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Broszeit S, Kron J, Leimbach T, Volkenandt J, Kron S. Vascular refilling in hemodialysis using feedback-controlled ultrafiltration profile. Int J Artif Organs 2024:3913988241264709. [PMID: 39097793 DOI: 10.1177/03913988241264709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2024]
Abstract
BACKGROUND The rate and the duration of ultrafiltration (UF) are considered the most important factors to affect vascular refilling. The aim of the study was to investigate whether a UF profile could improve the vascular refilling. METHODS Dialysis was delivered by a machine providing feedback control of ultrafiltration rates. Absolute blood volume (BV) was measured by dialysate bolus method. Vascular refilling volume (Vref) was calculated as UF volume - Δ absolute BV. RESULTS In 40 patients, refilling fraction (Vref/UF volume) was 30.5% in the first hour. Thereafter, refilling fraction steeply increased and reached maximum values in the third and fourth hour at about 95%. The cumulative refilling fraction was 68.5 ± 9.4% at the end. In 14 patients, refilling data from the feedback-controlled UF profile were compared to dialysis sessions with constant UF rates. In 12 of 14 patients, refilling fraction was significantly (p = 0.013) higher in sessions with UF profile (71.6% vs 64.4%).There was a significant negative correlation (r = -0.606; p = 0.002) between the blood volume to extracellular volume ratio and the refilling fraction. The sum of this ratio and the refilling fraction was 1.01 ± 0.06. CONCLUSIONS Despite significant differences, a feedback-controlled UF profile has no advantage over the previous refilling studies with regard to the refilling fraction because vascular refilling seems to depend mainly on the ratio of BV to ECV. This would explain the different results in studies using BV guided UF feedback programs.
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Affiliation(s)
- Stefanie Broszeit
- Department of Nephrology DRK Clinics Berlin-Köpenick, Berlin, Germany
| | - Joachim Kron
- KfH Kidney Center Berlin-Köpenick, Berlin, Germany
| | - Til Leimbach
- KfH Kidney Center Berlin-Köpenick, Berlin, Germany
| | - John Volkenandt
- Department of Nephrology DRK Clinics Berlin-Köpenick, Berlin, Germany
| | - Susanne Kron
- KfH Kidney Center Berlin-Köpenick, Berlin, Germany
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Kron J, Broszeit S, Volkenandt J, Leimbach T, Kron S. Vascular refilling depends on the ratio of blood volume to extracellular volume in hemodialysis patients. Int J Artif Organs 2023; 46:581-584. [PMID: 37749906 DOI: 10.1177/03913988231201905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
The ratio of blood volume to extracellular volume is approximately one to three under physiological conditions and also in stable chronic hemodialysis patients. Recently, it was found that this ratio remains unchanged during hemodialysis despite ultrafiltration. This would signify that the higher the ratio, the lower the refilling and vice versa. To test this hypothesis, treatment data of a previous study were re-analyzed. In 79 stable chronic hemodialysis patients, the refilling fraction was 0.749 ± 0.094. There was a significant negative correlation (r = -0.412; p < 0.001) between the blood volume to extracellular volume ratio and the refilling fraction. The blood volume to extracellular volume relationship seems to be a significant determinant of vascular refilling: the higher the ratio, the lower the refilling, and vice versa.
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Affiliation(s)
- Joachim Kron
- KfH Kidney Center Berlin-Köpenick, Berlin, Germany
| | - Stefanie Broszeit
- DRK Clinics Berlin-Köpenick, Department of Nephrology, Berlin, Germany
| | - John Volkenandt
- DRK Clinics Berlin-Köpenick, Department of Nephrology, Berlin, Germany
| | - Til Leimbach
- KfH Kidney Center Berlin-Köpenick, Berlin, Germany
| | - Susanne Kron
- KfH Kidney Center Berlin-Köpenick, Berlin, Germany
- DRK Clinics Berlin-Köpenick, Department of Nephrology, Berlin, Germany
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Alamilla-Sanchez ME, Alcala-Salgado MA, Cerezo Samperio B, Prado Lozano P, Diaz Garcia JD, Gonzalez Fuentes C, Yama Estrella MB, Morales Lopez EF. Advances in the Physiology of Transvascular Exchange and A New Look At Rational Fluid Prescription. Int J Gen Med 2023; 16:2753-2770. [PMID: 37408844 PMCID: PMC10319290 DOI: 10.2147/ijgm.s405926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 05/28/2023] [Indexed: 07/07/2023] Open
Abstract
The Starling principle is a model that explains the transvascular distribution of fluids essentially governed by hydrostatic and oncotic forces, which dynamically allow vascular refilling according to the characteristics of the blood vessel. However, careful analysis of fluid physiology has shown that the principle, while correct, is not complete. The revised Starling principle (Michel-Weinbaum model) provides relevant information on fluid kinetics. Special emphasis has been placed on the endothelial glycocalyx, whose subendothelial area allows a restricted oncotic pressure that limits the reabsorption of fluid from the interstitial space, so that transvascular refilling occurs mainly from the lymphatic vessels. The close correlation between pathological states of the endothelium (eg: sepsis, acute inflammation, or chronic kidney disease) and the prescription of fluids forces the physician to understand the dynamics of fluids in the organism; this will allow rational fluid prescriptions. A theory that integrates the physiology of exchange and transvascular refilling is the "microconstant model", whose variables include dynamic mechanisms that can explain edematous states, management of acute resuscitation, and type of fluids for common clinical conditions. The clinical-physiological integration of the concepts will be the hinges that allow a rational and dynamic prescription of fluids.
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Affiliation(s)
| | | | | | - Pamela Prado Lozano
- Department of Nephrology, Centro Medico Nacional “20 de Noviembre”, Mexico City, Mexico
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Lee JS, Lee LP. Factors Regulating Fluid Restitution and Plasma Volume Reduction over the Course of Hemodialysis. Toxins (Basel) 2022; 15:31. [PMID: 36668851 PMCID: PMC9861932 DOI: 10.3390/toxins15010031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023] Open
Abstract
Over the course of hemodialysis, fluid and protein are restituted from the tissue compartment to the circulation compartment through the endothelia. Our previous model analysis on fluid and protein transport during hemodialysis is expanded to account for changes occurring in the tissue. The measured initial and end plasma protein concentration (PPC, Cp and Cp') for six hemodialysis studies are analyzed by this expanded model. The computation results indicate that the total driving pressure to restitute fluid from the tissue to the circulation ranges from 5.4 to 20.3 mmHg. The analysis identifies that the increase in plasma colloidal osmotic pressure (COP) contributes 78 ± 6% of the total driving pressure, the decrease in microvascular blood pressure 32 ± 4%, the increase in the COP of interstitial fluid -6 ± 3%, and the decrease in interstitial fluid pressure -5 ± 2%. Let this ratio (Cp' - Cp)/Cp' be termed the PPC increment. The six HDs can be divided into three groups which are to have these PPC increments 25.7%, 14.5 ± 2.6(SD)% and 8.3%. It is calculated that their correspondent filtration coefficients are 0.43, 1.29 ± 0.28 and 5.93 mL/min/mmHg and the relative reductions in plasma volume (RRPV) -22.1%, -13.1 ± 6% and -9.4%. The large variations in PPC increments and RRPV show the filtration coefficient is a key factor to regulate the hemodialysis process.
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Affiliation(s)
- Jen-shih Lee
- Global Monitors, Inc., San Diego, CA 92067, USA
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
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Vascular refilling coefficient is not a good marker of whole-body capillary hydraulic conductivity in hemodialysis patients: insights from a simulation study. Sci Rep 2022; 12:15277. [PMID: 36088359 PMCID: PMC9464211 DOI: 10.1038/s41598-022-16826-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 07/18/2022] [Indexed: 12/03/2022] Open
Abstract
Refilling of the vascular space through absorption of interstitial fluid by micro vessels is a crucial mechanism for maintaining hemodynamic stability during hemodialysis (HD) and allowing excess fluid to be removed from body tissues. The rate of vascular refilling depends on the imbalance between the Starling forces acting across the capillary walls as well as on their hydraulic conductivity and total surface area. Various approaches have been proposed to assess the vascular refilling process during HD, including the so-called refilling coefficient (Kr) that describes the rate of vascular refilling per changes in plasma oncotic pressure, assuming that other Starling forces and the flow of lymph remain constant during HD. Several studies have shown that Kr decreases exponentially during HD, which was attributed to a dialysis-induced decrease in the whole-body capillary hydraulic conductivity (LpS). Here, we employ a lumped-parameter mathematical model of the cardiovascular system and water and solute transport between the main body fluid compartments to assess the impact of all Starling forces and the flow of lymph on vascular refilling during HD in order to explain the reasons behind the observed intradialytic decrease in Kr. We simulated several HD sessions in a virtual patient with different blood priming procedures, ultrafiltration rates, session durations, and constant or variable levels of LpS. We show that the intradialytic decrease in Kr is not associated with a possible reduction of LpS but results from the inherent assumption that plasma oncotic pressure is the only variable Starling force during HD, whereas in fact other Starling forces, in particular the oncotic pressure of the interstitial fluid, have an important impact on the transcapillary fluid exchange during HD. We conclude that Kr is not a good marker of LpS and should not be used to guide fluid removal during HD or to assess the fluid status of dialysis patients.
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Canaud B, Kooman J, Maierhofer A, Raimann J, Titze J, Kotanko P. Sodium First Approach, to Reset Our Mind for Improving Management of Sodium, Water, Volume and Pressure in Hemodialysis Patients, and to Reduce Cardiovascular Burden and Improve Outcomes. FRONTIERS IN NEPHROLOGY 2022; 2:935388. [PMID: 37675006 PMCID: PMC10479686 DOI: 10.3389/fneph.2022.935388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 06/07/2022] [Indexed: 09/08/2023]
Abstract
New physiologic findings related to sodium homeostasis and pathophysiologic associations require a new vision for sodium, fluid and blood pressure management in dialysis-dependent chronic kidney disease patients. The traditional dry weight probing approach that has prevailed for many years must be reviewed in light of these findings and enriched by availability of new tools for monitoring and handling sodium and water imbalances. A comprehensive and integrated approach is needed to improve further cardiac health in hemodialysis (HD) patients. Adequate management of sodium, water, volume and hemodynamic control of HD patients relies on a stepwise approach: the first entails assessment and monitoring of fluid status and relies on clinical judgement supported by specific tools that are online embedded in the HD machine or devices used offline; the second consists of acting on correcting fluid imbalance mainly through dialysis prescription (treatment time, active tools embedded on HD machine) but also on guidance related to diet and thirst management; the third consist of fine tuning treatment prescription to patient responses and tolerance with the support of innovative tools such as artificial intelligence and remote pervasive health trackers. It is time to come back to sodium and water imbalance as the root cause of the problem and not to act primarily on their consequences (fluid overload, hypertension) or organ damage (heart; atherosclerosis, brain). We know the problem and have the tools to assess and manage in a more precise way sodium and fluid in HD patients. We strongly call for a sodium first approach to reduce disease burden and improve cardiac health in dialysis-dependent chronic kidney disease patients.
