Diagnosis and management of inhalation injury: an updated review

Smoke Inhalation in Veterinary Patients: Pathophysiology, Diagnosis, and Management

Smoke contains a mixture of harmful gases, chemicals, and superheated particles. Inhalation of smoke causes generalized hypoxia and airway inflammation due to impaired oxygen transport and utilization, as well as thermal and chemical injury in the airways. Generally, treatment is supportive with oxygen therapy and airway management, including chest physiotherapy, bronchodilators, and nebulization. Immediate oxygen therapy is mandatory for all suspected smoke inhalation patients and should not be delayed pending diagnostic test results or due to "normal" oxygen saturation readings that can be falsely elevated in carbon monoxide intoxication. Smoke inhalation patients with mild clinical signs who respond well to initial stabilization generally have a favorable prognosis. However, patients with severe signs or progression despite initial stabilization may require more advanced or intensive care.

Quantitative assessment of chlorine gas inhalation injury based on endoscopic OCT and spectral encoded interferometric microscope imaging with deep learning

Chlorine exposure can cause severe airway injuries. While the acute effects of chlorine inhalation are well-documented, the structural changes resulting from the post-acute, high-level chlorine exposure remain less understood. Airway sloughing is one of the standards for doctors to evaluate the lung function. Here, we report the application of a high-resolution swept-source optical coherence tomography system to investigate the progression of injury based on airway sloughing evaluation in a chlorine inhalation rabbit model. This system employs a 1.2 mm diameter flexible fiberoptic endoscopic probe via an endotracheal tube to capture in vivo large airway anatomical changes before and as early as 30 min after acute chlorine exposure. We conducted an animal study using New Zealand white rabbits exposed to acute chlorine gas (800 ppm, 6 min) during ventilation and monitored them using optical coherence tomography (OCT) for 6 h. To measure the volume of airway sloughing induced by chlorine gas, we utilized deep learning for the segmentation task on OCT images. The results showed that the volume of chlorine induced epithelial sloughing on rabbit tracheal walls initially increased, peaked around 30 min, and then decreased. Furthermore, we utilized a spectral encoded interferometric microscopy system to study ex vivo airway cilia beating dynamics based on Doppler shift, aiding in elucidating how chlorine gas affects cilia beating function. Cilia movability and beating frequency were decreased because of the epithelium damage. This quantitative approach has the potential to enhance the diagnosis and monitoring of injuries from toxic gas inhalation and to evaluate the efficacy of antidote treatments for these injuries.

Rare multi-fungal sepsis: a case of triple-impact immunoparalysis

Patients with burn injury and inhalation injury are highly susceptible to infectious complications, including opportunistic pathogens, due to the loss of skin cover and mucosal damage of respiratory tract as well as the disruption of homeostasis. This case report, a 34-year-old man suffered critical burns, provides the first literature description of triple-impact immunoparalysis (critical burns, inhalation injury, and SARS-CoV-2 infection), leading to a lethal multifocal infection caused by several fungi including very rare environmental representatives Metschnikowia pulcherrima and Wickerhamomyces anomalus. The co-infection by these common environmental yeasts in a human is unique and has not yet been described in the literature. Importantly, our patient developed refractory septic shock and died despite targeted antifungal therapy including the most potent current antifungal agent-isavuconazole. It can be assumed that besides immunoparalysis, effectiveness of therapy by isavuconazole was impaired by the large distribution volume in this case. As this is a common situation in intensive care patients, routine monitoring of plasmatic concentration of isavuconazole can be helpful in personalization of the treatment and dose optimization. Whatmore, many fungal species often remain underdiagnosed during infectious complications, which could be prevented by implementation of new methods, such as next-generation sequencing, into clinical practice.

Polycyclic aromatic hydrocarbons and their metabolites in bronchoalveolar lavage and urine samples from patients with inhalation injury throughout their hospitalization: A prospective pilot study

BACKGROUND

Specific toxic compounds, such as polycyclic aromatic hydrocarbons (PAHs) and their metabolites, may affect the inhalation injury (INHI) grade, patients' status, and prognosis for recovery. This pilot prospective study aimed to: i) evaluate the suitability of bronchoalveolar lavage (BAL) for determination of PAHs in the LRT and of urine for determination of hydroxylated metabolites (OH-PAHs) in patients with INHI, ii) describe the dynamic changes in the levels of these toxic compounds, and iii) correlate these findings with clinical variables of the patients with INHI.

METHODS

The BAL and urine samples from 10 patients with INHI were obtained on Days 1, 3, 5, 7, and 14 of hospitalization, if possible, and PAHs (BAL) and OH-PAHs (urine) were analyzed using chromatographic methods (GC-MS and HPLC).

RESULTS

Concentrations of analyzed PAHs were in most cases and time points below the limit of quantification in BAL samples. Nine OH-PAHs were detected in the urine samples; however, their concentrations sharply decreased within the first three days of the hospitalization. On Day 14, the total amount of OH-PAHs in urine was higher in surviving patients with High-grade INHI (≥3) than in those with Low-grade INHI (<3, p = 0.032). Finally, a significant correlation between certain OH-PAHs and clinical variables (AST/ALT, TBSA, ABSI) from Day 1 of the hospitalization was observed (p<0.05).

CONCLUSIONS

BAL samples are not suitable for the analysis of PAHs. However, the OH-PAHs levels in urine can be measured reliably and were correlated with several clinical variables. Moreover, High-grade INHI was associated with higher total concentrations of OH-PAHs in urine.

Epidemiology and timing of infectious complications from battlefield-related burn injuries

BACKGROUND

Infections are the most frequent complication and cause of mortality in burn patients. We describe the epidemiology and outcomes of infections among deployed U.S. military personnel with burns.

METHODS

Military personnel who sustained a burn injury in Iraq or Afghanistan (2009-2014) and were admitted to the Burn Center at U.S. Army Institute of Surgical Research at Brooke Army Medical Center were included in the analysis.

RESULTS

The study population included 144 patients who were primarily young (median 24 years) males (99 %) with combat-related burns (62 %) sustained via a blast (57 %), resulting in a median total body surface area burned (TBSA) of 6 % (IQR 3-14 %). Twenty-six (18 %) patients developed infections, with pneumonia being the predominant initial infection (= 16), followed by skin and soft-tissue infections (SSTI, = 6), bloodstream infections (BSI, = 3), and intra-abdominal infections (IAI, = 1). Initial infections were diagnosed at a median of 4 days (IQR 3-5) post-injury for pneumonia, 7 days (IQR 4-12) for SSTIs, 7 days (IQR 6-7) for BSI, and 17 days for IAI. Patients with infections were more severely injured with greater TBSA (median 31 % vs 5 %), more inhalation injury (38 % vs 12 %), and longer time to definitive surgical management (median of 34 days vs 9) compared to those who did not develop infections (p < 0.001). Among patients with inhalation injury, a higher proportion developed pneumonia (42 %) compared to those without inhalation injury (5 %; p < 0.001). Five patients developed an invasive fungal infection. Gram-negative bacilli were most frequently recovered, with 32 % of Gram-negative isolates being multidrug-resistant. Four patients died, of whom all had ≥ 4 infections.

CONCLUSIONS

Military personnel with burn injuries who developed infections were more severely injured with greater TBSA and inhalation injury. Improved understanding of risk factors for burn-related infections in combat casualties is critical for effective management.

