ChiCTR2000028941.

Study name	Target blood pressure management during cardiopulmonary bypass improves postoperative lactic acid levels: a randomised controlled clinical study
Methods	Design: single‐centre parallel‐group double‐blind randomised controlled trial
Participants	Inclusion criteria: selective heart valve surgery; aged > 18 years; New York Heart Association class II–III; ejection fraction > 50%; blood lactate level < 1.6 mmol/L; alanine transferase < 50 U/L; brain natriuretic peptide < 100 pg/mL; stay overnight in intensive care unit after surgery Exclusion criteria: secondary aortic occlusion during operation; emergency surgery again within 24 hours after the operation.
Interventions	Experimental: mean arterial pressure 70–80 mmHg with noradrenaline Control: mean arterial pressure 50–60 mmHg with or without vasoactive drugs
Outcomes	Primary outcome: postoperative blood lactate value
Starting date	Date of approved by ethic committee: 31 October 2019
Contact information	Miao Qing Tel: +86 15026635802 E‐mail: miaoqmz@163.com Affiliation: Department of Anesthesiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
Notes	Prospective registration Status: recruiting