雪竹義也＊1・宮本泰行＊1
方法：2008年4月から2013年3月に当院に入院したELBWの診療録から後方視的に輸血の頻度とリスク因子を調べた。初回輸血時日齢7未満と以降に分け，初回輸血前の7 日間に認めたリスク因子を調査した。全入院期間で輸血リスク因子について多変量解析を行った。輸血率を周産期母子医療センターネットワークデータベース（以下NRN）と比較した。
結果：対象94例の輸血率は27％だった。初回輸血前の7日間に認めたリスク因子は日齢7未満で出生時ヘモグロビン（以下Hb）低値が，日齢7以降で感染症が多かった。ロジスティック回帰分析で出生体重と出生時Hb値，敗血症が独立したリスク因子だった。NRNよりも出生体重500～1,000g未満で当院の輸血率が低かった。
結論：ELBWへの輸血のリスク因子として従来報告のなかった敗血症が挙げられた。当院の輸血頻度は全国平均より低く，特に出生体重500～1,000g未満で顕著だった。
Methods：A retrospective review of the medical records of 94 ELBW infants admitted in the neonatal intensive care unit （NICU） of our hospital was conducted between April 2008 and March 2013. The frequency and risk factors for RBC transfusions were investigated. Risk factors for the first RBC transfusion were analyzed in the first 6 days and after the first 6 days of life. Risk factors for RBC transfusions that were related to hospital stay durations were identified in the multivariate analysis. The frequency of RBC transfusions in our NICU was compared with Japanese Neonatal Research Network（ NRN） data.
Results：Of the 94 ELBW infants, 27% received RBC transfusions during the study period. The most common factors associated with RBC transfusions were low initial hemoglobin level during the first week of life and in-hospital infection after 6 days of life. Using logistic regression analyses, birth weight, initial hemoglobin level, and sepsis were identified as independent contributing factors associated with RBC transfusions. The frequency of RBC transfusions in this study was lower than the NRN data for infants with birth weights of 500 to ＜1,000g.
Conclusions：The most important risk factor associated with RBC transfusions in ELBW infants in this study was sepsis, which has not been recognized as a factor in the literature. The frequency of RBC transfusions in this study was lower than that in the main NICUs in Japan, in particular in infants with birth weights of 500 to ＜1,000g.
