[Experience of wound treatment on extremely severe mass burn patients involved in August 2nd Kunshan factory aluminum dust explosion accident].

Objective: To explore experience of wound treatment of extremely severe mass burn patients involved in August 2nd Kunshan factory aluminum dust explosion accident. Methods: On August 2nd, 2014, 98 extremely severe burn mass patients involved in August 2nd Kunshan factory aluminum dust explosion accident were admitted to 20 hospitals in China. The patients with complete medical record were enrolled in the study and divided into microskin graft group with 56 patients and Meek skin graft group with 42 patients. Split-thickness skin in area of residual skin were resected to repair wounds of patients in microskin graft group and Meek skin graft group by microskin grafting and Meek miniature skin grafting, respectively. The residual wound size on 28 days post injury and wound infection after skin grafting of patients in the two groups, and position of donor site of all patients were retrospectively analyzed. Data were processed with t test and chi-square test. Results: The size of residual wound of patients in Meek skin graft group on 28 days post injury was (59±13)% total body surface area (TBSA), which was obviously smaller than that in microskin graft group [(70±14)%TBSA, t=4.379, P<0.05]. Twenty-nine patients in microskin graft group and 11 patients in Meek skin graft group suffered from obvious wound infection after skin grafting. Wounds of patients in two groups were repaired with residual skin around wound in head, trunk, groin, armpit, and uncommon donor sites of scrotum (4 patients), vola (10 patients), and toe or finger web (8 patients). Conclusions: Meek skin graft is the first choice for wound repair of extremely severe burn mass patients, with faster wound healing, less wound infection. Uncommon donor sites of scrotum, vola, and toe or finger web can also be used for wound repair in case of lack of skin.

Dynamic balance changes between elastase and antiprotease in the early stages after smoke inhalation injury.

Following the use of a rabbit smoke inhalation injury model established in this institute, there were marked reductions in elastase activities in neutrophils and alveolar macrophages; rapid increases in elastase activity in broncho-alveolar lavage fluid (BALF); reductions of serum trypsin inhibitory capacity; a decrease of Pao2 and an increase of PaCO2, and marked increases of lung water volume. Significant correlations were found between the increased extravascular lung water content and the rising elastase activity in BALF. It seems probable that the imbalance between elastase and antiprotease played an important role in the development of acute lung injury after smoke inhalation.

Changes of length of elastic fibers in rabbit lungs after smoke inhalation injury.

Pulmonary morphometry was determined in rabbit lungs after smoke inhalation. Twenty-four hours after injury, changes of the total lung volume (TLV) and the total length of all parenchymal elastic fibers (LT) were measured. Concomitant changes in arterial blood gas levels and pathomorphology of lung tissues were also studied. It was found that alveolar walls were broken and became thinner, and that alveoli were dilated. TLV was markedly increased and LT was markedly decreased as compared to normal lungs (P less than 0.05). These findings suggest that proteinases, especially elastase, released from phagocytes may play an important role in acute lung injury after smoke inhalation.

[Experimental study of dynamic changes in elastase-antiprotease in rabbits in the early stage of inhalation injury].

In this experiment, rabbit model with smoke inhalation injury was used. The study was designed to observe the dynamic changes of elastase activities of polymorphonuclear leukocytes (PMN), alveolar macrophages (AM) and bronchoalveolar lavage fluid (BALF); and trypsin inhibitory capacities of serum and BALF (STIC & BTIC). The relationships between these changes and acute lung injury, as well as the concomitant changes of arterial blood gas levels, lung water volume and pathomorphology of trachea and lung tissues were also observed. It was found that after injury the elastase activities of PMN and AM were markedly reduced, and the elastase activity of BALF was rapidly increased. STIC was also reduced. PaO2 progressively dropped and PaCO2 progressively increased. Animals showed respiratory distress. Pathomorphological phagocytes aggregations in lungs, pulmonary edema and pneumorrhagia were found. There were serious destructions of capillary endothelial cells, alveolar epithelial cells, basement membranes and interstitial fibers. The number of elastic fibers of parenchyma decreased. The lung water volume was markedly increased, and there was a significant correlation between the increment of extravascular lung water and the rising of elastase activity of BALF. On the basis of our observation, it is proposed that the imbalance of elastase-antiprotease may play an important role in the development of acute lung injury after smoke inhalation.