緩和ケアにおけるモルヒネ関連の木様胸症候群：症例報告

Wooden chest syndrome (WCS) is a rare, life-threatening complication of opioid use, characterized by chest wall rigidity and respiratory compromise. While most commonly associated with rapid intravenous fentanyl, we report a case of WCS following intravenous morphine and midazolam administration in a palliative care patient with metastatic lung sarcoma. The patient, who had a "do-not-intubate" (DNI) order, received morphine and midazolam for severe pain and dyspnea. Shortly after administration, he developed acute rigidity, including neck extension and trismus, consistent with WCS. Despite further sedative and analgesic administration, respiratory distress worsened leading to patient's death. The case highlights the diagnostic and therapeutic challenges of WCS in palliative care, particularly when airway interventions are limited by goals-of-care directives. It underscores the need for heightened clinical awareness and the development of alternative management strategies for WCS when intubation is contraindicated, as well as the potential role of the interaction between morphine and midazolam in triggering this syndrome.