A Crossover Trial of Hospital-Wide Lactated Ringer’s Solution versus Normal Saline

Whether lactated Ringer's solution is clinically superior to normal saline for routine intravenous administration of fluids is uncertain. In an open-label, two-period, two-sequence, cross-sectional, cluster-randomized, crossover trial, we assigned hospitals in Ontario, Canada, to use either lactated Ringer's solution or normal saline hospital-wide for a period of 12 weeks. After a washout period, hospitals switched to the other fluid for 12 weeks. The primary outcome was a composite of death or readmission to the hospital within 90 days after the index admission. Secondary outcomes were the individual components of the primary outcome, as well as the length of stay in the hospital, initiation of dialysis within 90 days after the index admission, a visit to the emergency department within 90 days, and discharge to a facility other than home. Data on outcomes were obtained from health administrative databases. The analyses were conducted at the hospital level, and the primary estimand was the effect of the use of lactated Ringer's solution as compared with normal saline averaged across all participating hospitals. Seven hospitals completed both 12-week periods before the trial was interrupted owing to the coronavirus disease 2019 pandemic. Data on the primary outcome were available for 43,626 eligible patients. The mean (±SD) incidence of the composite of death or readmission to the hospital within 90 days after the index admission was 20.3±3.5% with lactated Ringer's solution and 21.4±3.3% with normal saline (adjusted difference, -0.53 percentage points; 95% confidence interval, -1.85 to 0.79; P = 0.35). Results for all secondary outcomes were consistent with those for the primary outcome. No serious adverse events were reported. A hospital-wide policy to administer lactated Ringer's solution rather than normal saline did not result in a significantly lower incidence of death or readmission to the hospital within 90 days after the index admission. (Funded by the Canadian Institutes of Health Research and the Ottawa Hospital Academic Medical Organization; FLUID ClinicalTrials.gov number, NCT04512950.).