Inhalation injury is associated with long-term employment outcomes in the burn population: Findings from a cross-sectional examination of the Burn Model System National Database.

INTRODUCTION: Inhalation injuries carry significant acute care burden including prolonged ventilator days and length of stay. However, few studies have examined post-acute outcomes of inhalation injury survivors. This study compares the long-term outcomes of burn survivors with and without inhalation injury. METHODS: Data collected by the Burn Model System National Database from 1993 to 2019 were analyzed. Demographic and clinical characteristics for adult burn survivors with and without inhalation injury were examined. Outcomes included employment status, Short Form-12/Veterans Rand-12 Physical Composite Score (SF-12/VR-12 PCS), Short Form-12/Veterans Rand-12 Mental Composite Score (SF-12/VR-12 MCS), and Satisfaction With Life Scale (SWLS) at 24 months post-injury. Regression models were used to assess the impacts of sociodemographic and clinical covariates on long-term outcome measures. All models controlled for demographic and clinical characteristics. RESULTS: Data from 1,871 individuals were analyzed (208 with inhalation injury; 1,663 without inhalation injury). The inhalation injury population had a median age of 40.1 years, 68.8% were male, and 69% were White, non-Hispanic. Individuals that sustained an inhalation injury had larger burn size, more operations, and longer lengths of hospital stay (p<0.001). Individuals with inhalation injury were less likely to be employed at 24 months post-injury compared to survivors without inhalation injury (OR = 0.63, p = 0.028). There were no significant differences in PCS, MCS, or SWLS scores between groups in adjusted regression analyses. CONCLUSIONS: Burn survivors with inhalation injury were significantly less likely to be employed at 24 months post-injury compared to survivors without inhalation injury. However, other health-related quality of life outcomes were similar between groups. This study suggests distinct long-term outcomes in adult burn survivors with inhalation injury which may inform future resource allocation and treatment paradigms.

Comparison of three different methods to estimate the burden of disease of burn injuries in Western Australia in 2011-2018.

BACKGROUND: Priority setting and resource allocation in health care, surveillance and interventions is based increasingly on burden of disease. Several methods exist to calculate the non-fatal burden of disease of burns expressed in years lived with disability (YLDs). The aim of this study was to assess the burden of disease due to burns in Western Australia 2011-2018 and compare YLD outcomes between three existing methods. METHODS: Data from the Burns Service of Western Australia was used. Three existing methods to assess YLDs were compared: the Global Burden of Disease (GBD) method, a method dedicated to assess injury YLDs (Injury-VIBES), and a method dedicated to assess burns YLDs (INTEGRIS-burns). RESULTS: Incidence data from 2,866 burn patients were used. Non-fatal burden of disease estimates differed substantially between the different methods. Estimates for 2011-2018 ranged between 610 and 1,085 YLDs per 100.000 based on the Injury-VIBES method; between 209 and 324 YLDs based on the INTEGRIS-burns method; and between 89 and 120 YLDs based on the GBD method. YLDs per case were three to nine times higher when the Injury-VIBES method was applied compared to the other methods. Also trends in time differed widely through application of the different methods. There was a strong increase in YLDs over the years when the Injury-VIBES method was applied, a slight increase when the INTEGRIS-burns method was applied and a stable pattern when the GBD method was applied. CONCLUSION: This study showed that the choice for a specific method heavily influences the non-fatal burden of disease expressed in YLDs, both in terms of annual estimates as well as in trends over time. By addressing the methodological limitations evident in previously published calculations of the non-fatal burden of disease, the INTEGRIS-burns seems to present a method to provide the most robust estimates to date, as it is the only method adapted to the nature of burn injuries and their recovery.

Inhalation Injury: Unmet Clinical Needs and Future Research.