Revalidating the prognostic relevance of the Abbreviated Burn Severity Index (ABSI): A twenty-year experience examining the performance of the ABSI score in consideration of progression and advantages of burn treatments from a single center in Vienna

BACKGROUND

The Abbreviated Burn Severity Index (ABSI) is a five-variable scale to help evaluate burn severity upon initial assessment. As other studies have been conducted with comparatively small patient populations, the purpose of this study is to revalidate the prognostic relevance of the ABSI in our selected population (N = 1193) 4 decades after its introduction, considering the progress in the treatment of severe burn injuries over the past decades. In addition, we evaluate whether comorbidities influence the survival probability of severely burned patients.

METHODS

This retrospective study presents data from the Center for Severely Burned Patients of the General Hospital in Vienna. We included 1193 patients for over 20 years. Regression models were used to describe the prognostic accuracy of the ABSI.

RESULTS

The ABSI can still be used as a prognostic factor for the probability of survival of severely burned patients. The odds of passing increases by a factor of 2.059 for each unit increase in the ABSI with an area under the curve value of 0.909. Over time, the likelihood of survival increased. The existence of chronic kidney disease negatively impacts the survival probability of severely burned patients.

CONCLUSION

The ABSI can still be used to provide accurate information about the chances of survival of severely burned patients; however, further exploration of the impact of chronic kidney disease on the survival probability and adding variables to the ABSI scale should be considered. The probability of survival has increased over the last 20 years.

Factors Associated With Head and Neck Polytrauma Presentation and Admissions at Emergency Departments of Varying Sizes

Timely diagnosis of acute head and neck polytrauma presenting to emergency departments (EDs) optimizes outcomes. Since ED capacity influences triage and admission, the authors utilized the National Electronic Injury Surveillance System database to understand how ED size and trauma characteristics affect head and neck polytrauma presentation and admissions. Demographics and injury characteristics from the National Electronic Injury Surveillance System database from 2018 to 2021 were analyzed to delineate factors contributing to polytrauma presence and admission through multivariable logistic regressions. The authors' 207,951-patient cohort was primarily females (48.6%), non-Hispanic (62.4%), and white (51.4%) people who averaged 57.2 years old. Nonspecific head injuries were predominant (59.7%), followed by facial trauma (22.6%) with rare substance involvement (alcohol, 6.3%; drugs, 4.1%) presenting to high-volume EDs (48.5%). Of the patients, 20% were admitted, whereas 31.1% sustained polytrauma. Substance use [alcohol, odds ratio (OR) = 4.44; drugs, OR = 2.90] increased polytrauma likelihood; neck (OR = 1.35), face (OR = 1.14), and eye (OR = 1.26) associated with polytrauma more than head injuries. Burns (OR = 1.38) increased polytrauma likelihood more than internal organ injuries. Black patients sustained higher polytrauma when presented to non-small EDs (OR = 1.41-1.90) than white patients showed to small EDs. Admissions were higher for males (OR = 1.51). Relative to small EDs, large EDs demonstrated a higher increase in admissions (OR = 2.42). Neck traumas were more likely admitted than head traumas (OR = 1.71). Fractures (OR = 2.21) and burns (OR = 2.71) demonstrated an increased admission likelihood than internal organ injuries. Polytrauma presence and admissions likelihood are site, injury, and substance dependent. Understanding the impact of factors influencing polytrauma presence or admission will enhance triage to optimize outcomes.

The impact of inhalation injury on fluid resuscitation in major burn patients: a 10-year multicenter retrospective study

BACKGROUND

It remains unclear whether additional fluid supplementation is necessary during the acute resuscitation period for patients with combined inhalational injury (INHI) under the guidance of the Third Military Medical University (TMMU) protocol.

METHODS

A 10-year multicenter, retrospective cohort study, involved patients with burns ≥ 50% total burn surface area (TBSA) was conducted. The effect of INHI, INHI severity, and tracheotomy on the fluid management in burn patients was assessed. Cumulative fluid administration, cumulative urine output, and cumulative fluid retention within 72 h were collected and systematically analyzed.

RESULTS

A total of 108 patients were included in the analysis, 85 with concomitant INHI and 23 with thermal burn alone. There was no significant difference in total fluid administration during the 72-h post-burn between the INHI and non-INHI groups. Although no difference in the urine output and fluid retention was shown in the first 24 h, the INHI group had a significantly lower cumulative urine output and a higher cumulative fluid retention in the 48-h and 72-h post-burn (all p < 0.05). In addition, patients with severe INHI exhibited a significantly elevated incidence of complications (Pneumonia, 47.0% vs. 11.8%, p = 0.012), (AKI, 23.5% vs. 2.9%, p = 0.037). For patients with combined INHI, neither the severity of INHI nor the presence of a tracheotomy had any significant influence on fluid management during the acute resuscitation period.

CONCLUSIONS

Additional fluid administration may be unnecessary in major burn patients with INHI under the guidance of the TMMU protocol.

Exploring the similarities and differences of burn registers globally: Results from a data dictionary comparison study

INTRODUCTION

Pooling and comparing data from the existing global network of burn registers represents a powerful, yet untapped, opportunity to improve burn prevention and care. There have been no studies investigating whether registers are sufficiently similar to allow data comparisons. It is also not known what differences exist that could bias analyses. Understanding this information is essential prior to any future data sharing. The aim of this project was to compare the variables collected in countrywide and intercountry burn registers to understand their similarities and differences.

METHODS

Register custodians were invited to participate and share their data dictionaries. Inclusion and exclusion criteria were compared to understand each register population. Descriptive statistics were calculated for the number of unique variables. Variables were classified into themes. Definition, method, timing of measurement, and response options were compared for a sample of register concepts.

RESULTS

13 burn registries participated in the study. Inclusion criteria varied between registers. Median number of variables per register was 94 (range 28 - 890), of which 24% (range 4.8 - 100%) were required to be collected. Six themes (patient information, admission details, injury, inpatient, outpatient, other) and 41 subthemes were identified. Register concepts of age and timing of injury show similarities in data collection. Intent, mechanism, inhalational injury, infection, and patient death show greater variation in measurement.

CONCLUSIONS

We found some commonalities between registers and some differences. Commonalities would assist in any future efforts to pool and compare data between registers. Differences between registers could introduce selection and measurement bias, which needs to be addressed in any strategy aiming to facilitate burn register data sharing. We recommend the development of common data elements used in an international minimum data set for burn injuries, including standard definitions and methods of measurement, as the next step in achieving burn register data sharing.

Development and validation of a nomogram for pneumonia risk in burn patients with inhalation injury: a multicenter retrospective cohort study

BACKGROUND

Burn patients with inhalation injury are at higher risk of developing pneumonia, and yet there is no reliable tool for the assessment of the risk for such patients at admission. This study aims to establish a predictive model for pneumonia risk for burn patients with inhalation injury based on clinical findings and laboratory tests.

METHOD

This retrospective study enrolled 546 burn patients with inhalation injury. They were grouped into a training cohort and a validation cohort. The least absolute shrinkage and selection operator (LASSO) regression analysis and binary logistic regression analysis were utilized to identify risk factors for pneumonia. Based on the factors, a nomogram for predicting pneumonia in burn patients with inhalation injury was constructed. Areas under the receiver operating characteristic curves (AUC), calibration plots, and decision curve analysis (DCA) were used to evaluate the efficiency of the nomogram in both the training and validation cohorts.

