Protection of laryngeal mucosa and function in laryngeal burns by heat absorption of perilaryngeal tissue.

OBJECTIVE: The laryngeal tissue carries most of the heat during inhalation injury. This study aims to explore the heat transfer process and the severity of injury inside laryngeal tissue by horizontally studying the temperature rise process at various anatomical layers of the larynx and observing the thermal damage in various parts of the upper respiratory tract. METHODS: The 12 healthy adult beagles were randomly divided into four groups, and inhaled room temperature air (control group), dry hot air of 80 °C (group I), 160 °C (group II), and 320 °C (group III) for 20 min, respectively. The temperature changes of the glottic mucosal surface, the inner surface of the thyroid cartilage, the external surface of the thyroid cartilage, and subcutaneous tissue were measured every minute. All animals were immediately sacrificed after injury, and pathological changes in various parts of laryngeal tissue were observed and evaluated under a microscope. RESULTS: After inhaling hot air of 80 °C, 160 °C and 320 °C, the increase of laryngeal temperature in each group was ΔT = 3.57 ± 0.25 °C, 7.83 ± 0.15 °C, 11.93 ± 0.21 °C. The tissue temperature was approximately uniformly distributed, and the difference was not statistically significant. The average laryngeal temperature-time curve showed that the laryngeal tissue temperature in group I and group II showed a trend of "first decrease and then increase", except that the temperature of group III directly increased with time. The prominent pathological changes after thermal burns mainly concluded necrosis of epithelial cells, loss of the mucosal layer, atrophy of submucosal glands, vasodilatation, erythrocytes exudation, and degeneration of chondrocytes. Mild degeneration of cartilage and muscle layers was also observed in mild thermal injury. Pathological scores indicated that the pathological severity of laryngeal burns increased significantly with the increase of temperature, and all layers of laryngeal tissue were seriously damaged by 320 °C hot air. CONCLUSIONS: The high efficiency of tissue heat conduction enabled the larynx to quickly transfer heat to the laryngeal periphery, and the heat-bearing capacity of perilaryngeal tissue has a certain degree of protective effect on laryngeal mucosa and function in mild to moderate inhalation injury. The laryngeal temperature distribution was in accordance with the pathological severity, and the pathological changes of laryngeal burns provided a theoretical basis for the early clinical manifestations and treatment of inhalation injury.

Incidental operating room fire from a breathing circuit warmer system: a case report.

BACKGROUND: An airway-associated fire in an operating room can have devastating consequences for patients. Breathing circuit warmers (BCWs) are widely used to provide heated and humidified anesthetic gases and eventually prevent hypothermia during general anesthesia. Herein, we describe a case of a BCW-related airway fire. CASE PRESENTATION: In this case, an electrical short within a BCW wire caused a fire inside the circuit. Simultaneously, the fire was extinguished, ventilation was stopped, and the endotracheal tube was disconnected from the BCW. The patient was exposed to the fire for less than 10 s, resulting in burns to the trachea and bronchi. Immediately after airway burn, bronchoscopy showed no edema or narrowing except for soot in the trachea and both main bronchus. After the inhalation burn event, prophylactic antibiotics, bronchodilator, mucolytics nebulizer, and corticosteroid nebulizer were started. On bronchoscopy 3 days after the inhalation burn, mucosal erythematous edema was observed and the inflammatory reaction worsened. The inflammatory reaction showed aggravation for up to 2 weeks, and then gradually recovered, and the epithelium and mucous membrane of the upper respiratory tract returned to normal after 4 weeks. Eventually, the patient recovered without long-term complications and was successfully discharged. CONCLUSIONS: This is the first report of a fire caused by BCW. We wanted to share our experience of how we responded to an airway-related fire in an OR and treated the patient. It cannot be overemphasized that the electrical medical appliance associated with the airways are fatal to the patient in the event of a fire, so caution should always be exercised.

Inhalation Injury in the Burned Patient.

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

[Effect of dinitrosyl iron complexes on erythrocyte energy metabolism under thermal trauma conditions].

The effect of dinitrosyl iron complexes (DNIC) on the energy metabolism of erythrocytes under combined thermal trauma conditions has been studied on a group of 30 Wistar rats, which was divided into 3 groups: intact (n = 10), control (n = 10), and main (n = 10). Combined thermal trauma (skin burn + thermoinhalation damage) was modeled in animals of the control and main groups. Rats of control group received infusions of sodium chloride solution (n = 10) every day. Rats of the main group obtained infusions of DNIC solution in sodium chloride. Rat blood samples were characterized by the activity of lactate dehydrogenase in direct and reverse reaction, lactate level, and coefficients of the substrate provision and energy reactions balance. It was stated, that DNIC clearly normalized the energy metabolism of erythrocytes beginning with the third day after thermal trauma onset.

