Perioperative Anesthetic Management of Kleine-Levin Syndrome: Current Evidence, Mechanistic Rationale, and a Proposed Practice Framework.

Kleine-Levin syndrome is a rare disorder of central hypersomnolence characterized by relapsing-remitting severe sleepiness associated with cognitive impairment, derealization, apathy, behavioral change, and hyperphagia. Direct perioperative evidence remains limited and is insufficient to establish comparative safety, recurrence risk, or a preferred anesthetic technique. Reports with direct perioperative evidence described favorable immediate perioperative courses, but follow-up was heterogeneous, and the uniformly favorable published outcomes are susceptible to substantial publication bias. Most patients return to normal or near-normal function between episodes, although residual sleep, cognitive, behavioral, or autonomic symptoms persist in a subset. The perioperative period introduces factors that may obscure evaluation or disturb sleep-wake stability, including sleep disruption, physiologic stress, perioperative illness, and exposure to sedative and opioid medications. No specific perioperative trial data are available, so this narrative review synthesizes direct disease-specific evidence, mechanistic rationale, and established perioperative practice to propose a conservative, evidence-mapped framework. Disease-informed considerations include elective scheduling during a stable interepisodic period when feasible, documentation of baseline cognitive and behavioral status with collateral history, and treatment of suspected recurrence as a diagnosis of exclusion. Other considerations, including minimizing unnecessary sedatives and long-acting opioids, considering regional, neuraxial, or local techniques and opioid-sparing analgesia, using short-acting titratable agents, and applying anesthetic depth and neuromuscular monitoring, represent established perioperative practices adapted to this population. These considerations are conditional and hypothesis-generating, not formal guidelines.