[Retrospection and recent advances in fluid resuscitation during burn shock stage].

To retrospect the development of fluid resuscitation for burn shock and to look to the future. The main achievements in burn care in the past fifty years and existing problems are summarized, and the appropriate regime of fluid resuscitation for burn shock is suggested. Numerous achievements in burn care have been made, including the estimation of burn area, fluid replenishment formula, delayed resuscitation, fluid resuscitation for burn shock complicated by inhalation injury, covert compensatory shock and research on mechanism of burn shock etc. We had established and improved fluid resuscitation formula, and we had made clear how to properly resuscitate burn shock. However how to tide over the patient form burn shock smoothly had not yet reached a consensus. Effective treatment to alleviate hypoxic injuries as a result of severe shock had not been properly defined. Although significant achievements in fluid resuscitation for burn shock have been made, there is still a long way to go to attain a perfect regime. Therefore it is still utterly necessary to carry on in-depth research on this problem both in the laboratory and bedside.

[Application of carbon fiber dressing on burn wounds].

OBJECTIVE: To observe the effects of carbon fiber dressing on burn wounds. METHODS: Two hundreds and seventy seven burn patients were randomly divided into treatment group (group T) and control group (group C). The burn wounds were covered with carbon fiber dressing in T group, and with povidone iodine gauze in C group, respectively. The absorption capability of the dressing, inflammatory reaction and bacteria quantitation of wound tissues and wound healing time were observed, and biopsy of wounds were performed. RESULTS: The absorption capability of the dressing was higher, the wound inflammatory reaction was milder, and bacteria quantitation of wound tissues was lower in the group T than that in group C. The wound healing time in the group T was shorter than that in group C. CONCLUSIONS: Carbon fiber dressing is a new model dressing, it can absorb wound exudation, lessen inflammatory reaction and improve wound healing.

[Effects of zinc supplementation on zinc and calcium levels in serum and tissue in burned rats].

OBJECTIVE: To explore the effects of zinc supplementation on zinc and calcium levels in serum and tissue in burned rats. METHODS: Eighty SD rats were randomly divided into C group (control group without scald, n = 8), and N, W, H groups (each consisting of 24 rats), in which the rats were exposed to scalding resulting in partial thickness burns covering 15% of the total body surface area on the back, and then they were fed with diets containing zinc 40 microg/g in N and W groups, and 80 microg/g in H group. A cream containing zinc 761.1 microg/g was applied on the wound in W group at the same time. Eight rats of each group were sacrificed on day 1, 3 and 7 after scald respectively. Venous blood and samples of liver, femur and scald skin were harvested. Zinc and calcium contents in serum and tissues were determined with atomic absorption spectrophotometer. RESULTS: The serum Zn(2+) levels in N, W groups were lower than C group, however, it was obviously higher in H group (up to 16.2 micromol/L) on day 1 after scald. The liver Zn(2+) showed an increasing tendency in all groups, while Ca(2+) level declined in H group, but increased in N, W group. The bone Zn(2+) and Ca(2+) levels showed a progressive declination in all groups from day 1 to 7 after scald. The changes were more obviously in N group than H group (P < 0.05). The Zn(2+) content of the scalded skin increased obviously in H group on first day after scald and in W group on 7th day after scald. The Ca(2+) contents of scalded skin showed marked increases in all groups, especially in N group, but least in W group. CONCLUSION: There are obvious changes in Zn(2+) and Ca(2+) contents of serum and tissues after scald injury and zinc supplementation. The effects of zinc supplementation on calcium level in the tissue need to be further studied.

[The influence of lipopolysaccharide on adipose metabolism in liver during shock stage of scalded rats].

OBJECTIVE: To investigate the influence of lipopolysaccharide (LPS) on adipose metabolism in liver during shock stage of scalded rats. METHODS: Sixty adult Wistar rats were inflicted with 30% TBSA full thickness scald and were randomly divided into 3 groups: i. e. sham group (control, n = 20), simple scald group [(n = 20) and LPS group (n = 20, with intra-peritoneal injection of 3.0 mg/kg LPS at 2 postscald hour (PSH)]. The contents of LPS, tumor necrosis factor alpha (TNF-alpha), free fatty acids (FFA) in plasma and adenosine triphosphate (ATP), triglyceride (TG), malonaldehyde (MDA) in liver in each group were determined at 24 and 48 PSH. The histological changes in hepatic tissue in each group were also observed. RESULTS: The plasma contents of FFA in LPS group at 24 and 48 PSH were 2.3 +/- 0.3 mmol/L and 2.5 +/- 0.4 mmol/L, respectively, which were obviously higher than those in control (0.4 +/- 0.3 mmol/L, 0.5 +/- 0.3 mmol/L) and scald (0.9 +/- 0.3, 1.2 +/- 0.5 mmol/L, P <0.01) groups. Meanwhile, there was obvious difference in the contents of TG and ATP in liver between LPS group (TG: 530 +/- 30 mmol/g, ATP: 1.7 +/- 0.5 micromol/g) and scald group (TG: 242 +/- 27 mmol/g, ATP: 6.0 +/- 2.4 micromol/g, P < 0.01). Pathological examination revealed that adipose denaturalization and injury to mitochondria in hepatocytes in scald group were significantly milder than those in LPS group. The morphology of hepatocyte in control group appeared normal. CONCLUSION: LPS challenge to burn subjects could induce impairment in utilizing fat derived energy, and it would aggravate adipose denaturalization in the liver.

