Effect of of mean arterial pressure management on lactate levels and outcomes after heart valve surgery

Zhang Ying; Wang Yan; Qiu Hao; Tu Haiyan; Xiong Xinfa

doi:10.13498/j.cnki.chin.j.ecc.2025.03.07

Abstract：Objective To investigate the impact of mean arterial pressure(MAP)management during cardiopulmonary bypass(CPB)on postoperative lactate acidosis and perioperative outcomes in heart valve surgery.Methods A total of 76 adult patients undergoing cardiac valve replacement/valvuloplasty with CPB treated in our hospital from January 2021 to March 2023 were selected as the study objects.Based on a table of random numbers,all patients were randomly assigned to the traditional MAP group and the high MAP group on a 1:1 ratio.In the traditional MAP group,MAP during CPB was maintained at 50 to 60 mmHg,while in the high MAP group,MAP during CPB was controlled at 70 to 80 mmHg by intravenous injection of norepinephrine.The main outcome measure was the incidence of hyperprolactinemia and lactic acidosis at the end of the operation.Secondary outcome measures were blood lactate levels at perioperative time points(before surgery,at the end of CPB,at the end of surgery,at 4h,8 h,and 12 h after surgery)and overall prognosis(time to extubation,length of stay in ICU,length of stay in hospital,multiple organ dysfunction,readmission within 30 days,1-year reoperation,and 1-year all-cause mortality.Results At the end of operation,the incidence of hyperprolactinemia(81.58%vs.47.37%,P=0.002)and lactic acidosis(21.05%vs.5.26%,P=0.042)in the high MAP group was significantly lower than that in the traditional MAP group.The lactate levels of the two groups were significantly different from the end of CPB to 8h after surgery(P<0.05),and began to decline after reaching a peak at 8h after surgery.Compared with the traditional MAP group,the lactate levels in the high MAP group were significantly lower at the end of CPB,at the end of surgery,and at 4h and 8h after surgery(P<0.05).Compared with the traditional MAP group,the incidence of multiple organ dysfunction was significantly lower in the high MAP group,and the duration of extubation,ICU stay and total hospital stay were significantly shortened(P<0.05).Conclusion Controlling MAP at 70-80 mmHg during CPB can better control lactate levels,reduce the incidence of lactic acidosis after heart valve surgery,and thus help improve perioperative outcomes for patients.