難治性ショックを伴うβ遮断薬，カルシウム拮抗薬中毒に対し集学的治療で救命し得た1例(Successful intensive management of poisoning induced by beta adrenergic blockers and calcium channel blockers with refractory shock: a case report)

要旨 40歳代の男性が意識障害で搬送された。来院時，心拍数45/分，血圧61/40mmHgと徐脈性ショックの状態だった。病歴，各種検査からβ遮断薬，カルシウム拮抗薬およびアンギオテンシンII受容体拮抗薬による急性薬物中毒を疑い，集中治療室に入室し全身管理を開始した。昇圧薬を開始したがショックの離脱に苦慮した。血液透析および持続的血液濾過透析を行ったところ循環動態は徐々に安定し，昇圧剤を漸減できた。第28病日に合併症を残すことなく独歩退院した。後日，来院時の血液検体を分析した結果，β遮断薬とカルシウム拮抗薬の血中濃度高値が確認された。原因不明の徐脈・低血圧を呈した際は循環器疾患，代謝性疾患などに加え降圧薬中毒を鑑別疾患として想起することが重要である。また，2種類の降圧薬による急性薬物中毒は，稀ではあるが致死的経過をたどることがあり，初療においてはショックを呈し，昇圧薬を使用しても蘇生に難渋する。体外循環，もしくは降圧薬の特性によっては血液浄化療法が効果的である。本症例では，とくにβ遮断薬に関しては早期の血液透析の導入が救命に寄与したと考えられた。 ABSTRACT A 40–year–old man was brought to the emergency department due to disturbance of consciousness. At the time of arrival, he was in a state of shock and was admitted to the intensive care unit for suspected acute drug intoxication. He was receiving treatment with beta–blockers, calcium channel blockers, and angiotensin II receptor blockers, which were considered the causative agents for these symptoms. Vasopressors were administered to stabilize his circulation; however, it was difficult to overcome shock. His hemodynamics were stabilized following blood purification therapy, including hemodialysis and continuous hemodiafiltration. He was discharged after 28 days without occurrence of any complications. It was later confirmed that the concentrations of a beta–blocker and a calcium channel blocker in his blood were markedly high at the time of admission. When a patient presents with unexplained bradycardia and hypotension, it is important to consider antihypertensive drug poisoning as a differential diagnosis in addition to cardiovascular and metabolic dysfunction. Although antihypertensive drug poisoning is rare in Japan, it is often fatal, presenting as shock and complicating resuscitation. Extracorporeal therapy or, depending on the pharmacokinetics, hemodialysis may be effective. Early introduction of hemodialysis, especially for beta–blockers, may have contributed to a favorable prognosis.