Degree Of Overhydration Research Articles

Association between muscle strength and echogenicity using greyscale ultrasound software: a diagnostic accuracy study in kidney transplant candidates.

Advanced chronic kidney disease disrupts the delicate equilibrium between protein anabolism and catabolism, leading to alterations in muscle quantity, quality, and function. Musculoskeletal ultrasound emerges as a promising assessment tool due to its widespread availability and high reliability. To evaluate the efficacy of rectus femoris (RF) echogenicity, measured using greyscale software, in identifying diminished muscle quality and strength in candidates for kidney transplant. Post-hoc diagnostic accuracy study. Outpatients in a multimodal prehabilitation program pre kidney transplantation (KT). Patients on the waiting list for KT. Sensitivity, specificity, likelihood ratios and area under the curve (AUC) for diagnostic efficacy of echogenicity (index test) assessed with the ImageJ software greyscale as a potential marker of quadriceps muscle weakness (reference test) were calculated. Muscle weakness was considered as maximal voluntary isometric contraction of the quadriceps (Q-MVIC) <40% of body weight. Other variables included body composition parameters derived from multifrequency electrical bioimpedance, upper limb muscle strength (handgrip), and RF thickness assessed by ultrasound. Chi-square, t-Student, Pearson correlation coefficients (r), bivariate and multivariate logistic regression models. Statistical significance level ≤0.05. Of 112 patients (mean age: 63.6, 76% male), 72 (63.7%) exhibited quadriceps weakness, while 80 (70.8%) had some degree of overhydration (extracellular water/total body water ratio >0.390). The echogenicity cut-off point of highest concordance with muscle weakness was 70, boasting a sensitivity of 83%, specificity of 57%, and AUC of 0.671 (CI 95% 0.570-0.772 [P=0.003]). Echogenicity >70 was associated with a 3.4-fold higher risk of muscle weakness (crude OR = 3.4 [CI95% 1.4 to 8.0]), which persisted after adjusting for age, height, weight and RF thickness. The RF echogenicity exhibits fair validity in identifying muscle weakness among candidates for KT. However, it cannot be endorsed as a standalone diagnostic tool in this population. Early identification of muscle weakness would advance efforts to mitigate morbidity and mortality through targeted measures.

#1319 “Peritoneal volume influence on bedside ultrasound or point-of-care ultrasonography (POCUS) volume assessment in peritoneal dialysis patients”

Abstract Background and Aims To study the variations in hydrosaline overload ultrasound parameters using PoCUS in PD patients with full and drained peritoneum and their correlation with clinical parameters. Method PoCUS and intra-abdominal pressure (IAP) measurements were performed on included patients with a full peritoneum. After drainage, a new PoCUS and a bioimpedance analysis (BIA) were conducted. Results Seventeen patients were included: 70.6% male, mean age 66 ± 9.5 years. 65% had hydrosaline overload &amp;gt;1L as assessed by BIA. The mean IAP was 15 ± 3.9 mmHg. The maximum diameter of the IVC with full and drained peritoneum was 1.44 ± 0.35 cm and 1.53 ± 0.4 cm, respectively, with no significant difference (p = 0.179). The % collapsibility of IVC with full and drained peritoneum was 49 ± 23% and 47 ± 13%, respectively, with no significant difference (p = 0.58). Kerley B-lines with full peritoneum were 1.3 ± 1.5, and with drained peritoneum were 0.71 ± 1.16, with this difference approaching statistical significance (p = 0.063). The same analyses in subgroups of patients with volume overload by BIA (OH&amp;gt;1 or OH/ECW&amp;gt;15%) did not show significant differences. In the correlation analysis of variables, IAP and peritoneal dialysis fluid volume per m2 of body surface did not correlate with the diameters or collapsibility of IVC with full or drained peritoneum. The degree of overhydration by OH (L) correlated with IVC collapsibility with drained peritoneum (Spearman ρ = −0.43; p = 0.08), as did the overhydration by OH/ECW (Spearman ρ = −0.61; p = 0.02). These correlations disappeared with full peritoneum (p &amp;gt; 0.05). The same correlation analyses were performed in subgroups of patients with volume overload by BIA (OH&amp;gt;1L or OH/ECW&amp;gt;15%) and were not significant with either full or drained peritoneum. Conclusion We did not find significant differences in the ultrasound volume overload parameters with full vs. drained peritoneum in PD patients. However, indirect data indicate a lower sensitivity of PoCUS to hydrosaline overload with a full peritoneum.

