Anesthetic care for patients with anti-NMDA receptor encephalitis

Abstract

Introduction: Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis, an autoimmune disorder resulting from antibodies directed against the NMDA (glutamate) receptor, is the second most frequent cause of immune-mediated encephalitis. To date, the information related to the anesthetic care of children with this disorder is limited to anecdotal reports.

Methods: We reviewed the anesthetic care of six patients with anti-NMDA receptor encephalitis who underwent 21 procedures at our institution from 2014 through 2019.

Results: The study cohort included six patients, ranging in age from 2 to 18 years, who required anesthetic care during 21 procedures. Airway management included a laryngeal mask airway (n = 8), endotracheal intubation (n = 12), and native airway with spontaneous ventilation (n = 1). Intravenous (IV) induction with propofol was used in 17 procedures for five patients, including three that required rapid sequence intubation using rocuronium or succinylcholine. Inhalation induction with sevoflurane in nitrous oxide (N₂O)/oxygen (O₂) was chosen for two procedures in two patients. A combination of both induction techniques was used for two patients in two procedures. Maintenance anesthesia was accomplished with a volatile agent, predominantly sevoflurane, for 18 of the 21 procedures; propofol infusion for one procedure; and single dose of propofol was used for two short procedures. N₂O was not used for maintenance anesthesia in any of the encounters. None of the patients exhibited adverse events, including hemodynamic instability, thermoregulatory problems, or respiratory events perioperatively. Postoperatively, there was no observed deterioration in clinical status attributed to anesthetic care.

Discussion: Multisystem involvement in anti-NMDA receptor encephalitis includes memory loss, behavior irregularity, psychosis, arrhythmias, blood pressure (BP) instability, and hypoventilation. In our study cohort, we noted no intraoperative issues and deterioration in clinical status following the use of volatile anesthetic agents, opioids, dexmedetomidine, and propofol for general anesthesia (GA) or sedation. As ketamine, xenon, and N₂O mediate their anesthetic effects, primarily, through antagonism of NMDA receptors, theoretical concerns suggest that they should be avoided.

Keywords: Anti-NMDA receptor encephalitis; NMDA receptor; autoimmune; encephalitis.