Neuroanesthesia and outcomes: evidence, opinions, and speculations on clinically relevant topics

Purpose of review The objective of this review is to identify outstanding topics most relevant to neuroanesthesia practice and patient outcomes. We discuss the role of awake craniotomy, choice of general anesthetic agents, monitoring of anesthetic 'depth', mannitol-induced diuresis, neurophysiological monitoring, hyperventilation, and cerebral hypoperfusion. Recent findings Awake craniotomy, although a technique likely underused, is associated with enhanced recovery after surgery and prolonged survival after brain tumor resection compared with surgery under general anesthesia. The choice of general anesthetic must balance patient and surgical factors. Although propofol may be associated with favorable oncologic outcomes, currently available retrospective evidence does not specifically address neurosurgical patients. Both the definition and monitoring of anesthetic 'depth' remains elusive. Neuroanesthesiologists need to recognize and manage intraoperative light anesthesia in a timely fashion. Further evidence related to the optimal management of mannitol-induced diuresis and hyperventilation in neurosurgical patients is needed. Contemporary neurophysiological monitoring can reasonably detect intraoperative neurologic injury; however, its effect on patient outcome is unclear. Finally, cerebral hypoperfusion without stroke may be common; however, the clinical significance requires further investigation. We provide an overview of several topics that are relevant to neuroanesthesia practice and patient outcomes based on evidence, opinions, and speculations. Our review highlights the need for further outcome-oriented studies to specifically address these clinically relevant issues.