Pulmonary and systemic insults from inhalation injury can complicate the care of burn patients and contribute to significant morbidity and mortality. However, recent progress in diagnosis and treatment of inhalation injury has not kept pace with the care of cutaneous thermal injury. There are many challenges unique to inhalation injury that have slowed advancement, including deficiencies in our understanding of its pathophysiology, the relative difficulty and subjectivity of bronchoscopic diagnosis, the lack of diagnostic biomarkers, the necessarily urgent manner in which decisions are made about intubation, and the lack of universal recommendations for the application of mucolytics, anticoagulants, bronchodilators, modified ventilator strategies, and other measures. This review represents a summary of critical shortcomings in our understanding and management of inhalation injury identified by the American Burn Association's working group on Cutaneous Thermal Injury and Inhalation Injury in 2018. It addresses our current understanding of the diagnosis, pathophysiology, and treatment of inhalation injury and highlights topics in need of additional research, including 1) airway repair mechanisms; 2) the airway microbiome in health and after injury; and 3) candidate biomarkers of inhalation injury.

Early Surgical Management of Thermal Airway Injury: A Case Series.

Inhalation injury is an independent risk factor in burn mortality, imparting a 20% increased risk of death. Yet there is little information on the natural history, functional outcome, or pathophysiology of thermal injury to the laryngotracheal complex, limiting treatment progress. This paper demonstrates a case series (n = 3) of significant thermal airway injuries. In all cases, the initial injury was far exceeded by the subsequent immune response and aggressive fibroinflammatory healing. Serial examination demonstrated progressive epithelial injury, mucosal inflammation, airway remodeling, and luminal compromise. Histologic findings in the first case demonstrate an early IL-17A response in the human airway following thermal injury. This is the first report implicating IL-17A in the airway mucosal immune response to thermal injury. Their second and third patients received Azithromycin targeting IL-17A and showed clinical responses. The third patient also presented with exposed tracheal cartilage and underwent mucosal reconstitution via split-thickness skin graft over an endoluminal stent in conjunction with tracheostomy. This was associated with rapid abatement of mucosal inflammation, resolution of granulation tissue, and return of laryngeal function. Patients who present with thermal inhalation injury should receive a thorough multidisciplinary airway evaluation, including early otolaryngologic evaluation. New early endoscopic approaches (scar lysis and mucosal reconstitution with autologous grafting over an endoluminal stent), when combined with targeted medical therapy aimed at components of mucosal airway inflammation (local corticosteroids and systemic Azithromycin targeting IL-17A), may have potential to limit chronic cicatricial complications.

Inhalational injury and the larynx: A review.

OBJECTIVE: To review and discuss the existing research on the pathophysiology, impact and management of inhalational injury on the larynx and lower respiratory tract. DATA SOURCES: A literature search was conducted on the PubMed, MedLine, Embase, Web of Science and Google Scholar databases based on the keywords "airway burn", "inhalational injury" and "larynx". REVIEW METHODS: Inclusion criteria included English language studies containing original and review data on airway injury. Data was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. CONCLUSIONS: Abnormal laryngeal and lower airway findings are common in burns patients and the incidence tends to increase with severity of the burns. Most patients with abnormal findings remain dysphonic decades after the initial injury. Larynx, the inlet to the airway, is exposed to the most intense thermal damage and highest concentration of chemical in inhalational injury. Airway injury is common and may result in long term morbidity. Healing of this tissue architecture is prolonged and different from cutaneous burn. Many patients receive prolonged intubation for medical complications that arise due to the burn injury. The degree of subglottic damage, however, is more extensive and occurs sooner compared with those without inhalational injuries. IMPLICATIONS FOR PRACTICE: With advances in acute medical and surgical management of burn and inhalational injury, airway injury is an important secondary outcome with lasting impact. Awareness of these potential complications and early involvement of medical and allied health team are important steps in improving patient care. A multi-disciplinary approach to management will optimise the short and long-term morbidity management and ultimately our patients' quality of life.

Numerical investigation of airflow, heat transfer and particle deposition for oral breathing in a realistic human upper airway model.

