分離肺換気終了後も上昇する呼気終末二酸化炭素分圧から診断に至った悪性高熱症の1症例

A Patient with Malignant Hyperthermia Diagnosed Based on Persistently Elevated End-Tidal Carbon Dioxide Tension Following the Completion of One-Lung Ventilation

要旨

　閉塞性換気障害を合併した肺がん患者の肺切除術に際し，分離肺換気中に発症したため診断に難渋した悪性高熱症（malignant hyperthermia：MH）の1症例を経験した。MHの早期症状には呼気終末二酸化炭素分圧の上昇が知られているが，急激な体温上昇や代謝性アシドーシスなど，そのほかの特徴的所見にも注目し，総合的に判断することが肝要である。

　We report the case of malignant hyperthermia（MH）that developed during the provision of one-lung ventilation in a 81-year-old male with lung cancer and coexisting obstructive ventilatory impairment, which made the diagnosis particularly challenging. Although an increase in end-tidal carbon dioxide tension（EtCO₂）is a well-known early sign of MH, it is essential to also consider other characteristic features such as rapid elevation in body temperature and metabolic acidosis when MH is suspected. A comprehensive assessment of the patient’s symptoms led to the diagnosis in this case.