Methodological parameters to induction of seconddegree thermal injuries in experimental model

Resumo

Thermal injuries present a high severity potential, affecting adjacent organs with functional loss and even methabolic, cardiovascular and pulmonary disorders that can lead the animal to death. Over time, companion animals started to share smaller spaces and living very close to humans, due to these changes cases of thermal burns have been increasing. Therefore, studies embracing this area are needed, considering the skin tissue and its attachments loss have repercussions in thequality of the wound healing. The complexity of this kind of skin injuries does not allow in vitro experiments to clarify its pathophysiology, being necessary to use experimental animals to replicate a thermal injury corectly, in the same way that we have a diversity of methodologies for inducing termal burns, and yet there is no such padronization for the development of a type of injury. In this scenario, the purpose of the study is to stablish methodological parameters for the induction of second-degree thermal lesions. Six Wistar rats were used, creating, with the help of cubic-tipped metallic device, two lesions on the back of each animal, one in the thoracic region and the other in the abdominal region. Different temperatures (90 °C and 100 °C) were applied in different times of contact with the skin (10 s, 15 s and 20 s), each animal received a temperature and time of exposure for both lesion sites. After three days the animals were euthanized, a photographic record was created and the injured skin sites were collected to evaluate the extent of the lesion by digital planimetry. Skin samples were processed and stained with hematoxicillin-eosin. It was observed that lesions in the abdominal region with higher temperature (100 °C) and longer exposure time (15 s and 20 s) showed an expansion in the diameter of the initial thermal lesion, whereas lesions of the thoracic region with lower temperature (90 °C) and time of exposure (10 s) showed a reduction related to the initial lesion size. Regarding the histopathological parameters, it was determined that wounds performed in the thoracic region and that remained longer in contact to high temperatures (90 °C and 100 °C) presented greater severity, whereas lesions located in the abdomen and with a shorter time of exposure to high temperatures were lower. Thus, it is concluded that to obtain standardized second-degree wounds it must be applied temperatures between 90 °C and 100 °C, for 15 s or 20 s, in the thoracic region.

Referências

1. Abdullahi, A.; Amini-Nik, S.; Jeschke, M. G.
2. Animal models in burn research. Cellular
3. and Molecular Life Sciences, v. 71, no. 17,
4. p 3241-3255, 2014. https://doi.org/
5. 1007/s00018-014-1612-5
6. Albernaz, V. G. P.; Ferreira, A. A.; Castro, J. L.
7. C. Queimaduras térmicas em cães e gatos.
8. Veterinária e Zootecnia, v. 22, p. 322-334,
9. Andrews, C. J.; Cuttle, L. Comparing the
10. reported burn conditions for different
11. severity burns in porcine models: A
12. systematic review. International Wound
13. Journal, v. 14, p. 1199-1212, 2017.
14. https://doi.org/10.1111/iwj.12786
15. Blanes, L. Tratamento de feridas. In: BaptistaSilva, J. C. C. Cirurgia vascular: guia
16. ilustrado. 1. ed. São Paulo: Baptista-Silva JCC,
17. Bragulla, H.; Budras, D.; Mülling, C. H. R.;
18. Reese, S. Tegumento comum. In: König, H. E.;
19. Liebich, H.-G. Anatomia dos animais
20. domésticos: textos e atlas colorido. 1. ed.
21. Porto Alegre: Artmed, 2004.
22. Brasil. Resolução Normativa CONCEA nº
23. , de 15 de janeiro de 2018. Available
24. from: <https://www.mctic.gov.br/mctic/
25. opencms/institucional/concea/paginas/legis
26. lacao.html>. Accessed on: Apr. 25, 2018.
27. Campelo, A. P. B. S.; Campelo, M. W. S.; Britto,
28. G. A. C.; Ayala, A. P.; Guimarães, S. B.;
29. Vasconcelos, P. R. L. An optimized animal
30. model for partial and total skin thickness
31. burns studies. Acta Cirurgica Brasileira,
32. v. 26, Suppl. 1, p. 38-42, 2011.
33. https://doi.org/10.1590/S0102-86502011
34. Capella et al.
35. Braz. J. Biol. Sci., 2018, v. 5, No. 11, p. 757-764.
36. Kim, J. Y.; Dunham, D. M.; Supp, D. M.; Sen, C.
37. K.; Powell, H. M. Novel burn device for rapid,
38. reproducible burn wound generation. Burns,
39. v. 42, p. 384-391, 2016. https://doi.org/
40. 1016/j.burns.2015.08.027
41. Medeiros, A. C.; Dantas-Filho, A. M.
42. Cicatrização das feridas cirúrgicas. Journal of
43. Surgical and Clinical Research, v. 7, p. 87-
44. , 2016. https://doi.org/10.20398/
45. jscr.v7i2.11438
46. Rocha, C. L. J. V. Histofisiologia e classificação
47. das queimaduras: consequências locais e
48. sistêmicas das perdas teciduais em pacientes
49. queimados. Interdisciplinary Journal of
50. Experimental Studies, v. 1, p. 140-147,
51. Santos, C. A.; Santos, A. A. Assistência de
52. enfermagem no atendimento pré-hospitalar
53. ao paciente queimado: uma revisão da
54. literatura. Revista Brasileira de
55. Queimaduras, v. 16, no. 1, p. 28-33, 2017.
56. Singer, A. J.; Hirth, D.; McClain, S. A.;
57. Crawford, L.; Lin, F.; Clarck, R. A. F.;
58. Validation of a vertical progression porcine
59. burn model. Journal of Burn Care &
60. Research, v. 32, p. 638-646, 2011.
61. https://doi.org/10.1097/BCR.0b013e31822
62. dc439
63. Tillmann, M. T.; Felix, S. R.; Mundstok, C. P.;
64. Mucillo, G. B.; Fernandes, C. G.; Nobre, M. O.
65. Tratamento e manejo de feridas cutâneas em
66. cães e gatos (revisão de literatura). Nosso
67. Clínico, n. 103, p. 2-19, 2015.
68. Vaughn, L.; Beckel, N. Severe burn injury,
69. burn shock, and smoke inhalation injury in
70. small animals. Part 1: Burn classification and
71. pathophysiology. Journal of Veterinary
72. Emergency and Critical Care, v. 22, p. 179-
73. , 2012. https://doi.org/10.1111/j.1476-
74. 2012.00727.x
75. Wohlsein, P.; Peters, M.; Schulze, C.;
76. Baumgärtner, W. Thermal injuries in
77. veterinary forensic pathology. Veterinary
78. Pathology, v. 53, p. 1001-1017, 2016.
79. https://doi.org/10.1177/030098581664336