RESULTS

The training cohort included 432 patients, and the validation cohort included 114 patients, with a total of 225 (41.2%) patients experiencing pneumonia. Inhalation injury, tracheal intubation/tracheostomy, low serum albumin, and high blood glucose were independent risk factors for pneumonia in burn patients with inhalation injury and they were further used to build the nomogram. The AUC of the nomogram in the training and validation cohorts were 0.938 (95% CI: 0.917-0.960) and 0.966 (95% CI: 0.931-1), respectively. The calibration curve for probability of pneumonia showed optimal agreement between the prediction by nomogram and the actual observation, and the DCA indicated that the constructed nomogram conferred high clinical net benefit.

CONCLUSION

This nomogram can accurately predict the risk of developing pneumonia for burn patients with inhalation injury, and help professionals to identify high-risk patients at an early stage as well as to make informed clinical decisions.

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.

Inhalation Injury, Respiratory Failure, and Ventilator Support in Acute Burn Care

Sustaining an inhalation injury increases the risk of severe complications and mortality. Current evidential support to guide treatment of the injury or subsequent complications is lacking, as studies either exclude inhalation injury or design limit inferences that can be made. Conventional ventilator modes are most commonly used, but there is no consensus on optimal strategies. Settings should be customized to patient tolerance and response. Data for pharmacotherapy adjunctive treatments are limited.

Nebuliser therapy in critical care: The past, present and future

Nebulisers are devices that reduce a body of liquid into a fine aerosol suitable for inhalation. Utilising the efficiency of pulmonary drug absorption, they offer a safe and powerful modality for local and systemic drug delivery in the treatment of critical illness. In comparison to conventional jet (JN) and ultrasonic nebulisers (USN), the advent of vibrating mesh nebulisers (VMN) has significantly improved the therapeutic potential of modern devices. This review article aims to summarise the history and evolution of nebulisers from first inception through to the modern vibrating mesh technology. It provides an overview on the basic science of nebulisation and pulmonary drug delivery, and the current use of nebulised therapies in critical care.

Approach to burn treatment in the rural emergency department

OBJECTIVE

To outline an approach to the assessment and initial management of patients with burns in the rural emergency department setting. Three mnemonics are presented that can be used for both the assessment and the initial management of patients with burns in rural settings.

QUALITY OF EVIDENCE

Current and local guidelines compiled by a plastic surgeon were reviewed to develop a systematic approach to the treatment of patients with burns. PubMed and other databases were also searched for current literature on emergency care of patients with burns.

MAIN MESSAGE

Burn injuries are a common reason for presentation to the emergency department. However, the care of patients with these injuries can vary substantially depending on geographic location, provider training, and hospital resources. Classification of burns, fluid resuscitation guidelines, dressings and wound care, indications for referral, and pain management are discussed.

CONCLUSION

Using a systematic approach may help improve burn injury outcomes for patients and provide practitioners with a step-by-step framework for the management of patients with burns in rural settings.

Countermeasures against Pulmonary Threat Agents

Inhaled toxicants are used for diverse purposes, ranging from industrial applications such as agriculture, sanitation, and fumigation to crowd control and chemical warfare, and acute exposure can induce lasting respiratory complications. The intentional release of chemical warfare agents (CWAs) during World War I caused life-long damage for survivors, and CWA use is outlawed by international treaties. However, in the past two decades, chemical warfare use has surged in the Middle East and Eastern Europe, with a shift toward lung toxicants. The potential use of industrial and agricultural chemicals in rogue activities is a major concern as they are often stored and transported near populated areas, where intentional or accidental release can cause severe injuries and fatalities. Despite laws and regulatory agencies that regulate use, storage, transport, emissions, and disposal, inhalational exposures continue to cause lasting lung injury. Industrial irritants (e.g., ammonia) aggravate the upper respiratory tract, causing pneumonitis, bronchoconstriction, and dyspnea. Irritant gases (e.g., acrolein, chloropicrin) affect epithelial barrier integrity and cause tissue damage through reactive intermediates or by direct adduction of cysteine-rich proteins. Symptoms of CWAs (e.g., chlorine gas, phosgene, sulfur mustard) progress from airway obstruction and pulmonary edema to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), which results in respiratory depression days later. Emergency treatment is limited to supportive care using bronchodilators to control airway constriction and rescue with mechanical ventilation to improve gas exchange. Complications from acute exposure can promote obstructive lung disease and/or pulmonary fibrosis, which require long-term clinical care. SIGNIFICANCE STATEMENT: Inhaled chemical threats are of growing concern in both civilian and military settings, and there is an increased need to reduce acute lung injury and delayed clinical complications from exposures. This minireview highlights our current understanding of acute toxicity and pathophysiology of a select number of chemicals of concern. It discusses potential early-stage therapeutic development as well as challenges in developing countermeasures applicable for administration in mass casualty situations.

An atypical airway cast

A 60-year-old man intubated for airway protection after smoke inhalation was found to have decompensated hypercapnic respiratory failure. Fiberoptic bronchoscopy revealed obstructive airway slough and pseudomembrane, a manifestation of severe inhalation injury. Veno-venous extracorporeal membrane oxygenation was established for stabilization. The airway casts were removed successfully with periprocedural veno-venous extracorporeal membrane oxygenation support.

Predictors and Impact of Pneumonia on Adverse Outcomes in Inhalation Injury Patients

Inhalation injury (II) is the third mortality prognostic factor for burn injury following age and burn size. II can lead to pulmonary complications such as pneumonia and acute respiratory distress syndrome (ARDS); all of which have been hypothesized to increase morbidity and mortality in II. Herein, we aimed to identify variables associated with the risk of developing pneumonia and to determine the impact of pneumonia on selected II outcomes. De-identified data from the Prospective Inhalation Study titled Inhalation Injury Scoring System to Predict Inhalation Injury Severity (ISIS) were used. II was confirmed by fiberoptic bronchoscopy. Demographics, injury, and hospital course information were recorded. P < .05 was considered significant. One hundred subjects were included. On univariate analysis, pneumonia was associated with burn severity, race, and receipt of colloid during the first 24 hours. Patients who developed pneumonia spent more time on a ventilator, had longer hospitalizations (LOS) and were more likely to need a tracheostomy. On multivariate analysis, total number of ventilator days was associated with pneumonia (Odd ratio (OR) = 1.122 [1.048-1.200], P = .001). Both pneumonia and receipt of colloid were predictive of increased ventilator days (OR = 2.545 [1.363-4.753], P < .001 and OR = 2.809 [1.548-5.098], P < .001, respectively). Pneumonia was not an independent predictor of LOS, ARDS, or mortality. Pneumonia remains a high-risk complication associated with two times more ventilator days in II. Future research should focus on prevention of pneumonia and the relationship between colloid fluids and pneumonia and early ventilator liberation in II patients.

Inhalation Injury Severity Score on Admission Predicts Overall Survival in Burn Patients

Inhalation injury is diagnosed in up to one-third of burn patients and is associated with increased morbidity and mortality. There are multiple scoring systems to grade inhalation injury, but no study has evaluated the ability of these scoring systems to predict outcomes of interest such as overall survival. We conducted a prospective, observational study of 99 intubated burn patients who underwent fiberoptic bronchoscopy within 24 hr of admission and graded inhalation injury using three scoring systems: abbreviated injury score (AIS), inhalation injury severity score (I-ISS), and mucosal score (MS). Agreement between scoring systems was assessed with Krippendorff's alpha (KA). Multivariable analyses were conducted to determine if variables were associated with overall survival. At admission, median AIS, I-ISS, and MS scores were 2 for all scoring systems. Patients who died had higher overall injury burden than those who survived and had similar median admission AIS and MS scores, but higher I-ISS scores. There was strong correlation between the inhalation injury grade at admission using the three scoring systems (KA = 0.85). On regression analysis, the only scoring system independently associated with overall survival was I-ISS (score 3 compared to scores 1-2: OR 13.16, 95% CI 1.65-105.07; P = .02). Progression of injury after initial assessment may contribute to the poor correlation between admission score and overall survival for injuries graded with AIS and MS. Repeated assessment may more accurately identify patients at increased risk for mortality.

