Evoked Responses Monitoring in the Intensive Care Unit

Publisher Summary This chapter discusses evoked responses monitoring in the ICU. Experimental and clinical data exist that link changes in the SERs with acute changes in cerebral blood flow, cerebral perfusion pressure, hypoxia, ischemia, and compressive lesions. As flow continues to fall because of either focal ischemia or systemic hypotension, membrane homeostasis fails with the initial mild efflux of potassium from the cell and edema formation followed by massive effluxes of potassium and increased edema formation. Depending on the depth and duration of ischemia, infarction of the brain may occur. Every physician involved in the care of severely head-injured patients in the surgical intensive care unit has faced the problem of neurologically evaluating a patient in chemical paralysis or barbiturate coma. These patients do not lend themselves to the classical neurologic evaluation and therefore, the physician must rely on physiological parameters recorded at bedside and the CT scan.