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Affiliation(s)
- Bernard Canaud
- School of Medicine, Montpellier University, Montpellier, France
- Global Medical Office, Freseenius Medical Care (FMC)-France, Fresnes, France
| | - Jeroen Kooman
- Maastricht University Maastricht Medical Center (UMC), Maastricht University, Maastricht, Netherlands
| | - Andreas Maierhofer
- Global Research Development, Fresenius Medical Care (FMC) Deutschland GmbH, Bad Homburg, Germany
| | - Jochen Raimann
- Research Division, Renal Research Institute, New York, NY, United States
| | - Jens Titze
- Cardiovascular and Metabolic Disease Programme, Duke-National University Singapore (NUS) Medical School, Singapore, Singapore
| | - Peter Kotanko
- Research Division, Renal Research Institute, New York, NY, United States
- Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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Kron S, Schneditz D, Leimbach T, Schneider J, Kron J. Dynamics of vascular refilling in extended nocturnal hemodialysis. Hemodial Int 2022; 26:540-547. [PMID: 35711103 DOI: 10.1111/hdi.13029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 04/06/2022] [Accepted: 05/30/2022] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Long dialysis treatments are generally assumed to mitigate the ultrafiltration (UF) induced volume perturbation and to improve vascular refilling because of reduced UF rates and sufficient time for volume re-equilibration. The time course of vascular refilling was therefore examined during extended nocturnal dialysis. METHODS For each hour of dialysis, vascular refilling volume was calculated from the absolute blood volume changes and UF volume removed. Absolute blood volume was estimated by indicator dilution at the beginning of dialysis and then tracked with a relative blood volume monitor. The refilling fraction was defined as the ratio of refilling volume to UF volume. FINDINGS Ten stable chronic hemodialysis (HD) patients were studied during extended (7 h) nocturnal treatment sessions. Specific UF rate was 4.8 ± 1.8 ml/kg/h. In the 1 h, refilling volume amounted to only 23% of UF volume. Thereafter, refilling fraction steeply increased and reached maximum values in the 2, 3 and 4 h at about mean 90% (91.5%, 88.7%, and 91.1% respectively). From the 5 h on, refilling volume decreased (5 h 81.3%, 6 h 72.5%, 7 h 70.0% of UF volume). Cumulative refilling reached 73.6% of UF volume after 4 h of treatment time. This did not change during the further course of HD. Cumulative refilling volume showed a strong correlation (r = 0.94; p < 0.001) with UF volume. The ratio of blood volume to extracellular volume (Rbex ) was 0.306 ± 0.029 before and slightly but significantly increased to 0.326 ± 0.030 after UF. DISCUSSION In spite of low-UF rates and extended treatment times, overall refilling fraction reached only 74% and was not different from the refilling fraction observed in regular HD. This value seems to represent a point where UF-induced volume perturbation is adequately compensated by physiologic control mechanisms.
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Affiliation(s)
- Susanne Kron
- Department of Nephrology and Internal Intensive Care Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Daniel Schneditz
- Division of Physiology, Otto Loewi Research Center, Medical University of Graz, Graz, Austria
| | - Til Leimbach
- KfH Kidney Center Berlin-Köpenick, Berlin, Germany
| | - Johanna Schneider
- Department of Nephrology and Internal Intensive Care Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Joachim Kron
- KfH Kidney Center Berlin-Köpenick, Berlin, Germany
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Lee JS, Lee LP. Microvascular Dynamics and Hemodialysis Response of Patients With End-Stage Renal Disease. Front Bioeng Biotechnol 2022; 10:836990. [PMID: 35662845 PMCID: PMC9159995 DOI: 10.3389/fbioe.2022.836990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 03/23/2022] [Indexed: 11/13/2022] Open
Abstract
In our previous analysis of three sets of hemodialysis studies, we found that patients possessing higher hematocrit have a higher filtration coefficient KSo and more fluid being restituted from the tissue. A new dynamic analysis is developed to reveal how the plasma protein concentration, restitution volume, and plasma volume are changing over the time course of 240 min hemodialysis. For patients with the filtration coefficient KSo as 0.43 or 5.88 ml/min/mmHg, we find that the restitution rate would reach 50% of the extraction rate in 5.3 or 57.4 min, respectively. By the end of hemodialysis, the restitution rate of both patients asymptotically approaches a value of 0.93 ml/min which is slightly higher than the extraction rate of 9.03 ml/min. The plasma volume drops by 10% of the total plasma volume in 11 min for patients with low KSo and drops by 2.1% and turns around to an increasing trend in 5.6 min for patients with high KSo. These results suggest that the filtration coefficient acts like a facilitator in restituting more fluid from the tissue to compensate for the loss of plasma volume due to extraction. The hematocrit data of three sets of hemodialysis also indicate that significant microvascular blood volume is shifted from small veins toward the venous side of macrocirculation. A better understanding of how the factors examined here cause hypovolemia can be the basis for one to modify the hemodialysis process such that the development of hypovolemia can be avoided over the course of hemodialysis.
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Affiliation(s)
- Jen-Shih Lee
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States
- Global Monitors, Inc., San Diego, CA, United States
- *Correspondence: Jen-Shih Lee,
| | - Lian-Pin Lee
- Global Monitors, Inc., San Diego, CA, United States
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Kron S, Schneditz D, Kron J. The blood to extracellular volume relationship is stable and in the physiologic range in chronic haemodialysis patients. Nephrol Dial Transplant 2022; 37:2034-2036. [DOI: 10.1093/ndt/gfac151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Indexed: 11/12/2022] Open
Affiliation(s)
- Susanne Kron
- Department of Nephrology and Internal Intensive Care Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Daniel Schneditz
- Division of Physiology, Otto Loewi Research Centre, Medical University of Graz, Graz, Austria
| | - Joachim Kron
- KfH Kidney Centre Berlin-Köpenick, Berlin, Germany
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Cavallari G, Mancini E. The Nephrologist's Role in the Collaborative Multi-Specialist Network Taking Care of Patients with Diabetes on Maintenance Hemodialysis: An Overview. J Clin Med 2022; 11:jcm11061521. [PMID: 35329847 PMCID: PMC8949004 DOI: 10.3390/jcm11061521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 02/28/2022] [Accepted: 03/02/2022] [Indexed: 12/22/2022] Open
Abstract
Diabetes mellitus is the leading cause of renal failure in incident dialysis patients in several countries around the world. The quality of life for patients with diabetes in maintenance hemodialysis (HD) treatment is in general poor due to disease complications. Nephrologists have to cope with all these problems because of the “total care model” and strive to improve their patients’ outcome. In this review, an updated overview of the aspects the nephrologist must face in the management of these patients is reported. The conventional marker of glycemic control, hemoglobin A1c (HbA1c), is unreliable. HD itself may be responsible for dangerous hypoglycemic events. New methods of glucose control could be used even during dialysis, such as a continuous glucose monitoring (CGM) device. The pharmacological control of diabetes is another complex topic. Because of the risk of hypoglycemia, insulin and other medications used to treat diabetes may need dose adjustment. The new class of antidiabetic drugs dipeptidyl peptidase 4 (DPP-4) inhibitors can safely be used in non-insulin-dependent end-stage renal disease (ESRD) patients. Nephrologists should take care to improve the hemodynamic tolerance to HD treatment, frequently compromised by the high level of ultrafiltration needed to counter high interdialytic weight gain. Kidney and pancreas transplantation, in selected patients with diabetes, is the best therapy and is the only approach able to free patients from both dialysis and insulin therapy.
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Yashiro M, Kotera H. Impact of the nature of the capillary wall on plasma refilling during hemodialysis. Int J Artif Organs 2022; 45:262-270. [PMID: 35075929 DOI: 10.1177/03913988211070596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES Our aim was to clarify the impact of the nature of the capillary wall, defined by the contribution of large (LP), small (SP), and ultrasmall (UP) pores, on plasma refilling in a hemodialysis session. METHODS This study included data from 78 patients. The relative blood volume change (ΔBV%) was monitored using a Crit-Line monitor. A bioimpedance device was used to measure extracellular and intracellular fluid volumes, and the excess fluid mass (MExF) was calculated. We simulated blood volume change (sΔBV%) based on a three-pore model. Hydraulic permeability of the capillary wall (LpS) and fractional contribution of LP to LpS (αLP) were determined by fitting sΔBV to ΔBV. The total refilling volume (TVref) was calculated from the total ultrafiltration volume and total blood volume change. Values were standardized to a body surface area of 1.73 m2 and are denoted by the subscript BSA. RESULTS LpS and αLP were 3.09 (2.32, 4.68) mL/mmHg/min and 0.069 (0.023, 0.109), respectively. The standardized regression coefficient (β) of the ultrafiltration rate (UFRBSA) and initial excess fluid mass (MExF,BSA,0) by multiple linear regression analysis of TVref,BSA without (Model 1) and with (Model 2) αLP were as follows: UFRBSA, 0.714/<0.001 (β/p); MExF,BSA,0, 0.247/<0.001 (Model 1); UFRBSA, 0.799/<0.001; MExF,BSA,0, 0.066/0.237; and αLP, -0.327/<0.001 (Model 2). CONCLUSIONS The impact of volume overload (MExF,BSA,0) on plasma refilling became insignificant with the addition of αLP in the model, suggesting that the nature of the capillary wall described by inter-endothelial gaps (LP) may have a greater impact on plasma refilling than volume overload.
