Maintenance fluid practices in intensive care units in Australia and New Zealand

Administration of maintenance fluid is common practice in the intensive care unit, contributing to daily fluid and sodium intake and balance. Despite this, there is little evidence to describe clinical practices relating to its administration to ICU patients.

We conducted a prospective, observational, point-prevalence study in 49 Australian and New Zealand ICUs in 2014. We aimed to document the type and volume of maintenance fluid administered to ICU patients, and to describe additional fluid received. We also assessed changes in maintenance fluid administration practices compared with our similar study conducted in 2011.

Of 645 patients enrolled, 399 (62%) received maintenance fluid on the study day. A median volume of 630 mL (interquartile range [IQR], 272-1250 mL) was delivered, accounting for a median of 35% (IQR, 16%- 56%) of total daily administered fluids. This was in addition to other fluids administered as fluid resuscitation, drug infusions and boluses, flushes and enteral or parenteral feeds, as well as oral intake. 0.9% saline was the most commonly used maintenance fluid (36%), followed by balanced salt solutions (30%). Compared with data from 2011, there has been a decrease in the median volume of maintenance fluid administered (2011, 860 mL [IQR, 360- 1533 mL]; 2014, 630 mL [IQR, 287-1328 mL]; P = 0.01), although the proportion of patients receiving maintenance fluid remains unchanged. There has been no change in the types of fluids most commonly used for maintenance, but the use of balanced salt solutions has increased (2011, 24%; 2014, 30%; P = 0.01).

Administration of maintenance fluids to patients in Australian and New Zealand ICUs is common. Although the volume being delivered has decreased, maintenance fluids contribute over one-third of daily total fluid administration.