Dataset Information

Assessing Extracellular Volume in Hemodialysis Patients Using Intradialytic Blood Pressure Slopes.

ABSTRACT: BACKGROUND/AIMS:Extracellular volume (ECV) overload is a mortality risk factor in hemodialysis patients, but no standard approach exists to objectively assess this clinically. We aimed to quantify relationships between slopes of repeated intradialytic blood pressure (BP) measurements and ECV. METHODS:In a cross-sectional study of 71 hemodialysis patients, we calculated BP slopes from all intradialytic measurements using Gaussian regression. We measured extracellular and total body water (TBW) with bioimpedance spectroscopy. We analyzed unconditional and conditional associations between BP slope and volume metrics with mixed linear models and sensitivity analyses using non-linear intradialytic BP trajectory. RESULTS:Mean systolic intradialytic BP slope (IBPS) was -0.06 (0.1) mm Hg/min. Post-dialysis extracellular water (ECW)/weight was the volume metric mostly strongly associated with slope (r = 0.34, p = 0.007 for unconditional analysis; ? = 1.45, p = 0.001 for conditional analysis). Among subjects with post-dialysis systolic BP ?130 mm Hg, the association strengthened (r = 0.40, p = 0.006; ? = 1.42, p = 0.003). ECV was more strongly associated with the BP slope than with pre-dialysis, post-dialysis, or delta systolic BP (r = -0.07, 0.19, 0.28; p = 0.6, 0.1, 0.03). In nonlinear models, BP trajectory also had the strongest association with post-dialysis ECW/body weight (p < 0.001). CONCLUSIONS:In hypertensive hemodialysis patients, measurements of ECV excess are more strongly associated with IBPSs than with pre-dialysis, post-dialysis, or change in systolic BP. Among varying volume metrics, post-dialysis ECW/weight has the strongest association with these slopes. Determining IBPS is a novel method to optimize clinical assessment of ECV in hemodialysis patients.

SUBMITTER: Liu H

PROVIDER: S-EPMC6050636 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Assessing Extracellular Volume in Hemodialysis Patients Using Intradialytic Blood Pressure Slopes.

Liu Hao H Lu Rong R Shastri Shani S Sonderman Mark M Van Buren Peter Noel PN

Nephron 20180213 2

<h4>Background/aims</h4>Extracellular volume (ECV) overload is a mortality risk factor in hemodialysis patients, but no standard approach exists to objectively assess this clinically. We aimed to quantify relationships between slopes of repeated intradialytic blood pressure (BP) measurements and ECV.<h4>Methods</h4>In a cross-sectional study of 71 hemodialysis patients, we calculated BP slopes from all intradialytic measurements using Gaussian regression. We measured extracellular and total body ...[more]

PMID: 29439257

Similar Datasets

Project description:IntroductionExtracellular volume (ECV) predicts mortality in hemodialysis patients, but it is difficult to assess clinically. Peridialytic blood pressure (BP) measurements can help ECV assessment. Orthostatic BP is routinely measured clinically, but its association with ECV is unknown.MethodsIn a cohort of hypertensive hemodialysis patients, we measured posthemodialysis ECV/weight with bioimpedance spectroscopy and analyzed its association with post-HD orthostatic BP measurements obtained during routine care. Using linear and logistic regression, the primary outcomes were orthostatic BP change and orthostatic hypotension (OH) defined by systolic BP decrease of at least 20 mmHg or diastolic decrease of at least 10 mmHg. Model 1 controlled for sex, age, and diabetes. Model 2 additionally controlled for ultrafiltration rate and antihypertensive medications. We conducted sensitivity analysis using OH definition of systolic BP decrease of at least 30 mmHg.FindingsAmong 57 participants, mean orthostatic systolic BP change was -7.30 (20) mmHg and mean ECV/weight was 0.24 (0.04) L/kg. Post-HD ECV/weight was not associated with orthostatic systolic BP change (β = 8.2, p = 0.6). There were 16 participants with and 41 participants without OH. The ECV/weight did not differ between these groups (0.22 [0.04] vs. 0.24 [0.05] L/Kg, p = 0.09) and did not predict OH in logistic regression (OR 11, 4.04; 95% CI 0.2-671, 0.03-0.530 in the two models.) In a sensitivity analysis, ECV/weight was lower in the OH group (0.22 [0.03] vs. 0.25 [0.04] L/kg, p = 0.005), but this was accompanied by differences in sex and diabetes. Using logistic regression, there was no independent association between ECV/weight with OH.DiscussionOrthostatic systolic BP change after HD completion is not a reliable indicator of posthemodialysis ECV. When considering other factors associated with orthostatic BP, ECV/weight is not independently associated with OH. Although transient postdialytic differences in intravascular volume may be associated with OH, posthemodialysis OH does not necessarily indicate ECV depletion.

