診断に難渋しショックに至った衝心脚気の1例

A 63-year-old Man with Catastrophic Shoshin Beriberi with Prolonged High Venous Oxygen Saturation

要旨　患者は63歳，男性．1カ月半で進行した呼吸困難，下腿浮腫を主訴に2007年5月下旬当科に緊急入院した．当初，塵肺による肺高血圧，右心不全と診断し，安静および利尿薬投与継続にて経過観察したが軽快せず，第4病日に収縮期血圧60mmHgに低下した．心臓超音波検査では左室壁運動は過収縮で，右心カテーテル検査では肺動脈圧45/20mmHg，混合静脈血酸素飽和度89%，心係数12.3l/min/m²，全身血管抵抗100dyne・sec/cm⁵であった．衝心脚気を疑いビタミンB1投与したところ，数時間で血圧上昇し利尿も得られ，以後ビタミンB₁継続投与で心不全は軽快した．第19病日の右心カテーテル検査値はほぼ正常化し，第29病日独歩自宅退院した．脚気の原因はアルコール過量摂取，偏食であり，更にループ利尿薬投与で増悪させた可能性があると考えられた．なお，静脈血酸素飽和度高値および四肢末端のしびれは心不全軽快後も遷延した．

　A 63-year-old man was admitted to the hospital complaining of dyspnea and leg edema that had developed and worsened in the last one-and-a-half months. On admission, he was diagnosed with pulmonary hypertension and right heart failure due to pneumoconiosis and was ordered bed rest and continued taking of diuretics but it was in vain. On the fourth hospital day his systolic blood pressure dropped to 60 mmHg and Swan-Ganz catheterization revealed the following: pulmonary artery pressure 45/20 mmHg, mixed venous oxygen saturation 89 %, cardiac index 12.3 l/min/m², and systemic vascular resistance 100 dyne・sec/cm⁵. At this stage, suspecting shoshin beriberi, we put him on a drip of thiamine and his blood pressure rose and diuresis followed within several hours. He continued taking oral thiamine, and Swan-Ganz catheterization on the nineteenth hospital day showed almost normal data. Excessive alcohol intake and unbalanced diet were the causes of beriberi and loop diuretic might have aggravated the disease. He was discharged from the hospital and went home on the twenty-ninth hospital day but high venous oxygen saturation and peripheral neuropathy continued after the heart failure had resolved.