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Affiliation(s)
- Masatomo Yashiro
- Division of Medical Engineering, Faculty of Medical Care Sciences, Himeji Dokkyo University, Himeji City, Hyogo, Japan
| | - Hirohisa Kotera
- Division of Medical Engineering, Faculty of Medical Care Sciences, Himeji Dokkyo University, Himeji City, Hyogo, Japan
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Haroon S, Tai BC, Yeo X, Davenport A. Changes in total and segmental extracellular and intracellular volumes with hypotension during hemodialysis measured with bioimpedance spectroscopy. Artif Organs 2021; 46:666-676. [PMID: 34695245 DOI: 10.1111/aor.14096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 09/23/2021] [Accepted: 10/21/2021] [Indexed: 02/06/2023]
Abstract
BACKGROUND Bioelectrical impedance analysis (BIA) devices have been advocated to guide volume management in hemodialysis (HD) patients. We hypothesized that understanding the dynamics of fluid shifts in different body segments may provide additional insight on preventive measures to reduce the risk of intradialytic hypotension. METHODS A prospective observational study was conducted among 42 HD patients at risk of hypotension who were admitted as emergencies inpatient. RESULTS A total of 191 BIA measurements were made during the 42 HD sessions, and hypotension occurred during 52 measurements (27%). The extracellular water (ECW) to intracellular water ratio (EIR) was measured in different body segments and declined significantly only in the non-access arm with increasing HD session duration (β = -0.04; 95% confidence interval (CI): -0.05 to -0.03, p < 0.01). There was no significant association between EIR and hypotension with respect to the different body segments. Only pre-HD N-terminal-pro b-type natriuretic peptide was significantly associated with hypotension (β = 0.20, 95% CI: 0.04 to 0.89, p = 0.04). There was no association between relative blood volume monitoring change and EIR. CONCLUSION In summary, we found that segmental BIA during HD was unable to detect or predict hypotension during dialysis. Although BIA is able to provide information about ECW and guide clinical assessment of volume in HD patients prior to dialysis, our findings did not suggest the use of serial measurements of changes in EIR in different body segments during HD provided sufficient information to predict intradialytic hypotension. Similarly, changes in EIR did not provide information on changes in plasma volume that could potentially trigger interventions to prevent or reduce intra-dialytic hypotension.
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Affiliation(s)
- Sabrina Haroon
- Division of Nephrology, National University Hospital, Singapore, Singapore
| | - Bee Choo Tai
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Xier Yeo
- Epidemiology Unit, National University Hospital, Singapore, Singapore
| | - Andrew Davenport
- UCL Center for Nephrology, Royal Free Hospital, University College London, London, UK
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Chaudhuri S, Han H, Monaghan C, Larkin J, Waguespack P, Shulman B, Kuang Z, Bellamkonda S, Brzozowski J, Hymes J, Black M, Kotanko P, Kooman JP, Maddux FW, Usvyat L. Real-time prediction of intradialytic relative blood volume: a proof-of-concept for integrated cloud computing infrastructure. BMC Nephrol 2021; 22:274. [PMID: 34372809 PMCID: PMC8351092 DOI: 10.1186/s12882-021-02481-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 07/26/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Inadequate refilling from extravascular compartments during hemodialysis can lead to intradialytic symptoms, such as hypotension, nausea, vomiting, and cramping/myalgia. Relative blood volume (RBV) plays an important role in adapting the ultrafiltration rate which in turn has a positive effect on intradialytic symptoms. It has been clinically challenging to identify changes RBV in real time to proactively intervene and reduce potential negative consequences of volume depletion. Leveraging advanced technologies to process large volumes of dialysis and machine data in real time and developing prediction models using machine learning (ML) is critical in identifying these signals. METHOD We conducted a proof-of-concept analysis to retrospectively assess near real-time dialysis treatment data from in-center patients in six clinics using Optical Sensing Device (OSD), during December 2018 to August 2019. The goal of this analysis was to use real-time OSD data to predict if a patient's relative blood volume (RBV) decreases at a rate of at least - 6.5 % per hour within the next 15 min during a dialysis treatment, based on 10-second windows of data in the previous 15 min. A dashboard application was constructed to demonstrate how reporting structures may be developed to alert clinicians in real time of at-risk cases. Data was derived from three sources: (1) OSDs, (2) hemodialysis machines, and (3) patient electronic health records. RESULTS Treatment data from 616 in-center dialysis patients in the six clinics was curated into a big data store and fed into a Machine Learning (ML) model developed and deployed within the cloud. The threshold for classifying observations as positive or negative was set at 0.08. Precision for the model at this threshold was 0.33 and recall was 0.94. The area under the receiver operating curve (AUROC) for the ML model was 0.89 using test data. CONCLUSIONS The findings from our proof-of concept analysis demonstrate the design of a cloud-based framework that can be used for making real-time predictions of events during dialysis treatments. Making real-time predictions has the potential to assist clinicians at the point of care during hemodialysis.
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Affiliation(s)
- Sheetal Chaudhuri
- Fresenius Medical Care, Global Medical Office, 920 Winter Street, Waltham, MA, 02451, USA. .,Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Hao Han
- Fresenius Medical Care, Global Medical Office, 920 Winter Street, Waltham, MA, 02451, USA
| | - Caitlin Monaghan
- Fresenius Medical Care, Global Medical Office, 920 Winter Street, Waltham, MA, 02451, USA
| | - John Larkin
- Fresenius Medical Care, Global Medical Office, 920 Winter Street, Waltham, MA, 02451, USA
| | | | - Brian Shulman
- Fresenius Medical Care North America, Waltham, MA, USA
| | - Zuwen Kuang
- Fresenius Medical Care North America, Waltham, MA, USA
| | | | - Jane Brzozowski
- Fresenius Medical Care, Global Medical Office, 920 Winter Street, Waltham, MA, 02451, USA
| | - Jeffrey Hymes
- Fresenius Medical Care North America, Waltham, MA, USA
| | - Mike Black
- Fresenius Medical Care North America, Waltham, MA, USA
| | - Peter Kotanko
- Renal Research Institute, New York, NY, USA.,Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jeroen P Kooman
- Maastricht University Medical Center, Maastricht, The Netherlands
| | - Franklin W Maddux
- Fresenius Medical Care, Global Medical Office, 920 Winter Street, Waltham, MA, 02451, USA
| | - Len Usvyat
- Fresenius Medical Care, Global Medical Office, 920 Winter Street, Waltham, MA, 02451, USA
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14
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Kron S, Schneditz D, Keane DF, Leimbach T, Kron J. An improved method to estimate absolute blood volume based on dialysate dilution. Artif Organs 2021; 45:E359-E363. [PMID: 33908065 DOI: 10.1111/aor.13970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/09/2021] [Accepted: 04/12/2021] [Indexed: 12/01/2022]
Abstract
Online hemodiafiltration machines equipped with a blood volume monitor and the possibility to rapidly infuse exact amounts of ultrapure dialysate into the extracorporeal circulation can be used to determine absolute blood volume in clinical practice. The aim of the present study was to evaluate the reproducibility of such measurements. Intra-individual reproducibility was evaluated in four measurements taken in hourly intervals within the same dialysis treatment. Ten patients were studied. Absolute blood volumes measured at the beginning and after 1 hour of dialysis were significantly different (80.6 ± 14.5 and 63.9 ± 14.3 mL/kg, P < .001) and highly reproducible between the last three measurements (63.9 ± 14.3, 61.4 ± 13.8, and 60.9 ± 13.9 mL/kg, P = n.s.). Measurement of absolute blood volume after 1 hour of treatment is more precise than earlier measurements and might be better suited for guidance of ultrafiltration.
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Affiliation(s)
- Susanne Kron
- Department of Nephrology and Internal Intensive Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Daniel Schneditz
- Division of Physiology, Otto Loewi Research Center, Medical University of Graz, Graz, Austria
| | - David F Keane
- Department of Renal Medicine, Leeds Teaching Hospitals, Leeds, UK
| | - Til Leimbach
- KfH Kidney Center Berlin-Köpenick, Berlin, Germany
| | - Joachim Kron
- KfH Kidney Center Berlin-Köpenick, Berlin, Germany
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15
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Pstras L, Waniewski J, Lindholm B. Monitoring relative blood volume changes during hemodialysis: Impact of the priming procedure. Artif Organs 2021; 45:1189-1194. [PMID: 33908070 DOI: 10.1111/aor.13972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/28/2021] [Accepted: 04/01/2021] [Indexed: 11/27/2022]
Abstract
The monitoring of relative blood volume (RBV) changes during hemodialysis is increasingly used to evaluate the effect of dialyzer ultrafiltration on intravascular volume to guide the removal of excess fluid in a manner that maintains hemodynamic stability of the patient. RBV monitoring is typically based on an optical or acoustic sensor placed in the arterial blood line that measures a marker of hemoconcentration, such as hematocrit, hemoglobin, or total blood protein. However, the accuracy of RBV monitors and the impact of their clinical use remain the subject of ongoing debate. Here, we show that, depending on the procedure of filling the extracorporeal circuit with the patient's blood at the beginning of the dialysis session, the indications of an RBV monitor may be misleading as to the actual changes of the intravascular volume. When the blood is first pumped into the dialyzer, the priming fluid (saline) that fills the circuit may be either infused into the patient or disposed of to a drain bag. In the latter case, the intravascular volume is suddenly reduced, which is not accounted for by RBV monitors that track only the subsequent reductions in blood volume due to dialyzer ultrafiltration. We analyzed this general aspect of RBV monitoring using model-based simulations and showed quantitatively how RBV changes calculated using hematocrit differ depending on the priming procedure.
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Affiliation(s)
- Leszek Pstras
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Jacek Waniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Bengt Lindholm
- Division of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden
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16
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Jeong HY, Kim HJ, Han M, Seong EY, Song SH. Dialysis unit blood pressure two hours after hemodialysis is useful for predicting home blood pressure and ambulatory blood pressure in maintenance hemodialysis patients. Ther Apher Dial 2021; 26:103-114. [PMID: 33774930 DOI: 10.1111/1744-9987.13648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/13/2021] [Accepted: 03/23/2021] [Indexed: 11/29/2022]
Abstract
This study aimed to determine which BP measurement obtained in the HD unit correlated best with home BP and ambulatory BP monitoring (ABPM). We retrospectively analyzed data from 40 patients that received maintenance HD who had available home BP and ABPM data. Dialysis unit BPs were the averages of pre-, 2hr- (2 h after starting HD), and post-HD BP during a 9-month study. Home BP was defined as the average of morning and evening home BPs. Dialysis unit BP and home BP were compared over the 9-month study period. ABPM was performed once for 24 h in the absence of dialysis during the final 2 weeks of the study period and was compared to the 2-week dialysis unit BP and home BP. There was a significant difference between dialysis unit systolic blood pressure (SBP) and home SBP over the 9-month period. No significant difference was observed between the 2hr-HD SBP and home SBP. When analyzing 2 weeks of dialysis unit BP and home BP, including ABPM, SBPs were significantly different (dialysis unit BP > home BP > ABPM; P = 0.009). Consistent with the 9-month study period, no significant difference was observed between 2hr-HD SBP and home SBP (P = 0.809). The difference between 2hr-HD SBP and ambulatory SBP was not significant (P = 0.113). In conclusion, the 2hr-HD SBP might be useful for predicting home BP and ABPM in HD patients.
