[Auditory brainstem response in dead on arrival cases].

Abstract

The relationship between ABR on the one hand and acid-base balance, EEG findings and prognosis on the other was studied in 47 cases of DOA. As for the acid-base balance, the balance tipped to acidosis in almost all cases. The ABR showed wave I to wave V in 25 cases, wave I to wave III in 2 cases and only wave I or no response in 20 cases on the admission day. The EEG was isoelectric in 27 out of 35 cases. All the patients who showed some activity in EEG had ABR which showed waves I through V. However, 11 of the 27 patients who were isoelectric EEG showed wave I through V potentials in ABR. By the relationship between EEG and ABR, the cases could be classified into 4 types, namely, 1) there are EEG activities with ABR showing up to wave V and the other types EEG are isoelectric with ABR findings that 2) wave V appears, 3) wave V disappears to leave wave I-III and 4) only I wave or becomes no response. The acid-base balance of the cases was inclined to acidosis; therefore, the effect of acidosis on ABR, EEG and disturbance of the brain tissue due to anoxic state wave suspected. Prognosis of DOA cases was poor and 87.2% died. All the patients who exhibited no response in ABR and isoelectric EEG at anytime of their course, died eventually. These findings suggest that combination of EEG and ABR enables one to learn more exactly the central function in those with disturbance of consciousness.