Kerosene condenses in the trachea following inhalation.

PURPOSE: We have investigated the absorption dynamics of petroleum fuel components from the analytical results of autopsy samples. METHODS: Post-mortem samples of the severely burned case, including femoral blood, intratracheal contents (mucus) and intratracheal gas-phase samples were collected, and analysed by gas chromatography-mass spectrometer with head-space solid-phase microextraction. RESULTS: The composition of flammable substances in the tracheal gas phase differed slightly from that in mucus. CONCLUSION: High-boiling point components are retained in the trachea, whereas relatively lower-boiling point components are detected predominantly in the tracheal gas phase and blood.

Inhalation injury severity and systemic immune perturbations in burned adults.

OBJECTIVE: We aimed to determine whether the severity of inhalation injury evokes an immune response measurable at the systemic level and to further characterize the balance of systemic pro- and anti-inflammation early after burn and inhalation injury. BACKGROUND: Previously, we reported that the pulmonary inflammatory response is enhanced with worse grades of inhalation injury and that those who die of injuries have a blunted pulmonary immune profile compared with survivors. METHODS: From August 2007 to June 2011, bronchoscopy was performed on 80 patients admitted to the burn intensive care unit when smoke inhalation was suspected. Of these, inhalation injury was graded into 1 of 5 categories (0, 1, 2, 3, and 4), with grade 0 being the absence of visible injury and grade 4 corresponding to massive injury. Plasma was collected at the time of bronchoscopy and analyzed for 28 immunomodulating proteins via multiplex bead array or enzyme-linked immunosorbent assay. RESULTS: The concentrations of several plasma immune mediators were increased with worse inhalation injury severity, even after adjusting for age and % total body surface area (TBSA) burn. These included interleukin (IL)-1RA (P = 0.002), IL-6 (P = 0.002), IL-8 (P = 0.026), granulocyte colony-stimulating factor (P = 0.002), and monocyte chemotactic protein 1 (P = 0.007). Differences in plasma immune mediator concentrations in surviving and deceased patients were also identified. Briefly, plasma concentrations of IL-1RA, IL-6, IL-8, IL-15, eotaxin, and monocyte chemotactic protein 1 were higher in deceased patients than in survivors (P < 0.05 for all), whereas IL-4 and IL-7 were lower (P < 0.05). After adjusting for the effects of age, % TBSA burn, and inhalation injury grade, plasma IL-1RA remained significantly associated with mortality (odds ratio, 3.12; 95% confidence interval, 1.03-9.44). Plasma IL-1RA also correlated with % TBSA burn, inhalation injury grade, fluid resuscitation, Baux score, revised Baux score, Denver score, and the Sequential Organ Failure Assessment score. CONCLUSIONS: The severity of smoke inhalation injury has systemically reaching effects, which argue in favor of treating inhalation injury in a graded manner. In addition, several plasma immune mediators measured early after injury were associated with mortality. Of these, IL-1RA seemed to have the strongest correlation with injury severity and outcomes measures, which may explain the blunted pulmonary immune response we previously found in nonsurvivors.

Endoscopic treatment of glottic stenosis secondary to caustic injury with silastic keel placement: a case report.

The use of an endoscopic approach for the division of glottic webs or stenosis has been reported in the literature and has been mainly confined to the anterior commisure. We report a rare case of caustic injury to the upper aerodigestive tract that resulted in extensive web formation along the membranous vocal cord which was successfully treated with endoscopic lysis of the adhesions and the use of a silastic sheet keel as a stent.

[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.

Ovine smoke/burn ARDS model: a new ventilator-controlled smoke delivery system.