Bioimpedance Spectroscopy Reveals Important Association of Fluid Status and T1 -Mapping by Cardiovascular Magnetic Resonance.

Extracellular matrix expansion is a key pathophysiologic feature in heart failure and can be quantified noninvasively by cardiac magnetic resonance T1 -mapping. Free water within the interstitial space of the myocardium, however, may also alter T1 -mapping results. To investigate the association between systemic fluid status and T1 -mapping by cardiac magnetic resonance. Prospective, observational single-center study. Two-hundred eighty-five consecutive patients (44.4% female, 70.0 ± 14.9 years old) scheduled for cardiac MR due to various cardiac diseases. 1.5-T scanner (Avanto Fit, Siemens Healthineers, Erlangen, Germany). For T1 -mapping, electrocardiographically triggered modified-Look-Locker inversion (MOLLI) recovery sequence using a 5(3)3 prototype on a short-axis mid-cavity slice and with a four-chamber view was performed. MR parameters including native myocardial T1 -times using MOLLI and extracellular volume (MR-ECV) were assessed, and additionally, we performed bioimpedance analysis (BIA). Furthermore, demographic data and comorbidities were assessed. Wilcoxon's rank-sum test, chi-square tests, and for correlation analysis, Pearson's correlation coefficients were used. Regression analyses were performed to investigate the association between patients' fluid status and T1 -mapping results. A P-value <0.05 was considered statistically significant. The mixed cohort presented with a mean overhydration (OH) of +0.2 ± 2.4liters, as determined by BIA. By MR, native T1 -times were 1038 ± 51 msec and MR-ECV was 31 ± 9%. In the multivariable regression analysis, only OH was significantly associated with MR-ECV (adj. beta: 0.711; 95% CI: 0.28 to 1.14) along with male sex (adj. beta: 2.529; 95% CI: 0.51 to 4.55). In linear as well as multivariable analysis, only OH was significantly associated with native T1 times (adj. beta: 3.750; 95% CI: 1.27 to 6.23). T1 -times and MR-ECV were significantly associated with the degree of OH on BIA measurement. These effects were independent from age, sex, body mass index, and hematocrit. Patients' volume status may thus be an important factor when T1 -time and MR-ECV values are interpreted. 2 TECHNICAL EFFICACY STAGE: 3.

Overhydration as a modifiable cardiovascular risk factor in patients undergoing hemodialysis.

Introduction: Cardiovascular mortality in patients with end-stage renal disease (ESRD) remains high despite advances in dialysis techniques. This can be attributed to several traditional and nontraditional risk factors. Overhydration seems to be one of the promising cardiovascular risk factors that could be targeted to improve survival. Objectives: We aimed to assess the effect of chronic overhydration as well as changes in the degree of overhydration over time on cardiovascular and all-cause morbidity and mortality in patients undergoing hemodialysis. Patients and methods: We enrolled 511 patients with ESRD undergoing hemodialysis. The hydration status was assessed with whole-body bioimpedance spectroscopy. Patients were divided into 4 subgroups according to baseline hydration status. Additionally, patients with at least 2 follow-up visits (n = 277) were classified into 4 subgroups according to changes in the hydration status over time. Results: Statistical analysis showed that male sex (P <⁠0.001), diabetes (P <⁠0.001), cardiac insufficiency (P <⁠0.001), smoking (P = 0.049), and cerebrovascular events (P = 0.007) were significant risk factors for overhydration. Cardiovascular toxicity of overhydration was reflected by elevated levels of N-terminal pro-B-type natriuretic peptide (P <⁠0.001) and cardiac troponin T (P <⁠0.001). Albumin and total cholesterol levels were the lowest in patients with severe overhydration (P <⁠0.001). Mortality was lower in patients with normal hydration status and mild overhydration (P <⁠0.001) as well as in those with stable low or descending overhydration pattern (P = 0.002). Conclusions: We showed that the degree of overhydration is significantly associated with the incidence of cardiovascular complications and prognosis in patients with ESRD undergoing hemodialysis.

