Factors Associated With Intradialytic Systolic Blood Pressure Variability

Flythe, Jennifer E.; Kunaparaju, Srikanth; Dinesh, Kumar; Cape, Kathryn; Feldman, Harold I.; Brunelli, Steven M.

doi:10.1053/j.ajkd.2011.11.026

« Previous Next »American Journal of Kidney Diseases
Volume 59, Issue 3 , Pages 409-418, March 2012

Factors Associated With Intradialytic Systolic Blood Pressure Variability

Jennifer E. Flythe, MD
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA
Srikanth Kunaparaju, MD
- Division of Nephrology, Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA
Kumar Dinesh, MD
- Division of Nephrology, Department of Medicine, University of California, Davis School of Medicine, Sacramento, CA
Kathryn Cape, MPH
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA
Harold I. Feldman, MD, MSCE
- Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia, PA
Steven M. Brunelli, MD, MSCE
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA
- Division of Pharmacoepidemiology, Department of Medicine, Brigham and Women's Hospital, Boston, MA
- Harvard Medical School, Boston, MA
- Address correspondence to Steven M. Brunelli, MD, MSCE, Brigham and Women's Hospital, 75 Francis St, MRB-4, Boston, MA 02115

Received 19 July 2011; accepted 10 November 2011. published online 30 December 2011.

Background

Although blood pressure lability during hemodialysis has long been recognized, little is known about factors that promote nonsystematic intradialytic blood pressure variability.

Study Design

Prospective observational cohort.

Setting & Participants

Random cluster sample of 218 prevalent hemodialysis patients treated at 5 participating DaVita Dialysis units.

Predictors

Clinical variables that may plausibly influence intradialytic systolic blood pressure (SBP) variability.

Outcomes

SBP variability as described by: (1) the deviation of SBP from its anticipated course (primary metric) and (2) the absolute value of the difference between successive SBP measurements (secondary metric).

Measurements

SBPs measured and recorded (n = 19,170) per clinical protocol during hemodialysis treatments (n = 2,422; median 11 per patient) occurring in the first 30 days of study. Predictors were assessed through standardized interview, examination, and medical record abstraction.

Results

Results were similar when SBP variability was considered in terms of the primary and secondary metrics. Older age and longer dialysis vintage were associated with increased SBP variability, whereas other patient characteristics were not. Greater fluid removal during hemodialysis (whether considered as volume or rate either absolute or relative to total-body water) was associated with greater SBP variability independently of its effects on net pre- to posttreatment SBP reduction. Neither number nor dialyzability of antihypertensive medications nor individual classes of agents showed an association with SBP variability.

Limitations

Over-representation of African Americans and patients with congestive heart failure; observational design; use of clinically measured blood pressures; absence of medication adherence confirmation.

Conclusions

Increased intradialytic SBP variability is associated with greater dialytic fluid removal and rate, as well as demographic characteristics, such as older age and dialysis vintage. Further work is needed to confirm these findings and measure associations between SBP variability and clinical outcomes.

Index Words: Hemodialysis , blood pressure , variability