BACKGROUND: Our current ovine smoke/burn acute respiratory distress syndrome (ARDS) model utilizes a manual bee smoker. This smoke delivery system lacks standardization and reproducibility, with 20% of sheep failing to meet ARDS criteria. Time to reach ARDS criteria and survival time are also variable. The mild volutrauma (15 mL/kg) applied after smoke/burn injury may also fail to induce ARDS within 24 h. We hypothesized that these inconsistencies were associated with the bee smoker and the mild volutrauma. In the current study, we addressed these problems to improve the consistency of the smoke/burn ARDS model. METHODS: Adult female sheep (n = 10) were given a 40% total body surface area third degree cutaneous burn and 48 breaths (4 × 12) of cotton smoke under general anesthesia. A modified ventilator was then used to deliver a precise and consistent smoke volume (tidal volume) to the sheep. Additional barotrauma was induced by pressure control ventilation (40 cm H(2)0). When ARDS criteria (PaO(2)/FiO(2) < 200) were met, the ARDS Network low tidal volume ventilation protocol (6-8 mL/kg ideal body weight) was used. RESULTS: Carboxyhemoglobin levels were 81.4% ± 5.6% immediately following smoke injury. All sheep met ARDS criteria within 24 h (12.5 ± 4.9 h). Mean survival time post-injury was 62.1 ± 26.4 h. White blood cells and granulocytes were significantly elevated at 24 h post-smoke/burn injury. Lung tissue at necropsy was consistent with ARDS. CONCLUSIONS: The refinements made to the original ovine smoke/burn ARDS model produce a more reliable time to ARDS onset, injury severity, and time of death.

Simplified estimates of the probability of death after burn injuries: extending and updating the baux score.

BACKGROUND: : Generations of clinicians have used the Baux score, defined as the sum of age in years and percent body burn, to predict percent mortality after trauma, but advances in burn care have rendered the predictions of this score too pessimistic. Additionally, this score does not include the effects of inhalation injury. METHODS: : We revised the Baux score to include inhalation injury and recalibrated its predictions using a single-term logistic regression model developed using data on 39,888 burned patients provided by the national burn repository. We compared this revised Baux score to a more complex logistic regression model derived from the same data set and predictors. RESULTS: : A preliminary logistic regression model showed that age and percent burn contribute almost equally to mortality and further that the presence of inhalation injury added the equivalent of 17 years (or 17% burn). These observations suggested a revised Baux Score:Age + Percent Burn + 17 * (Inhalation Injury, 1 = yes, 0 = no)A logistic model based on the Revised Baux Score performed well, but a more complex model obtained using modern statistical model building tools had better discrimination and calibration. CONCLUSIONS: : Our proposed revised Baux score is simple enough for mental calculation, and its inverse logit transformation (provided with a calculator or nomogram) can provide precise predictions of mortality. Better predictions can be obtained using our more complex statistical model. Burn surgeons and nurses accustomed to using the original Baux score may welcome an updated version.

Inhalation burn injury in children.

With advances in burn care, many children are surviving severe burn injuries. Inhalation injury remains a predictor of morbidity and mortality in burn injury. Inhalation of smoke and toxic gases leads to pulmonary complications, including airway obstruction from bronchial casts, pulmonary edema, decreased pulmonary compliance, and ventilation-perfusion mismatch, as well as systemic toxicity from carbon monoxide poisoning and cyanide toxicity. The diagnosis of inhalation injury is suggested by the history and physical exam and can be confirmed by bronchoscopy. Management consists of supportive measures, pulmonary toilet, treatment of pulmonary infection and ventilatory support as needed. This review details the pathophysiology, diagnosis, and management options for inhalation injury.

[The effects of high frequency oscillatory ventilation (HFOV) and HFOV combined with pulmonary surfactant treatment on lung tissue of rabbits with steam inhalation injury].

OBJECTIVE: To investigate the effects of high frequency oscillatory ventilation (HFOV) and HFOV combined with pulmonary surfactant (PS) treatment on lung tissue after steam inhalation injury in rabbits. METHODS: Twenty-four New Zealand rabbits were randomly and equally divided into three groups after reproduction of severe steam inhalation injury, each n=8. Then they were ventilated by conventional mechanical ventilation (CMV), HFOV or HFOV+PS (100 mg/kg, drip via trachea), respectively. Animals were sacrificed after 4 hours, then the middle lobe in the right lung were excised for histological sections and the degree of injury was assessed. RESULTS: Histological injury in rabbits of HFOV groups were less serious than the CMV group. Among three groups, histological injury in rabbits of CMV group was most evident and least in the HFOV+PS group. It was also found that in CMV group showed the highest score of histological injury (3.71+/-0.43), and the lowest was found in HFOV+PS group (2.08+/-0.28), and that of HFOV group was 2.87+/-0.26. Comparison between whichever two of the three groups showed statistical significance (P<0.05 or P<0.01). CONCLUSION: HFOV can alleviate pulmonary edema and infiltration of inflammation cells, and it is shown that HFOV combined with exogenous PS gives the best outcome.

