日本未熟児新生児学会雑誌　第20巻　第1号　91～97頁（2008年）

日本未熟児新生児学会雑誌　20(1)：91-97；2008　

受付日：平成18．10．18

受理日：平成19．06．04

Stress-Velocity関係を指標としてarginine vasopressinで管理したdopamine不応性低血圧の超低出生体重児の1例

A Case of an Extremely-Low-Birth-Weight Infant Treated with Arginine Vasopressin for Dopamine Resistant Hypotension Under Stress-Velocity Relations of Echocardiography

＊1奈良県立奈良病院　新生児集中治療室，＊2奈良県立医科大学　周産期医療センター　新生児集中治療部門

＊1 Neonatal Intensive Care Unit, Nara Prefectural Hospital，＊2 Division of Neonatal Intensive Care, Center of Perinatal Medicine, Nara Medical University

釜本智之＊1＊2・西久保敏也＊1＊2・坂東由香＊1・内田優美子＊1・高橋幸博＊2

Tomoyuki KAMAMOTO＊1＊2, Toshiya NISHIKUBO＊1＊2，Yuka BANDOH＊1, Yumiko UCHIDA＊1, Yukihiro TAKAHASHI＊2

Key Words：arginine vasopressin，end-systolic wall stress，Stress-Velocity relationship，Rate-corrected mean velocity of circumferential fiber shortening，Patent Ductus Arteriosus

　症例は在胎23週5日，出生体重586gの女児。入院時からdopamineを開始したが，生後18時間から低血圧（32/18mmHg）と乏尿（0.3mL/kg/時間）が出現した。心臓超音波検査ではEF 71％，FS 34％，mVcfc 1.27circ/秒，ESWS 13.3 g/cm2と心機能は良好で循環血液量の不足を示す所見がなかったことから，末梢血管の拡張による低血圧と判断し血管収縮作用を有するarginine vasopressin（AVP）を開始した。血圧はすみやかに41/28mmHgに上昇し尿量も1.9mL/kg/時間に増加した。しかし体血圧の上昇にともない未熟児動脈管開存症（PDA）の左右短絡量の増加と肺動脈拡張期血流量が増加し，AVP開始2時間後にindomethacinを投与したところPDAは閉鎖した。しかし同時に心機能が低下しStress-Velocity関係から後負荷の上昇によると考えられたため，AVPを中止しdobutamineを増量したところ，心機能は改善した。この間，血圧や尿量の低下はなかった。超低出生体重児のdopamine不応性低血圧に対しStress-Velocity関係を指標としたAVPの少量持続投与は血圧の上昇と利尿効果に対し有効と考えられた。しかしPDAの増悪や後負荷上昇にともなう心機能の低下には十分な注意が必要である。

　We report an extremely-low-birth-weight infant who demonstrated a rise of blood pressure and diuresis by continuous administration of low-dose arginine vasopressin（AVP）following evaluation of cardiac activity by echocardiography with Stress-Velocity relationship.
　The infant was delivered with a birth weight of 586g and gestational age of 23 weeks and 5 days. The administration of dopamine at 5 μg/kg/min were started on admission to NICU. Blood pressure of 32/18mmHg and oliguria appeared 18 hours after birth. Cardiac activity evaluation indicated that EF 71％, FS 34％, mVcfc 1.27circ/s, ESWS 13.3g/cm2 and did not show a loss of intravascular volume. These data indicated that low blood pressure was induced by vascular expansion of peripheral vessels and AVP administration at 0.002U/kg/min was started. Blood pressure and urinary output were immediately increased after the commencement of AVP. However, pulmonary diastolic blood flow was increased by PDA, and indomethacin at 0.2mg/kg was administered 4 hours after the start of AVP. As a result, PDA closed and blood pressure increased to 66/33mmHg. However, cardiac dysfunction due to increased after-load was suggested with echocardiographic data showing EF 45％, FS 18％, mVcfc 0.63circ/s and ESWS 25.9g/cm2 14 hours after the beginning of AVP. Therefore, we stopped the administration of AVP and increased the dosage of dobutamine to 8μg/kg/min. As a result, echocardiography demonstrated improvement to EF 60％, FS 25％, mVcfc 1.07circ/s without decrease in blood pressure and urinary output.
　In conclusion, continuous administration of low-dose AVP was effective for the treatment of the angiectatic low blood pressure with oliguria in an extremely-low-birth-weight infant, though serial examination by echocardiography was necessary to evaluate PDA and cardiac activities.