Abstract: SA-PO666

24-Hour Urine Volume May Be a Practical and Convenient Method of Monitoring Change in Native Kidney Function in Patients on In-Center HD

Session Information

Category: Dialysis

  • 602 Dialysis for AKI: Hemodialysis, CRRT, SLED, Others

Authors

  • Marquez, Kevin D., University of California Davis Medical Center, Sacramento, California, United States
  • Chin, Andrew I., University of California Davis, Sacramento, California, United States
Background

Nephrologists are caring for more in-center HD patients with Acute Kidney Injury on Dialysis (AKI-D). Identifying renal recovery is important. In non-HD patients, change in serum creatinine is commonly used to determine change in renal function. In HD patients, the best indictor of a change in renal function is not known. We examined incident HD patients to determine which factors best correlated to the longitudinal change in residual kidney urea clearance (Kru).

Methods

Retrospective study of incident HD patients with 2 timed, 24-hour urine collections within a 6 month period. Demographic, laboratory, dialysis parameters, and urine data were analyzed to determine the best model to predict change of Kru.

Results

106 incident HD patients were included, mean age of 57 ± 17 years, 35% female and 40% diabetic. Mean time between paired 24 hour urine collections was 106 ± 34 days. Kru increased in 36% of the patients between urine collections. We modeled the change in Kru using: demographic data; post-HD body weight and fluid gain; change in body weight and fluid gain between the 2 urine collections; pre-dialysis BUN, creatinine and albumin; change in these blood tests between the 2 urine collections. The change in 24 hour urine volume was heavily weighted in best predicting the change in Kru (Figure 1). Increase or decrease of pre-dialysis serum creatinine poorly predicted the change in Kru.

Conclusion

While other factors were included in the model, change in 24 hour urine volume was most important in the correlation with kidney function urea clearance change in patients undergoing in-center HD. Pre-dialysis serum creatinine poorly correlated with change in Kru. Extrapolating these findings to AKI-D patients, formal urine collection and clearance calculation is the best method of gauging renal recovery, but serial measure of timed urine volume may be a convenient and appropriate way for weekly, frequent monitoring.

Urine volume contributes most to predicting change in kidney urea clearance.

Funding

  • Clinical Revenue Support