Effects of deep hypothermia and circulatory arrest on the auditory brain stem responses

Zusammenfassung

Die Latenz der akustischen Hirnstammpotentiale verlängert sich mit Absinken der Körpertemperatur. Dabei ist die Latenz der späteren Komponenten mehr verlängert als die der früheren. Alle Potentiale verschwinden ab einer Körpertemperatur unter 25° C sowie bei artifizieller Unterbrechung der Blutzirkulation. Steigt die Körpertemperatur an, so werden die Latenzen erst bei Erreichen von 34° C wieder normal. Die akustischen Hirnstammpotentiale scheinen so Auskunft über die Funktion des Hirnstammes während schwerer Hypothermie zu geben.

Summary

The effects of hypothermia on auditory brain stem response (ABR) in both children with congenital heart disease undergoing cardiac surgery and cats as an animal model were investigated. The latency of the ABR waves were prolonged with decreased body temperature. The latency of the later response components were prolonged more than that of the earlier response components; all waves disappeared below 25° C and during artificial cardiac arrest. When the body temperature was raised, the later component began to reappear above 25° C; the latency of all components shortened with temperature until normal responses were obtained at 34° C. The data from both humans and cats were comparable. The ABR seems to be a useful monitor for evaluating brain stem function during deep hypothermia.