The effect of well-known burn-related features on machine learning algorithms in burn patients' mortality prediction

BACKGROUND

Burns is one of the most common traumas worldwide. Severely injured burn patients have an increased risk for mortality and morbidity. This study aimed to evaluate well-known risk factors for burn mortality and comparison of six machine learn-ing (ML) Algorithms' predictive performances.

METHODS

The medical records of patients who had burn injuries treated at Izmir Bozyaka Training and Research Hospital's Burn Treatment Center were examined retrospectively. Patients' demographics such as age and gender, total burned surface area (TBSA), Inhalation injury (II), full-thickness burns (FTBSA), and burn types (BT) were recorded and used as input features in ML models. Pa-tients were analyzed under two groups: Survivors and Non-Survivors. Six ML algorithms, including k-Nearest Neighbor, Decision Tree, Random Forest, Support Vector Machine, Multi-Layer Perceptron, and AdaBoost (AB), were used for predicting mortality. Several different input feature combinations were evaluated for each algorithm.

RESULTS

The number of eligible patients was 363. All six parameters (TBSA, Gender, FTBSA, II, Age, BT) that were included in ML algorithms showed a significant difference (p<0.001). The results show that AB algorithm using all input features had the best predic-tion performance with an accuracy of 90% and an area under the curve of 92%.

CONCLUSION

ML algorithms showed strong predictive performance in burn mortality. The development of an ML algorithm with the right input features could be useful in the clinical practice. Further investigations are needed on this topic.

A Rare Case of Severe Burn Injury to the Oropharynx Caused by a Flare Gun

Flare gun injuries are rare, and patients often present with complex trauma that may require multiple operative interventions. Our objective is to explore a case of a 15-year-old male, who presented with second-degree flame burns to the face, left upper extremity and bilateral hands, as well as third-degree burns to the oropharynx and a tongue laceration after a flare gun was discharged into his mouth. The patient underwent multiple debridements of the oral cavity and oropharynx, and his hospital course was complicated by an intra-oral abscess. He eventually made a full recovery and was discharged. This case not only illustrates the need for early operative intervention, but it also underscores the need for awareness campaigns that highlight the dangers of flare guns and similar devices.

A Rare Mechanism of Inhalation Injury: Direct Thermal Damage to the Lower Airway

In patients with inhalation injury associated with major burns, the primary mechanism of tissue harm depends on the location within the respiratory tract. Proximal to the trachea, the upper respiratory tract epithelium is classically injured via direct thermal injury. Such injury occurs due to the inhalation of high-temperature air. These upper airway structures and the tracheobronchial tree's dense vasculature protect the lower airways and lung parenchyma from direct thermal damage. The lower respiratory tract epithelium and lung parenchyma typically become injured secondary to the cytotoxic effects of chemical irritants inhaled in smoke as well as delayed inflammatory host responses. This paper documents a rare case in which a patient demonstrated evidence of direct thermal injury to the lower respiratory tract epithelium. A 26-year-old Caucasian male presented to the emergency room with 66% total body surface area thermal burns and grade 4 inhalation injury after a kitchen fire. Instead of visualizing carbonaceous deposits in the bronchi, a finding common in inhalation injury, initial bronchoscopy revealed bronchial mucosa carpeted with hundreds of bullae. Despite the maximum grade of inhalation injury per the abbreviated injury score and a 100% chance of mortality predicted with the revised Baux score, as well as a clinical course complicated by pneumonia development, bacteremia, and polymicrobial external wound infection, this patient survived. This dissonance between his expected and observed clinical outcome suggests that the applicability of current inhalation injury classification systems depends on the precise mechanism of injury to the respiratory tract. The flaws of these grading scales and prognostic indicators may be rooted in their failure to account for other pathophysiologic processes involved in inhalation injury. It may be necessary to develop new grading and prognostic systems for inhalation injury that acknowledge and better account for unusual pathophysiologic mechanisms of tissue damage.

Sedation and Analgesia for Toxic Epidermal Necrolysis in the Intensive Care Unit: Few Certainties, Many Questions Ahead

Toxic epidermal necrolysis (TEN) is a rare, acute mucocutaneous life-threatening disease. Although research has focused on the pathophysiological and therapeutic aspects of the disease, there is a paucity of data in the literature regarding pain management and sedation in the intensive care unit (ICU). Most therapies have been extrapolated from other situations and/or the general ICU population. These patients present unique challenges during the progression of the disease and could end up requiring invasive mechanical ventilation due to inadequate pain management, which is potentially avoidable through a comprehensive treatment approach. In this review, we will present clinical and pathophysiological aspects of TEN, analyze pain pathways and relevant pharmacology, and propose therapeutic alternatives based on a rational and multimodal approach.

Outcomes of Tracheostomy on Burn Inhalation Injury

Background

Tracheostomy has been proposed for patients with expected prolonged intubation. This study aims to determine the outcomes of tracheostomy on patients with burn inhalation injuries requiring mechanical ventilation.

Methods

This study is a retrospective review from 2011 to 2019. Inclusion criteria were recording of inhalation injury, ventilator support (at least 24 hours), and total body surface area of <15%. The patients were stratified into 2 groups: tracheostomy (group 1) versus no tracheostomy (group 2). The outcome measures were in-hospital mortality rate, hospital length of stay, intensive care unit length of stay, ventilator days, and ventilator- associated pneumonia (VAP).

Results

A total of 33 burn patients met our inclusion criteria. Group 1 consisted of 10 patients and group 2 of 23 patients. There was no statistically significant difference in terms of percent total body surface area. There was a higher intensive care unit length of stay at 23.8 days in group 1 compared with 3.16 days in group 2, a higher hospital length of stay at 28.4 days in group 1 compared with 5.26 days in group 2, and higher ventilator days in group 1 with 20.8 days compared with 2.5 days in group 2. There was no statistically significant difference between the 2 groups in terms of mortality. The incidence of VAP was also significantly higher in group 1 than in group 2.

Conclusions

The ideal timing and implementation of tracheostomy with inhalation injury has yet to be determined. In this study, tracheostomy was associated with much longer lengths of stay and pneumonia. The impact of the underlying lung injury versus the tracheostomy itself on these observations is unclear. The challenge of characterizing the severity of an inhalation injury based on early visual inspection remains.

Inhalation Pneumonitis Caused by Nebulized Hydrogen Peroxide

Hydrogen peroxide is a chemical commonly used as a household antiseptic for cleaning and disinfecting. No cases of acute hydrogen peroxide inhalation-induced lung injury are previously described. We present a case of acute chemical pneumonitis caused by mixing hydrogen peroxide in a nighttime continuous positive airway pressure device's humidifier used for obstructive sleep apnea to prevent COVID-19 infection. The patient endorsed mixing hydrogen peroxide with distilled water in his nighttime continuous positive airway pressure device's humidifier at a ratio of 1:3-1:2 for the previous week before admission based on a friend's advice in preventing COVID-19. The presenting chest X-ray showed new multifocal consolidations with interstitial markings and alveolar edema throughout both lungs. Chest computed tomography (CT) imaging demonstrated multifocal, bilateral, hazy consolidations with increased interstitial markings and bilateral pleural effusions. The patient was subsequently initiated on systemic glucocorticoid therapy, significantly improving hypoxemia and dyspnea. Inhalation of hydrogen peroxide may produce acute pneumonitis distinct from what has been described previously with chronic inhalation. Given this case, systemic glucocorticoid therapy may be considered a viable treatment option for acute hydrogen peroxide-associated inhalation lung injury causing pneumonitis.

