Laryngeal morphologic changes and epidemiology in patients with inhalation injury: a retrospective study.

BACKGROUND AND OBJECTIVES: Laryngeal morphologic changes are important in risk assessment of upper airway obstruction (UAO) after inhalation injury. This retrospective study evaluates the clinical application of laryngeal burn classification system. MATERIALS AND METHODS: Clinical data from January 1999 to June 2013 were analyzed retrospectively. The following data collected: age, gender, total burned surface area (TBSA), third-degree burn surface area, co-morbid injuries and complications, proportion of patients with tracheotomy, interval between tracheotomy and injury, incidence and mortality of UAO, and reasons for death. RESULTS: Four hundred and forty-three patients were included; 405 patients underwent multiple fibro-laryngoscopic observation, of which I, II and III types of laryngeal burns were present in 49.9, 38.0, and 12.1% patients, respectively. Laryngeal burn severity was related to TBSA and third-degree burn surface area. Overall tracheotomy rate (n=443) was 37.02%. The mean interval between tracheotomy and injury was 10.0±12.17h. Over 75% patients underwent tracheotomy within 12h. Compared with moderate inhalation burn group, the severe inhalation burn group showed a significantly higher tracheotomy rate within 12h and a significantly shorter interval between tracheotomy and injury. Patient mortality was significantly related to the severity of inhalation injury. CONCLUSION: The classification system of the morphologic laryngeal changes in laryngeal burn patients could effectively evaluate the UAO risk, enable earlier prophylactic tracheotomy after UAO onset, reduce surgical difficulties and risks, decrease clinical pressure of doctors, and prevent UAO. Laryngeal burn severity was related to TBSA and mortality and may be an important severity and prognosis indicator of inhalation injury.

Pathological changes of the three clinical types of laryngeal burns based on a canine model.

OBJECTIVE: The study was designed to examine pathological changes of inhalational laryngeal burns of three clinical types: congestive, oedematous and obstructive. METHODS: A total of 18 healthy, male, adult Beagle dogs were randomly assigned to inhale hot dry air at room temperature (group C), 80°C (Group 1), 160°C (Group 2) or 320°C (Group 3) for 20min to induce inhalation injury. Each larynx was evaluated and scored based on the 'clinical scoring and typing system of laryngeal burns at early stage'. Tissue samples of the epiglottis, laryngeal vestibule, vocal folds and infraglottic cavity of the larynx were observed microscopically and evaluated based on a 'pathological scoring system'. RESULTS: Pathological changes of the larynxes of groups 1 and 2 were primarily characterised by slight atrophy of the mucosa and mild oedema of the submucosal tissues. Group 3 larynxes showed two distinct pathological changes: oedematous and atrophic types. The larynxes of the atrophic type showed lower clinical scores (29.5±0.7 vs. 44.3±2.1) but higher pathological scores (18.6±3.2 vs. 13.7±1.8) than the larynxes of the oedematous type. CONCLUSION: Severe laryngeal burns could manifest as severe laryngeal oedema or atrophic change. The laryngeal burns of the atrophic type might suggest an unsatisfactory prognosis, although it had less risk of laryngeal obstruction at an early stage.

Epidemiology of 1974 burn patients at a major burn center in Beijing: a nine-year study.

To date, little epidemiological data are available on burns in China. This study describes the characteristics of burn patients admitted to a major burn center in Beijing to show trends in admission and outcomes in burned patients to share information about the current state of care for burned patients in our burn center. A retrospective study on 1974 burn patients admitted to Jishuitan Hospital in Beijing was conducted during the 9-year period from 2000 to 2008, and data were collected on age, gender, TBSA, etiology, length of hospital stay, mortality, and inhalation injury. The male:female ratio of the burn population was 2.41:1 and did not differ significantly over the study period (P > .05). The mean age of admission was 36 ± 16.3 years, and most patients were 30 to 39 years old (24.0%) or 20 to 29 years old (23.8%). The mean TBSA of burn was 14.7 ± 3.4%, ranging from 1 to 100%, and the mean size/age did not change significantly over the course of the study (P > .05). The incidence in burn injury decreased over the study period (P < .05). The most common cause of burn was flame (67.9%) followed by electrical (16.1%) and scald (9.5%). The mean length of hospital stay was 33.2 ± 3.5 days, extending from 1 to 413 days, and it did not differ significantly over the study period (P > .05). The mortality and inhalation injury rate were 2.8 and 6.9%, respectively. Annual mortality rate did not differ significantly over the study period (P > .05). This retrospective review of the specific epidemiological features of burn patients will provide important information for the development of proper control programs to reduce the incidence of burns and burn-related deaths.

Quantification of type I and III collagen content in normal human skin in different age groups / 中华烧伤杂志

<p><b>OBJECTIVE</b>To quantify the content of type I, III collagen and their ratio in normal human skin of different age, and to explore the regulation of changes.</p><p><b>METHODS</b>The normal human skin specimens were obtained from 6 spontaneously aborted fetus and 56 burn patients of different ages, including infants (newborn -3 years), pre-school group ( > 3, < or =7 years), adolescent group ( >7, < or = 18 years), youth and middle age group ( > 18, < or = 50 years), and elderly group ( > 50 years), were studied. The total collagen content were determined by hydroxyproline method. The contents of type I, Ill collagen and their ratio were examined by immunohistochemistry.</p><p><b>RESULTS</b>The total collagen content decreased along with increase in age, and it was highest in fetus [(543 +/- 13) microg/g]. The ratio between type I and Ill collagen increased along with increase in age. The content of type III collagen was highest in fetus [(278 +/- 7) microg/g], and it decreased along with increase in age. The content of type I collagen content was [(265 +/- 7) microg/g] in fetus, and it was increased slightly in infant and pre-school groups, then decreased along with advance in age.</p><p><b>CONCLUSION</b>Decomposition of type III collagen in normal human skin may exceed its synthesis after birth immediately, leading to its reduction. Synthesis of type I collagen in normal human skin is dominant before 8 years old, and it shows an opposite tendency afterwards.</p>