Fatal Methaemoglobin Intoxication Following Ketamine Infusion in a Depressed MELAS Patient: A Possible Association?

Area of Science:

• Neurology
• Pharmacology
• Genetics

Background:

• Methemoglobinemia is an increase in methemoglobin (>2% of hemoglobin).
• Ketamine is increasingly used for treating severe depression.
• Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a rare genetic disorder.

Purpose of the Study:

• To report a case of sudden death in a MELAS patient following ketamine infusion.
• To investigate the potential role of ketamine in causing methemoglobinemia in a patient with MELAS.
• To highlight the risks associated with ketamine administration in patients with mitochondrial disorders.

Main Methods:

• Case report of a 32-year-old woman with MELAS (mtDNA variant m.3243A>G).
• Patient received a single ketamine infusion for depression and PTSD.
• Autopsy revealed a methemoglobin level of 71%.

Main Results:

• The patient experienced sudden, unexpected death 1-12 hours after ketamine infusion.
• High postmortem methemoglobin level (71%) was detected.
• Ketamine's potential mitochondrial toxicity and effect on methemoglobin reductase were discussed.

Conclusions:

• Ketamine administration requires caution in MELAS patients, especially those with a history of seizures.
• Close monitoring during and after ketamine infusion is crucial for MELAS patients.
• The case suggests a possible link between ketamine and methemoglobinemia in MELAS.