Inhalation injury from exposure to fire smoke is one of the causes of burn-related death. In this study, a realistic three-dimensional human upper airway model was built from magnetic resonance imaging (MRI) scanned images, including the nasal, oral, pharynx, larynx, trachea and part of the first generation of the tracheobronchial tree, as well as a tissue region from the pharynx to the upper bronchi. The Transition Shear Stress Transport (SST-transition) turbulence model, Pennes bioheat transfer equation, convective boundary conditions and a Lagrangian frame were applied and verified with experimental measurements to simulate the airflow fields, temperature distributions and particle deposition in the human airway model. The effects of flow rate, inhalation temperature and particle diameter were studied. It showed that the oral cavity is more likely to be affected by the inlet air conditions. The mucosa in the oral, pharynx and larynx are more likely to cause the thermal injury. The inspiration flow rate significantly influences the airflow fields, temperature distributions and particle deposition fraction interior of the human upper airway model, especially in the pharynx-larynx region. The rising flow rate, inhalation air temperature and particle diameter all contribute to boosting the total deposition fraction in the model. The heated particles with a higher temperature are more likely to be deposited in the oral cavity and the influence of the inlet temperature has a minor influence in the case of a bigger particle diameter.

Inhalation Injury: Pathophysiology, Diagnosis, and Treatment.

The classic determinants of mortality from severe burn injury are age, size of injury, delays of resuscitation, and the presence of inhalation injury. Of the major determinants of mortality, inhalation injury remains one of the most challenging injuries for burn care providers. Patients with inhalation injury are at increased risk for pneumonia (the leading cause of death) and multisystem organ failure. There is no consensus among leading burn care centers in the management of inhalation injury. This article outlines the current treatment algorithms and the evidence of their efficacy.

Laryngeal Trauma Following an Inhalation Injury: A Review and Case Report.

The primary concern when managing a patient with inhalation injury is security of the airway. Airflow may be impeded by both edema of the upper airway and reduction of oxygen delivery to the lower respiratory tract. Although there has been much discussion regarding management of the latter, the focus of this article is the management of the former. This review aimed to determine the optimum management in burn victims with upper airway inhalation injury as an attempt to prevent laryngeal trauma leading to long-term voice disorders and upper airway dyspnea. We describe the case of a 57-year-old woman with significant inhalation injury and discuss the natural progression of her injuries and the laryngeal controversies surrounding her care. We conclude with advice on the optimal management of this condition based on our experience, combined with current best evidence.

Mucosal fluid evaporation is not the method of heat dissipation from fourth-degree laryngopharyngeal burns.

This study was designed to explore whether mucosal fluid evaporation represents a method of heat dissipation from thermal air inhalation injury and to assess laryngopharyngeal tissue damage according to heat quantity changes of dry air and vapour. Fifteen adult male beagles were divided into five groups to inhale heated air or vapour for 10 min as follows: control group (ordinary air), group I (91-110 °C heated air), group II (148-175 °C heated air), group III (209-227 °C heated air), and group IV (96 °C saturated vapour). The heat quantity changes of the dry air and vapour were calculated via thermodynamic formulas. The macroscopic and histological features of the laryngopharynxes were examined and assessed by various tissue damage grading systems. Group IV exhibited the most serious laryngopharyngeal damage, including cilia exfoliation, submucosal thrombosis, glandular atrophy, and chondrocyte degeneration, which is indicative of fourth-degree injury. The quality, heat quantity, and proportional reduction of heat quantity of vapour in group IV were all higher than those in the other groups. Furthermore, we found that mucosal fluid evaporation is not the method of heat dissipation from thermal air inhalation injury used by the airways. Laryngopharyngeal tissue damage depends chiefly on the heat quantity of vapour in the air.

[Advances in the research of pathogenesis and treatment of severe smoke inhalation injury].

Among the fire victims, respiratory tract injury resulted from smoke inhalation is the major cause of death. Particulate substances in smoke, toxic and harmful gas, and chemical substances act together would rapidly induce the occurrence of dramatic pathophysiologic reaction in the respiratory tract, resulting in acute injury to the respiratory tract, thus inducing serious injury to it and acute respiratory distress syndrome, leading to death of the victims. In recent years, the pathophysiologic mechanism of severe smoke inhalation injury has been gradually clarified, thus appreciable advances in its treatment have been achieved. This paper is a brief review of above-mentioned aspects.