[Effect of growth hormone on non-protein respiratory quotient and oxidation rate of protein after burn injury].

OBJECTIVE: To investigate the changes in non-protein respiratory quotient (NPRQ) and oxidation rate of protein after burn injury, and the effect of growth hormone (GH) administration on metabolism. METHODS: Sixteen male minipigs were subjected to 35% total body surface area (TBSA) full thickness burn, and the burned minipigs were randomly divided into two groups: GH group and control group. NPRQ and oxidation rate of protein were monitored by means of the metabolic cart. RESULTS: After burns the oxygenation rate of protein increased slowly, with NPRQ reduced significantly. The extent of reduction was higher in GH group compared to the control group, but there was no significant difference in oxidation rate between the two groups. CONCLUSION: The results suggest that administration of GH could enhance lipid catabolism, with no obvious effect on protein catabolism. However, hyperglycemia is apt to occur.

[Effects of escharectomy during burn shock stage on the mRNA expression of IFN-gamma and IL-4 in spleen T lymphocytes in rats after thermal injury].

OBJECTIVE: To determine the serum level and mRNA expression of type-1/type-2 cytokines of T lymphocytes in spleens of rats after thermal injury and to investigate the effects of escharectomy during burn shock stage on IFN-gamma and IL-4. METHODS: One hundred and sixty male Wistar rats were randomized into four groups. In group A, animals were not subjected to escharectomy. In groups B, C and D, escharectomy and skin allograft were performed at 8, 24, 96 hours postburn (PB) respectively. At 4, 12, 24, 48, 96, 120 and 168 hours PB, animals were killed and blood and spleens samples were harvested. ELISA was applied to determine the concentration of IFN-gamma and IL-4 in serum. The expression pattern of IFN-gamma and IL-4 were observed at mRNA level in T lymphocytes isolated from spleen by RT-PCR. RESULTS: The serum level of IFN-gamma and IL-4 rose rapidly and significantly after scald injury, expression of IFN-gamma and IL-4 mRNA in rats' T lymphocyte were also up-regulated spontaneously. The serum level of IFN-gamma and its mRNA expression began to rise within 4 hours PB, peaking at 24 hours PB. Whereas IL-4 and its mRNA expression showed a persistent elevation. Thereby leading to a dominant tendency of Th2 cytokine response on 7 d PB. In group A all above parameters revealed most obvious changes compared with controls, then ranked in group D, B and C. CONCLUSION: Escharectomy during burn shock stage is helpful to decrease the harmful over expression of Th2-type lymphocyte after severe thermal injury.

[Application of digital subtraction angiography and type B ultrasonography in the evaluation of vascular injury in patients with high voltage electrical injury].

OBJECTIVE: To compare the difference between digital subtraction angiography (DSA) and type B ultrasonography in the evaluation of vascular injury in patients inflicted with high voltage electrical injury. METHODS: Nineteen patients with high voltage electrical injury of upper limbs were enrolled in the study as burn group, and another 12 healthy volunteers as controls. The endovascular membrane, vascular wall thickness, intra-vascular blood flow and endovascular thrombosis formation of ulnar and radial arteries at wound site and in regions 5, 10 and 15 cm proximal to the wounds were examined by DSA and type B ultrasonography and compared with imagings of healthy volunteers as control. The injury degree of the ulnar and radial arteries was examined during operation for evaluation to corroborate with DSA and ultrasonography findings. Necrotic and/or thrombotic vessels were excised and sent for pathomorphological examination. RESULTS: By DSA images abnormal signs as thrombosis, vascular lumen stenosis and blood flow deceleration were found in 14 ulnar and 11 radial arteries, and the signs were more pronounced in ulnar arteries. By type B ultrasonography, abnormal signs as roughing of tunica intima, swelling or exfoliation, thickening of vascular wall, lumen stenosis, decreased blood flow, even necrosis of vascular wall and thrombosis were identified in 19 ulnar and 16 radial arteries in burn group (P < 0.05 approximately 0.01). The blood flow in ulnar artery 5 cm to the approximal part of the wound edge was obvious lower than that of the control (31.60 +/- 13.90 ml/min vs 47.70 +/- 9.60 ml/min, P < 0.05). CONCLUSION: Type B ultrasonography and DSA could be helpful in the evaluation of vascular injury in patients inflicted with high voltage electrical injury.

