Timing and Dose of Fluid Deresuscitation in Critically Ill Patients

Primary objective:

The aim of this study is to identify determinants of successful deresuscitation in ICU patients, defined as achieving a negative fluid balance within 24 hours without hemodynamic consequences.

Secondary objectives:

* Timing of deresuscitation:

* Identify determinants of successful deresuscitation in ICU patients, defined as achieving a negative fluid balance within 24 hours; * Compare these determinants with determinants for the clinical decision of deresuscitation by the treating physician; * Identify differences in these determinants within subgroups of sepsis, ARDS and cardiac patients, provided the numbers are sufficient; * Rate (dose) of deresuscitation:

* Identify parameters associated with diuretic or natriuretic response during deresuscitation; * Find individualized optimal rates of deresuscitation based on these determinants; * Possible complications of deresuscitation:

* Determine whether there is an association between electrolyte or acid-base disturbances during deresuscitation (e.g. the Strong Ion Difference) and clinical outcomes; * Determine whether there is an association between the rate of deresuscitation and hemodynamic consequences; * Determine whether there is an association between the timing and rate of deresuscitation and atrial fibrillation (AF); * Determine whether there is an association between deresuscitation and the occurrence of delirium; * Determine whether there is an association between timing and rate of deresuscitation and acute kidney injury (AKI).

Study design:

The TIDE study is a multicenter, prospective, observational cohort study in the ICUs of the Amsterdam UMC and OLVG in Amsterdam, the Netherlands.

Study population:

Adult patients admitted to the ICU, who have a clinical indication for deresuscitation as set by the treating physician, using diuretics or ultrafiltration; first deresuscitation attempt during the ICU stay.

Sample size calculation:

For finding associations with logistic regression with a moderate (odds ratio \>1.5) to strong (odds ratio \>2.5) effect an alpha set at 0.05, power set at 0.8 and an estimated failure of 50% or more, we would need a sample size of around 150-210 patients.

Methods:

Patients in the participating ICUs are screened for eligibility when the treating physician sets a clinical indication for deresuscitation. Eligible patients will be included in the study. At that time, defined as baseline, clinical, ultrasound and laboratory measures will be collected. Clinical measures among others include: heart rate, mean arterial pressure, dose of vasopressors, and capillary refill time. Ultrasound measurements include: lung ultrasound scores (LUS), venous excess ultrasound (VExUS), and cardiac ultrasound, including VTI during a passive leg raise (PLR). Laboratory measurements include arterial blood gas analysis and urinalysis. Furthermore, baseline characteristics such as demographics, reason for ICU admission, severity of illness scores, and medical history are collected.

Deresuscitation will be performed according to standard care according to the treating physician's insights. Primary follow up is 24 hours in which granular data of deresuscitation tactics, deresuscitation output, electrolyte and acid-base disturbances, and hemodynamic consequences are collected. Secondary follow up is at 7 days for complications such as acute kidney injury and at 28 days for mortality, ICU length of stay (LOS) and ventilator free days (VFD), where available.

• Successful deresuscitation [Time frame: 24 hours]
• Rate of deresuscitation [Time frame: 24 hours]
• Dose of deresuscitation [Time frame: 24 hours]
• Natriuresis [Time frame: 24 hours]
• Delta Strong Ion Difference [Time frame: 24 hours]
• Delta serum sodium [Time frame: 24 hours]
• Delta serum chloride [Time frame: 24 hours]
• Atrial fibrillation [Time frame: 24 hours]
• Acute Kidney Injury (AKI) [Time frame: 7 days]
• Persistent AKI [Time frame: 7 days]
• Renal Replacement Therapy (RRT) [Time frame: 7 days]
• Delirium [Time frame: 7 days]