The History of Ketamine in Neurosurgery

Introduction: Ketamine, a short-acting anesthetic first synthesized in 1962, has been steeped with a myriad of controversies. Since its creation, ketamine’s use in neurosurgery has been contentious with a recent resurgence in neuro-intensive care units. This study explores the history of ketamine, misconceptions surrounding its safety, its effect on intracranial pressure (ICP) and current applications in the field of neurosurgery.

Methods: Original sources and published literature from the early 20th century until present day were evaluated for this review.

Results: During the early 20th century, the rise in elective surgeries drove the need for new anesthetics drugs. Victor Maddox developed phencyclidine (PCP), a powerful anesthetic inducing sensory deprivation syndrome with psychotic features deemed unsuitable for human use. In response to the demand for a safe short-acting anesthetic, Calvin Stevens, synthesized a PCP-derivative known as ketamine. The FDA approval in 1970 led to ketamine’s use as sedation in combat scenarios during the Vietnam War. Simultaneously, ketamine was recognized as effective agent for pediatric neurosurgical diagnostics due to its rapid onset, non-requirement for intubation, and smooth recovery. Ketamine analgesia was described as an altered state of consciousness, neither sleep nor anesthesia, later known as “dissociative anesthesia”. During the 1970s, the emergence of newer anesthetics like propofol, along with concerns about ketamine possibly raising ICP and its stigma as a recreational drug, contributed to a decline in ketamine's use. The early studies had several biases and perpetuated fear over ketamine use in neurosurgery, primarily in relation to shunt revisions. Recent research has questioned historical findings, especially as ketamine is now used as a therapeutic intervention in traumatic brain injury patients with cortical spreading depolarizations.

Conclusion : An in-depth discussion of the many controversies of ketamine’s use and effects will help improve our awareness and understanding of its utility, effectiveness, and role in neurosurgery and neuro-intensive care.