SNACC: 35 Years of Progress in Neuroanesthesia

he Society of Neurosurgical Anesthesia and Critical Care (SNACC) started life 35 years ago as a multidisciplinary group of anesthesiologists and neurosurgeons with a shared vision to create and disseminate knowledge about neurosurgical perioperative care. The previous decades had seen the development of techniques for the measurement of cerebral blood flow, metabolism, intracranial pressure and neurochemical compounds. These new research tools were used to examine the effects of anesthetics on cerebral blood flow and metabolism, on cerebrovascular responses after traumatic brain injury and on the dynamics of intracranial hypertension.¹

A consistent focus on original scientific research has remained an important characteristic of SNACC. At annual meetings, held immediately prior to the ASA Annual Meeting, a large proportion of time is allocated for presentation of scientific work: Typically more than 100 posters will be presented (to a total of 200-plus attendees), making SNACC one of the most research-driven subspecialty societies in anesthesiology. Junior researchers are encouraged to submit and present their work at the annual meeting, and various awards and travel grants serve as further incentives to our junior members. In addition at the SNACC Annual Meeting, there will up to two keynote speakers who present the latest in cutting-edge basic neuroscience. Recent topics have included neurodevelopment, neural repair, stem cell research, neuroprotection, preconditioning, anesthetic neurotoxicity and central nervous system (CNS) inflammation. The importance of these topics for clinical practice may not always seem obvious at the time, but these lectures are always well received. Many of the topics presented several years ago, which may have seemed esoteric at the time, have recently found clinical application.

SNACC is increasingly aware of the need to practice “evidence-based neuranesthesia.” For example in the 1990s, a large number of studies showed significant neuroprotection by mild hypothermia in experimental models of cerebral ischemia. This prompted clinicians to induce mild hypothermia intraoperatively in their patients undergoing surgical clipping of cerebral aneurysms. The Intentional Hypothermia for Aneurysm Surgery Trial, or HAST-2, study was designed to test the hypothesis that this practice will improve neurological outcome.

The study protocol for this randomized, controlled trial was designed and executed by a group of highly committed neuroanesthesiologists and neurosurgeons. A total of 1,001 patients undergoing aneurysm surgery were randomized to intraoperative mild hypothermia or normothermia — with only a single patient lost to follow up. The results showed that there was no clinical benefit of routinely cooling these patients,² which underscores the need to rigorously test neuroprotective strategies that seem promising in the experimental setting in clinical trials before incorporating them in clinical practice.

Some important adverse neurologic outcomes are too rare to study in randomized trials. The ASA Postoperative Visual Loss Registry aims to increase our knowledge about causes and contributing factors to this rare but disastrous postoperative complication. These ongoing, important efforts highlight the maturation of the Society — from one whose members primarily generated basic research — into an organization that defines how neuroanesthesia is practiced around the world.

SNACC’s official journal is the Journal of Neurosurgical Anesthesiology (JNA), which is produced under the able leadership of James E. Cottrell, M.D., and John D. Hartung, Ph.D. Founded in 1989, the journal publishes original material in the form of clinical and laboratory investigations, clinical reports, review articles, journal club synopses of current literature, presentation of points of view on controversial issues, book reviews, correspondence and selected abstracts from affiliated neuroanesthesiology societies. Neuroanesthesia societies from Austria, France, Germany, Japan, Korea, Mexico, Switzerland and the United Kingdom also have chosen JNA as their official journal.

Most of SNACC’s clinician members practice neuroanesthesia on a daily basis, and their interests typically focus on anesthesia and the CNS. Many exciting new areas in anesthesiology can be considered “neuron” anesthesia, but they are not necessarily linked to the practice of anesthesia for neurosurgery. Some examples that have captured the interest of SNACC members are: neurologic complications of carotid endarterectomy, cardiac and noncardiac surgery, intraoperative and intensive care unit neuromonitoring, visual loss due to ischemic optic neuropathy, quantitative evaluation of hypnosis and analgesia, and neurocognitive decline after surgery.

As a result of this widened scope, SNACC recently redefined its mission as: an organization dedicated to improving the perioperative and intensive care of patients, who are neurologically impaired or at risk of developing neurological complications, through advances in medicine and research.

Despite a decrease in membership in many anesthesiology subspecialty organizations, SNACC membership has remained at a stable 400-plus anesthesiologists and basic scientists worldwide, half of whom typically visit the annual meeting. One element of this stable membership has been an increasing proportion of overseas (non-U.S.) members during the last decade. This makes SNACC a truly international anesthesiology subspecialty organization. With the widened scope, we encourage those who traditionally do not consider themselves to be neuroanesthesiologists, but who are actively engaged in some aspect of the wider neuroscience community, to join SNACC.

To join, please complete and submit an online SNACC membership application form (which can be found on the SNACC Web Site: www.snacc.org.

References:
1. Albin MS. Celebrating silver: The genesis of a neuroanesthesiology society. J Neurosurg Anesthesiol. 1997; 9:296-307.
2. Todd MM, Hindman BJ, Clarke WR, Torner JC. Intraoperative Hypothermia for Aneurysm Surgery Trial (IHAST) Investigators. Mild intraoperative hypothermia during surgery for intracranial aneurysm. N Engl J Med. 2005; 352:135-145.
3. Lee LA, Roth S, Posner KL, et al. The American Society of Anesthesiologists Postoperative Visual Loss Registry: Analysis of 93 spine surgery cases with postoperative visual loss. Anesthesiology. 2006; 105:652-9; quiz 867-868.

Cor J. Kalkman, M.D., Ph.D., Division of Perioperative Care and Emergency Medicine, University Medical Center, Utrecht, the Netherlands.