Pulmonary changes in a mouse model of combined burn and smoke inhalation-induced injury

The morbidity and mortality of burn victims increase when burn injury is combined with smoke inhalation. The goal of the present study was to develop a murine model of burn and smoke inhalation injury to more precisely reveal the mechanistic aspects of these pathological changes. The burn injury mouse group received a 40% total body surface area third-degree burn alone, the smoke inhalation injury mouse group received two 30-s exposures of cotton smoke alone, and the combined burn and smoke inhalation injury mouse group received both the burn and the smoke inhalation injury. Animal survival was monitored for 120 h. Survival rates in the burn injury group, the smoke inhalation injury group, and the combined injury group were 70%, 60%, and 30%, respectively. Mice that received combined burn and smoke injury developed greater lung damage as evidenced by histological changes (septal thickening and interstitial edema) and higher lung water content. These mice also displayed more severely impaired pulmonary gas exchange [arterial Po2(PaO2)/inspired O2fraction (FiO2) < 200]. Lung myeloperoxidase activity was significantly higher in burn and smoke-injured animals compared with the other three experimental groups. Plasma NO2−/NO3−, lung inducible nitric oxide synthase (iNOS) activity, and iNOS mRNA increased with injury; however, the burn and smoke injury group exhibited a higher response. Severity of burn and smoke inhalation injury was associated with more pronounced production of nitric oxide and accumulation of activated leukocytes in lung tissue. The murine model of burn and smoke inhalation injury allows us to better understand pathophysiological mechanisms underlying cardiopulmonary morbidity secondary to burn and smoke inhalation injury.

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Pathophysiological analysis of combined burn and smoke inhalation injuries in sheep

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.2001.280.6.l1233 ◽

2001 ◽

Vol 280 (6) ◽

pp. L1233-L1241 ◽

Cited By ~ 81

Author(s):

Kazutaka Soejima ◽

Frank C. Schmalstieg ◽

Hiroyuki Sakurai ◽

Lillian D. Traber ◽

Daniel L. Traber

Keyword(s):

Burn Injury ◽

Inhalation Injury ◽

Smoke Inhalation ◽

Lung Edema ◽

Pulmonary Vascular Permeability ◽

Smoke Inhalation Injury ◽

Combined Injury ◽

Injury Group ◽

Initial Depression ◽

Two Phases

We investigated the pathophysiological alterations seen with combined burn and smoke inhalation injuries by focusing on pulmonary vascular permeability and cardiopulmonary function compared with those seen with either burn or smoke inhalation injury alone. To estimate the effect of factors other than injury, the experiments were also performed with no injury in the same experimental setting. Lung edema was most severe in the combined injury group. Our study revealed that burn injury does not affect protein leakage from the pulmonary microvasculature, even when burn is associated with smoke inhalation injury. The severity of lung edema seen with the combined injury is mainly due to augmentation of pulmonary microvascular permeability to fluid, not to protein. Cardiac dysfunction after the combined injury consisted of at least two phases. An initial depression was mostly related to hypovolemia due to burn injury. It was improved by a large amount of fluid resuscitation. The later phase, which was indicated to be a myocardial contractile dysfunction independent of the Starling equation, seemed to be correlated with smoke inhalation injury.

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Inhalation injury and burn trauma: an experimental investigation of oxidative stress and histopathology

Scandinavian Journal of Forensic Science ◽

10.2478/sjfs-2013-0007 ◽

2013 ◽

Vol 19 (2) ◽

pp. 39-44

Author(s):

Ghada A. Eshak ◽

Khaled A. Nasef

Keyword(s):

Lipid Peroxidation ◽

Glutathione Peroxidase ◽

Burn Injury ◽

Inhalation Injury ◽

Pulmonary Complications ◽

Smoke Inhalation ◽

Antioxidant Enzyme Activities ◽

Smoke Inhalation Injury ◽

Injury Group ◽

Major Burn

ABSTRACT Smoke inhalation injury is associated with high incidence of pulmonary complications as it represents a major cause of mortality after major burn injury. Burn is associated with release of inflammatory mediators which ultimately cause local and distant pathophysiological effects. The present study investigated the effect of smoke inhalation or\and burn injury on the antioxidants status in the lungs in a rat model to simulate an inhalation injury as might be encountered by firefighters and burn victims. Seventy five rats were equally randomized to five groups: Sham group, smoke inhalation injury group, burn group, sham burn group, and smoke burn group. At the end of the exposure protocol rats were killed by cervical decapitation and the lungs were removed completely and processed for histopathological and biochemical analysis by measuring lung antioxidant enzyme activities: Malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPs) level, as an index of lipid peroxidation. Grossly, results showed that rats´lungs in the smoke inhalation group and the smoke burn group showed multiple hemorrhagic spots. Light microscopic examination showed localized and diffuse alveolar hemorrhage. Two rats in the burn group had evidence of pneumonia and lung abscesses. Biochemically, results showed that both smoke inhalation and burn injury significantly elevated lung MDA and glutathione peroxidase levels when compared with controls. The combined smoke and burn group resulted in a more significant rise in both antioxidant levels indicating a higher level of lipid peroxidation. SOD level was significantly lowered on exposure to both conditions when compared to control. SOD level was significantly lower in the combined injury group when compared to either smoke or burn alone. In conclusion; the above data provide evidence that inhalation injury with and without burn decrease tissue antioxidant capacity and increase tissue peroxidative injury.

