CReep and Maintenance flUid Sodium Chloride ADministration rEduction in cRitically Ill adultS
- Conditions
- Fluid Balance OutcomesCritical Care, Intensive CareFluid AccumulationFluid and Electrolyte ImbalanceCritical Illness
- Interventions
- Drug: Glucose 5% for fluid creepDrug: NaCl 0.9% (normal saline) for fluid creepDrug: NaCl 0.3% in glucose 3.3% as maintenance fluidDrug: PlasmaLyte as maintenance fluid
- Registration Number
- NCT07189091
- Lead Sponsor
- University Hospital, Antwerp
- Brief Summary
This study is enrolling adult patients who require a prolonged stay in the intensive care unit (ICU). These patients often receive large amounts of intravenous fluids, which can contain more salt (sodium and chloride) than the body normally needs. Extra salt and water can build up in the body and may delay recovery.
The study will test two strategies:
Fluid creep: These are fluids used to dilute medications or keep intravenous lines open. Usually, the choice is based on habit. In the intervention group, a salt-free glucose 5% solution will be used (if the responsible pharmacist confirms it is compatible with the medication).
Maintenance fluids: These fluids cover daily needs for water and electrolytes. In the intervention group, a lower-salt solution (NaCl 0.3% in glucose 3.3%) will be given, with volume decided by the treating physician.
The comparison group will receive usual care: NaCl 0.9% (commonly called "normal saline") for fluid creep, and an isotonic solution (PlasmaLyte) for maintenance fluids.
The main outcome is the number of days patients are alive and free of life support (such as ventilator or dialysis) during the first 90 days. Other outcomes include abnormal sodium, chloride, or glucose levels, fluid balance and need for diuretics, kidney injury, use of dialysis, time on the ventilator, survival, and length of ICU and hospital stay.
A smaller substudy (SALADIN) will measure in detail how the body handles sodium, chloride, and water using additional calculation on blood tests, urine collections, body weight, and bioimpedance analysis
- Detailed Description
Critically ill patients admitted to the intensive care unit (ICU) often receive large volumes of intravenous fluids. Beyond resuscitation fluids, which have been extensively studied, two other sources contribute substantially to fluid, sodium, and chloride exposure:
Fluid creep, the use of diluents and small-volume infusions to dissolve medications or maintain line patency.
Maintenance fluids, prescribed to cover daily fluid and electrolyte needs when oral intake is insufficient.
Together, fluid creep and maintenance fluids account for more than half of all intravenous fluids given in ICU patients. These fluids frequently contain supraphysiologic amounts of sodium and chloride. Because the kidneys of critically ill patients are unable to excrete these excesses efficiently, sodium and chloride accumulate, leading to positive fluid balances, electrolyte disturbances, pulmonary edema, renal dysfunction, and prolonged organ support. Observational data have linked both fluid overload and hyperchloremia to higher morbidity and mortality.
Prior research has focused mainly on resuscitation fluids. Large randomized trials comparing chloride-rich saline to balanced crystalloids demonstrated only small differences in outcomes, in part because resuscitation fluids make up a limited fraction of overall fluid exposure. In contrast, fluid creep and maintenance solutions offer a larger and modifiable source of sodium and chloride. Small studies and volunteer experiments have shown that sodium-poor maintenance fluids and sodium-free diluents reduce fluid retention and hyperchloremia, but their effect on patient-centered outcomes has never been tested in a large randomized trial.
CRUSADERS (CReep and maintenance flUid Sodium chloride ADministration Reduction in cRitically ill adultS) is a multicenter, randomized, double-blind, phase IV, low-intervention trial designed to address this evidence gap. The trial compares two strategies:
NaCl-poor arm (intervention):
Fluid creep: medications are dissolved in glucose 5% (except when another diluent is mandatory); line patency fluids are glucose 5%.
Maintenance fluids: NaCl 0.3% in glucose 3.3%, with volume determined by the treating physician.
NaCl-rich arm (control):
Fluid creep: medications are dissolved in NaCl 0.9%; line patency fluids are NaCl 0.9%.
Maintenance fluids: PlasmaLyte, with volume determined by the treating physician.
All study fluids are licensed, widely used hospital products. Blinding is achieved through repackaging into opaque study bags labeled only with trial codes. Treating teams decide indications and volumes, ensuring pragmatic applicability while isolating the effect of fluid composition.
The primary endpoint is days alive and without life support (DAWOLS) at 90 days after ICU admission, an outcome that integrates survival and duration of mechanical ventilation or renal replacement therapy. Secondary outcomes include electrolyte disorders (hyponatremia, hypernatremia, hyperchloremia), fluid balance and diuretic use, acute kidney injury, renal replacement therapy, mechanical ventilation, glycemic control, mortality, and ICU/hospital length of stay. Exploratory outcomes include biochemical markers of salt-induced catabolism such as the serum urea-to-creatinine ratio.
