Practice and Principles of Neuroanesthesia for Imaging and Neurosurgery

An understanding of the interactions between anesthetic agents and neuronal pathophysiology is necessary for the rational management of patients with central nervous system (CNS) disease or trauma. Patients with neurologic diseases may potentially recover in a worse condition because of the effects of anesthetic drugs on CNS blood flow and pressure. Cranial nerve function is decreased after induction as the arterial blood containing anesthetic drugs will be flowing after induction through the basilar artery, reaching the cranial nerves. The Cushing reflex is a vasopressor/physiologic response to severely increased intracranial pressure (ICP) and can be characterized by systemic hypertension and profound bradycardia. An acute increase in ICP during anesthesia can be a severe setback in patients presenting with pre-existing elevated ICP. Monitoring nociception (pain stimulation perception) and antinociception during neuroanesthesia is done presently with heart rate, blood pressure monitoring, and, in some cases, respiratory rate when the patient is not on a mechanical ventilator.