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Affiliation(s)
- Hye Yun Jeong
- Department of Internal Medicine, Jeonggwan Ilsin Christian Hospital, Busan, Korea
| | - Hyo Jin Kim
- Department of Internal Medicine, Pusan National University Hospital, Busan, Korea.,Biomedical Research Institute, Pusan National University Hospital, Busan, Korea
| | - Miyeun Han
- Department of Internal Medicine, Hallym University Hangang Sacred Heart Hospital, Seoul, Korea
| | - Eun Young Seong
- Department of Internal Medicine, Pusan National University Hospital, Busan, Korea.,Biomedical Research Institute, Pusan National University Hospital, Busan, Korea
| | - Sang Heon Song
- Department of Internal Medicine, Pusan National University Hospital, Busan, Korea.,Biomedical Research Institute, Pusan National University Hospital, Busan, Korea
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17
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Álvarez Nadal M, Martín Capón I, Viera Ramírez ER, Fernández Lucas M. Absolute blood volume variations during hemodialysis: Does dialysate temperature play a role? Semin Dial 2021; 34:309-314. [PMID: 33580986 DOI: 10.1111/sdi.12958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/14/2020] [Accepted: 01/12/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND Vascular refilling occurs to preserve hemodynamic stability during hemodialysis (HD). Recent studies report a feasible and noninvasive method to determine absolute blood volume (ABV), and estimate vascular refilling during HD. The objective of this study is to analyze if lowering dialysate temperature modifies variations in ABV during HD. METHODS The study was performed in 50 patients under HD. During two different sessions, relative blood volume was assessed using dialysate temperatures of 35.5°C (cool dialysate) and 36.5°C (neutral dialysate). ABV and vascular refilling were calculated using Kron et al methodology. RESULTS Thirty-nine intradialytic morbid events (IMEs) were observed in 30 patients, 14 under cool dialysate and 25 during neutral dialysate. We did not found statistically differences in ABV or in refilling volume between cool and neutral temperature. When analyzing apart only those patients who presented IME, we observed lower drop in ABV in the 35.5°C dialysate treatments (0.57 L) versus 36.5°C dialysate treatments (0.71 L). When cool dialysate was used, the vascular refilling fraction tended to be higher, but data did not turn statistically significant. CONCLUSIONS In selected groups of patients the use of cool dialysate induces lower ABV variations that could improve hemodynamic stability during HD treatments.
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Affiliation(s)
- Marta Álvarez Nadal
- Department of Nephrology, IRYCIS, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Irene Martín Capón
- Department of Nephrology, IRYCIS, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | | | - Milagros Fernández Lucas
- Department of Nephrology, IRYCIS, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Universidad de Alcalá, Madrid, Spain
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18
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Álvarez Nadal M, Viera Ramírez ER, Martín Capón I, Fernández Lucas M. Absolute blood volume variations and vascular refilling in hemodialysis patients. Semin Dial 2021; 34:229-234. [PMID: 33556227 DOI: 10.1111/sdi.12952] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 12/10/2020] [Indexed: 11/29/2022]
Abstract
The imbalance between ultrafiltration volume (UF) and vascular refilling is considered a major cause for intradialytic hypotension. Recent studies report a noninvasive method to estimate vascular refilling (VREF ) by determining absolute blood volume (ABV). It was the aim of the study to analyze variations in ABV in a group of hemodialysis (HD) patients and examine VREF . Thirty one stable chronic HD patients were studied, aged 71.07 ± 13.31 years. Dialysis duration and UF requirements were based on physician prescription. VREF was calculated as: VREF = VUF - ΔV where ΔV is ABV variation during dialysis treatment. ABV at the beginning of the dialysis was 6.00 ± 2.39 L (92.82 ± 33.17 ml/kg) and at the end 5.38 ± 2.32 L (82.07 ± 31.41 ml/kg). Prescribed UF was 2.64 ± 0.83 L. Mean VREF was 2.05 ± 0.80 L, with a refilling fraction of 75.75 ± 12.79%. VREF was strongly correlated with UF volume (r2 0.877), and with pre-dialysis volume overload (r2 0.617). Patients under beta-blocker treatment showed significantly lower FREF . ABV measurement is an easy and noninvasive method that allows us to study VREF during HD. We found a strong correlation between VREF and UF.
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Affiliation(s)
- Marta Álvarez Nadal
- Department of Nephrology, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | | | - Irene Martín Capón
- Department of Nephrology, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Milagros Fernández Lucas
- Department of Nephrology, Hospital Universitario Ramón y Cajal, Madrid, Spain.,Department of Nephrology, Facultad de Medicina, Universidad de Alcalá, IRYCIS, Madrid, Spain
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19
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Dull RO, Hahn RG. Transcapillary refill: The physiology underlying fluid reabsorption. J Trauma Acute Care Surg 2021; 90:e31-e39. [PMID: 33491937 DOI: 10.1097/ta.0000000000003013] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Randal O Dull
- From the Department of Anesthesiology (R.O.D.), Department of Pathology (R.O.D.), Department of Surgery (R.O.D.), College of Medicine, University of Arizona, Tucson, Arizona; Research Unit (R.G.H.), Södertälje Hospital, Södertälje; and Karolinska Institute at Danderyds Hospital (R.G.H.), Stockholm, Sweden
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20
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Canaud B, Kooman JP, Selby NM, Taal MW, Francis S, Maierhofer A, Kopperschmidt P, Collins A, Kotanko P. Dialysis-Induced Cardiovascular and Multiorgan Morbidity. Kidney Int Rep 2020; 5:1856-1869. [PMID: 33163709 PMCID: PMC7609914 DOI: 10.1016/j.ekir.2020.08.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 08/27/2020] [Indexed: 12/14/2022] Open
Abstract
Hemodialysis has saved many lives, albeit with significant residual mortality. Although poor outcomes may reflect advanced age and comorbid conditions, hemodialysis per se may harm patients, contributing to morbidity and perhaps mortality. Systemic circulatory "stress" resulting from hemodialysis treatment schedule may act as a disease modifier, resulting in a multiorgan injury superimposed on preexistent comorbidities. New functional intradialytic imaging (i.e., echocardiography, cardiac magnetic resonance imaging [MRI]) and kinetic of specific cardiac biomarkers (i.e., Troponin I) have clearly documented this additional source of end-organ damage. In this context, several factors resulting from patient-hemodialysis interaction and/or patient management have been identified. Intradialytic hypovolemia, hypotensive episodes, hypoxemia, solutes, and electrolyte fluxes as well as cardiac arrhythmias are among the contributing factors to systemic circulatory stress that are induced by hemodialysis. Additionally, these factors contribute to patients' symptom burden, impair cognitive function, and finally have a negative impact on patients' perception and quality of life. In this review, we summarize the adverse systemic effects of current intermittent hemodialysis therapy, their pathophysiologic consequences, review the evidence for interventions that are cardioprotective, and explore new approaches that may further reduce the systemic burden of hemodialysis. These include improved biocompatible materials, smart dialysis machines that automatically may control the fluxes of solutes and electrolytes, volume and hemodynamic control, health trackers, and potentially disruptive technologies facilitating a more personalized medicine approach.
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Affiliation(s)
- Bernard Canaud
- Montpellier University, Montpellier, France
- GMO, FMC, Bad Homburg, Germany
| | - Jeroen P. Kooman
- Maastricht University Medical Centre, Department of Internal Medicine, Maastricht, Netherlands
| | - Nicholas M. Selby
- Centre for Kidney Research and Innovation, Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, UK
| | - Maarten W. Taal
- Centre for Kidney Research and Innovation, Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, UK
| | - Susan Francis
- Sir Peter Mansfield Imaging Centre, University of Nottingham, UK
| | | | | | | | - Peter Kotanko
- Renal Research Institute, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
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21
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Transcapillary transport of water, small solutes and proteins during hemodialysis. Sci Rep 2020; 10:18736. [PMID: 33127932 PMCID: PMC7603324 DOI: 10.1038/s41598-020-75687-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 10/15/2020] [Indexed: 11/08/2022] Open
Abstract
The semipermeable capillary walls not only enable the removal of excess body water and solutes during hemodialysis (HD) but also provide an essential mechanism for maintaining cardiovascular homeostasis. Here, we investigated transcapillary transport processes on the whole-body level using the three-pore model of the capillary endothelium with large, small and ultrasmall pores. The transcapillary transport and cardiovascular response to a 4-h hemodialysis (HD) with 2 L ultrafiltration were analyzed by simulations in a virtual patient using the three-pore model of the capillary wall integrated in the whole-body compartmental model of the cardiovascular system with baroreflex mechanisms. The three-pore model revealed substantial changes during HD in the magnitude and direction of transcapillary water flows through small and ultrasmall pores and associated changes in the transcapillary convective transport of proteins and small solutes. The fraction of total capillary hydraulic conductivity attributed to ultrasmall pores was found to play an important role in the transcapillary water transport during HD thus influencing the cardiovascular response to HD. The presented model provides a novel computational framework for a detailed analysis of microvascular exchange during HD and as such may contribute to a better understanding of dialysis-induced changes in blood volume and blood pressure.
