OBJECTIVETo investigate the basic pathogenetic rule and mechanism of deep burn by constant low heat.

METHODSAnimal burn model inflicted by constant low heat was established as follows. (1) The rats were randomly divided into groups in terms of temperature and duration of contact. The burn wound formation process, the skin tissue density and pathomorphological changes in the rats were observed after burn was produced on the back by contacting heat source constantly. (2) The subcutaneous temperature of the back was monitored at different time and temperatures of heat contacting by placing the thermometer under the fascia of the rat back.

RESULTS(1) The time of burn wound formation was shortened and the injury degree deepened along with the increase in the contact temperature. The rat skin density exhibited irregular hyperbola or triple curves. (2) The subcutaneous temperature exhibited a parabolic curve with fixed experimental conditions.

CONCLUSION(1) The sharp increase in subcutaneous temperature leading to degeneration and necrosis might be the primary cause of deep burn. (2) The regularity of the skin tissue injury was the result of multiple effects of heat-origin injury, increase of capillary permeability and the change in tissue mass.

Animals ; Burns ; etiology ; Female ; Hot Temperature ; adverse effects ; Male ; Models, Animal ; Rats ; Rats, Wistar ; Severity of Illness Index ; Skin ; pathology ; Time Factors ; Wounds and Injuries ; etiology

Objective: To explore the effects of citric acid on patients with severe burn complicated with acute renal injury treated by continuous renal replacement therapy (CRRT). Methods: Medical records of 83 patients with large area of burn complicated with acute renal injury admitted to intensive care unit (ICU) of our department from January 2015 to December 2018 and meeting the inclusion criteria were analyzed retrospectively. The patients were divided into heparin group [n=43, 25 males and 18 females, aged (35.0±2.5) years] and citric acid group [n=40, 22 males and 18 females, aged (37.0±6.6) years] according to different anticoagulation methods. After admission, routine support treatment and CRRT were performed after being diagnosed with acute renal injury in patients in 2 groups. Patients in heparin group were treated with low molecular weight heparin for anticoagulation with first dosage of 20 U/kg and an increase of 2.5 to 5.0 U per hour, and patients in citric acid group were given citric acid of 0.02 g/mL with dosage of 150~200 mL/h for anticoagulation. The use time of blood filter, recovery time of urine volume, and time of staying in ICU, and platelet count, activated partial thromboplastin time (APTT), prothrombin time (PT), and serum creatinine, urea nitrogen, cystatin C, procalcitonin, C-reactive protein, and neutrophil, leukocyte count, blood sugar, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and heart rate, body temperature, and mean arterial pressure before treatment and post treatment hour (PTH) 24 were recorded. Besides, occurrence of hemorrhage, hypocalcemia, metabolic acidosis, metabolic alkalosis, and death within 28 days post injury were recorded. Data were processed with t test and chi-square test. Results: The use time of blood filter of patients in citric acid group was (28.7±3.2)h, significantly longer than (19.4±2.6) h in heparin group (t=14.139, P<0.01). The recovery time of urine volume and time of staying in ICU of patients in citric acid group were respectively (7.6±0.9) and (9.6±1.3) d, significantly shorter than (9.2±1.5) and (11.2±1.8) d in heparin group (t=5.516, 4.697, P<0.01). Before treatment, there were no statistically significant differences in platelet count, APTT, and PT of patients in 2 groups (t=1.235, 0.515, 1.279, P>0.05). At PTH 24, the platelet count of patients in citric acid group was significantly higher than that in heparin group (t=10.947, P<0.01), and APTT and PT of patients in citric acid group were significantly shorter than those in heparin group (t=7.069, 9.142, P<0.01). Before treatment, there were no statistically significant differences in serum creatinine, urea nitrogen, and cystatin C of patients in 2 groups (t=1.684, 1.878, 1.472, P>0.05). At PTH 24, the serum creatinine, urea nitrogen, and cystatin C of patients in citric acid group were significantly lower than those in heparin group (t=7.778, 9.776, 5.117, P<0.01). Before treatment, there were no statistically significant differences in serum procalcitonin and C-reactive protein of patients in 2 groups (t=1.413, 0.898, P>0.05). At PTH 24, the serum procalcitonin and C-reactive protein of patients in citric acid group were significantly lower than those in heparin group (t=2.635, 2.297, P<0.05). Before treatment, there were no statistically significant differences in neutrophil, leukocyte count, blood sugar, AST, and ALT of patients in 2 groups (t=0.555, 0.816, 0.470, 1.896, 0.982, P>0.05). At PTH 24, the neutrophil, leukocyte count, blood sugar, AST, and ALT of patients in citric acid group were significantly lower than those in heparin group (t=2.054, 3.314, 7.185, 2.151, 3.013, P<0.05 or P<0.01). Before treatment, there were no statistically significant differences in heart rate, body temperature, and mean arterial pressure of patients in 2 groups (t=1.406, 0.474, 0.720, P>0.05). At PTH 24, the heart rate, body temperature, and mean arterial pressure of patients in citric acid group were significantly lower than those in heparin group (t=2.307, 4.498, 2.056, P<0.05 or P<0.01). The incidence of hemorrhage of patients in citric acid group while in hospital was significantly lower than that in heparin group (χ²=4.949, P<0.05). There were no statistically significant differences in incidence of hypocalcemia, metabolic acidosis, metabolic alkalosis, and death rate within 28 days post injury of patients in 2 groups while in hospital (χ²=3.346, 0.884, 0.297, 0.324, P>0.05). Conclusions Citric acid has significant anticoagulant effect on patients with large area of burn complicated with acute renal injury treated by CRRT, which can prolong the use time of the blood filter, shorten the recovery time of urine volume and time of staying in ICU, improve renal function indexes, blood biochemical indexes, and inflammation indexes, maintain the stability of internal environment, and reduce the risk of hemorrhage.

