Clinical applications of auditory evoked potentials in ICU / 中国小儿急救医学

ABSTRACT

In critically ill patients,evoked potential(EP) testing is an important tool for measuring neurologic function,signal transmission,and secondary processing of sensory information in real time.EP potential measures conduction along the peripheral and central sensory pathways with longer-latency potentials representing more complex thalamocortical and intracortical processing.In critically ill patients with limited neurologic exams,EP provides a window into brain function and the potential for recovery of consciousness.Brainstem auditory EP and cortical event-related potentials are most commonly used in ICU.The primary indications for EP in critically ill patients are prognostication in anoxic-ischemic or traumatic coma,monitoring for neurologic improvement or decline,and confirmation of brain death.Historically,EP has been regarded as a negative prognostic test,that is,the absence of cortical potentials are associated with poor outcomes while the presence cortical potentials are prognostically indeterminate.In recent studies,the presence of middle-latency and long-latency potentials as well as the amplitude of cortical potentials is more specific for good outcomes.Event-related potentials,particularly mismatch negativity of complex auditory patterns,is emerging as an important positive prognostic test in patients under comatose.In infants,other than anoxic-ischemic or traumatic brain injury,brainstem auditory is also widely used in premature baby,bilirubin encephalopathy and detection of possible hearing loss.