Low Dose Continuous Furosemide Effect on Cardiac Surgery Patients With Kidney Dysfunction

Chronic kidney disease is an independent risk factor for cardiovascular disease associated with increased mortality rate during cardiac surgery in proportion to the kidney function. Chronic kidney disease is defined by decreased glomerular filtration rate (GFR) as classified by Kidney Disease: Improving Global Outcome (KDIGO). Deterioration of kidney function has a complex and multifactorial pathophysiologic derangement. In order to counter kidney injury associated with cardiac surgery, several pharmacologic and non-pharmacologic interventions have been studied to prevent perioperative deterioration of kidney function. Diuretics as pharmacologic measure are often used post-cardiac surgery to treat fluid overload and managing patient with acute kidney injury by preventing anuria. Loop diuretics (furosemide) may improve renal blood flow, decrease reabsorption in renal tubules, decrease oxygen demand and energy consumption (blocking potassium/sodium/2cloride co-transport in loop of Henle), and prevent hypoxic injury of renal medulla. Low dose continuous furosemide hypothetically has a protective effect on cardiac surgery patients with kidney dysfunction, measured improved glomerular filtration rate, decreased indication for therapeutic furosemide infusion, and decreased need of renal replacement therapy. On the other hand, administration of furosemide is rather harmful in severe kidney dysfunction. Therefore, the objective of this study is to determine the protective effect of low-dose continuous furosemide perioperative in cardiac surgery patients with mild to moderate kidney dysfunction.