Objective: To observe the effect of early supplementation of exogenous carnitine on liver mitochondrial damage in severely scalded rats and to explore its pathological mechanism. Methods: Seventy-two adult female Sprague-Dawley rats were divided into sham injury group, scald injury group, and scald injury+ carnitine group according to the random number table, with 24 rats in each group. Rats in sham injury group was sham injured on the back by immersing in 37 ℃ water bath for 12 s without fluid replacement. While rats in scald injury and scald injury+ carnitine groups were inflicted with 30% total body surface area (TBSA) full-thickness scald on the back by immersing in 98 ℃water bath for 12 s. Immediately after injury, rats in scald injury group and scald injury+ carnitine group were injected with Ringer′s lactate solution with the dosage of 4 mL·kg^-1·%TBSA^-1 via tail vein according to the Parkland formula, meanwhile rats in scald injury+ carnitine group were injected with L-carnitine solution with dosage of 300 mg·kg^-1·d^-1 via tail vein from post injury hour (PIH) 1. At PIH 12, 24, 48 and 72, abdominal aorta blood and liver tissue were collected from 6 rats in each group. The serum levels of carnitine, β-hydroxybutyric acid, and ornithine carbamoyltransferase (OCT) were determined with enzyme-linked immuno sorbent assay, and the serum levels of lactate dehydrogenase (LDH), alanine aminotransferase(ALT), and aspartate transaminase (AST) was determined by automatic biochemical analyzer, Pathological changes of rats liver tissue were detected with HE staining. Data were processed with analysis of variance of factorial design and Student-Newman-Keulstest or Tamhane test, Bonferroni correction. Results: (1) Compared with sham injury group, the serum level of carnitine of rats in scald injury group was significantly lower at each time point (P<0.05), and that of scald injury+ carnitine group was significantly lower at PIH 12, 24, and 48 (P<0.05). The serum level of carnitine of rats in scald injury+ carnitine group at PIH 72 [(28.2±3.0) μg/mL] was similar to that in sham injury group[(29.4±4.0) μg/mL, P>0.05]. The serum level of carnitine in scald injury+ carnitine group was significantly higher than that in scald injury group at each time point (P<0.05). (2) The serum levels of β-hydroxybutyric acid of rats in scald injury group and scald injury+ carnitine group were significantly lower than those in sham injury group at each time point (P<0.05). The serum levels of β-hydroxybutyric acid of rats in scald injury and scald injury+ carnitine groups both showed a trend of increase, and they peaked at PIH 72 [(1.77±0.30) , (2.93±0.44) mmol/L, respectively]. The serum levels of β-hydroxybutyric acid in scald injury+ carnitine group were significantly higher than those of scald injury group at each time point (P<0.05). (3) The serum levels of OCT of rats in scald injury and scald injury+ carnitine groups were significantly higher than those of sham injury group at each time point (P<0.05). The serum levels of OCT of rats in scald injury group and scald injury+ carnitine groups both showed a trend of decrease, and they peaked at PIH 12 [(186.28±6.77), (163.38±9.34) ng/mL, respectively]. The serum levels of OCT of rats in scald injury+ carnitine group were significantly lower than those of scald injury group at each time point (P<0.05). (4) Compared with those of sham injury group, the serum levels of LDH of rats in scald injury group were significantly higher at each time point (P<0.05). Compared with those of sham injury group, those of scald injury+ carnitine group were significantly higher at PIH 12 and 24 (P<0.05), which peaked at PIH 12 [(2 226±274) U/L]. The serum levels of LDH of rats in scald injury+ carnitine group were close to those of sham injury group at PIH 48 and72 (P>0.05). The serum levels of LDH of rats in scald injury+ carnitine group were significantly lower than those of scald injury group at each time point (P<0.05). (5) The serum levels of ALT and AST of rats in scald injury group and scald injury+ carnitine group were significantly higher than those of sham injury group at each time point (P<0.05). In scald injury+ carnitine group, the serum levels of ALT of rats were significantly lower than those in scald injury group at PIH 48 and 72 (P<0.05), and the serum level of AST of rats was significantly lower than that in scald injury group at PIH 48 (P<0.05), and the serum levels of AST and ALT of rats were close to those in scald injury group at other time points (P>0.05). The serum levels of ALT and AST in scald injury+ carnitine group both showed a trend of decrease, and they peaked at PIH 12 [(260±25), (1 511±145) U/L, respectively]. (6) The liver tissue of rats in sham injury group was basically normal at each time point. The degree of liver injury of rats in scald injury+ carnitine group was lighter than that in scald injury group. The liver tissue of rats in scald injury group at PIH 72 showed obvious cytoplasm loose, liver tissue structure loss with diffuse fatty degeneration and large coagulative necrosis. Only partially scattered fatty degeneration was observed in the liver tissue of ras in scald injury+ carnitine group. Conclusions By early supplementation of exogenous carnitine, serum levels of carnitine and β-hydroxybutyric acid can be restored to normal levels faster, alleviate mitochondrial damage of hepatocytes, and maintain the metabolic stability of hepatocytes in early stage of severe scald.

