruit staff, and procure additional supplies, as needed. The victims suffered primarily from smoke inhalation and many required endotracheal intubation and mechanical ventilation. There was a shortage of ventilators; therefore, some had to be borrowed from local hospitals, neighboring cities, and distant areas in the state. A total of 54 patients1 were transferred to hospitals in the capital city of Porto Alegre (Brazil). The main issues with the response to the fire were scene control and communication. Areas for improvement were identified, namely the establishment of a disaster-response plan, as well as regularly scheduled training in disaster preparedness/response. These activities are the first steps to improving mass-casualty responses.

Health outcomes associated with smoke exposure in Albuquerque, New Mexico, during the 2011 Wallow fire.

OBJECTIVE: This study examined the association between PM2.5 levels and emergency department (ED) visits for selected health outcomes in Albuquerque, New Mexico, during the Wallow fire of 2011. DESIGN: Measurements of 24-hour average concentrations of PM2.5 obtained from the City of Albuquerque were used to calculate wildfire smoke exposure in Albuquerque. Daily ED visits were collected by the New Mexico Department of Health from individual nonfederal licensed facilities in the Albuquerque area. Poisson regression was used to assess the relationship between ED visits for selected respiratory and cardiovascular conditions and varying levels of PM2.5 exposure. SETTING: Albuquerque, New Mexico. PARTICIPANTS: Patients visiting an ED for select conditions before, during, and after the wildfire. MAIN OUTCOME MEASURE: Relative increase in ED visits for selected conditions during the wildfire period. RESULTS: Analysis of PM2.5 exposure data and ED visits in Albuquerque before and during the Wallow fire indicated that compared with the period prior to the fire, there was an increased risk of ED visits for some respiratory and cardiovascular conditions during heavy smoke conditions, and risk varied by age and sex. The population of 65+ years was especially at risk for increased ED visits. There was a significantly increased risk of ED visits among the 65+ population for asthma (RR [relative rate] = 1.73, 95% confidence interval [CI] = 1.03-2.93) and for diseases of the veins, lymphatic and circulatory system (RR = 1.56, 95% CI = 1.00-2.43). For the age group of 20 to 64 years, there was a statistically significant increase in ED visits for diseases of pulmonary circulation (RR = 2.64, 95% CI = 1.42-4.9) and for cerebrovascular disease (RR = 1.69, 95% CI = 1.03-2.77). CONCLUSIONS: High levels of PM2.5 exposure due to the Wallow fire were associated with increased ED visits for respiratory and cardiovascular conditions in Albuquerque. More effective and targeted preventive measures are necessary to reduce morbidity rates associated with wildfire smoke exposure among vulnerable populations.

Economic evaluation of smoke alarm distribution methods in Baltimore, Maryland.

OBJECTIVE: This paper analyses costs and potential lives saved from a door-to-door smoke alarm distribution programme using data from a programme run by the Baltimore City Fire Department in 2010-2011. DESIGN: We evaluate the impact of a standard home visit programme and an enhanced home visit programme that includes having community health workers provide advance notice, promote the programme, and accompany fire department personnel on the day of the home visit, compared with each other and with an option of not having a home visit programme (control). RESULTS: Study data show that the home visit programme increased by 10% the number of homes that went from having no working alarm to having any working alarm, and the enhanced programme added an additional 1% to the number of homes protected. We use published reports on the relative risk of death in homes with and without a working smoke alarm to show that the standard programme would save an additional 0.24 lives per 10,000 homes over 10 years, compared with control areas and the enhanced home visit programme saved an additional 0.07 lives compared with the standard programme. The incremental cost of each life saved for the standard programme compared with control was $28,252 per death averted and $284,501per additional death averted for the enhanced compared with the standard. CONCLUSIONS: Following the US guidelines for the value of a life, both programmes are cost effective, however, the standard programme may offer a better value in terms of dollars per death averted. The study also highlights the need for better data on the benefits of current smoke alarm recommendations and their impact on injury, death and property damage.

Frequency, complications, and mortality of inhalation injury in burn patients: A systematic review and meta-analysis protocol.