P1334PREOPERATIVE VOLUME STATUS IN VASCULAR ACCESS CREATION, A DESPISED INFLUENCE?

Abstract Background and Aims The most common causes of early primary failures of a vascular access (VA) is related to small caliber vessels. Weight gain between dialyses expands both extracellular and blood volume, which may lead to rises in intravascular filling and vessels caliber. If patients presented after weekend, their weight and probably volemia would be higher. Dry weight concept has evolved over time and nowadays incorporates objective measures of volume status like body bioimpedance spectroscopy (BIA) and lung ultrasound. We hypothesized that preoperative volume status may influence vascular filling and vessels diameter with a significant impact on VA outcomes. Method A clinical, prospective, randomized, open-label, single-center crossover trial. Inclusion criteria: age 18-80ys, under regular hemodialysis (3/week), no heart failure (CHF) and no acute pulmonar edema (APE) on the previous year. Exclusion criteria: &amp;gt;3 sessions/week, CHF or APE. Before the last-week session, patient’s clinical parameters were recorded. BIA and ultrasound vascular mapping were performed. After this first evaluation, dry weight was increased 0,5 Kg, and after weekend, the same protocol was conducted. Primary end point was to compare vein diameters. Results 126 vessels were evaluated (84 veins and 42 arteries) from 21 patients. Mean age was 69±10y and 52% female. Primary end point was achieved (Table 1). Other than humeral arterial blood flow, every parameters evaluated through ultrasound mapping significantly increased (p&amp;lt;0,05) after dry weight adjustment (&amp;gt;0,5 Kg) plus weekend weight gain. After cross over, weight, overhydration (OH), extracellular water (ECW) and OH/ECW significantly increased (p&amp;lt;0,05), however, most patients had a mild-moderate OH (86-90%). Blood pressure and total body water haven’t changed significantly. No complications were reported. Conclusion Some additional degree of OH comparing to midweek weight gain may be effective and safe in improving peripheral vascular conditions that are predictors of VA success. The currently lack of evidence of vascular mapping may be due to the lack of evaluation of cofactors such as volemia. Therefore, BIA and lung ultrasound may be future tools that combined to vascular ultrasound could be a safe and effective way to optimize and evaluate preoperative conditions to improve VA outcomes. Larger and multicentric studies are needed.

Preliminary observations on the association between serum IL-6 and hydration status and cardiovascular risk in patients treated with peritoneal dialysis

IntroductionSystemic inflammation, as defined by elevated blood IL-6, is a strong independent predictor of peritoneal dialysis (PD) patient survival. The present study has aimed to determine whether there exists a particular “phenotype” associated with high systemic IL-6 that characterizes PD patients in terms of their fluid status and cardiac parameters. MethodsFifty-seven prevalent PD patients were classified according to serum concentrations of IL-6. The degree of overhydration was assessed by bioimpedance analysis (BIA). Echocardiography and serum concentrations of NT-proBNP and troponin T were used to assess cardiovascular risk. ResultsPatients with high serum IL-6 were older, more often diabetic, treated with PD for longer, and significantly more overhydrated. There was a significant correlation between serum IL-6, hydration status (r=0.38; p=0.002) and serum albumin (r=−0.35; p=0.009). Multivariate regression analysis confirmed a strong association of overhydration, hypoalbuminemia, and systemic IL-6 concentration. Patients with high IL-6 had significantly increased levels of both NT-proBNP (r=0.36; p=0.006) and TnT (r=0.50; p<0.001) in the absence of abnormalities in echocardiography. ConclusionsHigh systemic IL-6 identifies PD patients with increased cardiovascular risk that is significantly related to overhydration. Thus, the measurement of serum IL-6 may contribute to the more accurate assessment of cardiovascular status in patients undergoing PD.

