Proactive Prescription-based Fluid Management vs Usual Care in Critically Ill Patients on Kidney Replacement Therapy

Severe acute kidney injury (AKI) in the intensive care unit (ICU) is almost uniformly complicated by fluid accumulation, thus making fluid removal a central component of the renal replacement therapy (KRT) prescription. Whereas the achievement and maintenance of euvolemia are critical objectives in the care of critically ill patients with severe AKI, there remain important knowledge gaps in our ability to effectively and safely deliver ultrafiltration. Multisystemic congestion resulting from fluid accumulation is believed to mediate adverse outcomes in this population and the timely use of mechanical fluid removal may improve prognosis. However, fluid removal may be associated with hemodynamic instability during KRT which may precipitate complications. The optimal fluid management strategy is currently unknown.

The study is a pilot randomized clinical trial comparing a protocol-based fluid management strategy with usual care in critically ill patients receiving KRT. The fluid management protocol is intended to achieve neutral or negative daily fluid balance by both preventing and treating fluid accumulation. The protocol was designed to provide a standardized framework to prescribe fluid removal while allowing the attending care team to modify treatment targets according to their clinical evaluation.

The primary objective of this trial is to determine whether the intervention results in a difference in cumulative fluid balance from randomization to 5 days. Feasibility will be documented including the ability to enroll the target population, protocol adherence, and the capacity to achieve follow-up through 90 days. Secondary outcomes will also include short-term patient outcomes, safety outcomes, and health resource utilization related to KRT delivery.

Inclusion criteria

• Age ≥ 18 years
• Admitted to the ICU
• AKI during current hospitalization defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria(1) as any of the following: Increase in serum creatinine by 27 µmol/L or more within any 48-hour window, or an increase in serum creatinine to 1.5 times baseline or more within the last 7 days, or a urine output less than 0.5 mL/kg/h for 6 hours.
• Planned initiation of KRT within the following 12 hours or the receipt of KRT for AKI for ≤48 hours

Exclusion criteria

• Lack of commitment to maintain kidney, pharmacologic or respiratory support at the time of screening, or probable transition to comfort care within 48 hours according to the treating physician
• Probable discharge from the ICU within the next 48 hours according to treating physician
• Severe burn injury (>10% of body surface area)
• Severe abnormality in serum sodium (>155 or <120 mmol/L)
• Important ongoing fluid losses are present and/or are expected to require continued maintenance IV fluids uring the next 48 hours
• The clinical care team believes that the proposed intervention is inappropriate.