Static pressures, intra-access blood flow and dynamic Kt/V profiles in the prediction of dialysis access function

Abhilash Koratala; Bhagwan Dass; Kawther F Alquadan; Simrun Sharma; Girish Singhania; Abutaleb A Ejaz

doi:10.5527/wjn.v8.i3.59

Static pressures, intra-access blood flow and dynamic Kt/V profiles in the prediction of dialysis access function

World J Nephrol. 2019 Jun 28;8(3):59-66. doi: 10.5527/wjn.v8.i3.59.

Authors

Abhilash Koratala¹, Bhagwan Dass², Kawther F Alquadan², Simrun Sharma², Girish Singhania³, Abutaleb A Ejaz²

Affiliations

¹ Division of Nephrology, Hypertension and Transplantation, University of Florida, Gainesville, FL 32610, United States. abhilash.koratala@medicine.ufl.edu.
² Division of Nephrology, Hypertension and Transplantation, University of Florida, Gainesville, FL 32610, United States.
³ Division of Nephrology and Hypertension, University of Utah, Salt Lake City, UT 84112, United States.

Abstract

Background: Hemodialysis machine-generated circuit pressures and clearance profiles are potential predictors of quality assurances. In our practice, we previously we observed that elevated static access pressures were associated with abnormal Kt/V values, high access recirculation and deviation of the Kt/V profile (Abnormal Kt/V profile) from normally expected values (Normal Kt/V profile).

Aim: To hypothesize that static or derived access pressures would correlate with direct intra-access blood flow rates and that clearance (Kt/V) profiles would correlate with measured Kt/V values.

Methods: Static access pressures, real-time adequacy of dialysis and intra-access blood flow were investigated in end stage renal disease patients undergoing hemodialysis. Wilcoxon-Mann-Whitney test, chi-square test or Fisher's exact test was used to investigate differences between the groups; Spearman's rank correlation test to investigate relationships between static pressures, direct intra-access pressures and Kt/V profiles; and multinomial logistic regression models to identify the independent effect of selected variables on Kt/V profiles. Odds ratio were calculated to measure the association between the variables and Kt/V profiles.

Results: One hundred and seven patients were included for analysis. There were no significant differences between genders, and types of vascular access between the normal vs. abnormal clearance (Kt/V) profile groups. No significant correlation could be demonstrated between static access pressures and Kt/V profiles, static access pressures and intra-access blood flow, intra-access blood flow and Kt/V profiles, measured Kt/V and Kt/V profiles or recirculation and Kt/V profiles.

Conclusion: In this study utilizing measured versus estimated data, we could not validate that dialysis machine generated elevated static pressures predict intra-access blood flow disturbances or that abnormal Kt/V profiles predict access recirculation or inadequate dialysis. These parameters, though useful estimates, cannot be accepted as quality assurance for dialysis adequacy or access function without further evidences.

Keywords: Hemodialysis; Intra-access; Kt/V; Pressures; Static.