Re-evaluation of the applicability of ketamine in neurosurgical anesthesia

ABSTRACT

Traditionally, Ketamine has been considered to be contraindicated in neurosurgical patients due to the risk of intracranial hypertension. The evidence for this contraindication originated from early case reports and case-control studies which were inadequately designed and controlled. However, several recent articles indicate that ketamine can be safely used in traumatic brain injured patients treated with mechanical ventilation and that there is no significant increase in the intracranial pressure (ICP). Ketamine is an N-methyl-D-aspartate antagonist. It is believed to provide neuroprotection through a reduction in the glutamate excitotoxicity. This evidence is based on in vitro and animal studies. However, studies about its neuroprotective effects in humans are scarce. Data to recommend ketamine as first-line anesthetics for neurosurgery are insufficient, but ketamine as an adjuvant anesthetic agent may have benefits for neurosurgical patients, such as traumatic head injured patients with unstable hemodynamics. Therefore, ketamine should not be considered as absolutely contraindicated for neurosurgical patients and adequately powered, high-quality randomized controlled studies are needed to provide clinical evidences.