Objective: To explore the influence of three-level collaboration network of pediatric burns in Anhui province on treatment effects of burn children. Methods: The data of medical records of pediatric burn children transferred from Lu′an People′s Hospital and Fuyang People′s Hospital to the First Affiliated Hospital of Anhui Medical University from January 2014 to December 2015 and January 2016 to September 2017 (before and after establishing three-level collaboration network of pediatric burns treatment) were analyzed: percentage of transferred burn children to hospitalized burn children in corresponding period, gender, age, burn degree, treatment method, treatment result, occurrence and treatment result of shock, and operative and non-operative treatment time and cost. Rehabilitation result of burn children transferred back to local hospitals in 2016 and 2017. Data were processed with t test, chi-square test, Mann-Whitney U test, and Fisher′s exact test. Results: (1) Percentage of burn children transferred from January 2014 to December 2015 was 34.3% (291/848) of the total number of hospitalized burn children in the same period of time, which was close to 30.4% (210/691) of burn children transferred from January 2016 to September 2017 (χ²=2.672, P>0.05). (2) Gender, age, burn degree, and treatment method of burn children transferred from the two periods of time were close (χ²=3.382, Z=-1.917, -1.911, χ²=3.133, P>0.05). (3) Cure rates of children with mild, moderate, and severe burns transferred from January 2016 to September 2017 were significantly higher than those of burn children transferred from January 2014 to December 2015 (χ²=11.777, 6.948, 4.310, P<0.05). Cure rates of children with extremely severe burns transferred from the two periods of time were close (χ²=1.181, P>0.05). (4) Children with mild and moderate burns transferred from the two periods of time were with no shock. The incidence of shock of children with severe burns transferred from January 2014 to December 2015 was 6.0% (4/67), and 3 children among them were cured. The incidence of shock of children with severe burns transferred from January 2016 to September 2017 was 3.9% (2/51), and both children were cured. The incidences and cures of shock of children with severe burns transferred from the two periods of time were close (χ²=0.006, P>0.05). Incidence of shock of children with extremely severe burns transferred from January 2014 to December 2015 was 57.1% (32/56), significantly higher than that of burn children transferred from January 2016 to September 2017 [34.5% (10/29), χ²=3.925, P<0.05]. Shock of 25 children with extremely severe burns transferred from January 2014 to December 2015 were cured, and shock of 9 children with extremely severe burns transferred from January 2016 to September 2017 were cured. The cures of shock of children with extremely severe burns transferred from the two periods of time were close ( χ²=0.139, P>0.05). (5) Time of operative treatment of children with moderate, severe, and extremely severe burns transferred from January 2014 to December 2015 was obviously longer than that of burn children transferred from January 2016 to September 2017 (t=2.335, 2.065, 2.310, P<0.05). Time of operative treatment of children with mild burns transferred from the two periods of time was close (Z=-0.417, P>0.05). Costs of operative treatment of children with moderate and severe burns transferred from January 2014 to December 2015 were significantly more than those of burn children transferred from January 2016 to September 2017 (Z=-3.324, t=2.167, P<0.05). Costs of operative treatment of children with mild and extremely severe burns transferred from the two periods of time were close (t=0.627, 0.808, P>0.05). (6)Time of non-operative treatment of children with mild, moderate, and severe burns transferred from January 2014 to December 2015 was obviously longer than that of burn children transferred from January 2016 to September 2017 (t=2.335, Z=-2.095, t=2.152, P<0.05). Time of non-operative treatment of children with extremely severe burns transferred from the two periods of time was close (t=0.450, P>0.05). Costs of non-operative treatment of children with moderate and severe burns transferred from January 2014 to December 2015 were obviously higher than those of burn children transferred from January 2016 to September 2017 (Z=-2.164, t=2.040, P<0.05). Costs of non-operative treatment of children with mild and extremely severe burns transferred from the two periods of time were close (t=0.146, 1.235, P>0.05). (7) Sixty-seven burn children transferred from January 2016 to September 2017 were transferred back to local hospitals for rehabilitation under the guidance of experts of the First Affiliated Hospital of Anhui Medical University, with 25 patients in 2016 and 42 patients in 2017. Effective rehabilitation rates of burn children transferred back to local hospitals for rehabilitation in 2016 and 2017 were both 100%. Conclusions The three-level collaboration network of pediatric burns treatment in Anhui province can effectively increase cure rate of children with mild, moderate, and severe burns, reduce incidence of shock of children with extremely severe burns, shorten time of operative treatment of burn children with moderate, severe, and extremely severe burns, and time of non-operative treatment of children with mild, moderate, and severe burns, reduce treatment costs of children with moderate and severe burns, and improve rehabilitation effectiveness of children transferred from Lu′an People′s Hospital and Fuyang People′s Hospital to the the First Affiliated Hospital of Anhui Medical University.