First-day computed tomography: does it has a role in the assessment of patients with inhalation lung injury?

Background

Inhalation lung injury occurs in almost one-third of all serious burns and is responsible for a considerable proportion of burn patient fatalities each year. History of closed space fire or unconsciousness at the accident site, occurrence of pharyngeal or facial burns, hoarseness, and wheezing, and laboratory tests that include blood gas abnormalities or Carboxyhemoglobin levels in blood ˃ 10% are used to diagnose inhalation lung injury. It is also characterized by radiological findings of alveolar or interstitial edema, atelectasis, and/or consolidations, as well as the presence of erythema with laryngeal or tracheal edema in the bronchoscope.

Objectives

To study the diagnostic and prognostic efficacy of radiologist score and bronchial wall thickening as radiological CT findings in inhalation lung injury.

Methods

This prospective case–control study included 48 patients with inhalation lung injury (ILI) as a case group and 10 patients without ILI were selected as the control group, all recruited from the burn and plastic department. Within the first 12 h of suspected ILI, a fiberoptic bronchoscope was done to confirm the diagnosis. An initial chest X-ray was done followed by computed tomography through which the radiologist score (RADS) together with bronchial wall thickening (BWT) was done.

Results

Duration of ventilation was higher in cases than in controls (8.50 ± 3.94 vs 3.25 ± 0.50). The hospital duration was higher in cases than in controls (13.6 ± 4.68 vs9.50 ± 4.52). The BWT was 2.12 ± 0.66 (mean ± SD) in the ILI group while the control group was 1.32 ± 0.48 (mean ± SD). Correlating between baseline PaO2 and RADS score and BWT, it was found that there was a highly significant negative correlation between PaO2 and RADS score and BWT among inhalation lung injury patients (P value 0.001). The sensitivity of BWT in the detection of the need for mechanical ventilation was 83% at a cut-off point of 1.65. Its specificity was 78% and accuracy 75%.

Conclusion

CT done within 24 h of burn patients has a good role in the diagnosis and management of ILI from the burn.

Long-Term Laryngotracheal Complications After Inhalation Injury: A Scoping Review

Long-term laryngotracheal complications (LTLC) after inhalation injury (II) are an under-recognized condition in patients with burns. The purpose of this study was to systematically review all available evidence on LTLC after II and identify gaps in knowledge to guide the direction of future research. A scoping review was performed to synthesize all available evidence on LTLC after II, as guided by the question, "What are the LTLC after II, in patients with or without a history of translaryngeal intubation and/or tracheostomy?". MEDLINE, Web of Science, Ovid Embase, Cochrane Library, and Google Scholar were searched for publications on this topic. Of the 3567 citations screened, a total of 153 full-text articles were assessed for eligibility and 49 were included in the scoping review. The overall level of evidence was low, with case reports constituting 46.7% of all included human studies. The lesions were most frequently in the trachea (36.9%), followed by the glottis (34.7%) and subglottis (19.0%). LTLC occur in 4.8 to 6.5% of patients after II and these complications are under-recognized in burns patients. The risk factors for LTLC include high-grade II, elevated initial inflammatory responses, prolonged translaryngeal intubation, and a history of tracheostomy. The goal of management is to restore airway patency, preserve voice quality, and restore normal diet and swallow function. There is limited high-level evidence on LTLC, particularly with regards to long-term functional morbidity in voice and swallow. Large, prospective studies are required to address this gap in knowledge.

European Burns Association guidelines for the management of burn mass casualty incidents within a European response plan

BACKGROUND

A European response plan to burn mass casualty incidents has been jointly developed by the European Commission and the European Burn Association. Upon request for assistance by an affected country, the plan outlines a mechanism for coordinated international assistance, aiming to alleviate the burden of care in the affected country and to offer adequate specialized care to all patients who can benefit from it. To that aim, Burn Assessment Teams are deployed to assess and triage patients. Their transportation priority recommendations are used to distribute outnumbering burn casualties to foreign burn centers. Following an appropriate medical evacuation, these casualties receive specialized care in those facilities.

METHODS

The European Burns Association's disaster committee developed medical-organizational guidelines to support this European plan. The experts identified fields of interest, defined questions to be addressed, performed relevant literature searches, and added their expertise in burn disaster preparedness and response. Due to the lack of high-level evidence in the available literature, recommendations and specially designed implementation tools were provided from expert opinion. The European Burns Association officially endorsed the draft recommendations in 2019, and the final full text was approved by the EBA executive committee in 2022.

RECOMMENDATIONS

The resulting 46 recommendations address four fields. Field 1 underlines the need for national preparedness plans and the necessary core items within such plans, including coordination and integration with an international response. Field 2 describes Burn Assessment Teams' roles, composition, training requirements, and reporting goals. Field 3 addresses the goals of specialized in-hospital triage, appropriate severity criteria, and their effects on priorities and triage. Finally, field 4 covers medical evacuations, including their timing and organization, the composition of evacuation teams and their assets, preparation, and the principles of en route care.

Veno-venous extracorporeal membrane oxygenation, cytokine removal and continuous renal replacement therapy in a severe burn adult patient

Acute respiratory distress syndrome (ARDS) can develop early in burn patients with inhalation injury in the presence of cytokine storm and the proinflammatory response can be a supplemental factor for ARDS aggravation. We report the case of a 41-years old male with 25% total body surface area deep partial thickness burns to upper body extremity and grade II inhalational injury who developed severe ARDS, nosocomial pneumonia, and septic shock. Veno-venous extracorporeal membrane oxygenation (VV ECMO) and continuous renal replacement therapy (CRRT) with hemoadsorption were successfully used at different moments to overcome critical situations. Although debatable, the use of ECMO in burn patients with severe ARDS could be considered when conventional treatment fails. The use of CRRT combined with hemoadsorption may limit the proinflammatory response sustained by the combination between major burn, ECMO and sepsis.

A Case of Esophago-Respiratory Fistula due to Inhalation Smoke Injury Diagnosed by Upper Endoscopy

Esophago-respiratory fistula (ERF) refers to the formation of a pathological connection between the esophagus and respiratory tract. Acquired ERF is a rare but life-threatening diagnosis in adults. We describe a 79-year-old male who was admitted with an inhalation smoke injury. He was diagnosed with ERF by endoscopic visualization and sampling of the hyaline cartilage within the wall of the esophagus. Percutaneous endoscopic gastrostomy placement and conservative measures were effective in the management of ERF.

