Anesthetic Management of a Rare Case of a Lactating Mother with Congenital Methemoglobinemia Undergoing Laparoscopic Surgery: A Case Report

Background: Methemoglobinemia is an uncommon hematological condition in which hemoglobin contains iron in an oxidized (Fe³+) state with limited oxygen-carrying ability. It can be congenital or acquired. Anesthetic management of methemoglobinemia poses a great challenge, as there is a risk of refractory hypoxemic crisis in the perioperative period. Case: Here, we present a case of a 24-year-old female with congenital methemoglobinemia who presented with gallstone disease for laparoscopic cholecystectomy under general anesthesia. She had a deficiency of cytochrome B5 reductase, which contributed to 26% of methemoglobin levels on co-oximetry. Despite taking considerable precautions to avoid hypoxemic episodes and metabolic acidosis, an episode of desaturation happened at the end of the procedure, which was managed with intravenous methylene blue. The patient recovered without any hypoxemic insult. Conclusion: Anesthetic management of patients with moderate (20% - 30%) methemoglobinemia can be successful with extreme precautions to avoid events that can increase the methemoglobin levels and adequate preparation and availability of intravenous methylene blue.