開心術後低心拍出量症候群に対するプロスタグランディンE1による血管拡張療法

Prostaglandin E1, as a vasodilator therapy, for low output syndrome after cardiac surgery

　強力な血管拡張作用を有するプロスタグランディンE₁（以下PGE₁と略す）は末梢循環不全，先天性心疾患などに使用され，低血圧麻酔法にも用いられる。その作用は容量血管より抵抗血管に強く血管拡張療法として用いることができる。今回2例の開心術後低心拍出量症候群に対してPGE₁を使用したので，若干の文献的考察を加えて報告する。

Prostaglandin E₁ (PGE₁) has a direct vasodilating effect to smooth muscles of resistant vessel much more than that of capacitant one. In afterload mis-match, vasodilator which acts on resistant vessel mainly should be selected.

We used PGE₁ for vasodilator therapy to two pa-tients with low cardiac output syndrome (LOS) in intensive care unit. One patient undergoing coronary artery bypass grafting developed LOS and dissemi-nated intravascular coagulation which derived from post-transfusional anaphylactoid reaction. Anotherpatient undergoing mitral valve replacement, tricus-pid valve annuloplasty and coronary artery bypass grafting also developed LOS with massive thrombosis caused by cold agglutinin during cardio-pulmonary bypass. In both patients, PGE₁ decreased systemic vascular resistance index and pulmonary arterial resistance index, and increased cardiac output.

PGE1 inhibits release of lysosomal enzymes from polymorphonuclear leukocytes and increases splanch-nic blood flow. These effects lead to inhibit pro-duction of myocadial depresant factor and might relate to the improvement of LOS partially.

We suggest that PGE₁ was effective for LOS after cardiac surgery, especially in afterload mismatch.