INTRODUCTION: Burns are tissue traumas caused by energy transfer and occur with a variable inflammatory response. The consequences of burns represent a public health problem worldwide. Inhalation injury (II) is a severity factor when associated with burn, leading to a worse prognosis. Its treatment is complex and often involves invasive mechanical ventilation (IMV). The primary purpose of this study will be to assess the evidence regarding the frequency and mortality of II in burn patients. The secondary purposes will be to assess the evidence regarding the association between IIs and respiratory complications (pneumonia, airway obstruction, acute respiratory failure, acute respiratory distress syndrome), need for IMV and complications in other organ systems, and highlight factors associated with IIs in burn patients and prognostic factors associated with acute respiratory failure, need for IMV and mortality of II in burn patients. METHODS: This is a systematic literature review and meta-analysis, according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). PubMed/MEDLINE, Embase, LILACS/VHL, Scopus, Web of Science, and CINAHL databases will be consulted without language restrictions and publication date. Studies presenting incomplete data and patients under 19 years of age will be excluded. Data will be synthesized through continuous (mean and standard deviation) and dichotomous (relative risk) variables and the total number of participants. The means, sample sizes, standard deviations from the mean, and relative risks will be entered into the Review Manager web analysis software (The Cochrane Collaboration). DISCUSSION: Despite the extensive experience managing IIs in burn patients, they still represent an important cause of morbidity and mortality. Diagnosis and accurate measurement of its damage are complex, and therapies are essentially based on supportive measures. Considering the challenge, their impact, and their potential severity, IIs represent a promising area for research, needing further studies to understand and contribute to its better evolution. The protocol of this review is registered on the International prospective register of systematic reviews platform of the Center for Revisions and Disclosure of the University of York, United Kingdom (https://www.crd.york.ac.uk/prospero), under number RD42022343944.

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.

Fire deaths in Cape Town, South Africa: A retrospective review of medico-legal and toxicological findings (2006 - 2018).

BACKGROUND: In South Africa, fire-related deaths are common, particularly within dense informal housing settlements. Published data on deaths from fire incidents in Cape Town is sparse. Additionally, little emphasis has been placed on the role of toxicological investigations in these deaths, despite the known risk of alcohol and drug impairment to burn injury. METHODS: A retrospective, descriptive analysis of post-mortem case reports from Salt River Mortuary was conducted to investigate all deaths in which fires were involved in the west metropole of Cape Town, between 2006 to 2018. Demographic, circumstantial, and toxicological data were analyzed using R software. RESULTS: In total 1370 fire deaths occurred over 13 years, with a mean of 106 (SD ± 18) cases per annum (≈3% of the annual caseload and a mortality rate of 5.5 per 100,000). Males (70.4%), adults (mean=30.7 years), and toddlers (1-4 years old) were notably at risk. Deaths typically occurred in the early morning (00h00 - 06h00) (45.7%), during winter (32.1%), and in lower socioeconomic areas with highly dense informal settlements (65.6%), with 29% of deaths occurring in multi-fatality incidents. Ethanol was detected (≥0.01 g/100 mL) in 55.1% of cases submitted for analysis (71.5%), with a mean of 0.18 g/100 mL, and with 93.8% of positive cases > 0.05 g/100 mL. Carboxyhaemoglobin (COHb) analysis was requested in 76.4% of cases, with 57% of cases having a %COHb of ≥ 20%. Toxicology results (for drugs other than ethanol) from the national laboratory were outstanding in 34.4% of the cases at the conclusion of the study. BAC and %COHb were significantly higher in deaths from burns and smoke inhalation (usually accidents) than deaths from combined trauma and burns (typically homicides). Fire deaths with high COHb levels were more likely to display cherry-red discoloration (OR=3.1) and soot in the airways (OR=2.7) at autopsy. CONCLUSION: This article provides an updated description of fire deaths in the west metropole of Cape Town. The importance of BAC and COHb testing in these cases was noted, and the authors call for an investigation of the role of drug impairment (specifically frequently misused drugs methamphetamine and methaqualone) as a risk factor in these deaths. Areas of high-density informal settlements, where open flames are used to heat, light, and cook, were noted as high risk.

