Anaesthesia for neuroimaging and interventional neuroradiology

Many factors contribute to the potentially hazardous anaesthetic environment where neuroradiological investigations and procedures are performed, increasing the risk of untoward anaesthetic events (e.g. airway disconnections and accidental removal of vascular catheters). The general principles of neuroanaesthesia must be applied at all times. Caring for patients with neurological problems in this environment requires the presence of an experienced neuroanaesthetist supported by highly trained anaesthetic assistants, and anaesthetic/monitoring equipment of operating theatre standard. Meticulous attention to detail is necessary during transfer of critically ill patients to these departments. Staff should be familiar with the safe management of patients with external ventricular drains, in whom sudden cerebrospinal fluid shifts could be catastrophic. Measurement of intracranial pressure should be continued if already in progress. Ionizing radiation and strong magnetic fields raise important safety issues for both patients and staff. The precautions that need to be taken to create a safe environment are discussed in this article, as are specific issues that need to be considered during interventional procedures, including coiling of cerebral aneurysms, treatment of vasospasm, and carotid and vertebral artery stenting. Many patients receive significant doses of contrast agents, and measures taken to minimize the risk of contrast medium-induced nephropathy are discussed. Hospitals should have a named consultant anaesthetist with responsibility for anaesthesia services in departments of radiology and/or MRI units.