Acute Kidney Injury, Cardiac Surgical Procedures, Fluid Therapy, Hemodynamics
Conditions
Keywords
Venous Congestion, Venous Excess UltraSound (VExUS), Fluid Responsiveness, Fluid Tolerance, Point-of-Care Ultrasound, Hemodynamic Management
Brief summary
This pilot randomized controlled trial will evaluate the use of point-of-care ultrasound (POCUS) to assess fluid tolerance and fluid responsiveness in patients following cardiac surgery. Participants will be randomized to an ultrasound-guided assessment strategy or standard care. In the intervention group, treating physicians will receive the results of a structured ultrasound assessment, including the Venous Excess UltraSound (VExUS) score and an assessment of fluid responsiveness. The primary objectives are to determine whether this information influences clinical management and to assess the feasibility of the study procedures. The study will also explore differences in fluid and hemodynamic management, kidney function, and postoperative clinical outcomes.
Detailed description
Postoperative management following cardiac surgery requires the integration of multiple clinical and hemodynamic variables to guide individualized treatment. Important therapeutic decisions include intravenous fluid administration, fluid removal with diuretics, and the use of vasoactive and inotropic medications. Point-of-care ultrasound (POCUS) may provide complementary physiologic information to support these decisions by assessing both fluid tolerance and fluid responsiveness. Fluid tolerance refers to the ability of a patient to receive additional fluid without developing or worsening clinically significant congestion. The Venous Excess UltraSound (VExUS) score is an ultrasound-based approach to evaluating systemic venous congestion. Abnormal VExUS findings have been associated with adverse outcomes following cardiac surgery; however, whether incorporating VExUS into clinical decision-making can meaningfully influence management remains uncertain. Fluid responsiveness refers to the capacity of cardiac output to increase following an increase in cardiac preload. Dynamic ultrasound-based assessments can be used to evaluate fluid responsiveness and may help identify patients who are more likely to benefit from fluid administration. Combining assessments of fluid tolerance and fluid responsiveness may therefore provide complementary information: identifying patients who may benefit from additional fluid while also identifying those at risk of adverse effects from fluid accumulation. USE-the-FORCE-in-Cardiovascular ICU (UTF-in-CVICU) is a pilot randomized controlled trial evaluating a structured POCUS-based assessment of fluid tolerance and fluid responsiveness in adult patients following cardiac surgery. Participants will be randomized to an intervention group or a standard-care group. In the intervention group, a structured ultrasound assessment will be performed and the results will be communicated to the treating team. The ultrasound evaluation includes assessment of venous congestion using VExUS and assessment of fluid responsiveness. The treating physician will retain responsibility for all therapeutic decisions and will determine whether the ultrasound findings warrant a modification of the management plan. Participants randomized to the control group will receive standard postoperative care. The trial has two co-primary objectives. The proof-of-concept objective is to determine how frequently information obtained from the ultrasound assessment leads the treating physician to modify the planned management strategy. The feasibility objective is to determine whether the study procedures can be successfully completed according to protocol, including completion of the ultrasound assessments and timely communication of the report to the treating team. Secondary and exploratory objectives will evaluate differences between groups in fluid balance and the use of diuretics, inotropes, and pulmonary vasodilators during the first 72 hours following randomization. Kidney outcomes will include the occurrence of acute kidney injury and changes in estimated glomerular filtration rate. Additional exploratory clinical outcomes include duration of vasopressor therapy, duration of mechanical ventilation, intensive care unit and hospital length of stay, cumulative time in perioperative organ dysfunction or death, kidney replacement therapy, and operative mortality. Qualitative feedback from treating physicians regarding the ultrasound assessment will also be evaluated.
Interventions
DIAGNOSTIC_TESTStructured Point-of-Care Ultrasound Assessment
A structured point-of-care ultrasound assessment combining evaluation of fluid tolerance using the Venous Excess UltraSound (VExUS) score and assessment of fluid responsiveness. Results are communicated to the treating physician to support postoperative fluid and hemodynamic management.
OTHERStandard Care (in control arm)
Participants will receive standard postoperative fluid and hemodynamic management. Study-specific point-of-care ultrasound assessment results will not be communicated to the treating physician.