[Effects of the escharectomy during burn shock stage on expression of glucose translator-4 mRNA in skeletal muscle and adipose tissue].

OBJECTIVE: To investigate the effect of the escharectomy during burn shock stage on expression of glucose translator-4 (GLUT4) mRNA in skeletal muscle and adipose tissue. METHODS: 30% TBSA scalded rats were employed. Escharectomy were conducted at 8 h, 24 h, 168 h after burns respectively. Insulin, glucagon, cortisol and glucose levels in serum were analyzed. RT-PCR were employed to analyze GLUT4 mRNA expression in skeletal muscle and adipose tissue. RESULTS: Glucagon, cortisol and glucose levels in serum were declined in groups which escharectomy were conducted during burn shock stage. GLUT4 mRNA expression in both skeletal muscle and adipose tissue were downregulated after burns and escharectomy conducted during burn shock stage made it restored to near normal. CONCLUSION: GLUT4 mRNA expression will declined after major burns in skeletal muscle and adipose tissue. Escharectomy during shock stage could make it upregulated, which will be helpful to improve glucose metabolism and hypermetabolism after major burns.

[The effects of early escharectomy on resting energy expenditure in the severely burned patients].

OBJECTIVE: To investigate the effect of early escharectomy on resting energy expenditure (REE) in severely burned patients dynamically with the metabolic monitoring and diagnostic system. METHODS: Fifty-six adult male patients with severe burns were divided into early escharectomy (group A, n = 39, escharectomy within 5 PBDs) and non-early escharectomy (group B, n = 17, escharectomy after 5 PBDs) groups. The wounds of full thickness and deep partial thickness burn in the two groups were all excised and covered with allogeneic skin and autologous micro-skin in the first operation. The changes in REE were observed dynamically at the bedside of the patients with the metabolic monitoring and diagnostic system. The plasma contents of IL-6, IL-8, TNF-alpha and LPS from 9 patients in group A and 7 in group B were also determined dynamically. RESULTS: All patients survived. The REE in both groups was elevated markedly, but REE in group A was lower compared with group B before and after escharectomy within 14 days. (P < 0.05). The plasma level of IL-6, IL-8, TNF-alpha and LPS in group A were obviously lower than those in group B (P < 0.05). CONCLUSION: The hypermetabolic response of burn patients with severe burns could be lowered by early escharectomy, and it seemed to be related to the decrease of the release of proinflammatory mediators.

[Changes in uncoupling protein-2, 3 mRNA expression in the scalded rats after escharectomy at different post scalding stages].

OBJECTIVE: To investigate the expression of uncoupling protein (UCP)-2, 3 mRNA in skeletal muscle of the scalded rats after escharectomy at different post scalding stages. METHODS: One hundred and twenty Wistar rats were employed in the study, in which 8 served as normal control (C) and 112 were subjected to 30% TBSA 3rd degree scalding and then again, divided into 4 groups. The rats in A group were sacrificed on 8th, 24th, 96th, 120th and 168th post scalding hours (PSHs) without escharectomy. The rats in B group underwent escharectomy at 8 PSH, and those in C group underwent escharectomy at 24 PSH. All the rats in both groups were sacrificed on 96, 120 and 168 PSHs after escharectomy, Escharectomy was performed at 96 PSH in rats of D group, and they were sacrificed on 120 and 168 PSHs after escharectomy. The serum levels of leptin and TNFalpha, and the expression level of UCP2 mRNA were determined at all time points in all groups of rats. RESULTS: (1) The serum levels of leptin in A group were obviously lower than that in C group (P < 0.01) during 24 approximately 168 PSHs, while those in B, C and D groups were much higher than those in A group (P < 0.01) during 24 approximately 168 PSH. (2) The serum TNFalpha levels in A group at all time points were higher than that in control group, while that in B group at all time points were lower than that in A group (P < 0.05 or 0.01), and that in C group at 168 PSH was lower than that in A group (P < 0.05). (3) The UCP2 mRNA expression in skeletal muscle in A group was increased evidently since 8 PSH (P < 0.01), peaking at 24 PSH and lowering thereafter, while that in B and C groups at 168PSH was significantly lower than that in A group at the same time points (0.32 and 0.35 vs 0.71, P < 0.05). The trend of the change in UCP3 mRNA expression in skeletal muscle was similar to that of UCP2. CONCLUSION: The postburn up-regulation of UCP mRNA expression might play important roles in the increase of metabolic rate. Escharectomy during shock stage could lower down the expression of UCP2 and UCP3 mRNA expression, and it could be beneficial by lowering metabolic rate.

