Maintenance and Medication-Related Fluids Dominate Fluid Use in Ventilated ICU Patients

A JAMA prospective observational cohort study characterized fluid administration in 2454 mechanically ventilated adults at 206 ICUs in 41 countries across six continents between April 2024 and July 2025. Patients received invasive ventilation within three days of ICU admission and remained ventilated for at least 24 hours. Investigators assessed fluid volume and daily balance over seven days after intubation, and fluid indications and types over the first three days.

Median daily fluid input peaked at 3.0 L on day 1 (IQR, 2.2–4.0 L), declining to 2.6 L by day 6 (IQR, 1.8–3.5 L). Median daily fluid balance fell from 0.9 L on day 1 to less than 0.3 L by day 3, remaining near-neutral through day 6. Maintenance and replacement fluids accounted for 31.9% of administered volume, while “creep” fluids used to deliver medications and maintain catheter patency accounted for 30.9%. Resuscitation fluids contributed 16.0%. Isotonic balanced crystalloids and isotonic saline represented 48.9% and 27.0% of volume, respectively; colloids accounted for 1.3%.

Substantial between-site variation persisted after adjustment for case mix. The findings highlight nonresuscitation fluids as a major component of ICU fluid exposure. However, this observational description does not establish whether reducing these volumes improves clinical outcomes; the supplied abstract does not report outcome comparisons between fluid strategies.