EEG AND PROGNOSIS OF NEUROLOGIC RECOVERY OF DOGS UNDER PROFOUND HYPOTHERMIC CIRCULATORY ARREST

Deep hypothermia (18-20-degrees-C) (DH) during prolonged circulatory a rrest and cardiopulmonary bypass is used to repair complex intracardia c lesions and vascular neurosurgical lesions. DH diminishes the risk o f ischemic damage and multiorgan failure after circulatory arrest. Pro found hypothermia (PH) to 6-7-degrees-C has recently been reported to improve the neurological outcome of dogs after 2 h of circulatory arre st. There are no reports of the possible utility of EEG activity to pr edict the neurological outcome. As a part of a controlled study of car diopulmonary bypass and 2 h of circulatory arrest we compared EEG reco very to the neurological outcome in 2 groups of dogs: 4 under DH and 4 under PH. All of the dogs under. PH had a good outcome: mean neurodef icit score was 6.25/500 in PH and 139.25/500 in DH dogs (P < 0.03); me an histopathological score was 19.25/100 for DH and 47.75/100 in PH do gs (P < 0.03). EEG activity 2 h after reperfusion and starting of rewa rming correlated with eventual neurological outcome. EEG variables ass ociated with good outcome were: main final frequency and degree of rhy thmicity of the activity. We conclude that PH exerted a protective eff ect for animals undergoing 2 h of circulatory arrest. EEG was a useful tool for predicting neurological outcome under the studied conditions .