[Clinical investigation of the correlation between blood concentration of lactic acid and tissue oxygenation in severely burned patients].

OBJECTIVE: To investigate the relationship between blood concentration of lactic acid (LA) and tissue oxygenation in severely burned patients with shock. METHODS: Thirty-four severely burned patients admitted during early postburn stage were included in this study and were randomly divided into A (n = 18) and B (n = 16) groups. The patients in A group were resuscitated with modified anti-shock programme by which the patients' urine output was maintained roughly around 100ml per hour, while the patients in B group were treated by our traditional resuscitation formula by which the patients urine was kept at 40 ml per hour. The blood concentration of LA and usual indices (urine output, blood pressure, heart rate, and mental status) were simultaneously monitored before and 1, 8, 16, 24, 48 and 72 hours after resuscitation in patients of both groups. RESULTS: (1) The average blood LA level in patients of A group was (3.2 +/- 0.4) mmol/L within 24 hours of resuscitation, while the monitored indices remained within normal range. Nevertheless the LA level in B group was (7.4 +/- 1.6) mmol/L (P < 0.01, compared with that of A group), and hyperlactacidemia lasted for more than 72 hours while other indices were normal. (2) The mortality in B group was high (31.2%), whilst that in A-group was only 5.5% (P < 0.01). (3) There was negative correlation between blood LA and urine output and positive correlation between blood LA and heart rate. CONCLUSION: (1) Blood LA concentration might be taken as an immediate, sensitive, simple and useful index of tissue oxygenation of the whole body during burn shock stage. (2) It was suggested by our results that fluid resuscitation should be extended to 72 PBHs (postburn hours) with urine output over 100 ml/h, so as to ensure the quality and effects of the resuscitation of burn shock.

[Repair of murine full skin loss with composite skin of collagen scaffold containing living cells].

OBJECTIVE: To construct composite skin containing living cells and to observe its significance in the repair of full skin loss in mice. METHODS: The dermal substitute was formed by culturing heterogeneous fibroblasts on the acellular chondrocyte collagen scaffold for 3 days, and then cultured on the epithelial membrane for another 10 days, to form the composite skin containing living cells. The composite skin was grafted onto full layer skin defect. The growth condition was observed and biopsies were harvested for histologic examination. RESULTS: Both fibroblasts and stratified epithelium grew well in the collagen scaffold. The composite skin adhered tightly to wounds of the mice, with obvious vascularization one week after grafting. The grafts began to merge with the wound margin at 6 post operation weeks without obvious signs of rejection. CONCLUSION: Full skin loss could be repaired by composite skin formed by acellular chondrocyte collagen scaffold as a skin substitute.