Computational simulation of temperature and velocity distribution in human upper respiratory airway during inhalation of hot air.

The present study provides an accurate simulation of velocity and temperature distributions of inhalation thermal injury in a human upper airway, including vestibule, nasal cavity, paranasal sinuses, nasopharynx, oropharynx, larynx, and upper part of main bronchus. To this end, a series of CT scan images, taken from an adult woman, was used to construct a three dimensional model. The airway walls temperature was adjusted according to existing in vivo temperature measurements. Also, in order to cover all breathing activities, five different breathing flow rates (10, 15, 20, 30, and 40 l/min) and different ambient air temperatures (100, 200, 300, 400, and 500 °C) were studied. Different flow regimes, including laminar, transitional, and turbulence were considered and the simulations were validated using reliable experimental data. The results show that nostrils, vestibule, and nasal cavity are damaged more than other part of airway. Finally, In order to obtain the heat flux through the walls, correlations for Nusselt number for each individual parts of airway (vestibule, main upper airway, nasopharynx etc.,) are proposed.

[Effects of high frequency oscillatory ventilation combined with incremental positive end-expiratory pressure on myocardial ischemia and hypoxia and apoptosis of cardiomyocytes in dogs with smoke inhalation injury].

OBJECTIVE: To compare the effects of high frequency oscillatory ventilation (HFOV) combined with incremental positive end-expiratory pressure (IP) and those of pure HFOV on myocardial ischemia and hypoxia and apoptosis of cardiomyocytes in dogs with smoke inhalation injury. METHODS: Twelve healthy male dogs were divided into group HFOV and group HFOV+IP according to the random number table, with 6 dogs in each group. After being treated with conventional mechanical ventilation, dogs in both groups were inflicted with severe smoke inhalation injury, and then they received corresponding ventilation for 8 hours respectively. After treatment, the blood samples were collected from heart to determine the activity of creatine kinase-MB (CK-MB) and lactate dehydrogenase 1 (LDH1) in plasma. The dogs were sacrificed later. Myocardium was obtained for determination of content of TNF-α per gram myocardium by ELISA, apoptotic rate of cardiomyocytes by flow cytometer, degree of hypoxia with HE staining, and qualitative and quantitative expression of actin (denoted as integral absorbance value) with streptavidin-biotin-peroxidase staining. Data were processed with t test. The relationship between the content of TNF-α per gram myocardium and the apoptotic rate of cardiomyocytes was assessed by Spearman linear correlation analysis. RESULTS: (1) After treatment for 8 h, the values of activity of CK-MB and LDH1 in plasma of dogs in group HFOV+IP were respectively (734 ± 70) and (182 ± 15) U/L, which were both lower than those in group HFOV [(831 ± 79) and (203 ± 16) U/L, with t values respectively 2.25 and 2.35, P values below 0.05]. (2) Compared with that in group HFOV [(0.060 ± 0.018) µg], the content of TNF-α per gram myocardium of dogs in group HFOV+IP after treatment for 8 h was decreased significantly [(0.040 ± 0.011) µg, t=2.32, P<0.05]. (3) Compared with that in group HFOV [(33.4 ± 2.2)%], the apoptotic rate of cardiomyocytes of dogs in group HFOV+IP after treatment for 8 h was significantly decreased [(28.2 ± 3.4)%, t=3.15, P<0.05]. There was a positive correlation between the content of TNF-α per gram myocardium and the apoptotic rate of cardiomyocytes (r=0.677, P<0.05). (4) HE staining showed that myocardial fibers of dogs in both groups were arranged in wave shape in different degrees, indicating there was myocardial hypoxia in different degrees. Compared with that of group HFOV, the degree of hypoxia in group HFOV+IP was slighter. (5) The results of immunohistochemical staining showed that there was less loss of actin in myocardial fibers of dogs in group HFOV+IP than in group HFOV. The expression level of actin in myocardium of dogs in group HFOV+IP after treatment for 8 h (194.7 ± 3.1) was obviously higher than that in group HFOV (172.9 ± 2.6, t=13.20, P<0.01). CONCLUSIONS: Compared with pure HFOV, HFOV combined with IP can alleviate the inflammatory reaction in myocardium of dogs, reduce the apoptosis of cardiomyocytes, and ameliorate the myocardial damage due to ischemia and hypoxia.

