Rodriguez R A, Audenaert S M, Austin E H, Edmonds H L
Department of Surgery (Neurological and Cardiothoracic), University of Louisville, Kentucky 40202, USA.
J Clin Neurophysiol. 1995 Mar;12(2):168-76. doi: 10.1097/00004691-199503000-00007.
Variations in core temperature and cerebral blood flow during open heart surgery may affect auditory brainstem responses (ABRs) and middle latency responses (MLRs) in both adults and children. We documented the changes in ABRs of two infants (ages 3 and 11 weeks, respectively) with variations in core temperature during hypothermic cardiopulmonary bypass and total circulatory arrest and compared them with those of a 19-year-old adult. Changes in MLRs that occurred in association with reductions in cerebral blood flow as monitored by transcranial Doppler are also reported in a 6-year-old child. With the reductions in temperature in both infants and the young adult, ABR latencies increased and amplitudes decreased. Effects of hypothermia on ABR latencies were completely reversed by rewarming. MLR amplitudes were transiently reduced during periods of normothermic hypoperfusion. Hypothermia partially prevented these changes, and normoperfusion after rewarming recovered MLRs. Monitoring ABRs and MLRs may be a useful technique for assessment of brain function during hypothermic cardiopulmonary bypass in children and infants.
在心脏直视手术期间，成人和儿童的核心体温及脑血流量变化可能会影响听觉脑干反应（ABR）和中潜伏期反应（MLR）。我们记录了两名分别为3周和11周大的婴儿在低温体外循环和完全循环停搏期间，随着核心体温变化其ABR的改变，并将其与一名19岁成年人的ABR变化进行比较。还报告了一名6岁儿童在经颅多普勒监测显示脑血流量减少时出现的MLR变化。随着婴儿和年轻成年人体温降低，ABR潜伏期延长，波幅降低。复温后，低温对ABR潜伏期的影响完全逆转。在常温性低灌注期间，MLR波幅短暂降低。低温部分预防了这些变化，复温后的正常灌注使MLR恢复。监测ABR和MLR可能是评估婴幼儿低温体外循环期间脑功能的一种有用技术。