Sponsors
Centre hospitalier de l'Université de Montréal (CHUM)
Montreal Heart Institute
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Adults aged ≥18 years * Undergoing planned cardiac surgery with anticipated postoperative admission to the intensive care unit
Exclusion criteria
* Known stage 5 chronic kidney disease according to the KDIGO classification (eGFR less than 15 mL/min/1.73m2) or on renal replacement therapy * Planned or ongoing mechanical circulatory support * Planned or history of heart transplantation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Feasibility of study procedures | 30 days after surgery | Feasibility will be assessed as the proportion of participants for whom all study procedures are successfully completed, including completion of the ultrasound examination, communication of the ultrasound report to the treating physician within two hours, and complete data collection. The study will be considered feasible if all study procedures are successfully completed in ≥80% of participants. |
| Clinical impact of the POCUS assessment on patient management | Postoperative day 1 | Proportion of participants in the intervention group for whom the treating physician reports that the POCUS assessment resulted in a change in the clinical management. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cumulative fluid balance | Up to 72 hours after randomization or ICU discharge, whichever occurs first | Cumulative fluid balance, measured in milliliters (mL), from randomization until 72 hours after randomization or ICU discharge, whichever occurs first. |
| Cumulative loop diuretic dose | Up to 72 hours after randomization or ICU discharge, whichever occurs first | Cumulative dose of loop diuretic medication, measured in milligrams (mg), from randomization until 72 hours after randomization or ICU discharge, whichever occurs first. |
| Number of diuretic agents used | Up to 72 hours after randomization or ICU discharge, whichever occurs first | Number of diuretic agents used (0, 1, or 2). Two agents indicate combination diuretic therapy with a loop diuretic and a thiazide diuretic. |
| Use of inotropic support | Up to 72 hours after randomization | Proportion of participants receiving inotropic medication following randomization |
| Inotrope-free hours | Up to 72 hours after randomization | Number of hours alive and free from inotropic support following randomization |
| Use of inhaled pulmonary vasodilators | Up to 72 hours after randomization | Proportion of participants receiving inhaled pulmonary vasodilator therapy, including inhaled epoprostenol, inhaled milrinone, or inhaled nitric oxide |
| Incidence of acute kidney injury | Up to postoperative day 7 | Proportion of participants developing acute kidney injury (AKI), defined according to KDIGO serum creatinine criteria. Urine output criteria will not be used. AKI is defined as an increase in serum creatinine ≥26.5 µmol/L within 48 hours or an increase to ≥1.5 times baseline within 7 days. |
| Severity of acute kidney injury | Up to postoperative day 7 | Severity of acute kidney injury according to the Kidney Disease: Improving Global Outcomes (KDIGO) staging system, ranging from stage 1 to stage 3, based on serum creatinine criteria. Renal replacement therapy is classified as stage 3. Higher stages indicate greater severity of acute kidney injury. |
| Kinetic estimated glomerular filtration rate (KeGFR) | Up to postoperative day 7 | Kinetic estimated glomerular filtration rate (KeGFR), derived from serial serum creatinine measurements using the kinetic GFR equation. |
| Initiation of renal replacement therapy | Up to postoperative day 28 | Proportion of participants requiring initiation of renal replacement therapy. |
| Vasopressor-free hours | Up to postoperative day 28 | Number of hours alive and free from vasopressor therapy. |
| Ventilator-free hours | Up to postoperative day 28 | Number of hours alive and free from mechanical ventilation. |
| ICU-free days | Up to postoperative day 28 | Number of days alive and outside the intensive care unit (ICU). |
| Hospital-free days | Up to postoperative day 28 | Number of days alive and outside the hospital. |
| Operative mortality | During the index hospitalization or up to 30 days after surgery following discharge | Proportion of participants who die during the hospitalization in which the operation was performed, regardless of timing, or following hospital discharge but within 30 postoperative days. |
| Cumulative time in perioperative organ dysfunction (TPOD) | Up to postoperative day 28 | Cumulative duration, in hours, of mechanical ventilation, vasopressor therapy, renal replacement therapy, and mechanical circulatory support. |
Countries
Canada
Contacts
CONTACTWilliam Beaubien-Souligny, MD, PhD, FRCPC
Outcome results
None listed