ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12625000904471p

Ethics application status

Submitted, not yet approved

Date submitted

31/07/2025

Date registered

20/08/2025

Date last updated

20/08/2025

Date data sharing statement initially provided

20/08/2025

Type of registration

Prospectively registered

Titles & IDs

Public title

Assessment of Quantity and Utility of water for ICU-Acquired hypernatraemia. A Pilot, Six-Centre, Open-Label, Safety and Physiological Efficacy Randomised Controlled Trial

Scientific title

Assessment of Quantity and Utility of water for ICU-Acquired hypernatraemia. A Pilot, Six-Centre, Open-Label, Safety and Physiological Efficacy Randomised Controlled Trial in ICU patients.

Secondary ID [1]

Nil known

Universal Trial Number (UTN)

Trial acronym

AQUA Trial

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Hypernatraemia

Critical illness

Condition category

Condition code

Metabolic and Endocrine

Other endocrine disorders

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

Patients will be randomised to receive protocolised administration of hypotonic fluid or usual care for 7 days or ICU discharge.

- Protocolised hypotonic fluid will be commenced at 100 mL/h, and repeat sodium as measured by blood gas machine will be performed at 6 hours.
- Hypotonic fluid can be administered as enteral free water, intravenous 5% glucose, or a combination to achieve the desired rate.
- The choice of hypotonic fluid will be at the discretion of the treating clinician.
- All patients will also receive 6-hourly sodium measurements for the first 24 hours.
- If sodium is less than 142 mmol/L, the hypotonic fluid will cease.
- If sodium is greater than or equal to 142 mmol/L AND less than the previous sodium, the hypotonic fluid will continue at the current rate.
- If sodium exceeds the previous sodium, the rate of hypotonic fluid will be increased by 100mL/h.
- The intervention protocol will be conducted for 7 days, after which all patients receive usual care.

There is no protocolised maximum hypotonic fluid rate.

Adherence to the protocol will be assessed by review of the medical records.

The intervention will be stopped if the patient is started on renal replacement therapy, if the patient is discharged from ICU, if the treating clinician has concerns about cerebral oedema, or, of course, in case of death.

Intervention code [1]

Treatment: Other

Comparator / control treatment

Patients allocated to the control group will receive standard care. Standard care is defined as usual practice according to local guidelines, local practice, and treating clinician decisions. The use of hypotonic fluid, intravenously or enterally, will be at the treating clinician's discretion.

Control group

Active

Outcomes

Primary outcome [1]

Time to normal sodium from randomisation up to day 7, or ICU discharge

Timepoint [1]

Hourly up to 7 days after randomisation, or until ICU discharge

Secondary outcome [1]

Peak serum sodium within 7 days of randomisation, or until ICU discharge

Timepoint [1]

Hourly up to 7 days after randomisation, or until ICU discharge

Secondary outcome [2]

Time to sodium less than 142 mmol/L within 7 days of randomisation

Timepoint [2]

Hourly up to 7 days after randomisation, or until ICU discharge

Secondary outcome [3]

Incidence of moderate to severe hypernatraemia (sodium >= 150 mmol/L) within 7 days of randomisation

Timepoint [3]

Hourly up to 7 days after randomisation, or until ICU discharge

Secondary outcome [4]

Incidence of hypokalaemia within 7 days after randomisation

Timepoint [4]

Daily up to 7 days after randomisation, or until ICU discharge

Secondary outcome [5]

Incidence of hypomagnesaemia within 7 days after randomisation

Timepoint [5]

Daily up to 7 days after randomisation, or until ICU discharge

Secondary outcome [6]

Incidence of hypophosphatemia within 7 days after randomisation.

Timepoint [6]

Daily up to 7 days after randomisation, or until ICU discharge

Secondary outcome [7]

Maximum blood glucose level within 7 days after randomisation

Timepoint [7]

Hourly up to 7 days after randomisation, or until ICU discharge

Secondary outcome [8]

Maximum insulin administration to day 7 after randomisation

Timepoint [8]

Hourly up to 7 days after randomisation, or until ICU discharge

Secondary outcome [9]

Minimum P/F ratio to day 7 after randomisation, or ICU discharge

Timepoint [9]

Hourly up to 7 days after randomisation, or until ICU discharge

Secondary outcome [10]

Duration of mechanical ventilation in days to day 30 after randomisation

Timepoint [10]