Comparison of the effects of TripleGates and Gates-Glidden burs on cervical dentin thickness and root canal area by using cone beam computed tomography

The search for new instruments to promote an appropriate cervical preparation has led to the development of new rotary instruments such as TripleGates. However, to the best of the authors' knowledge, there is no study evaluating TripleGates effect on the “risk zone” of mandibular molars. Objectives : The aim of this study was to evaluate the effects of a crown-down sequence of Gates-Glidden and TripleGates burs on the remaining cervical dentin thickness and the total amount of dentin removed from the root canals during the instrumentation by using cone beam computed tomography. The number of separated instruments was also evaluated. Material and Methods : Mesial roots of 40 mandibular first molars were divided into 2 equal groups: crown-down sequence of Gates-Glidden (#3, #2, #1) and TripleGates burs. Cervical dentin thickness and canal area were measured before and after instrumentation by using cone beam computed tomography and image analysis software. Student’s t-test was used to determine significant differences at p<0.05. Results : No significant differences (p>0.05) were observed between the instruments, regarding the root canal area and dentin wall thickness. Conclusion : Both tested instruments used for cervical preparation were safe to be used in the mesial root canal of mandibular molars. .

Simulation of the Velocity and Temperature Distribution of Inhalation Thermal Injury in a Human Upper Airway Model by Application of Computational Fluid Dynamics.

Inhalation injury is an important cause of death after thermal burns. This study was designed to simulate the velocity and temperature distribution of inhalation thermal injury in the upper airway in humans using computational fluid dynamics. Cervical computed tomography images of three Chinese adults were imported to Mimics software to produce three-dimensional models. After grids were established and boundary conditions were defined, the simulation time was set at 1 minute and the gas temperature was set to 80 to 320°C using ANSYS software (ANSYS, Canonsburg, PA) to simulate the velocity and temperature distribution of inhalation thermal injury. Cross-sections were cut at 2-mm intervals, and maximum airway temperature and velocity were recorded for each cross-section. The maximum velocity peaked in the lower part of the nasal cavity and then decreased with air flow. The velocities in the epiglottis and glottis were higher than those in the surrounding areas. Further, the maximum airway temperature decreased from the nasal cavity to the trachea. Computational fluid dynamics technology can be used to simulate the velocity and temperature distribution of inhaled heated air.

Management and sequelae of a 41-year-old jehovah's witness with severe anhydrous ammonia inhalation injury.

Anhydrous ammonia is a commonly used chemicals that are found in fertilizer, refrigeration, and in other occupational environments. Lung damage because of inhalation of ammonia can be devastating, producing debilitating lung disease and can ultimately lead to death. This is the case of a 41-year-old male, previously healthy, Jehovah's Witness, who was working at a poultry plant facility when an explosion occurred exposing him to toxic levels of anhydrous ammonia. Our patient developed end-stage lung disease after sustaining a severe ammonia inhalation injury. Despite aggressive pulmonary rehabilitation, the patient continued to deteriorate, and his only option for a chance at improved quality of life was a double-lung transplant. To our knowledge, this is the first report of a bloodless lung transplantation for inhalational lung injury in the literature. Further study is needed to better understand the effects of ammonia on lung physiology in order to better manage and treat patients who develop acute and chronic lung complications after exposure.

[Effects of high frequency oscillatory ventilation combined with incremental positive end-expiratory pressure on respiratory and circulatory functions of dogs with inhalation injury].

