Background: We aimed to investigate the effects of active mild hyperthermia and the effects of active mild hyperthermia with propofol on mortality and inflammatory responses during endotoxin-induced shock in rats.
Methods: Intravenous Escherichia coli endotoxin (15 mg/kg over 2 min) was injected in 48 rats. The animals were randomly allocated to one of the following four groups (n = 12 per group): normothermia group (group N), rectal temperature maintained between 36 °C and 38 °C; hyperthermia group (group H), rectal temperature was moderate and maintained between 39 °C and 40 °C; propofol with normothermia group (group PN), propofol (10 mg/kg/h) was administered, and temperature was between 36 °C and 38 °C; Propofol with hyperthermia group (group PH), propofol (10 mg/kg/h) administrated, and temperatures were maintained between 39 °C and 40 °C. The primary outcome was mortality 8 h after endotoxin injection. Secondary outcomes included changes in haemodynamics, arterial blood gases and plasma cytokine concentrations for the 8-h observation period.
Results: Mortality rates 8 h after endotoxin injection were 92%, 100%, 68% and 50% for N, H, PN and PH groups, respectively. There was no difference in hypotension, acidosis, and increase in plasma cytokine concentrations between N and H groups, but these parameters were attenuated in group PH.
Conclusion: The mortality rates in the present study were extremely high; further hypotension and elevations in plasma pro-inflammatory and anti-inflammatory cytokine concentrations after endotoxin injection were not attenuated by mild hyperthermia between 39 °C and 40 °C, but they were attenuated by propofol with mild hyperthermia.
© 2012 The Authors. Acta Anaesthesiologica Scandinavica © 2012 The Acta Anaesthesiologica Scandinavica Foundation.