Effect of Hydration with Bicarbonate Ringer’s Solution on Cisplatin-Induced Acute Kidney Injury in Patients with Esophageal Cancer: A Retrospective Cohort Study

<b><i>Introduction:</i></b> Cisplatin (CDDP) often causes acute kidney injury (AKI), and magnesium supplementation has been suggested to be important in preventing CDDP-induced AKI. Sodium bicarbonate Ringer’s solution (BRS) is a crystalloid solution composed of various electrolytes, including Mg²⁺, and can be generally used to supplement missing extracellular fluid and correct metabolic acidosis; however, the clinical outcomes of hydration with BRS for CDDP-induced AKI remain unclear. In this study, we retrospectively compared the effects of BRS and normal saline for hydration in patients undergoing CDDP treatment. <b><i>Methods:</i></b> We analyzed the incidence rate of AKI (grade ≥ 1), the severity of AKI, the serum magnesium level, and the incidence rate of grade ≥ 3 hematological toxicities (leukopenia, neutropenia, anemia, or thrombocytopenia) following CDDP and fluorouracil (5-FU) administration in 131 in-patients who received CDDP and 5-FU for the first time to treat esophageal cancer. <b><i>Results:</i></b> Fifty-six patients (43%) received saline alone, while 75 patients (57%) received BRS for hydration. The incidence rate of AKI (grade ≥ 1) was significantly lower in the BRS group (11%) than that in the saline group (39%, <i>p</i> &lt; 0.001). Moreover, severe AKI (grade ≥ 2) was significantly less common in the BRS group than in the saline group. Although the serum magnesium levels before CDDP administration were not significantly different between the two groups (<i>p</i> = 0.939), the serum magnesium levels on days 2–3 after CDDP administration in the BRS group were significantly higher than those in the saline group (<i>p</i> &lt; 0.001). In contrast, there were no significant differences in the incidence rates of hematological toxicity between the two groups. Multivariate analysis revealed that BRS use was an independent factor that significantly contributed to AKI prevention (odds ratio = 0.061, <i>p</i> &lt; 0.001). <b><i>Conclusion:</i></b> Hydration with BRS could prevent CDDP-induced AKI in patients with esophageal cancer.