Perioperative balanced crystalloids versus normal saline during kidney transplantation: a systematic review and meta-analysis of randomized controlled trials

Background In kidney transplant (KT) surgery, the perioperative administration of intravenous (IV) fluids plays a crucial role, with potential effects on graft function. Our meta-analysis aims to assess the post-KT outcomes of perioperative balanced crystalloids (BC) versus normal saline (NS). Methods We conducted a comprehensive search across five databases to identify relevant randomized controlled trials (RCTs). The search results were imported into Covidence for article eligibility screening, and all relevant outcome data were synthesized using risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CIs) in meta-analysis models within RevMan 5.4. PROSPERO ID: CRD42023448457. Results Pooled data from 15 RCTs with 2,008 participants showed that the rate of delayed graft function (DGF) was significantly lower with BC (RR: 0.78, 95% CI [0.68, 0.91], P = 0.0009). Also, BC was associated with significantly higher post-op blood pH (MD: 0.05, 95% CI [0.03, 0.07], P < 0.01), lower serum chloride (MD: - 7.31, 95% CI [- 10.58, - 3.77], P < 0.01), and sodium (MD: - 1.94, 95% CI [- 3.32, - 0.55], P = 0.006) as compared to NS. However, serum potassium, serum creatinine, and urine output at POD 1 to 7 did not differ between the two groups. Conclusion BC significantly reduced the incidence of DGF, resulting in more stable post-operative acid-base parameters, and lower chloride levels compared to NS. Hence, substituting NS with BC offers a strategy to protect grafts from acidotic and hyperchloremic insults, optimizing KT outcomes.