Abstract:

Abstract:Objective To observe the electroencephalogram (EEG) changes of asphyxial cardiac arrest (ACA) after hypoxic preconditioning (HP) in rats and investigate the activity of EEG in brain ischemic tolerance. Methods Sixty male Wistar rats were randomly assigned to three groups: ①ACA group (n=20),the rats  were subjected to 1 min of ACA and then resuscitated; ② HP+ACA group (n=20),the rats were pretreated with 4 times of 1 min HP 24 h before ACA;③HP group (n=20),the rats  were treated with 4 times of 1 min HP. The mortality, EEG, time from initiation of asphyxia to CA (TCA) and time from resuscitation to restoration of spontaneous circulation (TROSC) were recorded; neuro-functional outcome was assessed by neurodeficit score (NDS). Results The mortality was 5% in HP+ACA group and 30% in ACA group (P<0.01); compared with ACA group, the rats in HP+ACA group showed much shorter TCA and significant longer TROSC（P<0.01）. NDS in HP+ACA group was greatly better than in ACA group (P<0.01); the time to EEG silence and restoration of EEG were significantly shorter in HP+ACA group (P<0.05). Conclusion  Hypoxic preconditioning can induce brain ischemic tolerance through EEG activity modulation.

Key words: hypoxic preconditioning, brain ischemia, electroencephalogram