A nested substudy (SALADIN - SAlt baLAnce Detailed INsight) will provide mechanistic insights into sodium, chloride, and water handling. In this subgroup, detailed daily balances will be calculated from fluid intake and 24-hour urine collections, combined with measurements of free water clearance, bioelectrical impedance analysis, body weight, and volume kinetics modeling.
The trial will recruit 640 adult ICU patients across four Belgian mixed ICUs. Inclusion requires expected ICU stay \>48 hours and anticipated exposure to maintenance fluids or significant fluid creep. Patients with contraindications to hypotonic fluids, severe baseline hyponatremia, imminent death, chronic dialysis, or exclusive palliative/organ donation admission are excluded.
Patients are randomized 1:1 with stratification by site, mechanical ventilation, and surgical admission. Study treatment continues throughout the ICU stay or until study fluids are no longer available according to the blinded allocation schedule (minimum 28 days after randomization). Follow-up continues until 90 days after ICU admission.
The CRUSADERS trial is investigator-initiated, funded by the Research Foundation Flanders (FWO), and sponsored by Antwerp University Hospital. It is conducted under European Union (EU) Clinical Trial Regulation (536/2014) with central review via the Clinical Trial Information System (CTIS). Given the exclusive use of approved fluids in routine indications, the trial is classified as low-intervention. A Data and Safety Monitoring Board oversees safety with predefined stopping rules and interim analysis after half the planned population has been followed.
By targeting sodium and chloride in fluid creep and maintenance solutions rather than resuscitation fluids, CRUSADERS aims to test a simple, cost-neutral, and widely applicable strategy to improve survival and reduce life support dependence in critically ill patients. If positive, the trial may provide a strong evidence base for revising international fluid therapy guidelines and daily ICU practice.
Recruitment & Eligibility
- Status
- NOT_YET_RECRUITING
- Sex
- All
- Target Recruitment
- 640
Not provided
- A contraindication to hypotonic fluids due to risk of brain edema (including traumatic brain injury, major stroke, intracranial/subarachnoid hemorrhage, meningoencephalitis, intracranial malignancies…), with the timing and clinical judgment left at the discretion of the treating physician.
- Hyponatremia below 131 mmol/L at admission
- Admission solely for treatment of fluid accumulation due to cardiac decompensation, without other acute medical conditions requiring ICU-level care. Note: Patients with heart failure as a comorbidity, those on chronic diuretic therapy, or presenting with edema/bilateral lung infiltrates due to other conditions (e.g., sepsis, pneumonia) are not excluded.
- Patient's death is deemed imminent and inevitable, admission for palliative care or admission solely for organ donation
- Patient receiving chronic renal replacement therapy
- Patients referred after a stay of more than 24 hours in another ICU
- Patients randomized in CRUSADERS before
- Patient is co-enrolled in an unapproved concomitant ICU-trial or in any trial with an intervention that affects fluid administration or fluid balance
Additional exclusion criteria for the SALADIN nested substudy
- Patients expected to require renal replacement therapy within 24 hours
- Increased insensible fluid losses: burns, extensive wounds or skin defects or massive diarrhea,…
- Patients without a urine catheter
- Patients expected to require bladder irrigation within 24 hours
- Patients on chronic treatment with loop or thiazide diuretics (including combination preparations)
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Sodium chloride reduction strategy, the NaCl-poor arm Glucose 5% for fluid creep Participants receive a sodium-chloride reduction strategy during their ICU stay. Medications are diluted in glucose 5% (unless another solvent is mandatory), and intravenous line patency fluids are glucose 5%. Daily maintenance fluids are NaCl 0.3% in glucose 3.3%, with the volume determined by the treating physician. The goal is to reduce sodium and chloride exposure while maintaining fluid and electrolyte support. Interventions: Drug: Glucose 5% Drug: NaCl 0.3% in Glucose 3.3% Sodium chloride reduction strategy, the NaCl-poor arm NaCl 0.3% in glucose 3.3% as maintenance fluid Participants receive a sodium-chloride reduction strategy during their ICU stay. Medications are diluted in glucose 5% (unless another solvent is mandatory), and intravenous line patency fluids are glucose 5%. Daily maintenance fluids are NaCl 0.3% in glucose 3.3%, with the volume determined by the treating physician. The goal is to reduce sodium and chloride exposure while maintaining fluid and electrolyte support. Interventions: Drug: Glucose 5% Drug: NaCl 0.3% in Glucose 3.3% Isotonic fluid strategy, the NaCl-rich arm NaCl 0.9% (normal saline) for fluid creep Participants receive a standard isotonic fluid strategy during their