Thermal distribution, physiological effects and toxicities of extracorporeally induced whole‐body hyperthermia in a pig model

Abstract

Background Extracorporeally induced whole‐body hyperthermia (eWBH) might be a beneficial treatment in cancer patients. Objectives of this pig study were to assess thermal distribution, (patho‐)physiological effects, and safety of eWBH with a new WBH device. Methods Fourteen healthy adult pigs were anesthetized, mechanically ventilated, and cannulated; 12 were included in the analysis. Blood was heated in 11 pigs (one pig served as control) using a WBH device (Vithèr Hyperthermia B.V.) containing two separate fluidic circuits and a heat exchanger. Temperature was monitored on nine different sites, including the brain. Core temperature (average of 4 deep probes) was elevated to 42°C for 2 hr. Results Elevation of core body temperature to 42°C took on average (± standard deviation) 38 ± 8 min. Initially observed temperature spikes diminished after lowering maximal blood temperature to 45°C. Hereafter, brain temperature spikes never exceeded 42.5°C, mean brain temperature was at highest 41.9°C during maintenance. WBH resulted in increased heart rates and decreased mean arterial pressures. The vast amounts of fluids required to counter hypotension tended to be smaller after corticosteroid administration. Hemodialysis was started in three animals (potassium increase prevention in two and hyperkalemia treatment in one). Severe rhabdomyolysis was observed in all pigs (including the control). All animals survived the procedure until planned euthanasia 1, 6, or 24 hr post procedure. Conclusion Fast induction of eWBH with homogenous thermal distribution is feasible in pigs using the Vithèr WBH device. Severe hemodynamic disturbances, rhabdomyolysis, and hyperkalemia were observed.

On the Possibility of a Microwave Approach for Rooms and Objects Sterilization

“…Even if it does not completely resolve the problem, the induced reduction of the virus strength induces the consequent reduction of the immunity reaction of the body. This, in turn, allows the use of many drugs which have been to show efficient but only at low virus levels [13][14][15][16][17]. We have chosen the frequency of 2.15GHZ because it is the working frequency of the microwave ovens, as it is strongly absorbed by the water.…”

“…On this line of argument, we have proposed the idea of exploiting hyperthermia against COVID-19 to reduce the viral load and the Before going on, we must observe that a temperature increase is a strong enemy of the virus and of the Covid virus as well. In particular, it has been verified that the virulence of the covid starts to rapidly decrease when the temperature increase over 40°C [5][6][7][8][9][10][11][12][13][14][15][16].…”

“…corresponding immune reaction. We note that the idea of using heat against Covid and other disease is not new [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. In particular, radiofrequency electrical hyperthermia has been investigated [19][20][21][22][23][24][25][26].…”

An innovative high frequency hyperthermia approach against SARS-CoV-2 and related virus: feasibility analysis

“…Dewhirst et al (18) provided an exhaustive report of the time-temperature damage threshold of the human organs, having shown that animal tissues can tolerate temperature of 43-43.5°C for several hours without irreversible damage. Successive studies carried out in pigs (19) demonstrated that blood heating to 45 and 48 °C through an extracorporeal circulation device was effective in maintaining body temperature around 42-42,5 °C without major damages in organs, including brain; a sever rhabdomyolysis, which was not described by other laboratories, was, instead, observed. However, the WBHT as well as the local hyperthermia are currently used as an adjuvant therapy against many cancers, to increase the cytotoxic effect of many chemotherapeutic agents.…”

An Innovative High Frequency Hyperthermia Approach against SARS-Cov-2 and Related Virus: Feasibility Analysis

“…Dewhirst et al (18) provided an exhaustive report of the time-temperature damage threshold of the human organs, having shown that animal tissues can tolerate temperature of 43-43.5°C for several hours without irreversible damage. Successive studies carried out in pigs (19) demonstrated that blood heating to 45 and 48 °C through an extracorporeal circulation device was effective in maintaining body temperature around 42-42,5 °C without major damages in organs, including brain; a sever rhabdomyolysis, which was not described by other laboratories, was, instead, observed. However, the WBHT as well as the local hyperthermia are currently used as an adjuvant therapy against many cancers, to increase the cytotoxic effect of many chemotherapeutic agents.…”