Body Fluid Dynamics in Hemodialysis Patients, an Estimation of Dry Weight
Evaluation of Body Hydration Status in Hemodialysis Patients Using Segmental Bioimpedance Analysis
研究概览
地位
条件
详细说明
Estimation of the hydration state of chronic kidney disease (CKD) patients is an important aspect of clinical practice. Deterioration in renal function often leads to volume overload with resulting hypertension and there is no simple and accurate technique available to measure body hydration at the moment.
In hemodialysis (HD) patients, one limitation to adequate ultrafiltration necessary to achieve optimal hydration status (dry weight) is inadequate vascular refilling from the interstitial space. Blood pressure may decrease due to limitation of vascular refilling even when dry weight is far from being achieved. Therefore, an objective and accurate method to provide hydration state would be very useful for clinical practice. Whole body bioimpedance techniques have been used to measure body fluid volume for many years. However, it is difficult to accurately indicate the hydration state by body fluid volume of normal variations, and the accuracy of measurement is influenced by various body compositions. Recently, the investigators have proposed that hydration can be approached using a calf bioimpedance technique by monitoring change in resistance during HD. Since the lower limbs tend to contain more fluid than other body segments in ambulatory people due to the effect of gravity, measurement of the calf provides more accurate information about body hydration in the HD patient.
In this study, the investigators hypothesize that:
- Since the degree of hydration is greater in the leg than in the arm and the trunk due to the effect of gravity, monitoring change in resistance in the whole or part of the leg will provide information as to whether optimal hydration status (a state in which excess extracellular fluid is absent) has been attained. The investigators postulate that a change in the slope of resistance curve (CSR) in the calf approaches zero as optimal hydration status is achieved.
- Optimal hydration status can be approximated by comparison of two values: (1) measurement of local electrical resistivity in the interstitial compartment and (2) known range of resistivity in healthy subjects (HS). Combination of the normalized resistivity (μ) and CSR are considered as indicators of physiological optimal hydration status. Physiological optimal hydration status, as an objective index, is a major goal of hemodialysis so that the excess body water can be maximally removed according to this value. In practice this can be approached but should never be exceeded.
Because flattening of the curve should be verified by the near normal resistivity, a group of healthy subjects would have to be added to provide a normal range of resistivity at all ages and both sexes.
研究类型
注册 (实际的)
参与标准
资格标准
适合学习的年龄
接受健康志愿者
有资格学习的性别
取样方法
研究人群
描述
Inclusion Criteria:
- Stable hemodialysis patients believed to be at all levels of hydration by their treating physician should be chosen.
Exclusion Criteria:
- Myocardial infarction or stroke in the preceding 6 months
- Two episodes of hypotension (systolic BP < 90 mmHg) during the 3 dialysis procedures preceding entering the treatment phase
- Grade IV CHF by NY classification
- Simultaneous participation in another clinical study except observational trials.
- Any psychological condition which could interfere with the patient's ability to comply with the study protocol.
- Pregnancy.
- Amputation of a limb.
- Pace maker, implantable pump, artificial joint.
学习计划
研究是如何设计的?
设计细节
- 观测模型:病例对照
- 时间观点:预期
队列和干预
团体/队列 |
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Hemodialysis patients
Dialysis patients will have their estimated dry weight measured with calf segmental bioimpedance.
Based on these measurements, their dry weight will be adjusted and the amount of fluid removed during subsequent dialysis treatments will be increased by 200-300mL.
The additional fluid removal will occur during 3 consecutive hemodialysis sessions.
In addition, these subjects will also use VStim during these treatments.
to prevent common intradialytic symptoms by promoting vascular refilling.
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Healthy Controls
No Intervention was administered.
Both groups had their hydration status measured with segmental bioimpedance The group of healthy subjects was studied in order to obtain a range of values for normal hydration status.
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研究衡量的是什么?
主要结果指标
结果测量 |
大体时间 |
---|---|
Dry weight as determined by segmental bioimpedance in comparison to baseline
大体时间:1 month
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1 month
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次要结果测量
结果测量 |
措施说明 |
大体时间 |
---|---|---|
Mean pre dialysis and post dialysis blood pressure in comparison to baseline
大体时间:1 month
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1 month
|
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Numbers and doses of blood pressure medications prescribed
大体时间:1 month
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If the blood pressure is improved based on better assessment of dry weight, the need for multiple blood pressure meds and dosing will be reduced.
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1 month
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合作者和调查者
调查人员
- 首席研究员:Fansan Zhu, MD、Renal Research Institute
出版物和有用的链接
一般刊物
- Spiegel DM, Bashir K, Fisch B. Bioimpedance resistance ratios for the evaluation of dry weight in hemodialysis. Clin Nephrol. 2000 Feb;53(2):108-14.