Protective Effect of Nebulized Heparin in the Animal Models of Smoke Inhalation Injury: A Meta-analysis and Systematic Review of Experimental Studies

The pathophysiological mechanism of abnormal coagulation can result from smoke inhalation injury (SII). Heparin nebulization is a common treatment for lung disorders. This study aimed to use meta-analysis in animal models to examine the effectiveness of atomized heparin on SII. For our online searches, we used the Cochrane Central Register of Controlled Trials, PubMed, Web of Science, Chinese National Knowledge Infrastructure, Chinese BioMedical Literature Database, and Wanfang Database up to January 2022. Data for SII were retrieved and compared to control animals. The studies' findings were determined by combining standardized mean difference (SMD) analysis with 95% confidence intervals (CIs). The findings showed that as compared to the control group, the heparin-treated group had a lower death rate (relative risk 0.42; 95% CI 0.22, 0.80; p < .05). The meta-analysis demonstrated favorable changes in lung physiology, including PaO2/FiO2 (SMD 1.04; 95% CI 0.65, 1.44; p < .001), lung wet-to-dry weight ratio (SMD -1.83; 95% CI -2.47, -1.18; p < .001), and pulmonary shunt Qs/Qt (SMD -0.69; 95% CI -1.29, -0.08; p < .05) after heparin nebulization for lung injury. The present data indicated that pulmonary artery mean pressure in the heparin therapy group was significantly lowered after 24 and 48 hours of therapy, suggesting that the cardiovascular system could recover following heparin treatment. As a result, heparin nebulization appeared to be more effective against SII and improved cardiopulmonary function compared to the control group. Graphical Abstract.

Retrospective Evaluation of Characteristics of Patients with Burn Injuries Treated at the Largest Reference Hospital in Brazil

Burn injuries are a significant cause of morbidity and mortality in the Brazilian population. We conducted this study in a tertiary hospital in Brazil to discover the epidemiological characteristics of patients with burn injuries. We conducted a cohort review of patients admitted to the burn unit of our institute during a 5-year period. For each patient, we collected data that included age, gender, total percentage of burned body surface area, burn location, burn mode, and burn cause. We analyzed the data using the R programming language. We included a total of 496 patients in our study. The mean age of the patients was 28 ± 14.7 years. The median length of hospital stay was 2 weeks. We found a significant correlation between the total percentage of burned body surface area and the length of hospitalization (p < .001) and the length of hospitalization in the intensive care unit (p < .001). A total of 427 patients (86%) were discharged from the hospital after successful treatment. In contrast, 43 patients (8.67%) died. The mortality rate was highest in patients who had more than 70% of their total body surface area burned. The average length of hospitalization aligned with global and national statistics presented in the literature. The main causes of the burn injuries were thermal (e.g., fire, hot liquids). We found inhalation injuries present in more than one third of the patients who were hospitalized in the intensive care unit with thermal burns.

The Importance of Early Percutaneous Dilatational Tracheostomy in Inhalation Injury: A Case Report

Maintaining a patent airway is critical for treating patients with severe inhalation injuries. Percutaneous Dilatational Tracheostomy (PDT) has been used effectively for many patients treated in the Intensive Care Unit (ICU). In addition to its safety for use at the bedside, according to Friedman et al. PDT has the same or even lower complication rate than surgical tracheostomy. PDT can be performed in a shorter time and is more cost-effective. Herein, we report a 44 year old obese woman who sustained an inhalation injury related to a burn. The patient fell headfirst into a pot of boiling water at the time of the burn. The patient showed signs of inhalation injury and suffered a second-to-third degree burn injury. She was treated in the ICU, and early PDT was performed. The procedure was performed by first locating the trachea, followed by a 1-cm incision made between the second and third tracheal ring. She was intubated successfully and treated in the ICU for 7 days. The anesthesiologist chose to perform an early PDT to prevent further complications. This procedure was done successfully despite many comorbidities from the patient, such as being an obese female and having a short neck, which makes finding the exact location for the incision challenging. In this case, the early decision to proceed with PDT showed promising results in decreasing the patient's mortality risk.

Initial treatment strategies in new-onset atrial fibrillation in critically ill burn patients

INTRODUCTION

Atrial fibrillation is associated with increased morbidity and mortality in critically ill patients. Few studies have specifically examined this arrhythmia in burn patients. Given the significant clinical implications of atrial fibrillation, understanding the optimal management strategy of this arrhythmia in burn patients is important. Consequently, the purpose of this study was to examine rate- and rhythm-control strategies in the management of new onset atrial fibrillation (NOAF) and assess their short term outcomes in critically ill burn patients.

METHODS

We identified all patients admitted to our institution's burn intensive care unit between January 2007 and May 2018 who developed NOAF. Demographic information and burn injury characteristics were captured. Patients were grouped into two cohorts based on the initial pharmacologic treatment strategy: rate-(metoprolol or diltiazem) or rhythm-control (amiodarone). The primary outcome was conversion to sinus rhythm. Secondary outcomes included relapse or recurrence of atrial fibrillation, drug-related adverse events, and complications and mortality within 30 days of the NOAF episode.

RESULTS

There were 68 patients that experienced NOAF, and the episodes occurred on median days 8 and 9 in the rate- and rhythm-control groups, respectively. The length of the episodes was not significantly different between the groups. Conversion to sinus rhythm occurred more often in the rhythm-control group (P = 0.04). There were no differences in the incidences of relapse and recurrence of atrial fibrillation, and the complications and mortality between the groups. Hypotension was the most common drug-related adverse event and occurred more frequently in the rate-control group, though this difference was not significant.

CONCLUSIONS

Conversion to sinus rhythm occurred more often in the rhythm-control group. Outcomes were otherwise similar in terms of mortality, complications, and adverse events. Hypotension occurred less frequently in the rhythm-control group, and although this difference was not significant, episodes of hypotension can have important clinical implications. Given these factors, along with burn patients having unique injury characteristics and a hypermetabolic state that may contribute to the development of NOAF, when choosing between rate- and rhythm control strategies, rhythm-control with amiodarone may be a better choice for managing NOAF in burn patients.

Inhalation Injury Grading Using Transfer Learning Based on Bronchoscopy Images and Mechanical Ventilation Period

The abbreviated injury score (AIS) is commonly used as a grading system for inhalation injuries. While inhalation injury grades have inconsistently been shown to correlate positively with the time mechanical ventilation is needed, grading is subjective and relies heavily on the clinicians' experience and expertise. Additionally, no correlation has been shown between these patients' inhalation injury grades and outcomes. In this paper, we propose a novel inhalation injury grading method which uses deep learning algorithms in bronchoscopy images to determine the injury grade from the carbonaceous deposits, blistering, and fibrin casts in the bronchoscopy images. The proposed method adopts transfer learning and data augmentation concepts to enhance the accuracy performance to avoid overfitting. We tested our proposed model on the bronchoscopy images acquired from eighteen patients who had suffered inhalation injuries, with the degree of severity 1, 2, 3, 4, 5, or 6. As performance metrics, we consider accuracy, sensitivity, specificity, F-1 score, and precision. Experimental results show that our proposed method, with both transfer learning and data augmentation components, provides an overall 86.11% accuracy. Moreover, the experimental results also show that the performance of the proposed method outperforms the method without transfer learning or data augmentation.

Clinical characteristics and predictors of burn complicated with smoke inhalation injury: A retrospective analysis

Fire smoke enters the human lungs through the respiratory tract. The damage to the respiratory tract and lung tissue is known as smoke inhalation injury (SII). Fire smoke can irritate airway epithelium cells, weaken endothelial cell adhesion and lyse alveolar type II epithelia cells, leading to emphysema, decreased lung function, pneumonia and risk of acute lung injury/acute respiratory distress syndrome (ARDS). The purpose of the present study was to analyze the clinical characteristics of patients with SII and the risk factors affecting their prognosis. A total of 103 patients with SII admitted between January 2016 to December 2021 to the Burns Unit of the Characteristic Medical Center of Chinese People's Armed Police Force and 983 Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army were selected for the present study. The demographics and clinical features between different severities of SII were analyzed. Univariate/multivariate logistic regression was used to analyze the potential predictors for severity, ARDS and mortality of patients with SII. Receiver operating characteristic (ROC) curves were used to screen independent risk factors and identify their prediction accuracy. It was concluded that total body surface area (TBSA), III burn area (of total %TBSA), cases of respiratory infections, ARDS morbidity, mortality, acute physiology and chronic health evaluation II, lung injury prediction score, lactic acid, white blood cells (WBC), alanine transaminase, blood urea nitrogen, serum creatinine and uric acid were indicators that were raised with increasing severity of SII. However red blood cells, hemoglobin, platelet count, total protein, albumin, and albumin/globulin were decreased with the increasing severity of SII (P<0.05). WBC >20.91 (10⁹/l) was a reliable indicator for severe SII. Lactic acid >9.60 (mmol/l) demonstrated a high degree of accuracy in predicting ARDS development in patients with SII. Hemoglobin <83.00 (g/l) showed a high degree of accuracy in predicting mortality. In summary, the highlighted assessment parameters could be used to contribute to devising improved treatment plans to preempt worsening conditions (such as shock, ARDS, multiple organ dysfunction syndrome and death).