Occupational exposures and symptoms among firefighters and police during the carmel forest fire: the Carmel cohort study.

BACKGROUND: From 2 to 5 December 2010, Israel experienced the most severe forest fire In its history, resulting in the deaths of rescue workers. Little research exists on the health risks to emergency responders during forest fires, and there is no published research to date on occupational health among firefighters in Israel. OBJECTIVES: To describe the exposures experienced by emer gency responders to smoke, fire retardants and stress; the utilization of protective equipment; and the frequency of corresponding symptoms during and following the Carmel Forest fire. METHODS: A cohort of 204 firfighers and 68 police who took part in rescue and fire-abating activites during the Carmel Forest fire were recruited from a representative sample of participating stations throughout the country and interviewed regarding their activities during the fire and their coinciding symptoms. Unpaired two-sample t-test compared mean exposures and symptom frequency for firefighters and police. Chi-square estimates of OR and 95%CI are provided for odds of reporting symptoms, incurring injury or being hospitalied for various risk factors RESULTS: Of the study participants, 87% reported having at least one symptom during rescue work at the Carmel Forest fire,with eye irritation (77%) and fatigue (71%) being the most comon. Occupational stress was extremely high during the fire; the average length of time working without rest was 18.4 hours among firefighters. CONCLUSION: Firefighter and police were exposed to smoke and ocupational stress prolonged periods during the fire. Further research is needed on the residual health effects from exposure to forest fires among emergency responders, and to identify areas for improvement in health preparedness.

Suicide by burning: epidemiological and clinical profiles.

Self-immolation constitutes a rare form of suicide in developed countries, though it accounts for unique injury characteristics in the burn intensive care unit. The aim of this study was to present the epidemiological and clinical features of patients burned during a suicidal attempt seen in a North Rhine-Westphalia burn intensive care unit (BICU). To address this aim, we undertook a 21-year retrospective study involving patients with thermal injuries admitted to the largest burn unit in Germany. A total of 125 suicide-related burn victims were identified in the study period (9.4%). Comparing the self-immolation group with the rest burn patient cohort, suicide victims were more likely to be single and to act under the influence of alcohol. The suicidal group had a larger extent of burns, higher incidence of inhalation injury, required more surgical procedures, catecholamines, blood transfusions, and a longer BICU stay. Their clinical course was complicated by prolonged intubation period, higher rate of multiple drug-resistant bacteria acquisition and sepsis, leading to a higher mortality rate. Although the proportion of self-immolation victims among all burned patients is not high, the markedly higher severity of their burns and their poorer quality of outcomes makes them an important clinical subgroup for further study.

Hyperbaric Oxygen and Mortality in Burns With Inhalation Injury: A Study of the National Burn Repository.

Mortality in burn injury is primarily influenced by three factors: age, percent burn (%TBSA), and presence of inhalation injury. Numerous modalities have been tried in an attempt to treat those patients with burns and inhalation injury, including the use of hyperbaric oxygen (HBO). The aim of our study was to find the national prevalence of HBO for burns with inhalation injury, and whether HBO influenced mortality in these often severely injured patients. This retrospective study used the National Burn Repository (NBR) to identify hospital admissions of patients with both cutaneous burn and inhalation injuries. After applying exclusion criteria, a total of 13,044 patients were identified. Variables included in the multivariate regression analysis included age, sex, race, payer, mechanism of burn injury, TBSA group, total procedure number, mechanical ventilator days, and treatment with HBO. The main outcome variable was mortality. Of the 13,044 patients, 67 had HBO therapy. The HBO patients were older (mean age 51.7 vs 42.8 years, P < .001), but had smaller burns and thus a similar Baux score (66.6 vs 65.2, P = .661). The HBO patients had a higher mortality (29.9% vs 17.5%, P = .01). On multivariate regression analysis, HBO was an independent predictor of mortality (odds ratio = 2.484, P = .004). Other significant predictors of mortality included age, black race, Medicaid or uninsured patients, and %TBSA. The use of HBO for patients with burns and inhalation injury is uncommon in this database. It is unclear whether that reflects low prevalence or if individual centers do not all impute HBO into the NBR. For those patients in this database, HBO is an independent predictor of mortality. It can be difficult to determine the severity of inhalation injury in the NBR, so those patients receiving HBO could theoretically have more severe inhalation injury.

