Should Hospitalized Patients Receive Normal Saline or Lactated Ringer's Solution?

In randomized trials of critically ill hospitalized patients, balanced crystalloid solution (e.g., lactated Ringer's solution) was no better than normal saline for preventing death (NEJM Evid 2022; 1:oa2100010; NEJM JW Gen Med Mar 1 2022; and N Engl J Med 2022; 386:815). However, the effects of fluid type on outcomes in a broader swath of hospitalized patients are unknown. In a new open-label crossover trial, Canadian investigators randomized seven hospitals (including >43,000 patients) to use either lactated Ringer's or normal saline in all newly admitted patients for 12 weeks, after which hospitals switched to the opposite solution for an additional 12 weeks. (The initial plan was to randomize 16 hospitals, but the trial was terminated ea…