Medical and Surgical Care of Critical Burn Patients: A Comprehensive Review of Current Evidence and Practice

Critically ill burn patients pose several unique challenges to care providers. The concepts of fluid resuscitation, nutritional management, organ support and wound care are rapidly evolving. There is a pressing need to review emerging evidence and incorporate these into practice for the effective management of burn patients. We have searched the PubMed and Google Scholar databases to review the current evidence on the acute care management of adult as well as paediatric burn patients. The rationales for current practices have been integrated into the review. The management of critically ill burn patients requires an in-depth knowledge of the pathophysiology of burn injury, a tailored approach for timely resuscitation, timely diagnosis of organ specific problems, and comprehensive wound care. This review will help the doctors and healthcare providers involved in the management of critical burn patients in their day-to-day practice.

Characterization of the Basal and mTOR-Dependent Acute Pulmonary and Systemic Immune Response in a Murine Model of Combined Burn and Inhalation Injury

Severe burn injury leads to a cascade of local and systemic immune responses that trigger an extreme state of immune dysfunction, leaving the patient highly susceptible to acute and chronic infection. When combined with inhalation injury, burn patients have higher mortality and a greater chance of developing secondary respiratory complications including infection. No animal model of combined burn and inhalation injury (B+I) exists that accurately mirrors the human clinical picture, nor are there any effective immunotherapies or predictive models of the risk of immune dysfunction. Our earlier work showed that the mechanistic/mammalian target of rapamycin (mTOR) pathway is activated early after burn injury, and its chemical blockade at injury reduced subsequent chronic bacterial susceptibility. It is unclear if mTOR plays a role in the exacerbated immune dysfunction seen after B+I injury. We aimed to: (1) characterize a novel murine model of B+I injury, and (2) investigate the role of mTOR in the immune response after B+I injury. Pulmonary and systemic immune responses to B+I were characterized in the absence or presence of mTOR inhibition at the time of injury. Data describe a murine model of B+I with inhalation-specific immune phenotypes and implicate mTOR in the acute immune dysfunction observed.

Advantages and Disadvantages of Using Small and Large Animals in Burn Research: Proceedings of the 2021 Research Special Interest Group

Multiple animal species and approaches have been used for modeling different aspects of burn care, with some strategies considered more appropriate or translatable than others. On April 15, 2021, the Research Special Interest Group of the American Burn Association held a virtual session as part of the agenda for the annual meeting. The session was set up as a pro/con debate on the use of small versus large animals for application to four important aspects of burn pathophysiology: burn healing/conversion; scarring; inhalation injury; and sepsis. For each of these topics, 2 experienced investigators (one each for small and large animal models) described the advantages and disadvantages of using these preclinical models. The use of swine as a large animal model was a common theme due to anatomic similarities with human skin. The exception to this was a well-defined ovine model of inhalation injury; both of these species have larger airways which allow for incorporation of clinical tools such as bronchoscopes. However, these models are expensive and demanding from labor and resource standpoints. Various strategies have been implemented to make the more inexpensive rodent models appropriate for answering specific questions of interest in burns. Moreover, modelling burn-sepsis in large animals has proven difficult. It was agreed that the use of both small and large animal models have merit for answering basic questions about the responses to burn injury. Expert opinion and the ensuing lively conversations are summarized herein, which we hope will help inform experimental design of future research.

Temperature processing and distribution in larynx thermal inhalation injury with analogy to human airway cells: a mechanism of protection

OBJECTIVE

Inhalation injuries, especially laryngeal injuries, threaten the lives of burn patients. Unlike studies on temperature distribution in the upper airway, studies on temperature development in different laryngeal layers, including the mucosa, lamina propria, cartilage, muscle, and subcutaneous layer, are lacking.

METHOD

For the in-vivo study, 16 healthy adult male beagles were divided into four groups: control, low-, medium-, and high-heat groups, inhaling dry air at 26, 80, 160, and 320°C for 20 min, with temperature probes punctured through skin into layers as mentioned, and heat energy was calculated. For the in-vitro study, we heated human lung fibroblasts and bronchial epithelial cells using a similar heating profile with heat energy of 15-90 J/g to investigate cell survival and viability for clinical comparison.

RESULTS

No statistical difference emerged between the temperatures of different laryngeal layers at each timepoint. The temperatures decreased significantly and shortly before increasing unevenly in the low- and medium-heat groups. The survival rates and viability of the two cell lines correlated negatively with heat energy. The heat energy absorbed in the low-, medium-, and high-heat groups of beagles were 12, 29, and 44 J/g, with calculated in-vitro human cell survival rates of 114%, 90%, and 69%, respectively, for the corresponding energy levels.

CONCLUSIONS

The abnormal temperature processing and lack of a difference between layers indicate an effective self-protective mechanism of heat conduction in larynx. The in-vitro results demonstrate a high survival rate of lung cells at comparable heat energy levels to those measured in the larynx.

Aspartate transaminase/alanine transaminase (De Ritis ratio) predicts survival in major burn patients

BACKGROUND

Although treatment of burn patients has significantly improved in recent decades, major burns remain fatal. Therefore, the evaluation of the death risk of the patients with extensive burns is very important. The ratio between the serum levels of aspartate transaminase and alanine transaminase (De Ritis ratio) was an independent predictor of poor outcomes in patients with acute ischemic stroke, cardiac surgery, non-metastatic renal cell carcinoma, and upper urinary tract urothelial carcinoma. Our aim was to determine whether the ratio between the serum levels of AST and ALT (De Ritis ratio) was useful to assess prognosis in extensively burned patients.

METHODS

We conducted a single-center cohort study at the Burns Department of Changhai Hospital. This retrospective observational analysis was performed based on the clinical data of major burn patients admitted between May 1, 2005 and April 30, 2018. Univariate and multivariate logistic regression analyses were performed on variables such as age, sex, total body surface area (TBSA), De Ritis ratio, and serum albumin level, which may affect mortality in major burn patients. We assessed their diagnostic value and found the cut-off value by receiver operative characteristic (ROC) curve analysis. We used the Kaplan-Meier curve to display the impact of the De Ritis ratio and serum albumin level on survival in burn patients.

RESULTS

A total of 351 patients with extensive burns were included in the study. The cohort predominantly consisted of males (74.64%), and most of the patients (78.35%) had been burned by a flame. Age, TBSA, inhalation, and the De Ritis ratio were found to be independent risk factors for the 30-days mortality of major burn patients, while age, TBSA, inhalation, and the De Ritis ratio were independent risk factors for 90-day mortality. Further, the De Ritis ratio was a better mortality predictor than serum albumin in severely burned patients, whose area under ROC for 30-day and 90-day mortality was 0.771 (95% confidence intervals [CI], 0.708-0.835) and 0.750 (95% CI, 0.683, 0.818).

