Study of the body thermal response during a hyperacute phase of sepsis and its correlation with mortality in rats

• Grant number: 20/16407-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2021
• End date: January 31, 2022
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Ivan Hong Jun Koh
• Grantee: Thais Mie Hoshino
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Associated research grant: 17/21052-0 - Sepsis: mechanisms, therapeutic targets and epidemiology, AP.TEM

Abstract

Sepsis is a life-threatening organ dysfunction caused by a dysregulated organism's response to an infection, with an increasing incidence and reduced mortality, thanks to the growing understanding of the pathophysiology of the disease. However, the mortality rate is still high and in Brazil, it is approximately 65%. The current therapeutic approach has been guided by changes in systemic macro-hemodynamics and not by the dynamics of regional circulation and/or microcirculation, whose evidence indicates that they precede changes in the systemic circulation. This fact is due to the lack of methods that monitor these territories non-invasively, resulting in the difficulty of diagnosing the progression of organ dysfunction and the most appropriate therapeutic moment, thus denoting the need for new technologies for the early detection of the progression of the worsening of sepsis and improving the prognosis of sepsis. Considering that there is a direct relationship between blood flow, inflammation and local tissue temperature, the objective of this research was to analyze the dysfunction of thermal regulation, central and peripheral, in the progressive stages of sepsis by non-invasive thermography, and to relate with the prognosis of sepsis and mortality. Wistar-EPM rats, from 250 to 300g will be distributed in 2 groups: Control Group, submitted to intravenous infusion of 2mL of saline solution; and Sepsis Group submitted to an intravenous infusion of 2mL of E.coli at a concentration of 100.000.000 CFU/mL. All animals will be monitored by thermography with the Flir T540 42 ° camera, at times T = 0, T = 1h, T = 2h, T = 3h, T = 4h, T = 5h, T = 6h and T = 24h (n = 5 / period). During all procedures and monitoring, the animals will be under general anesthesia with isoflurane 3% via inhalation with a continuous flow of oxygen (1.5 L / min). After thermal monitoring, animals will be kept under observation for clinical outcomes. The thermographic photos will be analyzed with the FLIR ReasearchIR Max program. The expected results are that the central and peripheral temperature, both or alone, can correlate with the progressive stages of hemodynamic dysfunction or its recovery.