Abstract: TH-PO221
Post-Dialysis Orthostatic Blood Pressure Is Not Associated with Extracellular Volume in Hemodialysis Patients
Session Information
- Hemodialysis and Frequent Dialysis - I
November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 701 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Aryeetey, Prince Michael, UT Southwestern, Dallas, Texas, United States
- Gregg, L Parker, UT Southwestern, Dallas, Texas, United States
- Lederer, Swati, VA North Texas, Dallas, Texas, United States
- Concepcion, Michael Lopez, Dallas Veterans Hospital, Dallas, Texas, United States
- Penfield, Jeffrey G., VA North Texas Health Care System, Terrell, Texas, United States
- Van Buren, Peter N., UT Southwestern, Dallas, Texas, United States
Background
Blood pressure (BP) measurements are obtained before, during, and after hemodialysis (HD) for safety monitoring. The pattern of intradialytic seated BP changes is becoming recognized as an extracellular volume (ECV) assessment tool. It is unknown if orthostatic BP changes after HD provide information on ECV.
Methods
In a cohort of 55 hypertensive HD patients, we identified those with and without orthostatic BP decreases, defined as a >10 mmHg decrease in systolic BP from seated to standing position (both post-HD). We compared post-HD ECV/body weight using bioimpedance spectroscopy between the groups. We also compared orthostatic BP changes among tertiles of post-HD ECV/weight.
Results
Compared to those with orthostatic decreases (n=26), those without orthostatic BP decreases (n=29) were more likely to be African American. There were no differences in presence of diabetes or distribution of antihypertensive drug class. There were no differences in ECV/weight or cardiac hemodynamics between the groups (Table). There were no differences in orthostatic BP changes among tertiles of ECV/weight (Figure).
Conclusion
We found no associations between ECV/weight and post-HD orthostatic BP changes. Seated to standing BP changes should not be used to diagnose post-HD ECV overload or depletion in HD patients.
Differences in Volume and BP Related Variables
| Variable | Orthostatic Systolic BP Decrease >10 mmHg (n=26) | Orthostatic Systolic BP Increase or Decrease <10 mmHg (n=29) | p-value |
| Seated Pre-HD Systolic BP (mmHg) | 151 (19) | 155 (20) | 0.5 |
| Intradialytic Systolic BP Nadir (mmHg) | 115 (20) | 115 (21) | 0.9 |
| Seated Post-HD Systolic BP (mmHg) | 151 (21) | 133 (21) | 0.003 |
| Standing Post-HD Systolic BP (mmHg) | 126 (21) | 140 (21) | 0.02 |
| Change in post-HD Systolic BP from seated to standing (mmHg) | -24 (14) | 6.7 (12) | <0.0001 |
| Estimated Dry Weight (kg) | 83 (22) | 89 (18) | 0.3 |
| Ultrafiltration Rate (mL/kg/hr) | 7.1 (3) | 8.3 (4) | 0.2 |
| Pre-HD ECV/body weight (L/kg) | 0.27 (0.05) | 0.25 (0.05) | 0.3 |
| Post-HD ECV/body weight (L/kg) | 0.25 (0.05) | 0.23 (0.05) | 0.2 |
| Change in TPRI from pre to post HD (dyn sec/cm5) | -262 (860) | -218 (780) | 0.8 |
| Change in Cardiac Index from pre to post HD (L/min/m2) | 0.09 (0.4) | 0.04 (0.5) | 0.7 |
Funding
- NIDDK Support