Fluid-removal Guided by VeXUS Score With Usual Care in Patients With Acute Kidney Injury After Cardiac Surgery

Feasibility of a Randomised Trial Comparing a Fluid-removal Guided by VeXUS Score With Usual Care in Patients With Acute Kidney Injury After Cardiac Surgery: a Pilot Randomised Trial.

Acute kidney injury affects more than 30% of patients after cardiac surgery, and is associated with an excess in mortality. There is a clinical continuum between acute kidney injury (transient if <48h, persistent if >48h), the development of acute kidney and chronic renal failure. Each of these entities characterising renal recovery is associated with an increase in long-term morbidity and mortality. Fluid management in patients with acute kidney injury is challenging, as both hypovolaemia and hypervolaemia are detrimental. Venous congestion (reflecting intravascular hypervolaemia), is a well-established haemodynamic factor contributing to acute kidney injury after cardiac surgery. An ultrasound score, based on the venous doppler pattern explored in intra-abdominal organs, has recently been developed and is a better predictor of acute kidney injury than central venous pressure. Whether using the VeXUS score to guide fluid removal in haemodynamically stabilised patients could promote renal recovery after acute kidney injury remains to be investigated.

Before designing a large randomised trial to test such a strategy, its feasibility in a pilot randomised trial is assessed.

Inclusion Criteria:

• Intensive care unit admission within 72 hours of cardiac surgery with extracorporeal circulation
• Acute kidney injury defined by KDIGO criteria
• Vasoactive inotropic score <45 and capillary refill time <3s
• Informed written consent

Exclusion Criteria:

• Hypokalaemia <3.5mmol/L
• Hyponatremia<125mmol/L
• Hypernatremia >145mmol/L
• Metabolic alkalosis with pH >7.50
• Impossibility to measure capillary refill time
• Chronic liver disease
• Cirrhosis with portal hypertension
• Known thrombus of the inferior vena cava
• Mechanical circulatory assistance (ECMO or mono left ventricular assistance)
• Severe pre-operative chronic kidney disease (GFR < 30mL/min/1.73m2)
• Need for renal replacement therapy anticipated by the attending physician within 24 hours
• Known hypersensitivity to Furosemide and/or hydrochlorothiazide
• Severe allergy to wheat
• Patient already included in another interventional study with an exclusion period still in progress
• Pregnant, breast-feeding or women of childbearing age without suitable contraception
• Patients under guardianship, curatorship or safeguard of justice
• Patients under psychiatric care
• Patients not affiliated to a social security scheme or beneficiaries of a similar scheme