Rethinking the paradigm: evaluation of ketamine as a neurosurgical anesthetic

Although anesthetists have long assumed that ketamine's role in neuroanesthesia is limited because of its association with increased intracranial pressure, this article presents a review of recent clinical literature suggesting otherwise. When ketamine is used as an adjuvant anesthetic agent along with mechanical ventilation to maintain normocapnia, ketamine does not have adverse cerebral hemodynamic effects. Furthermore, ketamine possesses a unique pharmacologic profile that provides analgesia, bronchodilation, and sympathetic stimulation, thereby reducing patients' vasoactive agent requirements. Caution must be exercised because of ketamine's action at the N-methyl-D-aspartate receptor (NMDAR), as ketamine may antagonize both neuroprotective and neurodestructive NMDAR-mediated pathways. Still, ketamine may prove to be a safe part of a neuroanesthetic regimen, and it should no longer be considered absolutely contraindicated as a result of its cerebral hemodynamic effects.