Objective:To explore the effects of artificial dermis combined with autologous skin in repairing the wounds with exposed bone and/or tendon in fingers of children after electric burns.Methods:A retrospective observational study was conducted. From January 2017 to December 2022, 14 children with bone and/or tendon exposed wounds in fingers after electric burns who met the inclusion criteria were admitted to Zhengzhou First People's Hospital, including 9 males and 5 females, aged 2 to 11 years. A total of 38 fingers were affected, with 1 wound per finger. After debridement, artificial dermal coverage combined with vacuum sealing drainage was performed in all the wounds in the first stage, with wound area of 2.0 cm×1.0 cm-4.5 cm×2.5 cm after debridement. The second stage surgery was performed to close the wound with autologous thin intermediate thickness skin graft. Then the children were told to perform functional rehabilitation exercise as early as possible. The survival of autologous skin graft was observed at the 7 th day after the second stage surgery. The wound healing time was recorded. After 12 months of follow-up, the Vancouver scar scale was used to evaluate the scar hyperplasia at the skin grafting site of the affected finger; the total action mobility (TAM) of the affected finger joint was measured for evaluating the functional recovery of the affected finger; a self-made efficacy satisfaction rating table was used to investigate the parents' satisfaction with the curative effect of the children. Results:At the 7 th day after the second stage surgery, all the children had good survival of autologous skin grafts. The wound healing time was (24.1±2.7) d. After 12 months of follow-up, the scar score at the skin grafting site of the affected finger was 5.2±2.4; the TAM of the affected finger joint was (177±40)°; the functional assessment was good in 12 fingers, medium in 23 fingers, and poor in 3 fingers; the parents' satisfaction with the curative effect of the children in the survey was very satisfied in 10 cases, satisfied in 3 cases, and dissatisfied in 1 case. Conclusions:The combination of artificial dermis and autologous thin intermediate thickness skin graft is an alternative surgical method that can effectively repair the bone and/or tendon exposed wounds in fingers of children after electric burns. After wound healing, the scars are slight, the finger function is well recovered, and the parents of the children are highly satisfied with the curative effect of the children, which is worthy of clinical promotion.

On March 14, 2017, a thirty years old male severe burn patient accompanied by asphyxia, sudden cardiac arrest, and acute respiratory distress syndrome was admitted to Zhengzhou First People′s Hospital. During the shock stage, the pulse contour cardiac output was monitored for the restrictive rehydration, tracheotomy was performed, and fibrobronchoscope lavage was performed for the treatment of inhalation injury and pulmonary infection. An alternate application of suspended bed and turning bed was conducted to balance the treatment of cerebral edema and pulmonary infection; targeted antibiotics were used for anti-infective treatment; multiple operations were performed for eschar excision and skin grafting. At last, the wounds were all healed, the lung infection was cured, and the patient was discharged with severe disturbance of consciousness. Asphyxia and acute respiratory distress syndrome post-cardiopulmonary resuscitation are serious complications in severe burn patients. The clinical treatment of such patients is very difficult and should be highly alerted.

