日本未熟児新生児学会雑誌　第27巻第1号　84 ～ 88頁（2015年）

日本未熟児新生児学会雑誌　27(1)：84-88；2015　

受付日：平成26．01．15

受理日：平成26．08．04

5 か月間の低酸素換気療法を行い心姑息術を施行した18 - トリソミーの低出生体重児例

Successful Management of Trisomy-18 Using Hypoxic Gas Ventilation Therapy for 5 Months until Palliative Surgery： a Case Report

奈良県総合医療センター　新生児集中治療室

Department of Neonatal Intensive Care Unit, Nara Prefecture General Medical Center

美馬　文・箕輪秀樹・池田由香・安原　肇・恵美須礼子・扇谷綾子

Aya MIMA，Hideki MINOWA，Yuka IKEDA，Hajime YASUHARA，Reiko EBISU，Ayako OGITANI

Key Words：hypoxic gas ventilation therapy，nitrogen gas，pulmonary atresia with intact ventricular septum，low birth weight infant，trisomy-18

　窒素混合低酸素換気療法（以下，低酸素換気療法）を5 か月間施行し，急性期管理および心姑息術後に在宅移行が可能となった症例を経験した。症例は，在胎36 週6 日，出生体重1,580g の低出生体重児であり，18 - トリソミー，純型肺動脈閉鎖を合併していた。適切な肺体血流分布を得るために低酸素換気療法とprostaglandin E1（以下，PGE1）の持続静注を行った。低酸素換気療法を施行することにより，高肺血流に伴う急性循環不全から脱し，その後，良好な体重増加を得た。全身状態が安定した状況で待機的にBlalock-Taussig 手術を施行することできた。手術後は，低酸素換気療法およびPGE1 を中止し，在宅移行が可能となった。今回，低酸素換気療法による明らかな合併症はなかったが，長期施行に伴う合併症については今後の検討が必要である。

　We successfully managed a neonatal infant with trisomy-18 associated with pulmonary atresia and intact ventricular septum（PAIVS）by hypoxic gas ventilation using nitrogen gas for 5 months before palliative surgery. A female infant was referred to our neonatal intensive care unit with intubation after being born with a birth weight of 1580 g and Apgar scores of 3 and 7 at 1 and 5 minutes, respectively. We diagnosed her as having trisomy-18 associated with PAIVS, atrial septal defect and patent ductus arteriosus. She was started immediately on infusion therapy with prostaglandin E1（PGE1）to maintain ductus arteriosus patency. Pulmonary blood flow increased gradually, so PGE1 was discontinued on day 8 after birth. However, the occurrence of excess pulmonary blood flow decreased systemic blood flow and subsequently led to shock. Therefore, we started hypoxic gas ventilation therapy to reduce PaO2 to maintain high pulmonary vascular resistance and low pulmonary blood flow. Systemic blood flow was increased by maintaining the fraction of inspired oxygen（FIO2）at 0.17 using hypoxic gas ventilation therapy and infusion of 1.2 ng/kg/min PGE1, which continued for 5 months until she underwent a Blalock-Taussig shunt. After the operation, we discontinued hypoxic gas ventilation therapy and PGE1 infusion. She was discharged 7 months after birth with supplemental oxygen inhalation via a nasal cannula. This case demonstrates the efficacy of hypoxic gas ventilation therapy with nitrogen gas to prevent excess pulmonary blood flow and maintain systemic blood flow in a trisomy-18 patient. This further suggests that this therapy can be used to promote appropriate weight gain in low birth weight infants who cannot be treated surgically immediately after birth.