ICU stay. Medications are diluted in NaCl 0.9% (unless another solvent is mandatory), and intravenous line patency fluids are NaCl 0.9%. Daily maintenance fluids are PlasmaLyte, with the volume determined by the treating physician. This reflects the common standard of care in many ICUs. Interventions: Drug: NaCl 0.9% Drug: PlasmaLyte Isotonic fluid strategy, the NaCl-rich arm PlasmaLyte as maintenance fluid Participants receive a standard isotonic fluid strategy during their ICU stay. Medications are diluted in NaCl 0.9% (unless another solvent is mandatory), and intravenous line patency fluids are NaCl 0.9%. Daily maintenance fluids are PlasmaLyte, with the volume determined by the treating physician. This reflects the common standard of care in many ICUs. Interventions: Drug: NaCl 0.9% Drug: PlasmaLyte
- Primary Outcome Measures
Name Time Method Days alive and without life support at day 90 (DAWOLS90) From admission until day 90 counted from ICU admission (= Day 1) The composite endpoint DAWOLS90 is defined as the number of days alive and without the use of life support within 90 days counted from ICU admission. Unit of measure: days. Patients who die before D90 are assigned zero days. The following life-support therapies are considered 1/ Mechanical ventilation: includes invasive and noninvasive ventilation, including continuous positive airway pressure (CPAP) but excluding high-flow nasal oxygen. Each ICU day counts as a ventilator day if support is in place. Post-extubation days are counted as ventilator-free only if no re-intubation occurs within 48 hours. 2/ Renal replacement therapy (RRT): includes continuous RRT, peritoneal dialysis, or intermittent hemodialysis (IHD). If IHD is given, periods with up to 3 days between sessions are counted as days with RRT.
- Secondary Outcome Measures
Name Time Method Occurrence of moderate and severe hyponatremia From randomization until ICU discharge (up to day 90 counted from ICU admission) Defined as the number of participants with at least one episode of:
Moderate hyponatremia: serum sodium 125-129 mmol/L Severe hyponatremia: serum sodium \<125 mmol/L
To be counted as an event, the sodium level must decrease by at least 3 mmol/L from baseline to reduce misclassification due to pre-existing mild hyponatremia or analytical variation. Assessments are based on daily routine morning serum sodium values from the central laboratory (ion-specific electrode). If available, paired serum albumin and point-of-care sodium values (measured within 2 hours) will be recorded to allow cross-checks and sensitivity analysesOccurrence of moderate and severe hypernatremia From randomization until ICU discharge (up to day 90 counted from ICU admission) Defined as the number of participants with at least one episode of:
Moderate hypernatremia: serum sodium 151-155 mmol/L Severe hypernatremia: serum sodium \>155 mmol/L
To be counted as an event, the sodium level must increase by at least 3 mmol/L from baseline to account for pre-existing mild hypernatremia and analytical variation. Assessments are based on daily routine morning serum sodium values from the central laboratory (ion-specific electrode). If available, paired serum albumin and point-of-care sodium values (measured within 2 hours of the central measurement) will be recorded to allow cross-checks and sensitivity analyses.Occurrence of moderate and severe hyperchloremia From randomization until ICU discharge (up to day 90 counted from ICU admission) Defined as the number of participants with at least one episode of:
Moderate hyperchloremia: serum chloride 111-115 mmol/L Severe hyperchloremia: serum chloride \>115 mmol/L
To be counted as an event, the chloride level must increase by at least 2 mmol/L from baseline to account for pre-existing mild hyperchloremia and analytical variation. Assessments are based on daily routine morning serum chloride values from the central laboratory (ion-specific electrode). If available, paired serum albumin and point-of-care chloride values (measured within 2 hours of the central measurement) will be recorded to allow cross-checks and sensitivity analysesTime to first administration of intravenous loop diuretic From randomization until ICU discharge (up to day 90 counted from ICU admission) Defined as the time (in hours) from randomization until the first administration of an intravenous loop diuretic (e.g., furosemide or bumetanide). The exact timestamp of first administration is recorded.
Proportion of ICU days with intravenous loop diuretic use From randomization until ICU discharge (up to day 90 counted from ICU admission) Defined as the number of ICU days during which a participant receives at least one dose of an intravenous loop diuretic, expressed as a proportion of total ICU days.
Cumulative fluid balance in mL up to first IV loop diuretic use From ICU admission until ICU discharge (up to day 90 counted from ICU admission) Defined as the cumulative net fluid balance, excluding insensible losses. Daily fluid balance is calculated as total inputs minus total outputs (mL per ICU day).
