Effectiveness of sodium bicarbonate Ringer's solution as a priming fluid for cardiopulmonary bypass: a propensity score matching study.

PURPOSE: This study aimed to evaluate the clinical effects of sodium bicarbonate Ringer’s solution(BRS) as a priming fluid for cardiopulmonary bypass (CPB). METHODS: A total of 159 patients undergoing CPB cardiac surgery at Gaozhou People’s Hospital between August 2020 and August 2021 were enrolled. Participants were assigned to receive either sodium bicarbonate Ringer’s solution (designated as the BRS group) or lactated Ringer’s solution (designated as the control group). Blood gas variables were monitored at predetermined intervals: pre-surgery (T1), 30 min after CPB initiation (T2), upon CPB completion (T3), 6 h post-surgery (T4), and 24 h post-surgery (T5). To ensure comparability between groups, clinical variables were balanced using propensity score matching (PSM). RESULTS: Following PSM, the BRS group had significantly lower blood calcium levels (P < 0.001) at T2. By T3, the BRS group also presented lower standard bicarbonate, extracellular base excess and blood calcium levels, alongside significantly higher hematocrit levels compared to controls (all P < 0.05). At T5, the BRS group continued to show decreased levels of blood sodium and calcium (both P < 0.05). CONCLUSION: BRS was associated with better maintenance of acid-base balance and electrolyte stability compared to lactated Ringer’s solution, suggesting it is a favorable priming option for CPB.