超高齢の偶発性低体温症に対しVA–ECMOにより復温し救命し得た1例(Life–saving VA–ECMO rewarming in the oldest old with accidental hypothermia: a case report)

要旨 偶発性低体温症（accidental hypothermia: AH）により難治性心室細動を来した超高齢者に対し，補助人工心肺であるVA–ECMO（veno–arterial extracorporeal membrane oxygenation）を用いて救命し得た。症例はADL（activities of daily living）良好な90歳の女性。某年3月，浴槽内で意識障害の状態を発見され救急要請となった。当院搬送時，血圧41/26mmHg, 心拍数 37/分，呼吸数 6/分，膀胱温 24℃と高度低体温症で，ブランケットによる復温を開始した。心室細動を来し電気ショックで洞調律に復調したが，その後も心室細動となり難治性心室細動と判断した。超高齢だがADLを考慮し，家族に説明してVA–ECMOにより復温，および体外循環の確立を図る方針とした。導入後，復温したのち心室細動は収束した。翌日にVA–ECMOを離脱，第3病日に人工呼吸器を離脱した。その後，全身状態良好で転院した。体外循環式心肺蘇生法は難治性かつ可逆性の心停止に有効で，AHでVA–ECMOによる復温が奏功した報告は多い。一方，AHは高齢者に多く，超高齢者に侵襲的な中枢加温の導入は一般的に難しい。しかし，超高齢でも蘇生条件とADL次第で，難治性心室細動を伴うAHの循環不全に対して体外循環式心肺蘇生法を検討する必要がある。 ABSTRACT Veno–arterial extracorporeal membrane oxygenation (VA–ECMO) was used to save the life of an oldest old patient who developed refractory ventricular fibrillation due to accidental hypothermia (AH). The patient was a 90–year–old woman. In March, she became unconscious in a bathtub. During the transport, her vitals were a blood pressure of 41/26mmHg, heart rate of 37beats/min, and bladder temperature of 24oC, indicating severe hypothermia. The patient developed ventricular fibrillation which was converted to normal sinus rhythm with electrical shock. She, however, developed subsequent ventricular fibrillation. She was an oldest old patient, but we took her ADL into consideration. Thus, we performed rewarming and established extracorporeal circulation using VA–ECMO. The patient rewarmed after VA–ECMO implementation and then ventricular fibrillation was restored to normal sinus rhythm. VA–ECMO was withdrawn the following day. Extracorporeal cardiopulmonary resuscitation is effective for refractory and reversible cardiac arrest, and many reports have been made on successful rewarming using VA–ECMO for AH. AH is common in oldest old individuals and active core rewarming are generally difficult to implement in them. Even in the oldest old individuals, however, extracorporeal cardiopulmonary resuscitation should be considered using VA–ECMO for circulatory failure due to AH if they have good ADL function.