日本未熟児新生児学会雑誌　第17巻　第2号　83～88頁（2005年）

日本未熟児新生児学会雑誌　17(2)：-；2005　

受理日：平成17．04．01

一過性高アンモニア血症に対し持続的血液透析を施行した極低出生体重児の1例

A very low birth weight infant with transient hyperammonemia undergoing hemodialysis

県立広島病院　新生児科

Department of Neonatology，Hiroshima Prefectural Hospital

木原裕貴・福原里恵・藤原　信・古川　亮・中村朱里・岩永甲午郎

Hirotaka KIHARA，Rie FUKUHARA，Shin FUJIWARA，Ryo FURUKAWA， Akari NAKAMURA，Kougorou IWANAGA

Key Words：very low birth weight infant，transient hyperammonemia，continuous hemodialysis，continuous renal replacement therapy

　症例は在胎28週，1,162gで出生した男児。日齢1より活気不良があり，遷延する代謝性アシドーシスもみられた。日齢3，アンモニア1,000μg/d以上と著明な高アンモニア血症を認め持続的血液透析を行った。先天性代謝異常症は否定的で，アンモニアが一旦低下した後に再然はなかった。臨床経過，検査所見より，一過性高アンモニア血症と診断した。画像上異常は認めず，生後4ヶ月の時点で神経学的にも異常は認めなかった。一過性高アンモニア血症はいまだ原因不明の疾患であるが，多くは在胎35週前後の早産児に見られ，本症例の様に極低出生体重児での発症は極めてまれである。新生児期の急性血液浄化療法は，近年低出生体重児にも適応が拡大しているが，本症例においては低容量の回路を用い，体温管理を工夫する事によって安全に施行する事が出来た。

　A 1,162-gm male was born to a 33-year-old primigravida at 28-weeks of gestation. He was treated with mechanical ventilation as well as artificial surfactant and respiratory condition was remarkably improved. However, he was still not doing well and metabolic acidosis continued. A plasma ammonium determination at 72 hours after birth revealed hyperammonemia more than 1000μg/dL. He underwent continuous hemodialysis. An analysis of congenital metabolic disorders showed normal results. Plasma ammonium level did not increase again after discontinuation of the therapy and a diagnosis of transient hyperammonemia was made. His physical and mental development at 4 months of age was almost normal. Most of patients with transient hyperammonemia reported previously were preterm neonates. However, there are few reports of this disorder in very low birth weight infants in the past literature. Recently continuous renal replacement therapy has been applied in preterm infants. Continuous hemodialysis is safe and may be one of the tools of the treatment in a part of metabolic disorders.