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.

Repair of circumferential wound in the wrist region due to high-voltage electrical burn using combined abdominal axial pattern flaps / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the method for repairing circumferential wound in the wrist region due to high-voltage electrical burn.</p><p><b>METHODS</b>Six patients with circumferential wound in the wrist region after high-voltage electrical burn were admitted to our hospital from January 2009 to December 2011. After debridement, wounds in the wrist were repaired with combined abdominal axial pattern flaps. The wound of wrist on the flexor aspect was repaired with paraumbilical flap carrying a portion of rectus abdominis that filled the wound cavity of the wrist on the flexor aspect. The wound of wrist on the dorsal aspect was repaired with lower abdominal flap. Pedicle division was performed 4 - 5 weeks post surgery. Some donor sites were sutured directly, and the others were closed by skin grafting after the suture of anterior sheath.</p><p><b>RESULTS</b>Three flaps survived. Liquefaction necrosis of tissue was observed under two flaps, and they were healed after debridement. Radial artery embolism of wrist occurred in one flap when pedicle division was performed 5 weeks post surgery, and it was healed by a transplantation of a segment of the great saphenous vein to reconstruct radial artery right after debridement. Patients were followed up for 6 - 12 months, and satisfactory appearance and function of the flaps were observed.</p><p><b>CONCLUSIONS</b>It is a feasible option to repair circumferential wound in the wrist region due to high-voltage electrical burn by using paraumbilical flap carrying a portion of rectus abdominis muscle combined with lower abdominal flap.</p>

Large-area burns with pandrug-resistant Pseudomonas aeruginosa infection and respiratory failure / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Infection due to pandrug-resistant Pseudomonas aeruginosa (PDRPA) has become a challenge in clinical practice. The aim of this research was to summarize the treatment of large-area burns (60% - 80%) with PDRPA infection and respiratory failure in our hospital over the last two years, and to explore a feasible treatment protocol for such patients.</p><p><b>METHODS</b>We retrospectively analyzed the treatment of five patients with large-area burns accompanied by PDRPA infection and respiratory failure transferred to our hospital from burn units in hospitals in other Chinese cities from January 2008 to February 2010. Before PDRPA infection occurred, all five patients had open wounds with large areas of granulation because of the failure of surgery and dissolving of scar tissue; they had also undergone long-term administration of carbapenems. This therapy included ventilatory support, rigorous repair of wounds, and combined antibiotic therapy targeted at drug-resistance mechanisms, including carbapenems, ciprofloxacin, macrolide antibiotics and β-lactamase inhibitors.</p><p><b>RESULTS</b>Four patients recovered from burns and one died after therapy.</p><p><b>CONCLUSIONS</b>First, compromised immunity caused by delayed healing of burn wounds in patients with large-area burns and long-term administration of carbapenems may be the important factors in the initiation and progression of PDRPA infection. Second, if targeted at drug-resistance mechanisms, combined antibiotic therapy using carbapenems, ciprofloxacin, macrolide antibiotics and β-lactamase inhibitors could effectively control PDRPA infection. Third, although patients with large-area burns suffered respiratory failure and had high risks from anesthesia and surgery, only aggressive skin grafting with ventilatory support could control the infection and save lives. Patients may not be able to tolerate a long surgical procedure, so the duration of surgery should be minimized, and the frequency of surgery increased.</p>

Evaluation of the cytotoxicity of cell free dermal substitutes using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The cytotoxicity of dermal substitutes may be increased by the very processes used to deplete the cells. The present research aimed to investigate the method for monitoring the cytotoxicity of cell-free dermal substitutes using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method.</p><p><b>METHODS</b>The cytotoxicity of four dermal substitutes was evaluated using the MTT method according to the standards set by the Chinese State Food and Drug Administration (SFDA). Swine acellular dermal matrix (SADM) and goat acellular dermal matrix (GADM) were produced using a repeated freeze-thaw method. Human dermal matrix glutaraldehyde composite (HADM-G) and SADM cross-linked with glutaraldehyde (SADM-G) were produced using conventional methods.</p><p><b>RESULTS</b>The cytotoxicity of all dermal substitutes ranged from Grade 0 to Grade 1, meeting the standards of the Chinese FDA. The OD(490) of both SADM and GADM was higher than that of either HADM-G or SADM-G (P < 0.05).</p><p><b>CONCLUSION</b>Dermal substitutes produced by the freeze-thaw method are less cytotoxic than those produced using conventional methods.</p>

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>