- Jaeger JQ, Mehta RL. Assessment of dry weight in hemodialysis: an overview. J Am Soc Nephrol. 1999 Feb;10(2):392-403. doi: 10.1681/ASN.V102392.
- Leypoldt JK, Cheung AK. Evaluating volume status in hemodialysis patients. Adv Ren Replace Ther. 1998 Jan;5(1):64-74. doi: 10.1016/s1073-4449(98)70016-0.
- Zhu F, Schneditz D, Wang E, Martin K, Morris AT, Levin NW. Validation of changes in extracellular volume measured during hemodialysis using a segmental bioimpedance technique. ASAIO J. 1998 Sep-Oct;44(5):M541-5. doi: 10.1097/00002480-199809000-00045.
- Piccoli A. Identification of operational clues to dry weight prescription in hemodialysis using bioimpedance vector analysis. The Italian Hemodialysis-Bioelectrical Impedance Analysis (HD-BIA) Study Group. Kidney Int. 1998 Apr;53(4):1036-43. doi: 10.1111/j.1523-1755.1998.00843.x.
- Katzarski K, Charra B, Laurent G, Lopot F, Divino-Filho JC, Nisell J, Bergstrom J. Multifrequency bioimpedance in assessment of dry weight in haemodialysis. Nephrol Dial Transplant. 1996;11 Suppl 2:20-3. doi: 10.1093/ndt/11.supp2.20.
- Zhu F, Schneditz D, Levin NW. Sum of segmental bioimpedance analysis during ultrafiltration and hemodialysis reduces sensitivity to changes in body position. Kidney Int. 1999 Aug;56(2):692-9. doi: 10.1046/j.1523-1755.1999.00588.x.
- Steuer RR, Germain MJ, Leypoldt JK, Cheung AK. Enhanced fluid removal guided by blood volume monitoring during chronic hemodialysis. Artif Organs. 1998 Aug;22(8):627-32. doi: 10.1046/j.1525-1594.1998.06036.x.
- Lopot F, Kotyk P, Blaha J, Forejt J. Use of continuous blood volume monitoring to detect inadequately high dry weight. Int J Artif Organs. 1996 Jul;19(7):411-4.
- Bogaard HJ, de Vries JP, de Vries PM. Assessment of refill and hypovolaemia by continuous surveillance of blood volume and extracellular fluid volume. Nephrol Dial Transplant. 1994;9(9):1283-7.
- Leunissen KM, Kooman JP, van Kuijk W, van der Sande F, Luik AJ, van Hooff JP. Preventing haemodynamic instability in patients at risk for intra-dialytic hypotension. Nephrol Dial Transplant. 1996;11 Suppl 2:11-5. doi: 10.1093/ndt/11.supp2.11.
- Kouw PM, Kooman JP, Cheriex EC, Olthof CG, de Vries PM, Leunissen KM. Assessment of postdialysis dry weight: a comparison of techniques. J Am Soc Nephrol. 1993 Jul;4(1):98-104. doi: 10.1681/ASN.V4198.
- Franz M, Pohanka E, Tribl B, Woloszczuk W, Horl WH. Living on chronic hemodialysis between dryness and fluid overload. Kidney Int Suppl. 1997 Jun;59:S39-42.
- Zhu F, Kuhlmann MK, Sarkar S, Kaitwatcharachai C, Khilnani R, Leonard EF, Greenwood R, Levin NW. Adjustment of dry weight in hemodialysis patients using intradialytic continuous multifrequency bioimpedance of the calf. Int J Artif Organs. 2004 Feb;27(2):104-9. doi: 10.1177/039139880402700205.
- Frankel VH, McLeod KJ. Calf muscle pump stimulation as an adjunct to orthopaedic surgery. Surg Technol Int. 2005;14:297-304.
- Madhavan G, Stewart JM, McLeod KJ. Effect of plantar micromechanical stimulation on cardiovascular responses to immobility. Am J Phys Med Rehabil. 2005 May;84(5):338-45. doi: 10.1097/01.phm.0000159970.81072.8b.
- Madhavan G, Stewart JM, McLeod KJ. Cardiovascular systemic regulation by plantar surface stimulation. Biomed Instrum Technol. 2006 Jan-Feb;40(1):78-84. doi: 10.2345/0899-8205(2006)40[78:CSRBPS]2.0.CO;2.
- Stewart JM, Karman C, Montgomery LD, McLeod KJ. Plantar vibration improves leg fluid flow in perimenopausal women. Am J Physiol Regul Integr Comp Physiol. 2005 Mar;288(3):R623-9. doi: 10.1152/ajpregu.00513.2004. Epub 2004 Oct 7.
研究记录日期
研究主要日期
学习开始
初级完成 (实际的)
研究完成 (实际的)
研究注册日期
首次提交
首先提交符合 QC 标准的
首次发布 (估计)
研究记录更新
最后更新发布 (估计)
上次提交的符合 QC 标准的更新
最后验证
更多信息
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