腰椎固定術前の局所浸潤麻酔が偶発的に脊髄くも膜下麻酔を来したと考えられた症例

A Case of Incidental Spinal Anesthesia Caused by Local Anesthetic Infiltration with Levobupivacaine before Lumbar Spinal Fusion Surgery

要旨

　79歳，男性の腰椎固定術の開始前にレボブピバカインを用いた局所浸潤麻酔が施行された。手術中に下肢の運動誘発電位の反応が消失して血圧が低迷し，全身麻酔覚醒後にT4以下の知覚消失と両下肢運動障害を認めた。局所浸潤麻酔施行320分後に神経症状は消失し，局所浸潤麻酔が偶発的に脊髄くも膜下麻酔を来したと考えられた。

　A 79-year-old man received local anesthetic infiltration with 55 mL of 0.17％ levobupivacaine before the start of lumbar spinal fusion surgery under general anesthesia. During the surgery, the motor evoked potential signals of his lower limbs were undetectable and hypotension continued. After tracheal extubation was performed 118 min after the local anesthetic infiltration, paralyzed lower limbs and hypoalgesia under the T4 level were observed. His paraplegia and hypoalgesia recovered 320 min after the local anesthetic infiltration. We diagnosed incidental spinal anesthesia caused by local anesthetic infiltration. This case indicates that incidental spinal anesthesia should be considered as one of the potential complications in lumbar supine surgery with local anesthetic infiltration.