Effect of minimized cardiopulmonary bypass circuit on perioperative mortality in neonates with congenital heart disease

Abstract

Objective To explore the effect of the surgical treatment in neonates with congenital heart disease(CHD) and the factors related to the perioperative mortality during cardiopulmonary bypass. Methods Totally, 666 neonates undergoing CHD operation were reviewed in a single center from Jan 2006 to Dec 2014, of which, 431 cases had complete cardiopulmonary bypass records. Analysis was performed to investigate the association between perioperative mortality and potential factors, especially the cardiopulmonary bypass factors during different periods. In the multivariate Cox proportional hazard model, factors with statistical significance(P<0.1) in the univariate analysis were included in the model, such as, surgeon grouping, year of surgery, Aristotle score, preoperative weight, preoperative and intraoperative sodium bicarbonate volume and postoperative low cardiac output. Results The neonates enrolled ranged 8-22 days after birth, and 2.7-3.6 kg at weight. The mortality rate decreased from 23.7% in 2006 to 12.4% in 2014, showing a gradual decline(P=0.02). The mortalities of different CHDs were: pulmonary atresia(24.4%), coarctation of the aorta(16.7%), transposition of the great arteries(13.1%), total anomalous pulmonary venous connection(11.0%), ventricular septal defect(10.6%), and so on. The volume of preoperative and intraoperative 5% sodium bicarbonate was 30(20-50) mL in death group, higher than that in survival group[23(15-30) ml]. While the preoperative weight was 3.1(2.7-3.5) kg, lower than that in survival group[3.3(3.0-3.6) kg]. The total amount of Plasmalyte/Ringer, erythrocytes, ultrafiltration volume and the cardiac assist ratio were higher in the death group than in the survival group. After controlling the confounding effect of surgeons, the multivariable Cox proportional hazard model showed that: the independent risk factors for perioperative mortality were pulmonary atresia[aHR=3.89(1.78-8.42)], 5% sodium bicarbonate volume ≥50 ml[aHR=2.62(1.14-6.04)], erythrocytes volume >200 ml[aHR=2.26(1.1-4.06)]and postoperative low cardiac output[aHR=6.76(3.30-13.87)]. Conclusion During the study period, the preoperative mortality for neonates with CHD had a dramatical decrease, although the preoperative risk factors for the patients increased. Pulmonary atresia repair surgery had the highest mortality in neonates. Factors associated with the perioperative mortality includedpreoperative acidosis and postoperative low cardiac output. There is a significant association between the improvement of perioperative mortality and the improvement of the technology of minimized cardiopulmonary bypass circuit during neonatal operation. It is suggested that the total erythrocytes volume maintains less than 200 ml. Key words: Neonate; Congenital heart defect; Cardiopulmonary bypass; Mortality