Intraoperative Seizures: Anesthetic and Antiepileptic Drugs.

BACKGROUND: Epilepsy is a common condition with up to 1% prevalence in the general population. In the perioperative course of neurologic surgery patients, the use of prophylactic and therapeutic antiepileptic drugs is a common practice. Nonetheless, there is limited evidence supporting the use of prophylactic antiepileptics to prevent perioperative seizures and there are no guidelines for which anesthetic technique is preferred. OBJECTIVE: To discuss the seizurogenic potential of anesthetic drugs and to discuss intraoperative seizures in neurosurgical patients. METHOD: We performed a search of the literature available in PubMed and Ovid MEDLINE. We also included articles identified in the review of the references of these articles. RESULTS: The incidence of seizures is heterogenic among neurosurgical patients. Seizure prophylaxis is widely administered despite limited available evidence of its effectiveness. In epileptic patients, the recommendation is to continue antiepileptic drugs in the perioperative setting. In these patients, anesthesiologists may also limit the use of medications that alter the seizure threshold and avoid medications that pose significant pharmacological interaction with antiepileptic drugs. CONCLUSION: In conclusion, a knowledgeable multidisciplinary perioperative team is essential to avoid, identify and treat intraoperative seizures competently. In patients with a history of epilepsy it is recommended to continue antiepileptic therapy. Therefore, clinical judgment should guide the decision of administering seizure prophylaxis in neurosurgery patients according to an individual assessment of potential risk for seizures. Furthermore, there is a need for randomized controlled trials that support new protocols and/or guidelines for anesthetic and perioperative regimens to prevent and treat intraoperative seizures.

The Role of Permissive and Induced Hypotension in Current Neuroanesthesia Practice.

BACKGROUND: Induced hypotension (IH) had been used for decades in neurosurgery to reduce the risk for intraoperative blood loss and decrease blood replacement. More recently, this method fell out of favor because of concerns for cerebral and other end-organ ischemia and worse treatment outcomes. Other contributing factors to the decline in its popularity include improvements in microsurgical technique, widespread use of endovascular procedures, and advances in blood conservation and transfusion protocols. Permissive hypotension (PH) is still being used occasionally in neurosurgery; however, its role in current anesthesia practice remains unclear. Our objective was to describe contemporary utilization of IH and PH (collectively called PH) in clinical practice among members of the Society for Neuroscience in Anesthesiology and Critical Care (SNACC). METHODS: A questionnaire was developed and distributed among SNACC members that addressed practice patterns related to the use of PH. The responses were analyzed based on the number of individuals who responded to each specific question. RESULTS: Of 72 respondents, 67.6% reported over 10 years of clinical experience, while 15.5% reported 5-10 years of post-training experience. The respondents admitted to providing anesthesia for 300 (median) neurosurgical cases per year. PH was applied most commonly during open interventions on cerebral aneurysms (50.8%) and arteriovenous malformations (46%). Seventy-three percent of respondents were not aware of any complications in their practice attributable to PH. CONCLUSION: PH is still being used in neuroanesthesia practice by some providers. Further research is justified to clarify the risks and benefits of PH in modern neuroanesthesia practice.