Bioimpedance Spectroscopy for the Detection of Fluid Overload in Chinese Peritoneal Dialysis Patients

Fluid overload probably contributes to the cardiovascular risk of peritoneal dialysis (PD) patients. We studied the relationship between over-hydration as determined by bioimpedance spectroscopy and dialysis adequacy, nutritional status, and arterial stiffness in Chinese PD patients. We studied 122 asymptomatic prevalent PD patients: bioimpedance spectroscopy, arterial pulse wave velocity, dialysis adequacy and nutritional status were determined. Of the 122 patients, 88 (72.1%) had over-hydration of ≥ 1 L, while 25 (20.5%) were ≥ 5 L. Over-hydration significantly correlated with total body water (r = 0.474, p < 0.001) and extracellular water (r = 0.755, p < 0.001). Over-hydration was more severe in male and diabetic patients, and significantly correlated with Charlson's comorbidity score, blood pressure, body mass index, body weight, peritoneal transport characteristics, and carotid-femoral pulse wave velocity. Over-hydration significantly correlated with Kt/V (r = -0.287, p = 0.016), serum albumin level (r = -0.465, p < 0.001) and malnutrition inflammation score (r = 0.410, p = 0.006), but not residual renal function. Over-hydration is common in asymptomatic Chinese PD patients. The degree of over-hydration is particularly pronounced in patients who are inadequately dialyzed, have multiple comorbid conditions and low serum albumin levels. Over-hydration is associated with high blood pressure and arterial stiffness, and may contribute to the excessive risk of cardiovascular disease in this group of patients.

Volume Status in Patients on Peritoneal Dialysis: The Role of Apelin and Bio-Impedance Spectroscopy

One of the main factors determining the survival of peritoneal dialysis (PD) patients is volume status. We aimed to investigate hydration status of PD patients by bio-impedance spectroscopy (BIS) and echocardiography and to study the relation of them with apelin, which has effects related with volume status like vasodilation, positive inotropism, and inhibition of ADH release and RAS antagonism. Chronic PD patients without active cardiac disease or clinically prominent hypervolemia were included. Besides the demographic, clinical, and laboratory data, BIS and echocardiographic findings together with apelin levels were recorded. The study included 21 patients. Of them, eight patients were euvolemic, one patient was hypovolemic, and others have some degree of overhydration (1.1–6.8 L) with BIS, although all were euvolemic clinically. Mean apelin level was 1.49 ± 0.49 ng/mL. Apelin level was positively correlated with ejection fraction and negatively with total body water (TBW), intracellular and extracellular water, lean tissue mass, and left atrium diameter. On linear regression model, TBW was the major determinant of apelin. Although apelin is expected to increase in hypervolemic patients, the negative correlation with body water in this study may be related with yet unknown role of apelin in dialyzed patients. They may have important roles in volume status in future.

Dehydration Prevents The Development Of Hyponatremic Encephalopathy During Exercise

