Burst Suppression EEG during Hypothermia and Rapid Rewarming in Isoflurane-Anesthetized Rats

Induced hypothermia is known as an efficient neuro-protectant, while rapid posthypothermic rewarming has harmful effects on neural system and worsens cerebral injury. This study investigated burst suppression (BS) pattern in EEG during moderate hypothermia and rapid rewarming in 9 isoflurane-anesthetized rats. Temperature-induced changes were observed in BS features throughout the experiment: maximum BS ratio and burst amplitude, and minimum suppression amplitude appeared at the lowest temperature; BS pattern reappeared after rapid posthypothermic rewarming. In addition, it was observed that respiratory rate changed markedly between normothermia and moderate hypothermia while no significant fluctuation was observed in heart rate during the whole experiment. All these findings may have relevance to establish suitable protocol for therapeutic hypothermia in clinic.