Balanced crystalloids versus saline: many meta-analyses, uneven rigor

We performed an overview of systematic reviews and meta-analyses comparing balanced crystalloids with 0.9% saline in critically ill adults. Searches in MEDLINE (via PubMed), Web of Science, and Epistemonikos ran from inception through May 2026. Three reviewers independently selected studies and extracted data. Methodological quality was assessed using the A Measurement Tool to Assess Systematic Reviews (version 2), while certainty of evidence was evaluated using the GRADE framework. Eleven reviews from 2018 to 2024 were included; each combined 4 to 18 randomized controlled trials, covering 19,105 to 36,224 patients. The certainty of the evidence ranged from very low to moderate. Overall confidence was critically low in six reviews, low in two, and high in one. Five reviews lacked prospective protocol registration, four omitted certainty assessment, and two failed to report adherence to the reporting guideline. One review showed different patient counts in its methods and meta-analysis, and another favored a balanced solution in its conclusions despite a non-significant pooled estimate. Statistical methods varied widely, including frequentist and Bayesian models, trial sequential analysis, and a review that mixed randomized and observational studies. Two reviews using the same databases in the same year included different trial counts (eight versus four). Although pooled mortality estimates were similar, every review that favored balanced solutions on frequentist grounds was of critically low confidence. Conclusion Evidence syntheses on the same clinical question vary enough in methodological rigor to produce divergent conclusions from similar data. Systematic reviews deserve scrutiny comparable to that applied to primary trials, with greater weight given to those with prospective registration, formal certainty assessment, and conclusions aligned with pooled estimates.