OBJECTIVE: To study the effects of high frequency oscillatory ventilation (HFOV) combined with incremental positive end-expiratory pressure (IP) on respiratory and circulatory functions, and lung histopathology of dogs with smoke inhalation injury. METHODS: After being treated with conventional mechanical ventilation, 12 dogs were inflicted with severe smoke inhalation injury and divided into group HFOV and group HFOV+IP according to the random number table, with 6 dogs in each group. Then they received corresponding ventilation for 8 hours respectively. Blood gas analysis results (pH value, PaO2 and PaCO2 levels) and hemodynamic parameters [heart rate, mean arterial pressure (MAP), pulmonary arterial pressure (PAP), central venous pressure (CVP), cardiac output (CO)] were recorded before injury, immediately after injury, and at post ventilation hour (PVH) 2, 4, 6, and 8. The dogs of two groups were sacrificed at PVH 8. A healthy dog without any treatment and a dog with smoke inhalation injury but no subsequent treatment were sacrificed in addition. Lung tissues of all dogs were obtained for histopathological observation. Lung injury score examination was conducted in both groups. Data were processed with rank sum test, analysis of variance of repeated measurement, and LSD- t test. RESULTS: (1) The PaO2 levels in both groups were significantly decreased immediately after injury, compared with those before injury (with t values respectively 4.960, 5.310, P values all below 0.01). The PaO2 levels in both groups from PVH 2 to PVH 8 were significantly increased, compared with those observed immediately after injury (with t values from 4.930 to 6.050, P values all below 0.01). At PVH 2, 4, and 8, PaO2 levels in group HFOV+IP were significantly higher than those in group HFOV (with t values from 3.775 to 5.774, P values all below 0.01); no statistically significant differences were observed in pH value and PaCO2 level at each time point between two groups (with t values from 0.002 to 0.997, P values all above 0.05). (2) There were no statistically significant differences in MAP, PAP, and CVP within two groups at each time point (with F values from 1.316 to 4.959, P values all above 0.05). In group HFOV, heart rate from PVH 2 to PVH 8 was significantly lower than that observed immediately after injury (with t values from 3.780 to 8.970, P values all below 0.01). In group HFOV+IP, CO at PVH 4, 6, and 8 was significantly lower than that observed immediately after injury (with t values from 3.990 to 11.200, P values all below 0.01). There were no statistically significant differences in MAP, PAP, and CVP between two groups at the same time point (with t values from 0.089 to 2.123, P values all above 0.05). At PVH 4, 6, and 8, heart rate in group HFOV+IP was higher than that in group HFOV (with t values from 2.931 to 7.229, P < 0.05 or P < 0.01), while CO was lower (with t values from 4.297 to 11.206, P values all below 0.01). (3) Compared with those of the healthy dog, inflammatory cell infiltration and bleeding in the lung were observed in alveolar space in both group HFOV and group HFOV+IP, while the degree was less serious than that of the dog with smoke inhalation injury only. Compared with those of group HFOV, inflammatory cell infiltration in group HFOV+IP was less significant, the alveolar structure was relatively intact, and no thickening of alveolar walls was observed. The lung injury score in group HFOV [(3.27 ± 0.24) points] was higher than that of group HFOV+IP [(2.79 ± 0.31) points, t = 27, P < 0.05]. CONCLUSIONS: HFOV combined with IP can improve gas exchange and alleviate pulmonary injury without any adverse effect on blood gas analysis or hemodynamic parameters. Therefore, it may be considered as an appropriate mode of ventilation for the treatment of smoke inhalation injury.

Circulational heat dissipation of upper airway: Canine model of inhalational thermal injury.

