Apnea with ketamine sedation in a patient with severe anorexia nervosa: A case report

There is a paucity of literature around sedation and anesthesia in patients with severe anorexia nervosa. Chronically malnourished patients are known to have myopathy, neuropathy, and altered neurotransmitter signaling. Ketamine is a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist that is an established general anesthetic and short-acting dissociative analgesic agent. It generally has a reassuring adverse event profile and rarely has been reported to result in apnea. We aim to raise awareness of this untoward adverse event in patients with severe anorexia nervosa among sedation providers and those referring patients for hospitalization or sedation.

We describe an episode of apnea, a rare adverse event of ketamine, which was given for procedural sedation to a severely malnourished 13-year-old female with anorexia nervosa, generalized anxiety disorder, and high-functioning autism spectrum disorder. She had no history of apnea nor of ketamine sedation. She was given a standard dose of ketamine and had no other central nervous system depressants within 24 h. Within 1 min after slow medication administration, she had a 9-min period of apnea without laryngospasm. She was supported with bag-valve-mask ventilation throughout this period and did not require intubation. She returned to baseline shortly after procedural sedation.

This case describes apnea after ketamine sedation in a patient with severe anorexia nervosa. It supports the importance of a thorough pre-procedure review of a patient's underlying medical problems and the consideration of how sedatives may interact with these conditions. We aim to alert those who care for this complex population of the possible altered neurotransmitters, myopathy, and adverse response to sedation, anesthetics, and analgesics.