Target blood pressure management during cardiopulmonary bypass improves lactate level after cardiac surgery: A randomized controlled trial

Abstract Background：Hyperlactacidemia seriously affects the prognosis of cardiac surgery patients. This study was to explore the impact of target blood pressure management during cardiopulmonary bypass (CPB) on blood lactate level after cardiac surgery. Methods: Enrolled in this study were patients≧ 18 years who were scheduled for cardiac valve surgery between January 1, 2020 and June 30, 2020 at Shanghai Chest Hospital. The enrolled patients were randomized into a low mean arterial pressure (L-MAP) group (target MAP between 50-60mmHg) and a high mean arterial pressure (H-MAP) group (target MAP between 70-80 mmHg). Norepinephrine was titrated during CPB to maintain MAP at the target level.Blood lactate levels in the two groups were detect before operation (T0), at the end of CPB (T1), at the end of operation (T2), 1 h after operation (T3), 6 h after operation (T4) and 24 h after operation (T5) as the primary outcome. The secondary outcome was the dose of epinephrine and dopamine within 24 h after operation, at the time of extubation, during ICU stay, at the time of readmission within 30 days, and mortality in 1 year. Results: There was no significant difference in blood lactate level between the two groups at T0, T4 and T5. The lactate level in H-MAP group was significantly lower than that in L-MAP group (1.68±0.73, 2.33±0.93 and 2.90±1.09 mM;L-1 vs. 2.29±1.12, 3.63±1.86 and 4.60±2.24 mM;L-1) at T1, T2 and T3. The dose of epinephrine within 24 h after operation, at the time of extubation and during ICU stay in L-MAP group was significantly higher than that in H-MAP group. Conclusions: Target MAP management in patients with relatively high levels of MAP during CPB could decrease the blood lactate level, reduce epinephrine consumption, and shorten the time of extubation and length of ICU stay after surgery, thus improving the prognosis of cardiac surgery patients. Trial registration: This single-center single-blind RCT has completed the registration of the Chinese Clinical Trial Center with the registration number ChiCTR2000028941.