BACKGROUND: The upper airway has powerful heat-absorbing ability, in which the blood circulation may play an important role. OBJECTIVE: This study aimed to explore the circulational heat-dissipating ability, and to investigate the contribution of blood circulation to the heat-absorbing ability of upper airway. METHODS: 18 adult, male Beagle dogs were divided into three groups to inhale thermal dry air of 70-80°C, 150-160°C or 310-320°C for 20min. Blood temperatures and blood flow rates of bilateral common jugular veins (CJVs) were measured. Dogs' breathing rates and air temperatures in middle trachea were also measured. According to the formula "Q=c·m·ΔT", the heat dissipated by blood (Q-blood) and the heat release by air (Q-air) were calculated out. The contribution of circulational heat dissipation to the heat-absorbing ability of upper airway was defined as "C-blood". RESULTS: The blood temperature rise of CJV was 2.24±0.60°C. The blood flow rate of CJV was 44.5±5.9ml/min. The air temperature in middle trachea was 63.5±18.9°C. The mean breathing rate was 51.8±7.5/min. The calculated "Q-blood" and "Q-air" were 13197.3±4408.6J and 33540.2±24578.7J, and the "C-blood" was 55.2±25.0% (21.7-88.8%). CONCLUSION: Circulational heat dissipation plays an important role in the heat-absorbing process of upper airway when inhaled air is less than 160°C. However, for air higher than 160°C, some other mechanism might be dominant in the upper airway's heat-absorbing ability.

Measuring surface temperature and grading pathological changes of airway tissue in a canine model of inhalational thermal injury.

BACKGROUND: Airway tissue shows unexpected invulnerability to heated air. The mechanisms of this phenomenon are open to debate. OBJECTIVE: This study was designed to measure the surface temperatures at different locations of the airway, and to explore the relationship between the tissue's surface temperature and injury severity. METHOD: Twenty dogs were randomly divided into four groups, including three experimental groups (six dogs in each) to inhale heated air at 70-80 °C (group I), 150-160 °C (group II) and 310-320 °C (group III) and a control group (two dogs, only for histological observation). Injury time was 20 min. Mucosal surface temperatures of the epiglottis (point A), cricoid cartilage (point B) and lower trachea (point C) were measured. Dogs in group I-III were divided into three subgroups (two in each), to be assayed at 12, 24 and 36 h after injury, respectively. For each dog, four tissue parts (epiglottis, larynx, lower trachea and terminal bronchiole) were microscopically observed and graded according to an original pathological scoring system (score range: 0-27). RESULT: Surface temperatures of the airway mucosa increased slowly to 40.60±3.29 °C, and the highest peak temperature was 48.3 °C (group III, point A). The pathological score of burned tissues was 4.12±4.94 (0.0-18.0), suggesting slight to moderate injuries. Air temperature and airway location both influenced mucosal temperature and pathological scores very significantly, and there was a very significant positive correlation between tissue temperature and injury severity. CONCLUSION: Compared to the inhalational air hyperthermia, airway surface temperature was much lower, but was still positively correlated with thermal injury severity.

[Long-term results of airways' injury after a methane explosion]. / Odlegle skutki oparzenia dróg oddechowych w wyniku wybuchu metanu.

Injuries caused by thermal trauma more and more often affect people and they are an important problem of contemporary medicine. It is connected with the civilization development. Burn concerns not only the exterior integuments of the body but also airways, in those cases, the death rate among those who were injured with the thermal trauma increases. The treatment of both the burns and their complications is a long-lasting process, involving many specialists of various disciplines, and not always does it bring the wanted effects. The aim of the study was the assessment of the late morphological sequels inside the larynx and ventilation efficiency as a result of thermal inhalation trauma in the airways of the coal miners after the methane explosion. The methodology of examinations consisted of subjective evaluation of ventilation efficacy by MRC scale and ventilating rate measurement FEV1, FVC, FEV1%, PEF, MEF50, PIF, MIF 50, FIV. The morphological larynx evaluation was conducted based on videolaryngoscopy. 23 injured coal miners, who had been burnt at work in coal mines in 2003 in the methane explosion, were put under scrutiny. All the above mentioned examinations were done to the study group, but also to the specially selected control group, 23 coal miners. During the ventilating rates analysis in the study group, their lower values were noticed in comparison to the control group, however, the values were still within the clinical norms. Videolaryngoscopy showed hypertrophy of the laryngeal tissues.