肺高血圧を合併した先天性心疾患に対する関心術後のModified Ultrafiltrationの有用性

摘要

乳児新生児関心術の成績向上は著しいものがあ り，手術術式，術前術後管理の改良が大きな要因 であるが，体外循環の改善も成績向上の進歩を支 える重要な要因である．なかでも，体外循環回路 充填量の低容量化と体外循環中の血液異物炎症反 応への対処方法の進化はその大きな役割を担って いる．%Background: Systemic inflammatory response after a cardiopulmonary bypass is a key factor in the incidence of postoperative pulmonary hypertensive crises in children. Our study evaluated the effects of modified ultrafiltration (MUF) on the ability to remove chemical mediators, hemodynamics, and pulmonary function. Methods: We studied 24 consecutive patients with a ventricular septal defect and pulmonary hypertension who underwent venovenous MUF after cardiopulmonary bypass. Chemical mediators were measured and pulmonary function was examined before and after MUF. From 1999 through 2006, 48 patients underwent arteriovenous MUF or venovenous MUF (MUF group). From 1993 through 1998, 38 patients underwent cardiac surgery without MUF (control group). Ventricular septal defect with pulmonary hypertension was diagnosed in all patients. Use of dopamine hydrochloride and the incidence of pulmonary hypertensive crisis were compared between the groups. In the MUF group, changes in the pulmonary arterial-to-aortic pressure ratio (Pap/Aop) before and after MUF were examined. Results: 1) Levels of thromboxane B2, interleukin 6, and endothelin 1 were significantly lower after MUF (373 ± 241 pg/ml, 306±231 pg/ml, and 1.22± 1.41 pg/ml, respectively) than before MUF (757 ± 731 pg/ml, 380 ± 328 pg/ml, and 2.16±2.79pg/ml, respectively). MUF produced significant improvements in the ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen, the alveolar-arterial oxygen delivery gradient, and the respiratory index. 2) Use of MUF significantly decreased the Pap/Aop and the incidence of postoperative pulmonary hypertensive crisis. Use of dopamine hydrochloride was significantly lower in MUF group. Conclusions: MUF may help remove chemical mediators, especially thromboxane B2 and endothelin 1, associated with increased pulmonary vascular resistance in children. The Pap/ Aop decreased significantly after MUF. MUF may also help decrease the incidence of postoperative pulmonary hypertensive crisis and produce an immediate improvement in cardiopulmonary function. The results of this study suggest that MUF is beneficial for patients who have congenital heart diseases with pulmonary hypertension or impaired left ventricular function.