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22
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Haider T, Diaz-Canestro C, Pentz B, Montero D. Intravascular albumin loss is strongly associated with plasma volume withdrawal in dialysis patients. Hemodial Int 2020; 25:86-93. [PMID: 32996274 DOI: 10.1111/hdi.12881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 08/10/2020] [Accepted: 09/14/2020] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Low circulating albumin closely predicts mortality in end-stage renal disease (ESRD) patients. The cause(s) of hypoalbuminemia (hALB) in ESRD patients remains to be elucidated. The aim of the present study was to determine the role of plasma volume (PV) withdrawal in the reduction of total circulating albumin and essential blood solutes induced by hemodialysis (HD). METHODS PV determined with high-precision automated carbon monoxide-rebreathing, total circulating as well as concentration of plasma albumin and electrolytes were assessed prior to and after 4-hour HD in 10 ESRD patients. FINDINGS Baseline PV ranged from 3.5 to 6.2 l. After HD, PV was decreased by 689 ± 566 mL (-16%) (P = 0.004). Total circulating albumin was largely reduced after HD (170.8 ± 35.1 vs. 146.1 ± 48.9 g, P = 0.008), while albumin concentration was unaltered. According to a strong linear relationship (r = 0.91, P < 0.001), one-third of total circulating albumin is lost from the intravascular compartment for every liter of PV removed. Similar results were found regarding Na+ and Ca2+ electrolytes. DISCUSSION Total circulating albumin, but not albumin concentration, is substantially reduced by HD in proportion to the amount of PV removed from the circulation. This study highlights the potential contributing role of PV withdrawal to hALB in ESRD patients.
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Affiliation(s)
- Thomas Haider
- University Heart Center, University Hospital Zurich, Zurich, Switzerland
| | - Candela Diaz-Canestro
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
| | - Brandon Pentz
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
| | - David Montero
- University Heart Center, University Hospital Zurich, Zurich, Switzerland.,Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.,Cumming School of Medicine, Calgary, Alberta, Canada
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23
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Pstras L, Waniewski J, Wojcik-Zaluska A, Zaluska W. Relative blood volume changes during haemodialysis estimated from haemoconcentration markers. Sci Rep 2020; 10:14809. [PMID: 32908230 PMCID: PMC7481245 DOI: 10.1038/s41598-020-71830-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 06/17/2020] [Indexed: 11/15/2022] Open
Abstract
Relative blood volume (RBV) monitoring is frequently used in haemodialysis patients to help guide fluid management and improve cardiovascular stability. RBV changes are typically estimated based on online measurements of certain haemoconcentration markers, such as haematocrit (HCT), haemoglobin (HGB) or total blood protein concentration (TBP). The beginning of a haemodialysis procedure, i.e. filling the extracorporeal circuit with the patient’s blood (with the priming saline being infused to the patient or discarded) may be associated with relatively dynamic changes in the circulation, and hence the observed RBV changes may depend on the exact moment of starting the measurements. The aim of this study was to use a mathematical model to assess this issue quantitatively. The model-based simulations indicate that when the priming saline is not discarded but infused to the patient, a few-minute difference in the moment of starting RBV tracking through measurements of HCT, HGB or TBP may substantially affect the RBV changes observed throughout the dialysis session, especially with large priming volumes. A possible overestimation of the actual RBV changes is the highest when the measurements are started within a couple of minutes after the infusion of priming saline is completed.
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Affiliation(s)
- L Pstras
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Trojdena 4, 02-109, Warsaw, Poland.
| | - J Waniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Trojdena 4, 02-109, Warsaw, Poland
| | - A Wojcik-Zaluska
- Department of Physical Therapy and Rehabilitation, Medical University of Lublin, Lublin, Poland
| | - W Zaluska
- Department of Nephrology, Medical University of Lublin, Lublin, Poland
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24
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Pstras L, Debowska M, Wojcik-Zaluska A, Zaluska W, Waniewski J. Hemodialysis-induced changes in hematocrit, hemoglobin and total protein: Implications for relative blood volume monitoring. PLoS One 2019; 14:e0220764. [PMID: 31404089 PMCID: PMC6690539 DOI: 10.1371/journal.pone.0220764] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/23/2019] [Indexed: 12/04/2022] Open
Abstract
Background Relative blood volume (RBV) changes during hemodialysis (HD) are typically estimated based on online measurements of hematocrit, hemoglobin or total blood protein. The aim of this study was to assess changes in the above parameters during HD in order to compare the potential differences in the RBV changes estimated by individual methods. Methods 25 anuric maintenance HD patients were monitored during a 1-week conventional HD treatment. Blood samples were collected from the arterial dialysis blood line at the beginning and at the end of each HD session. The analysis of blood samples was performed using the hematology analyzer Advia 2120 and clinical chemistry analyzer Advia 1800 (Siemens Healthcare). Results During the analyzed 30 HD sessions with ultrafiltration in the range 0.7–4.0 L (2.5 ± 0.8 L) hematocrit (HCT) increased by 9.1 ± 7.0% (mean ± SD), hemoglobin (HGB) increased by 10.6 ± 6.3%, total plasma protein (TPP) increased by 15.6 ± 9.5%, total blood protein (TBP) increased by 10.4 ± 5.8%, red blood cell count (RBC) increased by 10.8 ± 7.1%, while mean corpuscular red cell volume (MCV) decreased by 1.5 ± 1.1% (all changes statistically significant, p < 0.001). HGB increased on average by 1.5% more than HCT (p < 0.001). The difference between HGB and TBP increase was insignificant (p = 0.16). Conclusions Tracking HGB or TBP can be treated as equivalent for the purpose of estimating RBV changes during HD. Due to the reduction of MCV, the HCT-based estimate of RBV changes may underestimate the actual blood volume changes.
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Affiliation(s)
- Leszek Pstras
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
- * E-mail:
| | - Malgorzata Debowska
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Alicja Wojcik-Zaluska
- Department of Physical Therapy and Rehabilitation, Medical University of Lublin, Lublin, Poland
| | - Wojciech Zaluska
- Department of Nephrology, Medical University of Lublin, Lublin, Poland
| | - Jacek Waniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
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25
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Yashiro M, Kotera H. Novel equations for bioimpedance spectroscopy to calculate body fluid volume based on the agreement between body weight and extracellular water change before and after hemodialysis as a guide. RENAL REPLACEMENT THERAPY 2019. [DOI: 10.1186/s41100-019-0203-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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26
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Pietribiasi M, Waniewski J, Wójcik-Załuska A, Załuska W, Lindholm B. Model of fluid and solute shifts during hemodialysis with active transport of sodium and potassium. PLoS One 2018; 13:e0209553. [PMID: 30592754 PMCID: PMC6310262 DOI: 10.1371/journal.pone.0209553] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 12/07/2018] [Indexed: 11/19/2022] Open
Abstract
Background Mathematical models are useful tools to predict fluid shifts between body compartments in patients undergoing hemodialysis (HD). The ability of a model to accurately describe the transport of water between cells and interstitium (Jv,ISIC), and the consequent changes in intracellular volume (ICV), is important for a complete assessment of fluid distribution and plasma refilling. In this study, we propose a model describing transport of fluid in the three main body compartments (intracellular, interstitial and vascular), complemented by transport mechanisms for proteins and small solutes. Methods The model was applied to data from 23 patients who underwent standard HD. The substances described in the baseline model were: water, proteins, Na, K, and urea. Small solutes were described with two-compartment kinetics between intracellular and extracellular compartments. Solute transport across the cell membrane took place via passive diffusion and, for Na and K, through the ATPase pump, characterized by the maximum transport rate, JpMAX. From the data we estimated JpMAX and two other parameters linked to transcapillary transport of fluid and protein: the capillary filtration coefficient Lp and its large pores fraction αLP. In an Expanded model one more generic solute was included to evaluate the impact of the number of substances appearing in the equation describing Jv,ISIC. Results In the baseline model, median values (interquartile range) of estimated parameters were: Lp: 11.63 (7.9, 14.2) mL/min/mmHg, αLP: 0.056 (0.050, 0.058), and JpMAX: 5.52 (3.75, 7.54) mmol/min. These values were significantly different from those obtained by the Expanded model: Lp: 8.14 (6.29, 10.01) mL/min/mmHg, αLP: 0.046 (0.038, 0.052), and JpMAX: 16.7 (11.9, 25.2) mmol/min. The relative RMSE (root mean squared error)averaged between all simulated quantities compared to data was 3.9 (3.1, 5.6) %. Conclusions The model was able to accurately reproduce most of the changes observed in HD by tuning only three parameters. While the drop in ICV was overestimated by the model, the difference between simulations and data was less than the measurement error. The biggest change in the estimated parameters in the Expanded model was a marked increase of JpMAX indicating that this parameter is highly sensitive to the number of species modeled, and that the value of JpMAX should be interpreted only in relation to this factor.
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Affiliation(s)
- Mauro Pietribiasi
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Warsaw, Poland
- * E-mail:
| | - Jacek Waniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Warsaw, Poland
| | - Alicja Wójcik-Załuska
- Department of Rehabilitation and Physiotherapy, Medical University of Lublin, Lublin, Poland
| | - Wojciech Załuska
- Department of Nephrology, Medical University of Lublin, Lublin, Poland
| | - Bengt Lindholm
- Renal Medicine and Baxter Novum, Karolinska Institutet, Stockholm, Sweden
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27
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28
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A model of vascular refilling with inflammation. Math Biosci 2018; 303:101-114. [DOI: 10.1016/j.mbs.2018.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 05/31/2018] [Accepted: 06/25/2018] [Indexed: 12/17/2022]
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29
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Variable-Volume Kinetic Model to Estimate Absolute Blood Volume in Patients on Dialysis Using Dialysate Dilution. ASAIO J 2018; 64:77-85. [PMID: 28742531 DOI: 10.1097/mat.0000000000000608] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Long- and short-term adverse outcomes in hemodialysis (HD) have been associated with intradialytic hypotension, a common HD complication and significant cause of morbidity. It has been suggested that knowledge of absolute blood volume (ABV) could be used to significantly improve treatment outcomes. Different dilution-based protocols have been proposed for estimating ABV, all relying on the classic mono-exponential back-extrapolation algorithm (BEXP). In this paper, we introduce a dialysate dilution protocol and an estimation algorithm based on a variable-volume, two-compartment, intravascular blood water content kinetic model (VVKM). We compare ABV estimates derived using the two algorithms in a dialysate dilution study including three arterio-venous (AV) and three central-venous (CV) access patients, and multiple bolus injection tests (3-5) within each of several (2-6) HD treatments. The distribution of differences between ABV estimated from the two methods showed negligible systematic difference between the mean values of ABVs estimated from the BEXP and VVKM algorithms, however, the VVKM estimates were 53% and 42% more precise for the CV and AV patients, respectively. Good agreement was observed between measured and VVKM-estimated blood water concentration with the root-mean-square error (RMSE) less than 0.02 kg/kg (2%) and 0.03 kg/kg (3%) for AV and CV patients, respectively. The dilution protocol and the new VVKM-based estimation algorithm offer a noninvasive, inexpensive, safe, and practical approach for ABV estimation in routine HD settings.