[Forensic medical evaluation of a burn injury from combustion of flammable fluids on the human body based on morphological changes in internal organs].

The author describes morphological features of splanchnic organs in the patients that suffered an injury from combustion of flammable fluids at the body surface. The burn injury is a specific form of trauma originating from a combination of several injurious factors including thermoinhalation and intoxication with combustion products in the absence of oxygen in the centre of the hot spot. A rather specific combination of morphological changes in internal organs along with results of laboratory studies provides the most reliable criterion for forensic medical diagnosis of burn injuries from combustion of flammable fluids on the human body.

Investigating the potential to assess severe lung inhalation injuries using computed tomography.

PURPOSE: The purpose of this study is to investigate the potential use of computed tomography (CT) in assessing inhalation injuries at various levels by studying the changes in lung imaging of rabbits with severe inhalation injury. METHODS: The sham, serious, critical, and extremely critical lung inhalation injury models were established by the New Zealand white rabbits' inhalation of steam for 0s, 0.25s, 0.50s, and 1.00s, respectively. Lung CT scans were performed at 1, 4, and 12h after the administration of steam and a radiologist's scores (RADS) were collected for each CT scan. Lung tissues were later collected to measure the lung wet/dry weight (W/D) ratio and to determine pathological scores. The correlation of the RADS with the lung-tissue pathological scores and W/D changes was investigated. RESULTS: The RADS and lung-tissue pathological scores are dependent on the time after injury and the level of injury. W/D ratios are dependent on the level of injury. The W/D ratio showed an increasing trend from 1h to 4h for the 0.25s, 0.50s, and 1s inhalation injury groups, while the W/D ratio decreased from 4h to 12h for the 0.25s and 0.50s inhalation injury groups. Further analysis indicates that, at the same time point, the lung RADS positively correlates with both the lung pathological scores and W/D ratios. CONCLUSION: A lung CT scan is able to reflect the early-stage lung injuries of rabbits with different levels of severe inhalation injury.

Point-of-care endoscopic optical coherence tomography detects changes in mucosal thickness in ARDS due to smoke inhalation and burns.

BACKGROUND: The prevalence of acute respiratory distress syndrome (ARDS) in mechanically ventilated burn patients is 33%, with mortality varying from 11-46% depending on ARDS severity. Despite the new Berlin definition for ARDS, prompt bedside diagnosis is lacking. We developed and tested a bedside technique of fiberoptic-bronchoscopy-based optical coherence tomography (OCT) measurement of airway mucosal thickness (MT) for diagnosis of ARDS following smoke inhalation injury (SII) and burns. METHODS: 16 female Yorkshire pigs received SII and 40% thermal burns. OCT MT and PaO2-to-FiO2 ratio (PFR) measurements were taken at baseline, after injury, and at 24, 48, and 72h after injury. RESULTS: Injury led to thickening of MT which was sustained in animals that developed ARDS. Significant correlations were found between MT, PFR, peak inspiratory pressure (PIP), and total infused fluid volume. CONCLUSIONS: OCT is a useful tool to quantify MT changes in the airway following SII and burns. OCT may be effective as a diagnostic tool in the early stages of SII-induced ARDS and should be tested in humans.

[Effect of high frequency oscillatory ventilation combined with exogenous pulmonary surfactant on apoptosis of lung tissue in rabbit with acute respiratory failure induced by steam inhalation injury].

OBJECTIVE: To investigate the effect of high frequency oscillatory ventilation (HFOV) combined with exogenous pulmonary surfactant (PS) on apoptosis of lung tissue in rabbit suffering from steam inhalation injury. METHODS: Thirty-two New Zealand rabbits were randomly divided into four groups, and acute respiratory failure model was reproduced by severe steam inhalation injury. Then they were ventilated and treated by controlled mandatory ventilation (CMV), HFOV, CMV+PS or HFOV+PS, respectively. After the animals were euthanized at 4 hours treatment time point, the right middle lobe of rabbit lung was harvested for the examination of caspase-3 and p73 contents and relative values, as well as mRNA expression of caspase-3 and p73. RESULTS: (1)Contents of caspase-3 and p73 in lung tissue homogenates in HFOV group and HFOV+PS group were significantly lower than those in CMV group and CMV+PS group (P<0.05 or P<0.01), and also contents of caspase-3 and p73 in lung tissue homogenates in groups with exogenous PS were significantly lower than those of groups without exogenous PS (all P<0.05). (2) Caspase-3, p73 mRNA expressions in lung tissue in HFOV group and HFOV+PS group were significantly lower than those of CMV group and CMV+PS group (all P<0.01). Caspase-3 and p73 mRNA expression in lung tissue in groups with exogenous PS group were significantly lower than those of the corresponding group without exogenous PS (all P<0.05). CONCLUSION: Compared with CMV or CMV+PS, HFOV or HFOV+PS can decrease the concentration of caspase-3 and p73, reduce the mRNA expression of caspase-3 and p73 in the lung homogenates, as a result lung tissue apoptosis in inhalation injury may be suppressed.

