Objectives: Preoperative renal dysfunction increases the risk of postoperative renal failure and mortality in cardiac surgery patients. Studies investigating the protective effect of furosemide in cardiac surgery were mostly conducted in patients with normal renal function. This study aimed to evaluate the effect of prophylactic low-dose furosemide in cardiac surgery patients with mild to moderate renal dysfunction.
Design: Double-blind randomized controlled trial.
Setting: This study was conducted at a cardiovascular surgery center.
Patients and participants: Eighty-seven patients of elective cardiac surgery with mild to moderate renal dysfunction (estimated glomerular filtration rate [eGFR] 30-89 ml/min/1.73 m2).
Interventions: Prophylactic furosemide infusion (2 mg/h) or 0.9% NaCl infusion (2 ml/h) was administered and continued for a total of 12 hours.
Measurement and results: We examined blood samples at 12, 24, 48, and 120 hours after infusion started to measure the change in eGFR. A decrease in eGFR ³20% was considered a worsening of renal function, while ³20% increase in eGFR was recovering of renal function. We compared the requirement for therapeutic furosemide infusion and renal replacement therapy in both groups.
The incidence of decreasing eGFR at the 12th, 24th, and 48th-hour was higher in the control compared to the furosemide group. Increasing eGFR at the 120th-h was the same in both groups. Subjects in the furosemide group required less administration of therapeutic furosemide infusion than the control group. Renal replacement therapy was needed more in the furosemide group than in the control group.
Conclusions: Low-dose furosemide infusion can reduce the incidence of worsening renal function, and the need for therapeutic furosemide infusion, but does not prevent the usage of renal replacement therapy.