Susu Zhou,1,2 Kai Zhao,1,2 Chunmei Liu,1,2 Hong Luo,3 Jun Shi,4 Chunhong Liu,5 Xiaoming Li,6 Fang Gao,7 Xiangnan Wu,8 Qin Shen,9 Wenhua Yuan,10 Xiaoqing Chai,1,2,* Xin Wei1,2,* 

1Department of Anesthesiology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China (USTC), Hefei, Anhui, People’s Republic of China; 2Department of Anesthesiology, Anhui Provincial Hospital, Hefei, Anhui, People’s Republic of China; 3Department of Anesthesiology, Hefei First People’s Hospital, Hefei, Anhui, People’s Republic of China; 4Department of Anesthesiology, the First Hospital of Anhui University of Science and Technology, Huainan, Anhui, People’s Republic of China; 5Department of Anesthesiology, Huainan Chaoyang Hospital, Huainan, Anhui, People’s Republic of China; 6Department of Anesthesiology, Affiliated Hospital of West Anhui Health Vocational College, Luan, Anhui, People’s Republic of China; 7Department of Anesthesiology, Bozhou People’s Hospital, Bozhou, Anhui, People’s Republic of China; 8Department of Anesthesiology, Anqing 116 hospital, Anqing, Anhui, People’s Republic of China; 9Department of Anesthesiology, Huainan Xinhua Hospital, Huainan, Anhui, People’s Republic of China; 10Department of Anesthesiology, General Hospital of Benxi iron and Steel Industry Group of Liaoning Health Industry Group, Benxi, Liaoning, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Xiaoqing Chai; Xin Wei, Department of Anesthesiology, The First Affiliated Hospital of USTC (Anhui Provincial Hospital), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, People’s Republic of China, Tel +8613805518889; +86 13956975101, Email xiaoqingchai@163.com; kekaiyuan628@126.com

Purpose: Sodium bicarbonate Ringer’s solution (BRS) is an intravenous fluid that does not rely on hepatic or renal metabolism. It contains bicarbonate ions (HCO3−) and lacks lactate ions. This study hypothesizes that BRS is more effective in maintaining acid-base balance during prolonged open abdominal surgeries. The aim is to investigate the effects of sodium bicarbonate Ringer’s solution on lactate metabolism, acid-base balance, and clinical outcomes in patients undergoing extended-duration open abdominal surgery, with the objective of refining fluid replacement strategies for this patient population.
Patients and Methods: A multicenter randomized controlled trial was conducted involving 112 patients undergoing open abdominal surgery. Participants were randomly assigned to either the BRS group (n=55) or the lactated Ringer’s solution (LRS) group (n=57). The primary outcome was the incidence of postoperative hyperlactacidemia, while secondary outcomes included serum lactate (Lac), pH, base excess (BE), buffered base (BB), bicarbonate (HCO3−), blood glucose (Glu), electrolytes, postoperative liver and kidney function, and postoperative complications. Linear regression analysis was performed to identify factors influencing lactate concentration.
Results: The incidence of hyperlactic acidemia was lower in Group A compared to Group B (9.1% vs 19.3%, P = 0.177), although the difference did not reach statistical significance. No significant differences were observed in lactate (Lac), pH, base excess (BE), bicarbonate (BB), HCO₃⁻, glucose (Glu), or electrolytes between the two groups at any time point (Ptime < 0.001, Pgroup > 0.05, Ptime * group > 0.05). Linear regression analysis revealed that diabetes, hypotension and blood loss were significant factors influencing blood lactate concentration (R² = 0.349, P < 0.001).
Conclusion: Sodium bicarbonate Ringer’s solution and lactate Ringer’s solution are both safe options for fluid replacement during long-term open abdominal surgeries. There is no significant difference observed in perioperative lactate levels, acid-base balance, or clinical postoperative outcomes between the two solutions.

Keywords: sodium bicarbonate Ringer’s solution, lactate Ringer’s solution, open abdominal surgery, lactate levels