Inpatient and Postdischarge Outcomes Following Inhalation Injury Among Critically Injured Burn Patients.

Inhalation injury is associated with high inpatient mortality, but the impact of inhalation injury after discharge and on non-mortality outcomes is poorly characterized. To address this gap, we evaluated the effect of inhalation injury on postdischarge morbidity, mortality, and hospital readmissions among patients who sustained burn injury, as well as on in-hospital outcomes for context. This was a retrospective cohort study of patients with cutaneous fire/flame burns admitted to a burn center intensive care unit from January 1, 2009 to December 31, 2015, with or without inhalation injury. Records were linked to statewide hospital admission and vital statistics databases to assess postdischarge outcomes. Mixed-effects Poisson regression was used to assess mortality, complications, and readmissions. The overall cohort included 830 patients with cutaneous burns; of these, 201 patients had inhalation injury. In-hospital mortality was 31% among inhalation injury patients vs 6% in patients without inhalation injury (adjusted OR 2.35; 95% CI 1.66-3.31). Inhalation injury was also associated with an increased risk of in-hospital pneumonia and tracheostomy (P < .05 for all). Inhalation injury was not associated with greater postdischarge mortality, all-cause readmission, readmission for pulmonary diagnosis, or readmission requiring intubation. Among the subset of patients with bronchoscopy-confirmed inhalation injury (n = 124; 62% of inhalation injuries), a higher injury grade was not associated with greater inpatient or postdischarge mortality. Inhalation injury was associated with increased early morbidity and mortality, but did not contribute to postdischarge mortality or readmission. These findings have implications for shared decision making with patients and families and for estimating healthcare utilization after initial hospitalization.

Soluble suppression of tumorigenicity-2 predicts pneumonia in patients with inhalation injury: Results of a pilot study.

INTRODUCTION: Several mechanisms play a role in the development of pneumonia after inhalation injury. Our aim was to analyze whether higher concentrations of inflammatory markers or of biomarkers of epithelial injury are associated with a higher incidence of pneumonia in patients with inhalation injury. MATERIAL AND METHODS: Secondary analysis of a single-center prospective observational cohort pilot study, performed over a two-year period (2015-2017) at the Burns Unit of the Plastic and Reconstructive Surgery Department of Vall d'Hebron University Hospital. All patients aged 18 with suspected inhalation injury undergoing admission to the Burns Unit were included. Plasma biomarkers of the lung epithelium (RAGE and SP-D), inflammation markers (IL6, IL8), and IL33, as well as soluble suppression of tumorigenicity-2 (sST2) levels, were measured within the first 24 h of admission. RESULTS: Twenty-four patients with inhalation injury were included. Eight (33.3%) developed pneumonia after a median of 7 (4-8) days of hospital stay. Patients with pneumonia presented higher plasma concentrations of sST2 (2853 [2356-3351] ng/mL vs 1352 [865-1839] ng/mL; p < 0.001), IL33 (1.95 [1.31-2.59] pg/mL vs 1.26 [1.07-1.45] pg/mL; p = 0.002) and IL8 (325.7 [221.6-430.0] pg/mL vs 174.1 [95.2-253.0] pg/mL; p = 0.017) on day 1 of inclusion. Plasma sST2 concentration in the first 24 h demonstrated excellent diagnostic accuracy for predicting the occurrence of pneumonia in patients with smoke inhalation (AUROC 0.929 [95%CI 0.818-1.000]). A cutoff point of ≥2825 ng/mL for sST2 had a sensitivity of 75% and a specificity of 100%. The risk ratio of pneumonia in patients with sST2 ≥ 2825 ng/mL was 7.14 ([95% CI 1.56-32.61]; p = 0.016). CONCLUSIONS: Plasma sST2 in the first 24 h of admission predicts the occurrence of pneumonia in patients with inhalation injury.