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THE EFFECT OF INDUCIBLE NITRIC OXIDE SYNTHASE (iNOS) INHIBITION ON SMOKE INHALATION INJURY IN SHEEP

Shock ◽

10.1097/00024382-200004000-00002 ◽

2000 ◽

Vol 13 (4) ◽

pp. 261-266 ◽

Cited By ~ 37

Author(s):

Kazutaka Soejima ◽

Roy McGuire ◽

Ned Snyder ◽

Tatsuo Uchida ◽

Csaba Szabó ◽

...

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Inducible Nitric Oxide Synthase ◽

Inhalation Injury ◽

Smoke Inhalation ◽

Smoke Inhalation Injury ◽

Oxide Synthase ◽

Inos Inhibition ◽

Inducible Nitric Oxide

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The Inducible Nitric Oxide Synthase Inhibitor BBS-2 Prevents Acute Lung Injury in Sheep after Burn and Smoke Inhalation Injury

American Journal of Respiratory and Critical Care Medicine ◽

10.1164/rccm.200209-1031pp ◽

2003 ◽

Vol 167 (7) ◽

pp. 1021-1026 ◽

Cited By ~ 101

Author(s):

Perenlei Enkhbaatar ◽

Kazunori Murakami ◽

Katsumi Shimoda ◽

Akio Mizutani ◽

Lillian Traber ◽

...

Keyword(s):

Nitric Oxide ◽

Acute Lung Injury ◽

Lung Injury ◽

Inhalation Injury ◽

Smoke Inhalation ◽

Nitric Oxide Synthase Inhibitor ◽

Smoke Inhalation Injury ◽

Synthase Inhibitor ◽

Oxide Synthase ◽

Inducible Nitric Oxide

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EFFECT OF INDUCIBLE NITRIC OXIDE SYNTHASE (iNOS) INHIBITION ON SMOKE INHALATION INJURY IN SHEEP

Shock ◽

10.1097/00024382-199906001-00203 ◽

1999 ◽

Vol 11 (Supplement) ◽

pp. 58

Author(s):

K. Soejima ◽

L. D. Traber ◽

D. L. Traber

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Inducible Nitric Oxide Synthase ◽

Inhalation Injury ◽

Smoke Inhalation ◽

Smoke Inhalation Injury ◽

Oxide Synthase ◽

Inos Inhibition ◽

Inducible Nitric Oxide

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519 Retrospective Pilot Study to Examine Potential Predictors of a Standardized Scoring System for Smoke Inhalation Injury

Journal of Burn Care & Research ◽

10.1093/jbcr/iraa024.151 ◽

2020 ◽

Vol 41 (Supplement_1) ◽

pp. S97-S98

Author(s):

Joshua Frost ◽

Grant Sorensen ◽

Nicole Van Spronsen ◽

Jordan Howell ◽

Donna Ayala ◽

...

Keyword(s):

Scoring System ◽

Burn Injury ◽

Inhalation Injury ◽

Physical Exam ◽

Smoke Inhalation ◽

Continuous Variables ◽

Diagnostic Significance ◽

Smoke Inhalation Injury ◽

Carbon Particles ◽

Significant Difference

Abstract Introduction Smoke inhalation injury is strongly associated with increased morbidity/mortality. Bronchoscopy is used to diagnosis smoke inhalation injury, but its interpretation is subjective. This study sought to assess diagnostic significance of physical exam, history, location, and adjunct studies characteristically performed on patients suspected of smoke inhalation by comparing these findings to outcomes. The primary goal was to examine variables that could be used to create an accurate smoke inhalation injury scoring system in order to develop an objective method that considers the severity of inhalation injury. Methods This retrospective study evaluated demographics, clinical presentation, carboxyhemoglobin level, intubation on arrival, bronchoscopy, comorbidities, hospital course, and outcomes associated with smoke inhalation. Bronchoscopy findings included: red mucosa, carbon particles at carina, and numerical score (1–4). The primary outcome was resuscitation fluid required in the first 24 hours of treatment compared to that predicted by the modified Brooke formula (2cc*weight in kg* Total Burn Surface Area). If the patient received more fluid than predicted, this was considered positive for smoke inhalation. Differences between predictor/outcome variables were determined using Wilcoxon rank sum test for continuous variables and Chi-squared test for categorical. Results A positive bronchoscopy score was defined on the condition of having positive physical exam finding and/or bronchoscopy score 1–4. Physical exam findings consisted of soot or carbon sputum present on the patient along with hoarseness, wheezing, or a red oropharynx on physical exam. If the patient met one of these conditions, we considered this a positive result. Inclusion criteria: age 18–89, admission from 1/1/2004 and 5/31/18, and diagnosis of smoke inhalation injury/burn injury. There was a significant difference in positive bronchoscopy between those positive for our condition of inhalation injury and no injury (p< 0.001; Table 1). Patients with a positive bronchoscopy score were 9 times more likely (OR=9.91, 95% CI = 2.8–35.01) to be diagnosed with inhalation injury as compared to those without a positive bronchoscopy score. Conclusions These results display the importance of bronchoscopy in suspected smoke inhalation injury and reinforce the need for an objective bronchoscopy assessment. Future studies can build upon these results by creating an objective scoring system to guide providers performing bronchoscopy. Applicability of Research to Practice Due to the 9-fold benefit of performing bronchoscopy, it should be the primary tool used to assess potential smoke inhalation injury; other tests may be secondary in nature.

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