Inputs: study fluids, non-study fluid creep, non-study maintenance and replacement fluids, non-study resuscitation fluids, enteral and parenteral nutrition, blood products, and oral intake.
Outputs: urine output, net ultrafiltration by renal replacement therapy, gastric aspirates, drain outputs, and diarrhea (if precisely measured).
The cumulative fluid balance is the sum of all daily fluid balances from ICU admission until the morning of the first ICU day on which an intravenous loop diuretic is prescribed.Occurrence of hyperglycemia From randomization until ICU discharge (up to day 90 counted from ICU admission) Defined as the proportion of glucose measurements \>180 mg/dL relative to the total number of glucose assessments during the ICU stay. Mean daily glucose values will also be calculated for each ICU day. Assessments are based on point-of-care blood gas analyzer values, which are routinely collected multiple times per day in all ICU patients.
Occurrence of hypoglycemia From randomization until ICU discharge (up to day 90 counted from ICU admission) Defined as the number of participants with at least one episode of hypoglycemia, serum glucose \<70 mg/dL, measured on routine point-of-care blood gas analysis. Severe hypoglycemia (\<40 mg/dL) is separately recorded as a serious adverse reaction.
Occurrence of new-onset acute kidney injury (AKI) From third ICU day after randomization until ICU discharge (up to day 90 counted from ICU admission) Defined as the number of participants who develop new-onset AKI stage 2 or 3 according to KDIGO criteria (Kidney Disease: Improving Global Outcomes), starting from the third ICU day after randomization. AKI classification is based on daily serum creatinine (central laboratory morning samples) and urine output collected every 12-24 hours. KDIGO stage 1 is not assessed in this trial.
Occurrence of new-onset need for renal replacement therapy (RRT) From the second ICU day after randomization until ICU discharge (up to day 90 counted from ICU admission) Defined as the number of participants requiring new initiation of RRT (continuous renal replacement therapy, peritoneal dialysis, or intermittent hemodialysis). To attribute RRT to the intervention, only events starting on or after the second ICU day following randomization are considered.
Renal replacement therapy-free days at day 90 From ICU admission until day 90 counted from ICU admission. Calculated as the number of days during the 90-day observation period that a participant is alive and not receiving renal replacement therapy (RRT). For intermittent hemodialysis, periods with up to 3 days between sessions are counted as days on RRT.
Occurrence of new-onset need for mechanical ventilation From the second ICU day after randomization until ICU discharge (up to day 90 counted from ICU admission) Defined as the number of participants who newly require mechanical ventilation after randomization. Mechanical ventilation includes invasive and noninvasive ventilation (including continuous positive airway pressure (CPAP)) but excludes high-flow nasal oxygen. To attribute events to the intervention, only new initiation from the second ICU day after randomization is considered.
Ventilator-free days at day 90 From ICU admission until ICU discharge (up to day 90 counted from ICU admission) Calculated as the number of days during the 90-day observation period that a participant is alive and free of mechanical ventilation. Mechanical ventilation includes invasive and noninvasive ventilation (including CPAP) but excludes high-flow nasal oxygen. Following extubation, days are counted as ventilator-free only if no re-intubation occurs within 48 hours.
Days alive and out of hospital at day 90 (DAOH90) From ICU admission until day 90 counted from ICU admission. Defined as the number of days a participant is alive and outside the hospital during the 90 days after ICU admission. If a patient is discharged and later readmitted, both admissions are included in the total number of hospitalization days. Mortality is penalized and assigned a value of zero DAOH. DAOH is calculated at day 90 counted from ICU admission.
ICU length of stay From ICU admission until ICU discharge (up to day 90 counted from ICU admission). Defined as the number of calendar days from ICU admission to ICU discharge, including referral or transfer to other ICUs following the same admission.
Hospital length of stay From ICU admission until hospital discharge (up to day 90 counted from ICU admission) Defined as the number of calendar days from ICU admission to hospital discharge, including transfers to other hospitals. Discharges or transfers to rehabilitation wards within the same hospital are not counted as hospital length of stay.
ICU mortality From ICU admission until discharge from the index ICU episode, including any continuous referrals/transfers to other ICUs (up to day 90 counted from ICU admission) Death occurring at any time while continuously in ICU during the index (initial) ICU episode. Inter-ICU transfers are considered part of the same continuous ICU episode. Deaths after discharge from the index ICU episode-whether on the ward or during any later ICU readmission within the same hospital admission-are not counted.
Hospital mortality From ICU admission until discharge from the index hospital admission (up to day 90 counted from ICU admission) Death occurring at any time during the index (initial) hospital admission, irrespective of location (ICU or ward within the same hospital) and including transfers to other hospitals within the same continuous admission. Deaths after discharge from the index hospital admission are not counted, even if the patient is readmitted later.