Abstract: TH-PO290

Identification of the Oliguric Patient Using a Novel Electronic Device for Measuring Urine Output

Session Information

Category: Acute Kidney Injury

  • 001 AKI: Basic

Authors

  • Grinstein, Mor, RENALSENSE LTD, Brookline, Massachusetts, United States
  • Goldman, Aliza D., RENALSENSE LTD, Brookline, Massachusetts, United States
  • Azran, Hagar, RENALSENSE LTD, Brookline, Massachusetts, United States
  • Stern, Tal, RENALSENSE LTD, Brookline, Massachusetts, United States
  • Willner, Dafna, Hadassah-Hebrew University Hospital, Efrat, Israel
Background

The AKIN and KDIGO criteria for acute kidney injury (AKI) define oliguria as urine output (UO) over 6 hours of less than 0.5ml/kg/hr. While UO is an available biomarker of kidney function, only a small percentage of AKI studies incorporate UO criteria. In these retrospective studies, hourly UO is often inaccessible, and corresponds to the nursing shift. We developed a prospective observational study using real-time electronic monitoring of UO, and applied the AKIN criteria of UO to identify the oliguric patient in the intensive care unit (ICU).

Methods

57 General ICU patients in Hadassah Hospital, Israel were electronically monitored for hourly UO using The RenalSense® Clarity RMS™ sterile sensor kit. The drainage bag was connected to the Foley catheter and placed on a scientific scale for measurement validation. Patient data was analyzed as follows: AKI defined by the AKIN criteria for oliguria only: NON-AKI UO (n=26), AKI UO Stage 1(n=10), AKI UO Stage 2 (n=21). AKI defined by AKIN criteria for SCr only (where available): NON-AKI SCr (n=44) and all stages AKI SCr (n=12). Additional analysis using both SCr and UO criteria was performed on all patients.

Results

54% of patients had AKI according to UO criteria only. Patients with AKI UO Stage 2 received more fluid boluses than NON-AKI UO and AKI UO Stage 1 in the first two 12 hour periods of UO monitoring (p=0.0051 and 0.0091, respectively). 9 out of 21(43%) patients with AKI UO Stage 2 also had increased SCr. NON-AKI UO had an average ICU stay of 5.7 days, and AKI UO Stage 1 and 2 had 8.6 and 9.9 days respectively (p= 0.1048). Using only SCr criteria, NON-AKI SCr averaged 7.1 days in the ICU vs. all stages of AKI SCr of 10.8 days. When both UO and SCr were applied, 40% of patients were NON-AKI and averaged 5.9 days in the ICU. 15% of patients had AKI by both criteria and averaged 13.3 days (p=0.1002).

Conclusion

Studies have shown worse outcomes in patients that fulfill AKIN criteria for both SCr and UO versus SCr alone. Increased SCr alone may be an insufficient indicator of AKI, as ICU patients tend to be fluid overloaded. Our data shows a trend of increased ICU stay when AKI is analyzed according to UO. This unique study presents a tool for future research using reliable real time UO monitoring, where early intervention and appropriate treatment of oliguria may improve outcomes.

Funding

  • Commercial Support