Prilocaine-Induced Methemoglobinemia During Surgically Assisted Rapid Palatal Expansion (SARPE) Under General Anesthesia: A Case Report.

Methemoglobinemia is a condition in which methemoglobin levels in the blood increase. Methemoglobin lacks oxygen-binding ability, resulting in oxygen deprivation in tissues. This high level of methemoglobin in the blood presents as a severely worsening condition. Herein, we report a case of methemoglobinemia caused by the administration of 3% prilocaine hydrochloride containing 0.03 IU/mL feripressin as a local anesthetic during orthognathic surgery. Following drug administration, the patient's atrial oxygen saturation (SpO) decreased. We diagnosed methemoglobinemia based on arterial blood gas analysis, which revealed an increased level of methemoglobin. To maintain the SpO level, oxygen was administered. The patient's condition improved over time. Careful monitoring and maintenance of SpO levels are essential to ensure proper diagnosis and effective management.