[Right heart failure during modified ultrafiltration in pediatric living donor lobar lung transplantation].

A six-year-old girl with bronchiolitis obliterans was scheduled for living donor lobar lung transplantation from her mother. Under cardiopulmonary bypass (CPB), she underwent right pneumonectomy and her mother's right lower lobe was transplanted. Weaning from CPB was smooth, by the use of olprinone as an inotrope, nitric oxide (NO) and alprostadil as pulmonary vasodilators. Immediately after weaning from CPB, modified ultrafiltration (MUF) was started, in which blood was drained from the aorta, concentrated, filtered and returned to the right atrium. During MUF, systolic arterial blood pressure (sABP) declined and systolic pulmonary arterial pressure (sPAP) increased gradually. Although administration of dopamine and noradrenaline was started and the inhaled concentration of NO was increased, sPAP overwhelmed sABP after all. Transesophageal echocardiography showed that the left ventricular wall contracted well but its lumen was small, and that both right atrial and ventricular lumen enlarged. After starting administration of adrenaline, under the diagnosis of right heart failure, both sABP and sPAP were normalized and circulatory status got stable until the end of operation. We considered that pulmonary vasoconstriction due to ischemic reperfusion injury might cause right heart failure, which might be exacerbated by MUF, because MUF produces artificial left-to-right shunt and can increase right heart volume load.