Inhalation injury caused by cornstarch dust explosion in intubated patients-A single center experience.

BACKGROUND: Around 10%-20% of burned patients have inhalation injuries, and the severity of these injuries is correlated with mortality. Fiberoptic bronchoscopy is an important tool for the early diagnosis of inhalation injury. This study investigated correlations between the severity of inhalation injury and outcomes of patients involved in a cornstarch dust explosion in northern Taiwan in 2015. METHODS: Patients with burns who were intubated after the explosion were enrolled. Their medical records were reviewed, and data including patient characteristics, percentage of total body surface area (%TBSA) burned, severity of the inhalation injury, mechanical ventilation settings, and outcomes were collected and analyzed. RESULTS: Twenty patients underwent fiberoptic bronchoscopy during the first 24h to evaluate an inhalation injury. Their mean age was 22.4±5.5 years and the mean %TBSA burned was 55.7±19.4%. Fourteen patients had a grade 1 inhalation injury and six had a grade 2 injury. There was a higher %TBSA burned in the grade 1 group than in the grade 2 group, although the difference did not reach statistical significance (60.0±20.3% versus 45.5±13.5%, p=0.129). Compared to the grade 2 group, the grade 1 group had a significantly higher white blood cell count (29.4±9.3 versus 18.6±4.6, p=0.015) and frequency of facial burns (85.7% versus 33.3%, p=0.037). The overall intensive care unit mortality rate was 10% (n=2), with no significant intergroup difference (grade 1, 14.3% versus grade 2, 0%, p=0.192). CONCLUSION: Although the explosion resulted in a high rate of inhalation injuries in critically ill patients, there was no significant correlation between mortality and the severity of the inhalation injuries.

[Morphological and pathological changes of larynx after severe laryngeal burn in dogs and their relationship with laryngostenosis].

