Fluid overload is independently associated with an increased risk for initiation of renal replacement therapy (RRT) and rapid decline in kidney function, new findings suggest.
Yi-Chun Tsai, MD, of Kaohsiung Medical University Hospital in Kaohsiung, Taiwan, and colleagues enrolled 472 non-dialysis-dependent patients with stage 4 or 5 chronic kidney disease (CKD). They measured the severity of fluid overload using a bioimpedance spectroscopy technique.
During a median 17.3-month follow-up, 71 patients (15%) initiated RRT and 187 (39.6%) experienced a rapid decline in estimated glomerular filtration rate (faster than 3 mL/min/1.73 m2 per year). Compared with patients in the first tertile of fluid overload (the reference group), those in the third tertile (most severe fluid overload) had a 3.1 times increased risk of RRT initiation and a 4.7 times increased risk of rapid eGFR decline after adjusting for other risk factors, the researchers reported online in the American Journal of Kidney Diseases.
“Our results show that fluid overload increases the risk of RRT and we therefore recommend that the care team begin preparation for RRT earlier, such as arteriovenous fistula creation or Tenckhoff catheter implantation,” the authors stated.
CKD patients with fluid overload have expanded extravascular volume and decreased intravascular volume, the investigators explained. “This imbalance in fluid distribution of the body alters kidney perfusion, thereby further deteriorating kidney function,” they wrote. “Furthermore, because fluid overload status may lead to underestimates of creatinine level, clinicians should use particular care in monitoring kidney function in patients with possible fluid overload.”