Overview

Fluid overload (FO) is a common complication after cardiac surgery, associated with increased morbidity and mortality. Loop diuretics, especially furosemide, are routinely used to manage FO, but their use is often empirical. Recent data suggest that natriuresis-guided furosemide titration using point-of-care urinary sodium sensors (LAQUAtwin NA-11, Horiba) may improve the efficiency and safety of fluid removal, but no randomized trial has yet evaluated this approach in postoperative cardiac surgery patients

Our goal is to assess the clinical impact, safety, and feasibility of a natriuresis-guided furosemide protocol after cardiac surgery requiring cardiopulmonary bypass.

Eligibility

Inclusion Criteria:

• Adult patient (age \> 18 years)
• Scheduled for cardiac surgery, including mitral valve repair or replacement, aortic valve replacement, coronary artery bypass grafting (CABG), ascending aortic repair, or combined procedures
• Undergoing surgery with cardiopulmonary bypass (CPB)
• Eligible to receive intravenous furosemide for fluid overload within 48 hours following surgery, as prescribed by the referring physician
• Written and oral informed consent obtained
• Covered by the French national health insurance (Sécurité Sociale)

Exclusion Criteria:

• Aortic arch repair requiring deep hypothermic circulatory arrest
• Active endocarditis
• Hemodynamic instability requiring vasopressor or inotropic support (norepinephrine, dobutamine, epinephrine, or vasopressin)
• Failure to wean from CPB requiring mechanical circulatory support
• Chronic kidney disease with an estimated glomerular filtration rate (eGFR) \< 60 mL/min
• Chronic use of loop diuretics
• Known allergy to furosemide
• Active postoperative bleeding and/or reoperation for bleeding
• Participation in another interventional study that may affect the primary outcome measure
• Patient deprived of liberty by administrative or judicial decision, or placed under legal protection (guardianship or curatorship)