复杂先天性心脏病术后正性肌力药物的早期合理应用

Reasonable application of positive inotropic agent during the postoperative period in patients with complicated congenital heart disease

目的探讨复杂先天性心脏病（CHD）术后正性肌力药物的早期合理应用。方法选择接受一期矫治手术的复杂CHD患儿51例。利用UrnRandomization法将患儿随机分配进入相应试验组，给予相应剂量的正性肌力药物，用正性肌力药物评分（Is）来表示，分为低剂量组（0〈IS〈10）和高剂量组（10≤IS〈20）。通过脉波指示剂连续心排血量（PiCCO）监测患儿术后24h的心脏指数（cI）、体循环血管阻力指数（SVRI）和肺循环血管阻力指数（PVRI）等血液动力学指标，以术后3h的血液动力学指标作为基础对照值。结果15例发生低心排血量综合征（LCOS），发病率为29．4％。术后12h低剂量组和高剂量组C1分别下降了12．5％[（3．0±0．8），P〈0．01]和18．8％[（2．94-0．8），P〈0．01]，两组SVRl分别增加了5．4％[（1780．4±526．7），P〈0．05]和19．9％[（1741．1±575．2），P〈0．01]。结论复杂CHD患儿心排血量的降低通常发生在术后6—18h，该时段是防治心功能降低的关键时期，低剂量联合应用米力农、多巴胺等正性肌力药物对改善CHD术后的心脏功能有重要意义，高剂量（10≤IS〈20）应用正性肌力药物并不能很好改善患儿心脏功能。

Objective To assess the reasonable application of inotropic agents during the early postoperative period of complicated congenital heart surgery. Methods Forty-one children with complex congenital heart disease （CHD） undergoing corrective open heart surgery were randomly selected using Urn Randomization method from the pediatric cardiac intensive care unit. Their mean age was 14. 0 months; and mean weight was 8.2 kg. Cardiac index （CI） , systemic vascular resistance index （ SVRI ） and pulmonary vascular resistance index （PVRI） were measured persistently during the first 24 hours postoperatively. After operation, patients were divided into two groups, inotropic agents were administrated. The dose of inotropic agents was determined by inotropie score （IS） ： the low dose group （0 〈 IS 〈 10） and the high dose group （10 ≤ IS 〈 20）. The data of 3 hours after operation was considered as the baseline. CI 〈 3.0 L. min^-1·m^-2 was defined as low cardiac output state （LCOS）. Results Fifteen （29.4%） patients developed LCOS in the early 24 hours after operation. Compared with the baseline, at the 12th h after operation, CI was decreased by 12. 5% （P 〈 0. 01 ）, SVRI was increased by 5. 4% （19 〈0. 05） in the low dose group, and CI was decreased by 18.8% （P 〈0. 01 ） in the high dose group, SVRI was increased by 19. 9% （ P 〈 0. 01 ） in the high dose group. Nevertheless, PVRI was decreased by 8.6% （P 〈 0. 05 ） in the low dose group and increased by 10. 1% （ P 〈 0. 05 ） in the high dose group. Conclusions The reduction of CI occurs within 6 - 18 hours postoperatively in the infants and children with complex CHD. It is the key phase to prevent and treat the cardiac dysfunction with the application of minute dose dopamine, milrinone and other inotropic agents. High dose inotropic agents can＇t make the heart function more preferable.