CONCLUSIONS

The De Ritis ratio was useful as a prognostic indicator for major burn patients, which can be conveniently obtained through blood examination. Regardless of whether the prediction was for 30-day or 90-day mortality, the accuracy remained high. Moreover, compared to serum albumin level, the De Ritis ratio was superior in assessing the prognosis of extensively burned patients.

Mortality prediction models for severe burn patients: Which one is the best?

BACKGROUND

For prediction of mortality and clinical course, various scoring systems had been developed. We choose four well known burn specific scoring systems and a general scoring system that using in Intensive Care Units. The primary outcome of this study was evaluate the predictive performances of this models and define the optimal one for our patient population.

METHODS

Variables analyzed were age, gender, burn type, total burned surface area (TBSA), total partial thickness burn area, total full thickness burn area, inhalation injuries, mechanical ventilation supports, blood products usage, total scores of Abbreviated Burn Severity Index (ABSI), revised Baux, Belgian Outcome in Burn Injury, Fatality by Longevity, Acute Physiology and Chronic Health Eval-uation II (APACHE II) score, Measured Extent of burn and Sex (FLAMES) and APACHE II, and their relations with mortality.

RESULTS

In our study, a statistically significant relationship was found with mortality between age, TBSA, full thickness burn percent-age, inhalation injury, burn type, and it was similar to literature. Female gender was found to be a significant risk factor for mortality.

CONCLUSION

We compared several burn mortality scoring systems and their predictional mortality rates. ABSI scores of patients for estimated mortality rates were similar to our mortality rate. Consequently, it was thought that ABSI was included all mortality-re-lated parameters.

Spectral Reflectance as a Unique Tissue Identifier in Healthy Humans and Inhalation Injury Subjects

Tracheal intubation is the preferred method of airway management, a common emergency trauma medicine problem. Currently, methods for confirming tracheal tube placement are lacking, and we propose a novel technology, spectral reflectance, which may be incorporated into the tracheal tube for verification of placement. Previous work demonstrated a unique spectral profile in the trachea, which allowed differentiation from esophageal tissue in ex vivo swine, in vivo swine, and human cadavers. The goal of this study is to determine if spectral reflectance can differentiate between trachea and other airway tissues in living humans and whether the unique tracheal spectral profile persists in the presence of an inhalation injury. Reflectance spectra were captured using a custom fiber-optic probe from the buccal mucosa, posterior oropharynx, and trachea of healthy humans intubated for third molar extraction and from the trachea of patients admitted to a burn intensive care unit with and without inhalation injury. Using ratio comparisons, we found that the tracheal spectral profile was significantly different from buccal mucosa or posterior oropharynx, but the area under the curve values are not high enough to be used clinically. In addition, inhalation injury did not significantly alter the spectral reflectance of the trachea. Further studies are needed to determine the utility of this technology in a clinical setting and to develop an algorithm for tissue differentiation.

Approaches of 112 ambulance service staffers to children with burns: A survey assessment

BACKGROUND

We aimed to evaluate the knowledge of 112 ambulance service staffers (doctors, nurses, emergency medical technicians [EMTs], and paramedics [PMs]) who were the first intervention to pediatric patients with burn injuries regarding first intervention and patient transfer.

METHODS

The study included 373 personnel working in 112 ambulance services in Ankara province. Participants were asked 17 questions to measure their knowledge of burns in children. Statistical analysis was performed with the Statistical Package for Social Sciences 21.0.

RESULTS

Of the participants, 26 (7%) were doctors, 25 (6.7%) nurses, 180 (48.3%) EMTs, and 142 (35.3%) PMs. Of the participants, 118 stated that they always calculate the burn surface area, while only five (1.3%) marked the correct choice of the Lund Browder scheme to the question by which method they calculated. One hundred twenty one personnel (32.4%) use the Parkland formula to calculate the amount of fluid to be given during transfer while only 7 (1.9%) use the Galveston formula, which is more suitable for chil-dren. Of the participants, 56 (15%) answered as lactated Ringer's solution which is the correct fluid to the question of which fluid do you give at the scene and during the transfer. One hundred fifty-three participants (41%) responded correctly to the scenario question expected to recognize inhalation damage while only 138 (37%) responded correctly as 'I do immediately intubate' to the inhalation injury described scenario question. One out of 373 (0.3%) participants marked the appropriate procedure for a patient who had a 50% scald burn during the first intervention and transfer. The rate of topical lidocaine use of participants was high (70.8%). Of the 373 participants, only 33 (8.8%) thought themselves competent for first aid and transfer of children with burns. If training on the subject was held, 333 personnel (89.3%) wanted to participate.

CONCLUSION

It is expected that the knowledge of 112 ambulance services who see pediatric burn patients first, perform the first intervention, and provide transfer would be suitable. However, our questionnaire shows that these personnel have insufficient knowledge and need to be trained.

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.

Inhalational injury and use of heparin & N-acetylcysteine nebulization: A case report

Inhalational injury to the upper and lower airway occurs due to thermal or chemical irritation causing airway edema, capillary leak, mucin, and fibrin debris forming clots and soot. The use of unfractionated heparin (UFH) nebulization was found to be effective by dissolving airway clots. We report a case of inhalational burn injury where UFH nebulization led to a better outcome. A healthy male was trapped in a residential room during a fire in the building. He sustained facial, neck, upper chest, and left upper extremity burns accounting for 25% of body surface area. He was intubated at the site and started on supportive care. In the surgical intensive care unit, bronchoscopy showed severe tracheobronchial burn injury; a thorough lavage was done, started on UFH and N-acetylcysteine nebulization (NAC). The patient improved, and his trachea was extubated on day 6. In our patient, unfractionated heparin nebulization was beneficial as the patient was extubated early without landing to acute respiratory distress syndrome.

The expression profile of lung long non-coding RNAs and mRNAs in a mouse model of smoke inhalation injury

To study the potential expression of lung long non-coding RNAs (lncRNAs) and mRNAs during smoke inhalation injury (SII), using a SII mouse model that we created in our previous work. Microarray was used to investigate the lncRNAs and mRNAs profiles. A bioinformatics analysis was performed. Changes in the top 10 down-regulated and 10 up-regulated lncRNAs were validated using Quantitative Reverse Transcription-PCR (RT-qPCR). The acute lung injury (ALI) mouse model was successfully induced by smoke inhalation, as confirmed by the aberrantly modified cell numbers of red blood cells and neutrophils counts, increased levels of TNF-α, IL-1β, Bax, caspase-7, caspase-3, and decreased Bcl-2 content in lung tissues. When compared to the control mice, 577 lncRNAs and 517 mRNAs were found to be aberrantly expressed in the SII mice. According to the Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, the altered mRNAs were enriched in acute-phase response, oxidoreductase activity, oxidation-reduction process, glutathione metabolism, the wnt signaling pathway, and ferroptosis. A lncRNA-related competitive endogenous RNA (ceRNA) network, including 383 lncRNAs, 318 MicroRNAs (miRNAs), and 421 mRNAs specific to SII, was established. The changes in NONMMUT026843.2, NONMMUT065071.2, ENSMUST00000235858.1, NONMMUT131395.1, NONMMUT122516.1, NONMMUT057916.2, and NONMMUT013388.2 in the lung matched the microarray results. Our findings help to provide a more comprehensive understanding of the pathogenesis of SII as well as new insights into potential therapeutic targets.