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Affiliation(s)
- Dominic S.C. Raj
- Department of Medicine, Louisiana State University School of Medicine, Shreveport, LA - USA
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Ursino M, Colì L, Brighenti C, De Pascalis A, Chiari L, Dalmastri V, La Manna G, Mosconi G, Avanzolini G, Stefoni S. Mathematical Modeling of Solute Kinetics and Body Fluid Changes during Profiled Hemodialysis. Int J Artif Organs 2018. [DOI: 10.1177/039139889902200207] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A mathematical model of solute kinetics oriented to improve hemodialysis treatment is presented. It includes a two-compartment description of the main solutes (K+, Na+, Cl–, urea, HCO–3, H+, CO2), acid-base equilibrium through two buffer systems (bicarbonate and non-carbonic buffers) and a three-compartment model of body fluids (plasma, interstitial and intracellular). The main model parameters can be individually assigned a priori, on the basis of body weight and plasma concentration values measured before beginning the session. Model predictions are compared with clinical data obtained during 11 different hemodialysis sessions performed on six patients with profiled sodium concentration in the dialysate and profiled ultrafiltration rate. In all cases, the agreement between the time pattern of model solute concentrations in plasma and clinical data turns out fairly good as to urea, sodium, chloride and potassium kinetics. Finally, the time patterns of plasma bicarbonate concentration and pH can be reproduced fairly well with the model, provided CO2 concentration remains constant. Only in two sessions, blood volume was directly measured in the patient, and in both cases the agreement with model predictions was good. In conclusion, the model allows a priori computation of the amount of sodium removed during hemodialysis, and may enable the prediction of plasma volume changes and plasma osmolarity changes induced by a given sodium concentration profile in the dialysate and by a given ultrafiltration profile. Hence, it can be used to improve the dialysis session taking the characteristics of individual patients into account, in order to minimize intradialytic imbalances (such as hypotension or disequilibrium syndrome).
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Affiliation(s)
- M. Ursino
- Department of Electronics, Computer Science and Systems
| | - L. Colì
- Department of Clinical Medicine and Applied Biotechnology, University of Bologna, Bologna - Italy
| | - C. Brighenti
- Department of Electronics, Computer Science and Systems
| | - A. De Pascalis
- Department of Clinical Medicine and Applied Biotechnology, University of Bologna, Bologna - Italy
| | - L. Chiari
- Department of Electronics, Computer Science and Systems
| | - V. Dalmastri
- Department of Clinical Medicine and Applied Biotechnology, University of Bologna, Bologna - Italy
| | - G. La Manna
- Department of Clinical Medicine and Applied Biotechnology, University of Bologna, Bologna - Italy
| | - G. Mosconi
- Department of Clinical Medicine and Applied Biotechnology, University of Bologna, Bologna - Italy
| | - G. Avanzolini
- Department of Electronics, Computer Science and Systems
| | - S. Stefoni
- Department of Clinical Medicine and Applied Biotechnology, University of Bologna, Bologna - Italy
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Nordic M, Giove S, Lorenzi S, Marchini P, Saporiti E. A New Approach to Blood Pressure and Blood Volume Modulation during Hemodialysis: An Adaptive Fuzzy Control Module. Int J Artif Organs 2018. [DOI: 10.1177/039139889501800907] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The paper proposes a fuzzy logic based procedure able to control as far as possible the behaviour of the blood pressure of a patient during a dialysis session, allowing him to reach the foreseen dry weight. A PI discrete-time fuzzy control is used in order to compare the controlled variables concerning the (blood pressure and blood volume) to the reference values. Two different reference tables, concerning the pressure and volume errors and rates are introduced, then the proposed control actions are mixed in order to obtain the final value (net ultrafiltration rate). A smooth function of volemia acts on the second control variable, Na concentration in the dialysate. The adaptive control system was simulated on an IBM-PC, rules and terms were expressed by linguistic judgements like: IF “situation”, THEN “action”. A pre-processor converts the rules into the numerical values of the reference tables. The obtained simulation results are satisfactory, the introduction of the Na control allows reaching the target dry weight of the patient with a stable blood pressure.
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Affiliation(s)
- M. Nordic
- Division of Nephrology and Dialysis, Ospedale Civile, Venezia
| | - S. Giove
- Department of Computer and Management Sciences, University of Trento, Trento - Italy
| | - S. Lorenzi
- Division of Nephrology and Dialysis, Ospedale Civile, Venezia
| | - P. Marchini
- Division of Nephrology and Dialysis, Ospedale Civile, Venezia
| | - E. Saporiti
- Division of Nephrology and Dialysis, Ospedale Civile, Venezia
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Affiliation(s)
- A. Santoro
- Division of Nephrology and Dialysis, Hospital S. Orsola Malpighi, Bologna - Italy
| | - E. Mancini
- Division of Nephrology and Dialysis, Hospital S. Orsola Malpighi, Bologna - Italy
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Arrigo G, Bucci R, Colasanti G, Rustici A, Sivo M, Rizza V, D'Amico G. Blood Volume Modeling and Refilling Rate Estimation in Hemodialysis by Continuous Hemoglobin Monitoring. Int J Artif Organs 2018. [DOI: 10.1177/039139889501800906] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Eleven bicarbonate hemodialyses (HD) of 6 patients under constant ultrafiltration were continuously monitored with an optical Hb-meter, considered to be a marker of blood volume (BV) changes. A theoretical model was fed experimental data for prediction of blood volume and estimation of vascular parameters, and a time course of rate of refilling was extrapolated. The adequacy of the model was very good for the time course of BV prediction (r2=0.85-0.95, n=11) and for plasma protein concentration (r2=0.83-0.86, n=2). Parameters estimated included (mean-DS): filtration coefficient (Cf)=0.22 (0.16) dl/min∗mmHg, transcapillary hydrostatic pressure (DP)=17.80 (3.44) mmHg and protein concentration of the refilling fluid (Cref)=0.45 (0.30) g/dl. In conclusion our study has shown that the model chosen fits the observed BV profile well in all cases, thus the Hb data series can be used for BV dynamic modeling and for estimation of vascular parameters.
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Affiliation(s)
- G. Arrigo
- Division of Nephrology and Dialysis, Milano - Italy
| | - R. Bucci
- Division of Nephrology and Dialysis, Milano - Italy
| | - G. Colasanti
- Division of Nephrology and Dialysis, Milano - Italy
| | - A. Rustici
- Division of Nephrology and Dialysis, Milano - Italy
| | - M. Sivo
- Technical Department, Milano - Italy
| | - V. Rizza
- Clinical Biochemistry Laboratory, Ospedale San Carlo Borromeo, Milano - Italy
| | - G. D'Amico
- Division of Nephrology and Dialysis, Milano - Italy
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Daugirdas JT, Schneditz D. Hemodialysis Ultrafiltration Rate Targets Should Be Scaled to Body Surface Area Rather than to Body Weight. Semin Dial 2018; 30:15-19. [PMID: 28043081 DOI: 10.1111/sdi.12563] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The association between higher ultrafiltration rates and poor outcomes in hemodialysis patients has received increased attention, to the point that various regulatory entities are considering adding ultrafiltration rate as a quality measure to be monitored and controlled. Most of the discussion to date has focused on ultrafiltration rate scaled to body weight, or more correctly, body mass (ml/hour per kg). One outcome study suggests that ultrafiltration rate might best be not scaled at all to body size, as modestly higher ultrafiltration rate in very small-size patients may be associated with some survival benefit, probably via increased dietary intake. Outcomes studies also suggest that the risk of exceeding a weight-scaled ultrafiltration target may be magnified in very large patients, and that body weight-scaled ultrafiltration targets in such patients should be set a lower level. Here, we present an analysis, based on physiological hemodynamic arguments, that it would be better to scale ultrafiltration rate to body surface area rather than to body mass. Whatever ultrafiltration rate is scaled to, attempts to restrict ultrafiltration rate by limiting interdialytic weight gain in small, possibly malnourished patients, should be done cautiously, to prevent an inadvertent lowering of intake of calories and dietary protein.
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Affiliation(s)
- John T Daugirdas
- Department of Medicine, Division of Nephrology, University of Illinois at Chicago, Chicago, Illinois
| | - Daniel Schneditz
- Institute of Physiology, Medical University of Graz, Graz, Austria
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Schneditz D, Sarikakis G, Kontodima M, Sauseng N. The Influence of Colloid Osmotic Pressure on Hydrostatic Pressures in High- and Low-Flux Hemodialyzers. Artif Organs 2018; 42:525-532. [PMID: 29341167 DOI: 10.1111/aor.13081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 10/15/2017] [Accepted: 10/16/2017] [Indexed: 11/29/2022]
Abstract
The aim of this study was to examine the relationship between hydrostatic trans-membrane pressure (TMPh ) and colloid osmotic pressure (COP) in low-flux (LF) and high-flux (HF) dialyzers. Hydrostatic pressures were measured in dialyzers distinguished by their ultrafiltration coefficient Kuf (16 and 85 mL/h/mm Hg) under constant dialysate flow and variable blood flow (Qb ) ranging from 0 to 400 mL/min using (i) alginate (70 kDa) dissolved in dialysate, (ii) diluted, undiluted, and concentrated plasma, or (iii) whole blood at different hematocrit, all in absence of ultrafiltration (UF). For a given fluid, TMPh linearly increased with increasing Qb . The intercept of the linear TMPh to Qb relationship correlated with measured COP with an average bias of 1.00 ± 2.26 mm Hg and a concordance correlation coefficient of 0.98. The slope of the linear TMPh to Qb relationship increased with increasing sample viscosity and was much larger in HF dialyzers under otherwise identical operating conditions, most likely because of increased internal filtration. The TMPh to Qb relationship measured in dialyzers in absence of UF can be described by the intercept related to measured COP and the slope related to internal filtration. This relationship could be of interest to estimate internal filtration and COP under in vivo conditions.
