Fenoldopam Increases Urine Output in Oliguric Critically Ill Surgical Patients

Background Fenoldopam is a short-acting dopamine A1 receptor agonist which mediates vasodilation of the renal arteries, thereby increasing urine output. The objective of this study was to compare the effects of fenoldopam and its synergistic effect on furosemide for improving the urine output in postoperative critically ill patients with acute kidney injury (AKI). Methods This is a retrospective study of postoperative critically ill patients with AKI. Patients who received furosemide (control group) were compared with those who received furosemide plus fenoldopam (treatment group) and evaluated at 12 and 24 hours post-treatment. Patients with oliguria and AKI were included in the study, while patients with chronic kidney disease (CKD) were excluded. Glomerular filtration rate, serum creatinine, blood pressure, calculated fluid accumulation, fluid intake, urine output, and total fluid output were used as variables to assess the medication effect. Results Of the 126 patients who met the inclusion and exclusion criteria, 87 patients received furosemide alone, and 39 patients received furosemide plus fenoldopam during their first 24 hours of admission to the surgical intensive care unit (SICU). Although not statistically significant, the addition of fenoldopam demonstrated an increase in mean urine output of 1525ml (IQR; 1530-2095) in the first 24 hours (P=0.06). There was also noted an increase in the urine output (p= 0.07) and a decrease in the total fluid accumulation when fenoldopam was co-administered with furosemide when compared to the patients who were only treated with furosemide (p=0.06). There was no significant change in creatinine clearance from baseline in either group.  Conclusion Fenoldopam may increase urine output in postoperative critically ill patients with acute kidney injury when administered within the first 24 hours of presentation. Based on our results, fenoldopam appears to have a synergistic effect with furosemide in our study population.