| Burn is not only the local tissue injury but also can causing systemic response and damage. Especially the extensive burn, in which the tissue and system of the body can be involved and lead to hardly treatment with time-consuming and high mortality, is a burn surgical research focus with much attention home and abroad. The main causes of death in burn patients are visceral complications, serious infections and inhalation injury. The respiratory failure caused by inhalation injury is the first place of multiple organ dysfunction syndrome in morbidity and mortality. The inhalation injury caused by heat and smoke has a high morbidity in the fire accidents and chemical spills and has an increasing trend because of the change of the modern living environment and chemical products widely used. The clinical course and outcome are closely related the severity of damage of the airway, as well as burns. According to foreign literature, the mortality was60%in burn patients with severe inhalation injury compared4%in burn patients without inhalation injury. A clinical summary also proved that burn with inhalation injury had more than50%mortality and3.4%mortality without inhalation injury. Another literature reported that extensive burn with inhalation injury had a cumulative effect to the severity of the disease. Inhalation injury only had a incidence rate of respiratory failure of12%, and the mortality of7%, while combined with body burns the incidence of respiratory was as high as62%and the mortality increased to20%to40%.Since the late1970s, the scholars carried out a lot of basic and clinical research about the mechanism, the pathophysiologic changes and the clinical treatment and had got some guiding theoretical and practical results. In the basic research, it has confirmed that heat can damage the airway mucosa and lung tissue to promote cell dehydration, protein denaturation and inflammation. The severity of damage is related with the temperature, humidity, velocity and time of the inhalational gas. Some toxic chemicals in the smoke can combines with water to form acids, alkalis or other compounds and can cause airway mucosal damage; some fat-soluble gases can dissolve in the lipid composition on the cell membrane and lead to lung injury; some can damage the mucosa and ling parenchyma directly. The main pathophysiologic changes are airway trauma, pulmonary edema, pulmonary collapse and atelectasis caused by inhalation injury and with a subsequent of infection damage. Airway mucosa edema, debauched, fall off and obstruction, lungs and capillary permeability increase, the increasing water content of lung tissue, the lymph which fail to back into blood, the decreased lung surface active substances and the lots of inflammatory mediators and cell factors from the activated complement system, all of these are causes of the pathophysiologic changes of inhalation injury. In clinical studies, we have established standardized diagnostic methods of inhalation injury and its severity of damage, including the clinical manifestations such as hoarseness, wheezing and disturbance of consciousness, the chest X-ray performance and the airway mucosal damage performance by the fiberoptic bronchoscopy. In the study of treatment, it has been proved that we should increase the fluid volume in burn patients with inhalation injury with in-depth study on the mechanism of inhalation injury, and we had better do the tracheotomy in the6to8hours after injury in order to avoid airway obstruction caused by edema, and promote airway secretions and necrotic tissue by suction and lavage. Also, it has proved that the positive effect of mechanical ventilation to correct hypoxemia and respiratory failure. This series of treatment measures had significantly reduced the mortality. As a leading cause of death, the improving therapy of inhalation is a key measure to improve the cure rate.ObjectivesSevere burn with inhalation injury is a significant issue internal and international because of its hard management and high mortality. Two hundred and twenty-six Cases of extensive burn with inhalation injury in the past20years in our department were retrospective analyzed to learn more about the epidemiological characteristics and analyze the impact factor of clinical outcome, and to sum some positive treatment to improve prognostic so as to provide some reference for the treatment in the future.Data and methodsTwo hundred and twenty-six burn patients which TBSA over50%and combined with inhalation injury were admitted to our department over the20years period from1991to2010. Data on age, gender, weight(kg), the admission time(h), the causes of injury, total burn area(%TBSA) and depth of burn, burn index, inhalation injury degree, the incidence of shock, infection and the visceral complication, the mortality and the time and causes of death, the changes of therapy were collected and analyzed.All the data were processed and analyzed by SPSS13.0software package, and analysis of measurement data to the mean±SD, count data to the frequency (n) and percentage (%). Correlations between variables were analyzed using the Spearman correlation coefficient method. The binary logistic regression was used to analyzed the correlation between the outcome and the impact factors when whether dead was the binary dependent variable. Matching measurement data were compared using paired t-test; measurement data between in the two groups were compared using independent samples t test. When we need to remove the linear effect of the covariates to the dependent, we used the analysis of covariance. The difference was statistically significant when P<0.05.Results1. The age of extensive bum patients with inhalation injury was concentrated in20to50years old and the distribution of burn surface area was more average. The flame bum was the main cause of extensive bum patients with inhalation injury, accounting for69.9%, followed by hydrothermal bum and chemical bums, accounting for11.9%and8.8%.2. There was34male and5female in the dead cases, with a mean age of (28.71±11.67) years old, total bum surface area (80.18±15.73)%TBS A and third degree (51.69±33.16)%TBSA. Time of death:eight cases within48hours after injury,8cases of3to7days and23cases after8days. Causes of death:11cases due to MOF and12cases due to MOF and sepsis,1case due to sepsis only,8cases due to respiratory failure caused by inhalation injury,4cases due to shock,1case due to renal failure and2cases due to Gastrointestinal hemorrhage.3. There were a positive correlation between the severity of inhalation injury and the total burn area(r=0.148, P=0.026),and a positive correlation between the severity of inhalation injury and the thickness area (r=0.154, P=0.020) in extensive bum patients with inhalation injury.4. There was a positive correlation between the third degree area, bum index, shock, visceral complication and the death (P<0.05); and visceral complication was a risk factors in extensive bum patients with inhalation injury (P<0.001).5. Compared with the Third Military Medical University formula, there was a significant difference between the amount of fluid, the crystal and water in the first24hour (P<0.05), no statistically significant about the colloid (P>0.05). And there was statistically significant between the amount of fluid, the crystal, the colloid and water compared with the formula in the second24hours (P<0.001)6. Analysis of the airway management measure in extensive burn patients with inhalation injury, prevent tracheotomy group had a lower mortality rate than the emergency tracheotomy group mortality rate by12.2%. There was significantly statistically significant of the value of PaO2/FiO2before and after mechanical ventilation (P<0.001). No significant difference was found the value of PaCO2before and after mechanical ventilation (P>0.05), and no significant difference was found about the value of PaO2/FiO2and PaCO2after conventional mechanical ventilation and protective mechanical ventilation (P>0.05).Conclusions1. The patients whose burn surface area over80%always combine with severe inhalation injury, so the mortality of patients in our study was as high as46%.2. The leading cause in extensive burn patients with inhalation injury is visceral complication, followed by severe infection such as sepsis.3. The amount of fluid should be more than the formula in the shock stage, especially the water and the crystal.4. Early preventive tracheotomy, early judging the damage degree of airway and positive protective mechanical ventilation can reduce the lung complication and mortality.5. The positive wound therapy is not only an important measure for extensive and deep burn, but also conducive to repair the airway for severe inhalation injury. |
PDF Full Text Request