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Kidney Week

Abstract: TH-PO538

Lab Vigilance in Patients with CKD on Renin Aldosterone Inhibitors and Diuretics: Are We Monitoring Appropriately?

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 307 CKD: Health Services, Disparities, Prevention


  • Garlo, Katherine, Brigham and Women's Hospital, Boston, Massachusetts, United States
  • Seger, Diane, Partners Healthcare System, Somerville, Massachusetts, United States
  • Fiskio, Julie, Brigham & Womens Hospital, Boston, Massachusetts, United States
  • Bates, David W., Brigham and Women's Hospital/Harvard Medical School , Brookline, Massachusetts, United States
  • Charytan, David M., Brigham and Women's Hospital, Boston, Massachusetts, United States

Renin Aldosterone Inhibitors (RASi) are first line agents for hypertension. Their efficacy has been shown in reducing blood pressure, slowing progression of chronic kidney disease (CKD), and cardiovascular protection. Grade A level 1 evidence supports their use in CKD with or without proteinuria. However, ideal lab monitoring during initiation of RASi is uncertain and guidelines are opinion based if present at all. We assessed outpatient lab monitoring in a large cohort of patients with CKD prescribed a new RASi or diuretic.


We evaluated adults with pre-dialysis CKD stage 3-5 who received a new outpatient RASi or diuretic prescription during 2009-2011. Lab data was collected electronically and analyzed for baseline and follow-up labs creatinine and potassium.


A total of 8,272 individuals (mean age 72±13.5 years, 44% male, 86% white) with CKD (90% stage 3) were included. The average interval following baseline labs to first prescription was 41±79 days. Fewer individuals in the RASi group received baseline labs within two weeks 61% compared to the diuretic group 59%, P =0.02. Mean time to follow up labs was 78 days and was longer in the RAS inhibitor group 86±103 days compared to the diuretic group 69 days ±90.4 days, P<0.01. Follow up labs were checked within 2 weeks in 28% (RASi: 24%, diuretic: 31%, P<0.01). Nearly half of individuals did not receive labs for >6 weeks (overall:45%, RASi: 48%, diuretic: 41%). Male sex, black race, CKD stage, cardiovascular disease, and diabetes were associated with lab monitoring within 14 days. Age >65 years and RASi were associated with a lower risk of having baseline labs within 14 days (OR 0.69, 95% CI 0.63-0.76, P <0.01, OR 0.91, 95% CI 0.83-0.98, P =0.02) and follow up (OR 0.74, 95% CI 0.66-0.82, P <0.01, OR 0.69, 95% CI 0.63-0.76, P <0.01).


Many patients with CKD do not receive lab monitoring with 2 weeks of initiating a RASi or diuretics. Elderly individuals and women may be at higher risk. The results suggest that advancements in electronic prescription ordering or automated reminders may improve safety of RASi and diuretic use in patients with CKD.