Objective:To explore the value of renal injury marker protein in early diagnosis of acute kidney injury (AKI) in burn patients with delayed resuscitation.Methods:The retrospective case-control research was conducted. Forty-three burn patients with delayed resuscitation (27 males and 16 females, with age of 18-75 (35±3) years)who were admitted to Zhengzhou First People′s Hospital from May 2018 to May 2020 met the inclusion criteria. The patients were divided into AKI group with 23 patients and non-AKI group with 20 patients according to whether AKI occurred within 7 days after burns. The gender, age, deep partial-thickness burn area, full-thickness burn area, and acute physiology and chronic health evaluation Ⅱ of patients were compared between the two groups.The fluid supplement volume and serum creatinine at 12, 24, and 48 h after burn, serum albumin/fibrinogen ratio (AFR), urinary heat shock protein 70 (HSP70), tissue inhibitor of metalloproteinase-2 (TIMP-2)×insulin-like growth factor binding protein 7 (IGFBP-7), and neutrophil gelatinase associated lipocalin (NGAL)at 12, 24, 48, 72, 120, and 168 h after burn were detected.Data were statistically analyzed with Mann-Whitney U test, analysis of variance for repeated measurement, independent-samples t test, chi-square test and Bonferroni correction. The independent variable to predict the occurrence of AKI was screened by multi-factor logistic regression analysis. The receiver′s operating characteristic curve was drawn for predicting the occurrence of AKI in burn delayed resuscitation patients, and the area under the curve (AUC), the best threshold, and the sensitivity and specificity under the best threshold were calculated. Results:The gender, age, deep partial-thickness burn area, full-thickness burn area, acute physiology and chronic health evaluation Ⅱ of patients in two groups were similar ( χ2=1.98, t=1.98, 1.99, 1.99, 1.99, P>0.05). The fluid supplement volume of patients in AKI group at 24 and 48 h after burn was significantly less than that in non-AKI group ( t=15.37, 6.51, P<0.01). The serum creatinine of patients in AKI group at 12, 24, and 48 h after burn was significantly higher than that in non-AKI group ( Z=2.16, 5.62, 6.72, P<0.01). The serum AFR of patients in AKI group at 12, 24, 48, 72, 120, and 168 h after burn was significantly lower than that in non-AKI group ( t=16.14, 35.35, 19.60, 20.47, 30.20, 20.17, P<0.01). The levels of urinary HSP70 of patients in AKI group at 12, 24, 48, 72, 120, and 168 h after burn were (6.89±0.87), (6.42±0.73), (5.81±0.72), (5.17±0.56), (4.63±0.51), (3.89±0.51) μg/L, which were significantly higher than (3.89±0.75), (3.57±0.63), (2.66±0.41), (1.83±0.35), (1.48±0.19), (1.28±0.19) μg/L in non-AKI group ( t=12.00, 13.61, 17.39, 22.98, 26.34, 21.59, P<0.01). Urinary TIMP-2×IGFBP-7 and NGAL of patients in AKI group at 12, 24, 48, 72, 120, 168 h after burn were significantly higher than those in non-AKI group ( t=26.94, 101.11, 35.50, 66.89, 17.34, 14.30, 14.00, 13.78, 12.32, 14.80, 21.36, 22.62, P<0.01). Urinary HSP70 and serum AFR at 12 h after burn, urinary TIMP-2×IGFBP-7 and NGAL at 24 h after burn were included into multi-factor logistic regression analysis (odds ratio=2.42, 3.47, 7.52, 5.61, 95% confidence interval=1.99-2.95, 1.86-3.92, 2.87-9.68, 2.14-14.69, P<0.01). For 43 patients with burn delayed resuscitation, the AUC of receiver′s operating characteristic curve of serum AFR at 12 h after burn for predicting AKI was 0.739 (95% confidence interval=0.576-0.903), the optimal threshold was 9.90, the sensitivity was 82%, and the specificity was 90%. The AUC of urinary HSP70 at 12 h after burn was 0.990 (95% confidence interval=0.920-1.000), the optimal threshold was 1.40 μg/L, the sensitivity was 98%, and the specificity was 96%. The AUC of urinary TIMP-2×IGFBP-7 at 24 h after burn was 0.715 (95% confidence interval=0.512-0.890), the optimal threshold was 114.20 μg 2/L 2, the sensitivity was 91%, and the specificity was 95%. The AUC of urinary NGAL at 24 h after burn was 0.972 (95% confidence interval=0.860-1.000), the optimal threshold was 78 μg/L, the sensitivity was 95%, and the specificity was 96%. Conclusions:Urinary HSP70 and NGAL have higher value in early diagnosis of AKI in burn patients with delayed resuscitation.