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Affiliation(s)
- Daniel Schneditz
- Institute of Physiology, Medical University of Graz, Graz, Austria
| | | | - Maria Kontodima
- Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Notburga Sauseng
- Institute of Physiology, Medical University of Graz, Graz, Austria
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Safety and efficacy of cell-free and concentrated ascites reinfusion therapy (CART) in refractory ascites: Post-marketing surveillance results. PLoS One 2017; 12:e0177303. [PMID: 28510606 PMCID: PMC5433707 DOI: 10.1371/journal.pone.0177303] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 04/25/2017] [Indexed: 12/19/2022] Open
Abstract
We performed post-marketing surveillance to evaluate the safety and efficacy of cell-free and concentrated ascites reinfusion therapy (CART). In total, 356 CART sessions in 147 patients at 22 centers were performed. The most common primary disease was cancer (128 cases, 300 sessions). Mean amount of ascites collected was 3.7 L, and mean concentration ratio was 9.2. Mean amount of reinfused protein was 67.8 g (recovery rate, 72.0%). Performance status, dietary intake, urine volume, body weight and abdominal circumference were significantly improved after CART. Body temperature increased significantly, by 0.3°C on average. Concomitant steroids and/or NSAIDs use before reinfusion was significantly and negatively associated with increases in body temperature. Most adverse events were fever and chills. This study examined a large number of patients compared with previous studies, and showed that CART is an effective and relatively safe treatment for refractory ascites, such as malignant ascites.
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Kron S, Schneditz D, Leimbach T, Aign S, Kron J. Vascular Refilling Is Not Reduced in Dialysis Sessions with Morbid Events. Blood Purif 2017; 43:309-314. [DOI: 10.1159/000453441] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 11/15/2016] [Indexed: 11/19/2022]
Abstract
Background: It is commonly believed that insufficient vascular refilling leads to hypovolemia during hemodialysis and contributes to intradialytic morbid events (IME). But data of refilling volumes at the time of IME are lacking. Methods: We compared the vascular refilling in 10 patients with IME with 14 stable patients with normal blood volume at the dialysis end (66-80 mL/kg). Results: The refilling characteristics in patients with IME did not differ from those in stable patients. The refilling fraction (refilling/ultrafiltration [UF] ratio) was 73.8 ± 9.4% in patients with IME, and 70.2 ± 6.4% in patients with normal blood volume at the end of the treatment. Refilling volume strongly correlated with UF volume in both patient groups (r2 = 0.93 and r2 = 0.81, respectively). Conclusion: IME are associated with a specific blood volume below 65 mL/kg. Vascular refilling is a constant fraction of UF in stable as well as in symptomatic dialysis sessions.
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Bourdenx JP, Fartoux L. Place des « outils embarqués » (BVM et BTM) dans la prise en charge de la surcharge hydro-sodée. Nephrol Ther 2016; 12:S17-S19. [DOI: 10.1016/s1769-7255(17)30023-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Assimon MM, Wenger JB, Wang L, Flythe JE. Ultrafiltration Rate and Mortality in Maintenance Hemodialysis Patients. Am J Kidney Dis 2016; 68:911-922. [PMID: 27575009 DOI: 10.1053/j.ajkd.2016.06.020] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 06/14/2016] [Indexed: 12/23/2022]
Abstract
BACKGROUND Observational data have demonstrated an association between higher ultrafiltration rates and greater mortality among hemodialysis patients. Prior studies were small and did not consider potential differences in the association across body sizes and other related subgroups. No study has investigated ultrafiltration rates normalized to anthropometric measures beyond body weight. Also, potential methodological shortcomings in prior studies have led to questions about the veracity of the ultrafiltration rate-mortality association. STUDY DESIGN Retrospective cohort. SETTING & PARTICIPANTS 118,394 hemodialysis patients dialyzing in a large dialysis organization, 2008 to 2012. PREDICTORS Mean 30-day ultrafiltration rates were dichotomized at 13 and 10mL/h/kg, separately and categorized using various cutoff points. Ultrafiltration rates normalized to body weight, body mass index, and body surface area were investigated. OUTCOMES All-cause mortality. MEASUREMENTS Multivariable survival models were used to estimate the association between ultrafiltration rate and all-cause mortality. RESULTS At baseline, 21,735 (18.4%) individuals had ultrafiltration rates > 13mL/h/kg and 48,529 (41.0%) had ultrafiltration rates > 10mL/h/kg. Median follow-up was 2.3 years, and the mortality rate was 15.3 deaths/100 patient-years. Compared with ultrafiltration rates ≤ 13mL/h/kg, ultrafiltration rates > 13mL/h/kg were associated with greater mortality (adjusted HR, 1.31; 95% CI, 1.28-1.34). Compared with ultrafiltration rates ≤ 10mL/h/kg, ultrafiltration rates > 10mL/h/kg were associated with greater mortality (adjusted HR, 1.22; 95% CI, 1.20-1.24). Findings were consistent across subgroups of sex, race, dialysis vintage, session duration, and body size. Higher ultrafiltration rates were associated with greater mortality when normalized to body weight, body mass index, and body surface area. LIMITATIONS Residual confounding cannot be excluded given the observational study design. CONCLUSIONS Regardless of the threshold implemented, higher ultrafiltration rate was associated with greater mortality in the overall study population and across key subgroups. Randomized controlled trials are needed to investigate whether ultrafiltration rate reduction improves clinical outcomes.
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Affiliation(s)
- Magdalene M Assimon
- University of North Carolina Kidney Center, Division of Nephrology and Hypertension, Department of Medicine, UNC School of Medicine, Chapel Hill, NC; Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, NC
| | - Julia B Wenger
- University of North Carolina Kidney Center, Division of Nephrology and Hypertension, Department of Medicine, UNC School of Medicine, Chapel Hill, NC
| | - Lily Wang
- Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, NC; Cecil G. Sheps Center for Health Services Research, University of North Carolina, Chapel Hill, NC
| | - Jennifer E Flythe
- University of North Carolina Kidney Center, Division of Nephrology and Hypertension, Department of Medicine, UNC School of Medicine, Chapel Hill, NC; Cecil G. Sheps Center for Health Services Research, University of North Carolina, Chapel Hill, NC.
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Flythe JE. Ultrafiltration Rate Clinical Performance Measures: Ready for Primetime? Semin Dial 2016; 29:425-434. [DOI: 10.1111/sdi.12529] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jennifer E. Flythe
- Department of Medicine; Division of Nephrology and Hypertension; UNC School of Medicine; University of North Carolina Kidney Center; Chapel Hill North Carolina
- The Cecil G. Sheps Center for Health Services Research; University of North Carolina; Chapel Hill North Carolina
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Pietribiasi M, Waniewski J, Załuska A, Załuska W, Lindholm B. Modelling Transcapillary Transport of Fluid and Proteins in Hemodialysis Patients. PLoS One 2016; 11:e0159748. [PMID: 27483369 PMCID: PMC4970790 DOI: 10.1371/journal.pone.0159748] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/07/2016] [Indexed: 11/18/2022] Open
Abstract
Background The kinetics of protein transport to and from the vascular compartment play a major role in the determination of fluid balance and plasma refilling during hemodialysis (HD) sessions. In this study we propose a whole-body mathematical model describing water and protein shifts across the capillary membrane during HD and compare its output to clinical data while evaluating the impact of choosing specific values for selected parameters. Methods The model follows a two-compartment structure (vascular and interstitial space) and is based on balance equations of protein mass and water volume in each compartment. The capillary membrane was described according to the three-pore theory. Two transport parameters, the fractional contribution of large pores (αLP) and the total hydraulic conductivity (LpS) of the capillary membrane, were estimated from patient data. Changes in the intensity and direction of individual fluid and solute flows through each part of the transport system were analyzed in relation to the choice of different values of small pores radius and fractional conductivity, lymphatic sensitivity to hydraulic pressure, and steady-state interstitial-to-plasma protein concentration ratio. Results The estimated values of LpS and αLP were respectively 10.0 ± 8.4 mL/min/mmHg (mean ± standard deviation) and 0.062 ± 0.041. The model was able to predict with good accuracy the profiles of plasma volume and serum total protein concentration in most of the patients (average root-mean-square deviation < 2% of the measured value). Conclusions The applied model provides a mechanistic interpretation of fluid transport processes induced by ultrafiltration during HD, using a minimum of tuned parameters and assumptions. The simulated values of individual flows through each kind of pore and lymphatic absorption rate yielded by the model may suggest answers to unsolved questions on the relative impact of these not-measurable quantities on total vascular refilling and fluid balance.
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Affiliation(s)
- Mauro Pietribiasi
- Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
- * E-mail:
| | - Jacek Waniewski
- Institute of Biocybernetics and Biomedical Engineering, Warsaw, Poland
| | - Alicja Załuska
- Department of Rehabilitation and Physiotherapy, Medical University of Lublin, Lublin, Poland
| | - Wojciech Załuska
- Department of Nephrology, Medical University of Lublin, Lublin, Poland
| | - Bengt Lindholm
- Baxter Novum and Renal Medicine, Karolinska Institutet, Stockholm, Sweden
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Mitsides N, Mitra S, Cornelis T. Clinical, patient-related, and economic outcomes of home-based high-dose hemodialysis versus conventional in-center hemodialysis. Int J Nephrol Renovasc Dis 2016; 9:151-9. [PMID: 27462173 PMCID: PMC4940011 DOI: 10.2147/ijnrd.s89411] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Despite technological advances in renal replacement therapy, the preservation of health and quality of life for individuals on dialysis still remains a challenge. The high morbidity and mortality in dialysis warrant further research and insight into the clinical domains of the technique and practice of this therapy. In the last 20 years, the focus of development in the field of hemodialysis (HD) has centered around adequate removal of urea and other associated toxins. High-dose HD offers an opportunity to improve mortality, morbidity, and quality of life of patients with end-stage kidney disease. However, the uptake of this modality is low, and the risk associated with the therapy is not fully understood. Recent studies have highlighted the evidence base and improved our understanding of this technique of dialysis. This article provides a review of high-dose and home HD, its clinical impact on patient outcome, and the controversies that exist.
