AQUA Pilot Trial

Assessment of Quantity and Utility of water for ICU-Acquired hypernatraemia (The AQUA Pilot Trial)

A Pilot, Six-Centre, Open-Label, Safety and Physiological Efficacy Randomised Controlled Trial

Aim:

The study's primary aim is to determine whether protocolised administration of hypotonic fluid decreases the duration of hypernatraemia compared to usual care in patients requiring intensive care.

The secondary aims of the study are to demonstrate the feasibility of conducting a randomised clinical trial and to determine whether protocol administration of hypotonic fluid affects serum glucose measurements and P/F ratios compared to usual care.

Rationale:

Intensive care unit-acquired hypernatraemia (ICU-AH), a common electrolyte disturbance, is characterised by a sodium level above 145 mmol/L after admission to the intensive care unit.  It has recently been estimated to occur in 7.5% of eligible admissions, and has been consistently associated with adverse patient outcomes, such as mortality.

Current guidelines recommend a slow rate of sodium correction, which aims to prevent potential complications.  However, a recent systematic review demonstrated faster correction rates did not significantly change overall mortality, and faster correction was associated with lower mortality in specific subgroups, including those with severe hypernatremia on admission. Overall, these results challenge existing recommendations and highlight the need for further research to optimise sodium correction strategies.

A pilot trial is warranted to determine the efficacy of a hypotonic fluid protocol (hypotonic fluid given to patients following a specific guideline) in reducing the duration of hypernatraemia. The AQUA Pilot Trial is an open-label randomised control trial comparing protocolised hypotonic fluid administration with usual care in critically ill patients with ICU-AH.

Study Progress:

The study obtained ethics approval in late 2025.  Recruitment will commence in 2025. A target of 70 patients (35 patients per arm) will be enrolled across 6 participating hospital sites.

Data Entry Webpage: https://redcap.helix.monash.edu/redcap_v15.0.32/index.php?pid=3689

Trial Registration: The study has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12625000904471.

Contacts:

Dr Kyle White, Principal Investigator

A/Prof Ary Serpa Neto, Co-Principal Investigator