AIM  To explore the changes of systemic vascular resistance and its influencing factors in the early postoperative period of congenital heart disease (CHD).

  METHODS  Randomly included in this study were the children in the PICU of Fuwai Hospital from October 2020 to December 2020. A total of 80 children were enrolled, 19 in non-cardiopulmonary bypass group and 61 in cardiopulmonary bypass group. In order to better study the status of peripheral SVR in different diseases, the cardiopulmonary bypass group was subdivided into non-cyanotic group (40 cases) and cyanotic group (21 cases). At the time when children returned to PICU, we immediately recorded SVR and other hemodynamic parameters as well as related preoperative and intraoperative data, and analyzed the SVR and its influencing factors.

  RESULTS  Compared with the non-CPB group, the body mass, height, preoperative blood oxygen saturation, and postoperative blood oxygen saturation in the CPB group decreased (P<0.05); compared with the non-cyanotic CHD group , in the cyanotic CHD group, the preoperative blood oxygen saturation decreased, the postoperative blood oxygen saturation decreased, the CPB time increased, and the postoperative LVEF value decreased (P<0.05). The postoperative SVRI of the children in the CPB group was significantly lower than that in the non-CPB group (1357±299 vs. 1129±330, P<0.01). The SVRI of the CPB subgroups was further compared with the non-CPB group, the postoperative SVRI of the children with non-cyanotic CHD was not significantly different from that of the non-CPB group, while the peripheral SVRI of the children with cyanotic CHD was significantly decreased (P<0.01). In the cardiopulmonary bypass group, the postoperative SVRI of the children with cyanoticCHD was significantly lower than that of the non-cyanotic children (P<0.01), while the postoperative CI of the children with cyanotic CHD was significantly higher than that of the non-cyanotic children (P<0.01). Although the postoperative SVV of the cyanotic group was higher than that of the non-cyanotic children, there was no significant difference.Regression analysis showed that postoperative SVRI was positively correlated with body weight (r=25.079, P<0.05) and negatively correlated with cardiopulmonary bypass time (r=−2.831, P<0.05). There were 5 cases of Vasoplegic syndrome in CPB group.

  CONCLUSION  The SVR of non-cyanotic CHD children can be maintained at a normal level after surgery. The SVR of children with cyanotic CHD will decrease significantly after surgery. The exudation increases and Vasoplegic syndrome may even occur. SVRI in children after cardiopulmonary bypass is mainly affected by the weight and the time of CPB. The lower the weight and the longer the time of CPB, the lower the systemic vascular resistance may be after the operation.