Kidney Week

Abstract: FR-PO415

Preoperative Kt/Vurea and Postoperative Outcomes in Patients on Maintenance Hemodialysis

Session Information

• Hemodialysis Epidemiology and Outcomes
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 801 Dialysis: Hemodialysis and Frequent Dialysis

Authors

• Fielding-Singh, Vikram, Stanford University School of Medicine, Stanford, California, United States

Vikram Fielding-Singh, MD

• Chertow, Glenn M., Stanford University School of Medicine, Stanford, California, United States

Glenn M. Chertow, MD, MPH, FASN

• Lin, Eugene, University of Southern California, Los Angeles, California, United States

Eugene Lin, MD, MS, FASN

Background

Little is known about whether the hemodialysis prescription prior to surgery affects outcomes. This study investigated the association between changes in preoperative hemodialysis dosing and postoperative outcomes.

Methods

We identified adult patients receiving thrice weekly maintenance hemodialysis who underwent surgical procedures from 2011-2020 in the USRDS. The primary exposure was the difference between the Kt/V_urea of the last hemodialysis session prior to the procedure and the patient’s average Kt/V_urea over the previous 6 months (i.e., whether the preoperative session was lower, the same, or higher than usual). All models included the mean and standard deviation of Kt/V_urea values for the 6 months preceding the surgical procedure, in addition to demographic and procedural characteristics. To estimate the association between preoperative deviation in Kt/V_urea and postoperative outcomes, we fit multivariable Cox proportional hazards models. A 2-sided p<0.05 was considered statistically significant.

Results

Of 151,240 procedures, 31,825 (21.0%) of procedures had a preoperative decrease in Kt/V_urea of 0.10 or more, 43,790 (29.0%) had a preoperative decrease in Kt/V_urea of less than 0.10, 45,058 (29.8%) had a preoperative increase in Kt/V_urea of 0 to <0.10, and 30,567 (20.2%) had a preoperative increase in Kt/V_urea of 0.10 or more. In adjusted analysis, compared to patients with a preoperative increase in Kt/V of 0 to <0.10, risk of 30-day mortality was 1.50 (95% CI, 1.32, 1.70) times higher with a preoperative Kt/V decrease of more than 0.10 and was 1.16 (95% CI, 1.02,1.31) times higher with a preoperative Kt/V decrease of less than 0.10.

Conclusion

Among Medicare beneficiaries receiving maintenance hemodialysis, preoperative decreases in Kt/V_urea were significantly associated with postoperative mortality.

Association Between Change in Preoperative Kt/V From 6-Month Baseline Kt/V and Perioperative Outcomes

Funding

• Private Foundation Support