[Escharectomy during burn shock on Th1/Th2 polarization of helper T lymphocytes in rats after thermal injury].

OBJECTIVE: To determine the type-1/type-2 cytokine response of helper T lymphocytes after thermal injury, and to investigate the effects of escharectomy during burn shock stage on the polarization of Th cells. METHODS: One hundred and sixty male Wistar rats were randomized into four groups. In group A, animals were subjected to a 30 percent full-thickness thermal injury without escharectomy. In groups B, C and D, escharectomy and skin allograft were done at 8, 24, and 96 hours postburn, respectively. At 4, 12, 24, 48, 96, 120 and 168 hours postburn, animals were killed and bloods samples as well as spleens were harvested. Enzyme linked immunoadsorbent assay (ELISA) was applied to determine interferon-gamma(IFN-gamma) and interleukin-4(IL-4) levels in blood and spleen tissues. RESULTS: Levels of IFN-gamma and IL-4 rapidly and significantly were increased after scald injury. IFN-gamma levels began to rise within 4 hours postburn, peaking at 24 hours later. IL-4 showed a persistent elevation up to 168 hours postburn, thereby leading to a dominant tendency of Th2 cytokine response on postburn day 7. In group A, all above parameters revealed most obvious changes compared with controls, then ranked in group D, B and C. CONCLUSION: Escharectomy during burn shock stage is helpful to prevent the shift to Th2 cell response after severe thermal injury.

[Effects of escharectomy during shock stage on the plasma lipid and serum free fatty acid levels in scalded rats].

OBJECTIVE: To investigate the influence of escharectomy during shock stage on plasma lipid and free fatty acid levels in scalded rats. METHODS: Thirty-two adult Wistar rats inflicted with 30% TBSA III degree scalding were employed as the model and were divided into normal control (NC), scalding control (SC) and treatment groups (T), and the latter was further divided into three sub groups according to the time of escharectomy, i.e. 8 postburn hour (PBHs) (T8), 24 PBHs (T24) and 96 PBHs (T96) groups. The rats were sacrificed at 168 PBHs. The postburn changes in the rat plasma lipid and free fatty acid levels were determined. RESULTS: 1) There was significant increase in serum triglyceride (TG), cholesterol (CHO), high density lipoprotein (HDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL), apolipoprotein A (ApoA), apolipoprotein B (ApoB) and all the free fatty acids (FFAs) in the total serum FFAs excluding myristic acid (P < 0.05) at 168 PBHs in rats of all the T groups. 2) The serum levels of TG, CHO, ApoB, total FFA, lauric acid, palmitic acid, zoomaric acid, oleic acid and linoleic acid in T8 and T24 groups were evidently lower than those in SC group (P < 0.05). The plasma levels of VLDL, stearic acid and arachidonic acid in T8 were obviously lower than those in SC group (P < 0.05); 3) In T96 group, the serum levels of ApoB and lauric acid were significantly lower than those in SC group (P < 0.05), but all the other indices remained higher than those before injury. CONCLUSION: There was enhanced fat mobilization after severe burn injury. Escharectomy during shock stage might decrease fat mobilization, which was beneficial to the restoration of normal lipid metabolism.

[The application of ultrasonography in the diagnosis of deep electric injury].

OBJECTIVE: To explore the application of ultrasonography in the diagnosis of deep electric injury. METHODS: HP-IPHX high resolution color and pulse doppler ultrasonography was employed in the study. The hemodynamic indices were determined in the burn wound area and tissues 5 - 15 cm proximal to the wound in 12 patients with deep electric injury. At the same time, injuries to subcutaneous and muscular tissue and blood vessels (fifty-six blood vessels detected) were detected. RESULTS: 1. It was found by two-dimentional ultrasonography that the injury degree in different tissue after deep electric injury was different, i.e. blood vessels were most liable to injury followed by muscles and subcutaneous tissue. In the burn wound area, endothelium was not visualized in 7 blood vessels and endothelial swelling was identified in 12 blood vessels. Furthermore, vascular occlusion was found in 4 blood vessels and thrombosis found in 5 vessels. 2. It was also demonstrated by color ultrasonography that change in course of blood vessel and tortuesity were observed in 12 blood vessels, stenosis of lumen in 21 vessels and widened intravascular space in 11 vessels, All these findings were confirmed in the subsequent operations. 3. It was revealed by pulse Doppler that the top blood flow speed increased during vascular contraction period in narrowed blood vessels with decreased blood flow per minute. CONCLUSION: Being an non-invasive examination, ultrasonography could directly demonstrate the morphological changes in subcutaneous tissue, muscle and blood vessels after a deep electric injury, which might help determine the injury degree and the hemodynamic changes in the injured site.