Project description:BACKGROUND AND OBJECTIVES:Intradialytic hypotension (IDH) is associated with morbidity. The effect of blood volume-guided ultrafiltration biofeedback, which automatically adjusts fluid removal rate on the basis of blood volume parameters, on the reduction of IDH was tested in a randomized crossover trial. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS:We performed a 22-week, single blind, randomized crossover trial in patients receiving maintenance hemodialysis who had >30% of sessions complicated by symptomatic IDH in five centers in Calgary, Alberta, Canada. Participants underwent a 4-week run-in period to standardize dialysis prescription and dry weight on the basis of clinical examination. Those meeting inclusion criteria were randomized to best clinical practice hemodialysis (control) or best clinical practice plus blood volume-guided ultrafiltration biofeedback (intervention) for 8 weeks, followed by a 2-week washout and subsequent crossover for a second 8-week phase. The primary outcome was rate of symptomatic IDH. RESULTS:Thirty-five participants entered, 32 were randomized, and 26 completed the study. The rate of symptomatic IDH with biofeedback was 0.10/h (95% confidence interval, 0.06 to 0.14) and 0.07/h (95% confidence interval, 0.05 to 0.10) during control (P=0.29). There were no differences in the rate or proportion of sessions with asymptomatic IDH or symptoms alone. Results remained consistent when adjusted for randomization order and study week. There were no differences between intervention and control in the last study week in interdialytic weight gain (difference [SD], -0.02 [0.8] kg), brain natriuretic peptide (1460 [19,052] ng/L), cardiac troponins (3 [86] ng/L), extracellular water-to-intracellular water ratio (0.05 [0.33]), ultrafiltration rate (1.1 [7.0] ml/kg per hour), and dialysis recovery time (0.43 [19.25] hours). CONCLUSION:The use of blood volume monitoring-guided ultrafiltration biofeedback in patients prone to IDH did not reduce the rate of symptomatic IDH events.

Project description:Background/aimsIntradialytic hypertension (IDH), or paradoxical rise in blood pressure (BP) during hemodialysis (HD) is associated with increased morbidity and mortality. The association between IDH and increased left ventricular mass (LVM), a well-known risk factor for adverse cardiovascular outcomes in HD patients, has not been studied. The aim of our study is to evaluate the cross-sectional association of intradialytic change in BP with cardiac structure and function measured by cardiac MRI in hypertensive HD patients enrolled in the multi-center Blood Pressure in Dialysis (BID) clinical trial.MethodsParticipants in the BID study were categorized into 3 groups based on average change (Δ) in systolic blood pressure (SBP) (post-HD SBP minus pre-HD SBP) during HD over a 1 month period: group 1 - patients with an increase in SBP ≥ 10mm Hg during HD (IDH); group 2 -patients with SBP decrease of greater ≥10mm Hg during HD; group 3 - patients with SBP increase or decrease by < 10mm Hg during HD. LVM index (LVMI) was measured using cardiac MRI, which were centrally read. Baseline characteristics were compared in the 3 groups and multivariable regression models were fitted for the adjusted association of IDH with LVMI.ResultsAmong the 80 participants, 7 (8.8%) had IDH and had average Δ SBP 17.0 ± 10.1 mmHg during HD. Patients with IDH were less likely to be diabetic, had lower pre-dialysis SBP and lower percent interdialytic weight gain as compared to the other 2 groups (p=0.02, p< 0.001 and p=0.02 respectively). In multivariable regression analyses, IDH was significantly associated with LVMI (adjusted mean difference relative to SBP decreased group [95% confidence interval (CI)] = 12.5 [3.6, 21.5], p=0.01) after adjusting for age, sex, diabetes, IDWG%, pre-HD SBP and beta blocker use. Every 1 mm rise in ΔSBP during HD was associated with 0.2 g/m2 increase in LVMI in adjusted models (p=0.04).ConclusionIDH is independently associated with higher LVMI in hypertensive HD patients and may contribute to increased cardiovascular events.

Dataset Information

Assessing Extracellular Volume in Hemodialysis Patients Using Intradialytic Blood Pressure Slopes.

Publications

Assessing Extracellular Volume in Hemodialysis Patients Using Intradialytic Blood Pressure Slopes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets