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Published on: October 2, 2020
Extracellular volume changes and blood pressure levels in hemodialysis patients
Krassimir S Katzarski1, José C Divino Filho, Jonas Bergström
1Divisions of Renal Medicine, Baxter Novum,Dialysis UnitStockholm, Sweden. kkatzarski@hotmail.com
Insights
Fluid overload removal significantly improves blood pressure (BP) control in hemodialysis patients, particularly reducing nocturnal BP. This intervention allows for decreased antihypertensive drug (AHD) use, enhancing overall patient management.
Area of Science:
- Nephrology
- Cardiovascular Medicine
- Hypertension Management
Background:
- Blood pressure (BP) control remains a challenge in hemodialysis (HD) patients despite antihypertensive drugs (AHD).
- Poor nocturnal BP control is linked to left ventricular hypertrophy in HD patients.
- Investigating fluid overload removal's impact on BP is crucial for this population.
Purpose of the Study:
- To assess the effect of fluid overload removal on ambulatory BP over 48 hours in hypertensive HD patients.
- To achieve gradual reduction in post-dialysis body weight (BW) over 3-4 months.
- To correlate extracellular volume (ECV) changes with BP response.
Main Methods:
- Gradual reduction of post-dialysis BW by increasing ultrafiltration over 3-4 months.
- Reduced dialysate sodium concentration.
- Measured extracellular volume (ECV) using bioimpedance analysis.
- Subdivided patients into groups based on ECV reduction.
Main Results:
- Patients with ECV reduction showed significant decreases in 48-hour systolic and diastolic BP, and mean arterial pressure (MAP).
- Nocturnal BP reduction was more pronounced than diurnal BP reduction in the ECV reduction group.
- Significant reduction in systolic and diastolic BP load, especially during nighttime.
- Antihypertensive drug (AHD) dosages were reduced or stopped in patients with ECV reduction.
Conclusions:
- Removal of excess fluid is essential for effective BP control in hemodialysis patients.
- Fluid management is particularly critical for normalizing elevated nocturnal BP.
- Optimizing fluid status can lead to reduced reliance on antihypertensive medications.
Background:
Despite the use of highly efficient antihypertensive drugs (AHD), blood pressure (BP) is poorly controlled in the vast majority of hemodialysis (HD) patients. Many of them show no reduction in nocturnal BP, a finding that is associated with left ventricular hypertrophy. The aim of the study was to investigate the effect of the removal of a fluid overload on BP by monitoring the ambulatory BP during 48 hours in 16 hypertensive HD patients treated with AHD. Our aim was to obtain a gradual reduction in post-HD body weight (BW) over a period of 3 to 4 months.
Methods:
During a period of 3-4 months, the postdialysis BW was reduced as the minimal tolerable BW was gradually achieved by slightly increasing the ultrafiltration volume. The Na concentration in the dialysate was reduced from 143-141 mmol/L to 139-138 mmol/L. Extracellular volume (ECV) was measured with a multiple-frequency bioimpedance analyzer (Xitron 4000B, Xitron Technologies Inc., San Diego, CA, USA). Based on the change in ECV, the patients were subdivided into two groups: group 1 with a reduction in ECV (n = 10), and group 2 with no reduction (n = 6). At the start of the study, BW, BP, and AHD in group 1 and group 2 were virtually identical.
Results:
Group 1 showed a significant reduction during the entire 48-hour period in systolic (156 +/- 16 mmHg vs. 140 +/- 14 mmHg, P = 0.030) and diastolic BP (97 +/- 12 mmHg vs. 87 +/- 9 mmHg, P = 0.026) as well as in mean arterial pressure (MAP, 117 +/- 13 vs. 105 +/- 10 mmHg, P = 0.027). This reduction was more marked during the night (systolic BP 156 +/- 15 mmHg vs. 138 +/- 14 mmHg, P = 0.007; diastolic BP 97 +/- 12 mmHg vs. 85 +/- 9 mmHg, P = 0.009) than during the day (157 +/- 18 mmHg vs. 142 +/- 15 mmHg, P = 0.067; diastolic BP 97 +/- 13 mmHg vs. 90 +/- 9 mmHg, P = 0.126). A significant reduction in systolic load also occurred during the entire 48-hour period (76 +/- 24% vs. 46 +/- 28%, P = 0.043) as well as in night systolic load (75 +/- 21% vs. 41 +/- 30%, P = 0.015) and night diastolic load (67 +/- 32% vs. 39 +/- 31%, P = 0.030). AHD were stopped in eight and reduced in two patients. There were no significant reductions in BP and AHD in group 2.
Conclusions:
The removal of excess fluid is necessary for adequate BP control and especially for the reduction in elevated BP during the night.
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