Objective:To investigate the clinical effects of medical ozone autologous blood transfusion combined with Xingnaojing in the treatment of septic encephalopathy in burns.Methods:The retrospective cohort study was conducted. From August 2015 to May 2019, 90 patients with burn septic encephalopathy and conforming to the inclusion criteria were admitted to Zhengzhou First People's Hospital. Forty-six patients (25 males and 21 females, aged (35±4) years ) treated with Xingnaojing were included in Xingnaojing alone group, and forty-four patients (20 males and 24 females, aged (34±5) years) treated with medical ozone autologous blood transfusion combined with Xingnaojing were included in ozone autologous blood transfusion+Xingnaojing group. Heart rate, body temperature, mean arterial pressure, acute physiology and chronic health evaluation Ⅱ(APACHEⅡ) score and Glasgow coma score (GCS) of patients in 2 groups were recorded before treatment and on 7 d after treatment. The blood-brain barrier injury markers including occludin, nitric oxide synthase (NOS), neuron-specific enolase (NSE), central nervous system specific protein S100β, glial fibrillar acidic protein (GFAP), and excitatory amino acid (EAA) in serum of patients in 2 groups were detected before treatment and on 1, 3, and 7 d after treatment. Computer tomography perfusion imaging for brain was performed in patients of 2 groups to calculate the region of interest cerebral blood flow (rCBF), region of interest blood volume (rCBV), and region of interest mean transit time (rMTT) before treatment and on 1, 3, and 7 d after treatment. Data were statistically analyzed with chi-square test, analysis of variance for repeated measurement, independent sample t test, and Bonferroni correction. Results:On 7 d after treatment, heart rate, body temperature, and mean arterial pressure of patients in 2 groups were decreased compared with those before treatment, heart rate of patients in ozone autologous blood transfusion+Xingnaojing group was obviously higher than that in Xingnaojing alone group ( t=2.886, P<0.01), body temperature of patients in ozone autologous blood transfusion+Xingnaojing group was obviously lower than that in Xingnaojing alone group ( t=5.020, P<0.01), and mean arterial pressure of patients in 2 groups were close ( t=0.472, P>0.05). On 7 d after treatment, APACHEⅡ score of patients in ozone autologous blood transfusion+Xingnaojing group was obviously lower than that in Xingnaojing alone group ( t=3.797, P<0.01), and GCS of patients in ozone autologous blood transfusion+Xingnaojing group was obviously higher than that in Xingnaojing alone group ( t=4.934, P<0.01). On 3 and 7 d after treatment, the levels of occludin, NOS, NSE, S100β, GFAP, and EAA in serum of patients in ozone autologous blood transfusion+Xingnaojing group were significantly lower than those in Xingnaojing alone group ( t=2.100, 2.090, 2.691, 2.013, 2.474, 2.635, 2.225, 4.011, 3.150, 2.691, 3.145, 2.781, P<0.05 or P<0.01). On 1, 3, and 7 d after treatment, rCBF and rCBV of patients in ozone autologous blood transfusion+Xingnaojing group were significantly increased compared with those in Xingnaojing alone group ( t=3.127, 3.244, 3.883, 7.274, 3.661, 2.777, P<0.01). On 7 d after treatment, rMTT of patients in ozone autologous blood transfusion+Xingnaojing group was (3.02±0.57) s, which was significantly lower than (3.11±1.20) s in Xingnaojing alone group ( t=2.409, P<0.05). Conclusions:Transfusion of medical ozone autologous blood combined with Xingnaojing therapy can effectively relieve brain injury and improve cerebral blood perfusion in patients with burn septic encephalopathy, which is with safety and credibility.