Objective: To investigate the morphological and pathological changes of the larynx after severe laryngeal burn in dogs and their relationship with laryngostenosis. Methods: Eighteen healthy, male beagle dogs were assigned into control group, immediately after injury group, and 2, 4, 6, and 8 weeks after injury groups according to the random number table, with 3 dogs in each group. Dogs of injury group inhaled saturated steam through mouth for 5 seconds to reproduce severe laryngeal burn. Tracheotomy and intubation were performed immediately after injury, and 400 000 U/d penicillin was intravenously infused for 1 week. The feeding, activity, and vocalization of dogs in each group after injury were observed until they were sacrificed. Immediately after injury and 2, 4, 6, and 8 weeks after injury, the laryngeal morphology of the dogs in corresponding time point groups were observed by endoscope. After the observation, the dogs in each injury group were sacrificed, and the laryngeal tissue was taken. The epiglottis, glottis, and cricoid cartilage were collected to make full-thickness tissue slice, respectively, and their pathological changes were observed with hematoxylin and eosin staining. The dogs of control group were not specially treated, and their life activities, laryngeal morphological and pathological changes were observed. Results: (1) The dogs of control group had normal feeding, activities, and vocalization. All the dogs in injury group survived until they were sacrificed, and their feeding, activities, and vocalization were obviously reduced after injury compared with those of control group. The dogs of 2, 4, 6 and 8 weeks after injury groups ate and moved normally 2 weeks after injury but vocalized abnormally in frequency and volume compared with those of control group, which lasted until they were sacrificed. (2) The dog's laryngeal mucosa in control group was complete and pink, without obvious exudation. The laryngeal mucosa of the dog in immediately after injury group was pale and edematous, with obvious exudation, local ulceration, necrosis, and exfoliation, and dilated microvessels on the surface. The laryngeal mucosa of the dogs in 2 weeks after injury group was pale, edematous, and oozed less than that of immediately after injury group, and the glottis was blocked by an obviously extruding mass. The paleness and edema of laryngeal mucosa were significantly reduced in the dogs of 4 weeks after injury group compared with those of 2 weeks after injury group, without dilated microvessel, and the glottic extruding mass was obviously smaller than that of 2 weeks after injury group. The sizes of glottic mass were similar between the dogs of 6 and 8 weeks after injury groups, which were obviously smaller than that in 4 weeks after injury group. (3) In the dogs of control group, the epithelial cells of epiglottis, glottis, and cricoid cartilage were normal in morphology, the proper glands were visible in the intrinsic layer, and the muscle fibers and the chondrocytes were normal in morphology. In the dogs of immediately after injury group, large sheets of epiglottis epidermis exfoliated, the epithelial cells were swollen and necrotic, the intrinsic glands were atrophic and necrotic, and the chondrocytes were degenerated and necrotic. The epidermis of the glottis partially exfoliated, the epithelial cells were swollen and necrotic, the intrinsic glands were atrophic and necrotic, the muscle fibers were partially atrophic and fractured, and the vacuolar chondrocytes were visible. The cricoid cartilage epidermis was ablated, the epithelial cells were swollen, the intrinsic layer and submucosal layer were slightly edematous, and the morphological structure of glands, chondrocytes, and muscle fibers were normal. In the dogs of 2 weeks after injury group, the epiglottis epidermis was completely restored, a small amount of glands in the intrinsic layer were repaired, and obsolete necrotic chondrocytes and new chondrocytes could be seen. A large number of fibroblasts, new capillaries, and inflammatory cells infiltration were observed in the epidermis of glottis, and intrinsic layer glands were repaired. The cricoid cartilage epidermis was repaired intactly, and there was no edema in the intrinsic layer. In the dogs of 4 weeks after injury group, the epiglottis intrinsic layer glands were further repaired compared with those of 2 weeks after injury group, and new chondrocytes were seen in the submucosa of the glottis. The condition of cricoid cartilage was consistent with that of control group. The dog's epiglottis, glottis, and cricoid cartilage were similar between the 6 and 8 weeks after injury groups, and no significant change was observed compared with those of 4 weeks after injury group. Conclusions: The morphological changes of larynx after severe laryngeal burn in dogs include mucosa detachment and necrosis, and mass blocking glottis. Pathological changes include epidermis shedding and necrosis, gland atrophy and necrosis, vascular congestion and embolism, chondrocytes degeneration, necrosis and proliferation, even local granulation tissue formation and cartilaginous metaplasia. These results may be the cause of laryngostenosis after laryngeal burn.

Macroscopic and histological findings in the healing process of inhalation injury.

Although many investigators reported the diagnostic and therapeutic value of bronchoscopy in the early stage of inhalation injury, few findings in the late stage of inhalation injury have been reported. We investigated histopathological changes of in trachea and bronchi after inhalation injury. Five survivors with inhalation injury underwent bronchoscopic examinations combined with biopsies from the early stage to the late stage. Although the bronchotracheal membranes improved to near normal under the bronchoscopic findings in the late or recovery stage, invasion of inflammatory cells and the capillary dilatation in the subepithelial region were still remarkable histologically. Goblet cells also increased on the surface of mucous membranes. In cases of the inhalation injury with severe burn, pulmonary edema, bronchial edema and secretions tended to be prolonged. Results suggested that continuous secretions in the respiratory tracts sometimes cause airway obstruction. Bronchoscopic and histologic findings in the healing process of inhalation injury predict long-term pulmonary functional outcome. Moreover, the aggressive pulmonary toilet seemed to be effective in removing foreign particles and accumulated secretions which also cause the inflammatory response and the obstruction in inhalation injury.

[Suicide by self-immolation]. / Zur Kasuistik der Selbstverbrennung.

In the Western world, self-incineration is a rare event compared with the Asian countries. The circumstances of death are often unusual, and differentiation from homicide is sometimes possible only after evaluating all the investigation results and findings. In many cases of self-cremation, a fire accelerant is used. In our study material at least 30% of the body surface were burned. Unaffected skin was predominantly found on the back of the body. The cases presented by us are inhomogenous as to the motive and differ from those reported in the literature with regard to gender distribution, scene, motivational situation and psychological constitution.