Balanced crystalloid versus saline for resuscitation in adult sepsis: a systematic review and meta-analysis.

BACKGROUND: Fluid resuscitation is the cornerstone of sepsis management, however, the choice between balanced crystalloid solutions and normal saline remains debated. This meta-analysis aimed to compare the efficacy of balanced solutions versus saline for fluid resuscitation in adult patients with sepsis. METHODS: A systematic literature search was performed in PubMed, Embase, Scopus, and other relevant sources. Retrieved studies were rigorously screened according to predefined inclusion and exclusion criteria. Data from the included studies were extracted for analysis. The primary outcome was defined as mortality rate. Secondary outcomes included acute kidney injury (AKI), hyperchloremia, renal replacement therapy (RRT), ICU-free days, ventilator-free days, vasopressor-free days. The study protocol was registered with PROSPERO (CRD420261368142). RESULTS: A total of eight studies (8,173 patients; 4,056 assigned to balanced solutions, 4,117 to saline) met the inclusion criteria. In the primary analysis restricted to seven randomized controlled trials, balanced solutions were associated with significantly lower mortality than saline (RR 0.92; 95% CI 0.86-0.98; P = 0.01; I2 = 37%), and a sensitivity analysis incorporating a post-hoc observational study yielded consistent results (RR 0.91; 95% CI 0.85-0.97). Balanced solutions were also associated with lower incidences of AKI (RR 0.86; 95% CI 0.78-0.96; P = 0.004), hyperchloremia (RR 0.68; 95% CI 0.52-0.90; P = 0.007), and RRT requirement (RR 0.74; 95% CI 0.56-1.00; P = 0.05), and with a greater number of ICU-free, ventilator-free, and vasopressor-free days (all P < 0.05). CONCLUSION: In adult patients with sepsis, treatment with balanced crystalloid solutions for fluid resuscitation significantly reduces mortality (moderate certainty), decreases kidney-related adverse events, and better maintains electrolyte balance, thereby improving patient outcomes. These findings support the preferential use of balanced crystalloids over saline in this population. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/CRD420261368142, identifier CRD420261368142.