Objective: To explore the clinical effect of free anterolateral thigh flap in repairing large annular soft tissue defect of lower leg after burn. Methods: From January 2014 to December 2018, 9 patients with large annular soft tissue defects of lower legs after burns were hospitalized in Zhengzhou First People′s Hospital, including 1 case with wounds on both legs. After debridement, area of wounds was 16 cm×11 cm-38 cm×21 cm, and the burn wounds were repaired with free anterolateral thigh flaps in the area of 18 cm×12 cm-32 cm×24 cm. End-to-end anastomosis of posterior tibial vessels or anterior tibial vessels with lateral circumflex femoral vessels was performed in manual way or by microvascular stapler. For the affected legs without condition for anastomosis, the sound medial lower leg flaps with areas of 10 cm×8 cm-15 cm×10 cm were excised and made into skin tubes, the posterior tibial vessels of the flaps were anastomosed with the vessels of free anterolateral femoral flaps, and the wounds of the injured lower legs were repaired by bridge-type cross-over free transplantation of anterolateral thigh flaps. The pedicles were broken 4 to 5 weeks later. The donor site was transplanted with autologous intermediate split-thickness skin graft from thigh. The outcome of the treatment, the number of perforators included in the flaps, and the anastomotic vessel in the recipient area of patients were recorded. The anastomosis time between manual way and microvascular staplers was recorded and compared. The patency of blood vessels, methods of free transplantation, and follow-up condition were recorded. Data were processed with Wilcoxon rank sum test for two independent samples. Results: All the 10 free flaps and skin grafts of 9 patients survived, and all the wounds were closed by primary operation. Seven flaps contained two perforators each, and three flaps contained three perforators each. The anastomotic vessels were posterior tibial vessels in 6 recipient areas and anterior tibial vessels in 4 recipient areas. Microvascular stapler was used to anastomose 12 veins, while 8 veins and 10 arteries were anstomosed manually. The time consumed by the former method was 4.00 (3.55, 4.38) min, significantly shorter than 12.80 (12.13, 13.40) min of the latter (W=78.00, P<0.01). The patency rates of veins and arteries were 100%. There was no vascular crisis due to vascular anastomosis. Three patients underwent bridge-type cross-over free transplantation, while the others underwent conventional free transplantation. Follow-up for 3 to 30 months showed that the donor site of the thigh had good motor function, without numbness or pain, but hypertrophy of scar could be seen. Four patients had slightly overstaffed flaps transplanted in the recipient area of the lower legs, while the other patients were satisfied with their appearance, and the walking function of the affected limbs gradually recovered. Conclusions Free anterolateral thigh flap transplantation is a safe and reliable clinical limb salvage method for the repair of large annular soft tissue defect of lower leg after burn. Intraoperative application of microvascular stapler for venous anastomosis can shorten the time of vascular anastomosis and has great clinical application value.

Objective: To explore the effects of free anterolateral femoral or medial calf flaps in the repair of severe facial burns. Methods: From January 2014 to October 2017, 18 patients with severe facial burns were admitted to Zhengzhou First People′s Hospital, including 12 males and 6 females, aged 15-78 years. Autologous intermediate split-thickness skin grafts were transplanted to replace oral mucosa in 4 patients with perforating cheek defects, and 8 patients underwent early vacuum sealing drainage and autologous intermediate split-thickness skin grafting to reduce the wound area to 14 cm×6 cm-22 cm×14 cm before flap transplantation. The wounds of 15 patients were repaired with free anterolateral femoral flaps, and the wounds of the other 3 patients were repaired with free medial calf flaps. The area of flaps ranged from 16 cm×7 cm to 24 cm×17 cm. The facial artery or superficial temporal artery was anastomosed end-to-end with lateral femoral circumflex artery or posterior tibial artery under microscope routinely and manually, and the two accompanying veins were anastomosed end-to-end by Coupler microvascular anastomat. The donor site was sutured or transplanted with autologous intermediate split-thickness skin graft. The anastomosis time of veins was recorded. The patency rate of vascular was calculated. The survival status of flaps were observed. The recovery of recipient area was observed during follow-up. Results: The anastomosis time of two veins in this group was 6-10 minutes, with an average of 8.5 minutes. The patency rates of veins and arteries were 100%. There was no vascular crisis due to the anastomosis problem. The free flaps survived well in 16 patients; one patient had hemorrhage under the flap 6 hours after operation, and the blood circulation of flaps turned well after hemostasis by surgical exploration; the other patient had 3 cm necrosis at the distal end of flap after operation, and the wound was closed after dressing change and autologous intermediate split-thickness skin grafting. The patients were followed up for 2 to 24 months after discharge. Most of the five senses function recovered. The color and texture of the flaps were not consistent with those of the normal facial skin. Some flaps were slightly swollen. Oral integrity was restored in 4 patients with perforating cheek defect with mouth opening of 2.2-3.5 cm. Conclusions Free anterolateral thigh flaps or medial calf flaps can repair severe facial burn wounds. It takes less time to anastomose venous vessels by microvascular anastomat during operation and can ensure the quality of venous anastomosis.