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Affiliation(s)
- Nicos Mitsides
- Department of Renal Medicine, Manchester Royal Infirmary, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Center, Manchester; National Institute for Healthcare Research Devices for Dignity Healthcare Co-operative, Sheffield, UK
| | - Sandip Mitra
- Department of Renal Medicine, Manchester Royal Infirmary, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Center, Manchester; National Institute for Healthcare Research Devices for Dignity Healthcare Co-operative, Sheffield, UK
| | - Tom Cornelis
- Department of Nephrology, Jessa Hospital, Hasselt, Belgium
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Yashiro M, Ochiai M, Yanai Y, Kotera H, Iehara N. Patient-Specific Relationship Between Hydraulic Permeability of Microvasculature and the Extent of Burden of Excess Fluid in Hemodialysis Patients. Ther Apher Dial 2016; 20:492-500. [DOI: 10.1111/1744-9987.12414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 01/08/2016] [Accepted: 01/13/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Masatomo Yashiro
- Division of Medical Engineering, Faculty of Medical Care Sciences; Himeji Dokkyo University; Hyogo Japan
| | - Miyuki Ochiai
- Division of Nephrology; Kyoto City Hospital; Kyoto Japan
| | - Yuko Yanai
- Division of Nephrology; Kyoto City Hospital; Kyoto Japan
| | - Hirohisa Kotera
- Division of Medical Engineering, Faculty of Medical Care Sciences; Himeji Dokkyo University; Hyogo Japan
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Kron S, Schneditz D, Leimbach T, Aign S, Kron J. Vascular refilling is independent of volume overload in hemodialysis with moderate ultrafiltration requirements. Hemodial Int 2016; 20:484-91. [DOI: 10.1111/hdi.12417] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Susanne Kron
- Department of Nephrology; Charité Universitätsmedizin Berlin; Berlin Germany
| | - Daniel Schneditz
- Institute of Physiology, Medical University of Graz; Graz Austria
| | - Til Leimbach
- KfH Kidney Center Berlin-Köpenick; Berlin Germany
| | - Sabine Aign
- KfH Kidney Center Berlin-Köpenick; Berlin Germany
| | - Joachim Kron
- KfH Kidney Center Berlin-Köpenick; Berlin Germany
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Blood Volume Changes Induced By Low-Intensity Intradialytic Exercise in Long-Term Hemodialysis Patients. ASAIO J 2016; 62:190-6. [PMID: 26720736 DOI: 10.1097/mat.0000000000000320] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Intradialytic exercise-induced blood volume (BV) reduction may cause intradialytic hypotension in hemodialysis (HD) patients. However, BV recovery time after intradialytic exercise remains unknown. Hemodialysis patients were recruited, and their relative BV change (%ΔBV) were measured with intradialytic exercise (n = 12). After confirming the linearity of %ΔBV for 30 min, patients exercised using a stationary cycle in the supine position. The target exercise intensity was a 10% increase in heart rate (HR), corresponding to relatively low-intensity exercise. Baseline %ΔBV (assumed baseline) were calculated for the 30 min before exercise using linear regression analysis. The mean intradialytic exercise start and end times after HD initiation were 93.0 ± 8.4 and 116.4 ± 8.3 min, respectively, a mean exercise duration of 23.5 ± 2.6 min. Percentage change in blood volume declined rapidly upon exercise initiation and gradually increased above the assumed baseline throughout HD. At the end of HD, %ΔBV in the exercise group was significantly higher than the assumed baseline (measured - assumed baseline %ΔBV: 2.17 ± 0.62%; p = 0.02). Intradialytic exercise with low intensity in the supine position attenuated ultrafiltration-induced BV reduction at the end of HD. Therefore, intradialytic exercise may prevent intradialytic hypotension during later HD, although its intensity was relatively low level.
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Schneditz D, Ribitsch W, Schilcher G, Uhlmann M, Chait Y, Stadlbauer V. Concordance of absolute and relative plasma volume changes and stability of Fcells in routine hemodialysis. Hemodial Int 2016; 20:120-8. [PMID: 26246366 PMCID: PMC4937455 DOI: 10.1111/hdi.12338] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Central hematocrit (H) measurements are currently used to track the degree of ultrafiltration-induced hemoconcentration with the aim to detect and prevent excessive intravascular fluid depletion during hemodialysis (HD). Failure to maintain hemodynamic stability is commonly attributed to the misinterpretation of H caused by an unaccountable increase in Fcells , the ratio of whole-body hematocrit to H. It was the aim to examine Fcells under everyday conditions in a group of stable HD patients. Absolute plasma volume (Vp ) and H were concomitantly measured during routine HD in the extracorporeal system in hourly intervals by noninvasive and continuous technology (CritLine-Instrument-III) and indocyanine green dye dilution to derive relative plasma volumes from Vp and H (RPVp , RPVH ), respectively, and to calculate Fcells . Thirteen patients were studied during two midweek treatments (n = 26). Both absolute Vp (P < 0.05) and relative plasma volumes RPVH (P < 0.001) decreased during HD. Vp at any time point was positively correlated to RPVH (r = 0.52). Moreover, relative plasma volumes RPVH and RPVp determined by independent techniques were identical and showed negligible bias (-0.2%) but considerable limits of agreement (-15.6% to +15.3%). Fcells was stable and in the range of 0.9 ± 0.05 throughout HD and not different from the value assumed at the beginning of HD. Although Fcells remains constant in patients on routine dialysis and relative plasma volumes (RPVH and RPVp ) determined by independent techniques are therefore comparable, the variability of experimental conditions during dialysis and the limited accuracy of absolute volume measurements using available technology continues to complicate the ultrafiltration control problem.
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Affiliation(s)
- Daniel Schneditz
- Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Werner Ribitsch
- Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Gernot Schilcher
- Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Matthias Uhlmann
- Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Yossi Chait
- Department of Mechanical & Industrial Engineering, University of Massachusetts, Amherst, MA, USA
| | - Vanessa Stadlbauer
- Division of Gastroenterology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
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48
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Increased Hepato-Splanchnic Vasoconstriction in Diabetics during Regular Hemodialysis. PLoS One 2015; 10:e0145411. [PMID: 26713734 PMCID: PMC4695079 DOI: 10.1371/journal.pone.0145411] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 12/03/2015] [Indexed: 11/19/2022] Open
Abstract
Background and Objectives Ultrafiltration (UF) of excess fluid activates numerous compensatory mechanisms during hemodialysis (HD). The increase of both total peripheral and splanchnic vascular resistance is considered essential in maintaining hemodynamic stability. The aim of this study was to evaluate the extent of UF-induced changes in hepato-splanchnic blood flow and resistance in a group of maintenance HD patients during regular dialysis. Design, Setting, Participants, & Measurements Hepato-splanchnic flow resistance index (RI) and hepato-splanchnic perfusion index (QI) were measured in 12 chronic HD patients using a modified, non-invasive Indocyaningreen (ICG) dilution method. During a midweek dialysis session we determined RI, QI, ICG disappearance rate (kICG), plasma volume (Vp), hematocrit (Hct), mean arterial blood pressure (MAP) and heart rate (HR) at four times in hourly intervals (t1 to t4). Dialysis settings were standardized and all patient studies were done in duplicate. Results In the whole study group mean UF volume was 1.86 ± 0.46 L, Vp dropped from 3.65 ± 0.77L at t1 to 3.40 ± 0.78L at t4, and all patients remained hemodynamically stable. In all patients RI significantly increased from 12.40 ± 4.21 mmHg∙s∙m2/mL at t1 to 14.94 ± 6.36 mmHg∙s∙m2/mL at t4 while QI significantly decreased from 0.61 ± 0.22 at t1 to 0.52 ± 0.20 L/min/m2 at t4, indicating active vasoconstriction. In diabetic subjects, however, RI was significantly larger than in non-diabetics at all time points. QI was lower in diabetic subjects. Conclusions In chronic HD-patients hepato-splanchnic blood flow substantially decreases during moderate UF as a result of an active splanchnic vasoconstriction. Our data indicate that diabetic HD-patients are particularly prone to splanchnic ischemia and might therefore have an increased risk for bacterial translocation, endotoxemia and systemic inflammation.
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49
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A physiologically based model of vascular refilling during ultrafiltration in hemodialysis. J Theor Biol 2015; 390:146-55. [PMID: 26643943 DOI: 10.1016/j.jtbi.2015.11.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 10/27/2015] [Accepted: 11/03/2015] [Indexed: 11/22/2022]
Abstract
An assessment of fluid status can be obtained by monitoring relative blood volume (RBV) during hemodialysis (HD) treatment. The dynamics of RBV is determined by fluid removal from the intravascular compartment by ultrafiltration (UF) and vascular refill from the interstitium. To characterize this dynamics, a two-compartment model describing the short-term dynamics of vascular refilling and UF is developed. Fluid movement between the compartments is governed by lymphatic and microvascular fluid shifts. Further, protein flux is described by convection, diffusion and the lymphatic protein flux. Patient specific parameters are identified based on hematocrit (Hct) measurements by the Crit-Line monitor (CLM). Different measurement frequencies and UF profiles are compared to determine data fidelity and influence on the quality of parameter estimates. This relevant information can be used to assess the (patho)physiological status of hemodialysis patients and could aid in individualizing therapy.
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50
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Morales-Alvarez R, Martínez-Memije R, Becerra-Luna B, García-Paz P, Infante O, Palma-Ramírez A, Caviedes-Aramburu A, Vargas-Barrón J, Lerma C, Pérez-Grovas H. Hemodynamic Response to Hemodialysis With Ultrafiltration Rate Profiles Either Gradually Decreasing or Gradually Increasing. Artif Organs 2015; 40:684-91. [DOI: 10.1111/aor.12628] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ricardo Morales-Alvarez
- Departamento de Nefrología; Instituto Nacional de Cardiología Ignacio Chávez; México City México
| | - Raúl Martínez-Memije
- Departamento de Instrumentación Electromecánica; Instituto Nacional de Cardiología Ignacio Chávez; México City México
| | - Brayans Becerra-Luna
- Departamento de Instrumentación Electromecánica; Instituto Nacional de Cardiología Ignacio Chávez; México City México
| | - Paola García-Paz
- Departamento de Instrumentación Electromecánica; Instituto Nacional de Cardiología Ignacio Chávez; México City México
| | - Oscar Infante
- Departamento de Instrumentación Electromecánica; Instituto Nacional de Cardiología Ignacio Chávez; México City México
| | - Alfredo Palma-Ramírez
- Departamento de Nefrología; Instituto Nacional de Cardiología Ignacio Chávez; México City México
| | - Amaya Caviedes-Aramburu
- Departamento de Nefrología; Instituto Nacional de Cardiología Ignacio Chávez; México City México
| | - Jesús Vargas-Barrón
- Dirección de Investigación; Instituto Nacional de Cardiología Ignacio Chávez; México City México
| | - Claudia Lerma
- Departamento de Instrumentación Electromecánica; Instituto Nacional de Cardiología Ignacio Chávez; México City México
| | - Héctor Pérez-Grovas
- Departamento de Nefrología; Instituto Nacional de Cardiología Ignacio Chávez; México City México
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