PURPOSE The aim of this study was to evaluate the possible roles of dehydration or, conversely, overhydration in the etiology of exertional hyponatremic encephalopathy. METHODS Bodyweight changes and post race serum sodium concentrations ([Na+]) were collected from 1423 athletes competing in endurance events on three continents: the 2000–2001 SA 226 km Ironman triathlon, 1997 NZ 226 km Ironman triathlon, 2001–2003 Houston marathon (USA), 2002 Christchurch marathon (NZ) and 109 km Argus Cycle Tour (SA). Data were grouped according to serum [Na+] levels into hypernatremia (> 145mmol/L), normonatremia (< 145 >135mmol/L), biochemical hyponatremia (< 134 >130mmol/L), borderline hyponatremia (<129>128mmol/L) and symptomatic hyponatremia (<128mmol/L). The degree of overhydration (> +0.00 kg weight gain), euhydration (0.01 to −2.49 kg weight loss) and dehydration (>-2.5 kg weight loss) defined overall fluid balance from pre to post race. RESULTS Almost all (95%) athletes completed these races either euhydrated (45%) or mildly dehydrated (50%) with normal (82%) or elevated (11 %) serum [Na+]. There was a significant inverse relationship between body weight gain during exercise and the post-race serum [Na+] so that increasingly more severe hyponatremia accompanied higher levels of weight gain during exercise (r = 0.40; p <0.0001). Thirty-two (2% of the sample) subjects had post-race serum [Na+] below 130mmol/L; 30 were either overhydrated (26 athletes) or euhydrated (4 athletes) and only 2 athletes with hyponatremia (0.14% of the total sample) lost more than 2.5 kg and were therefore probably dehydrated. Of the 25 subjects with symptomatic hyponatremia, 22 were overhydrated after exercise, two lost less than 800 g during exercise and one with mild hyponatremia lost 3.7 kg. CONCLUSION These data confirm that the vast majority of athletes finish prolonged competitive athletic events without either significant dehydration or overhydration and with normal serum [Na+]. Overdrinking sufficient to cause weight gain during exercise was increasingly likely to cause hyponatremia leading to hyponatremic encephalopathy in those with the greatest weight gains during exercise. In contrast, dehydration was associated with hypernatremia and protection from clinically significant hyponatremic encephalopathy. Hence dehydration and the avoidance of overdrinking protects against hyponatremic Encephalopathy

PERITONEAL ULTRAFILTRATION(UF)WITH EXTRANEAL® FOR OVERHYDRATION DUE TO CONGESTIVE HEART FAILURE (CHF) AND NEPHROTIC SYNDROME

Congestive heart failure unresponsive to maximal drug treatment has been known to benefit from UF. We wish to report our experience with peritoneal UF using Extraneal®. Eight patients with severe CHF (NYHA stages III in 3 and IV in 5 with ejection fractions under 30% in all), and one with diabetic nephrotic syndrome, unresponsive to dietary and drug treatments (ACE-I, diuretics, digitalis, vasodilators) were offered to try Extraneal® therapy after informed consent. Three of them had normal renal function while six had various degrees of renal impairment (creatinine clearances ranging from 25 to 60 ml/min.). The causes of CHF were diabetic and ischemic cardiomyopathies in 1 and 7 patients, respectively. Depending on the level of renal function (< or ± 50 ml/mm) and on the degree of overhydration, one or two 2 L exchanges were applied with dwells of 24 or 12 hrs, respectively. Resulting daily ultrafiltration varied from 750 to 1400 ml, achieving a weight loss of 4 to 6.3 kg during the first week. Thereafter, UF was adapted to the desired weight loss (maximum: 20 kg over 1 month). No significant hypotension occurred despite a basal BP no higher than 115/60 mm Hg. Four patients progressed to more severe renal failure needing 3 or more glucose exchanges, 3 patients did regain enough compensation to stop UF, and one received a successfull heart transplantation after 29 months. There were 4 episodes of peritonitis over 100 patients-months. Hospitalisation rate was reduced from 1.5/month in the 6 months before UF to 0.2/month over the mean 12 months of follow-up. There were no side effects of Extraneal®. In conclusion, UF with Extraneal® is practical (1 or 2 manipulations per day), efficient and well-tolerated. It can improve possibly survival and certainly quality of life in patients with severe CHF or nephrotic syndrome.

Continuous Blood Volume Monitoring and Ultrafiltration Control.

Continuous blood volume monitoring (CBVM) is believed to be a promising method for making the determination of patients' "dry weight" more objective, and ultrafiltration (UF) control more appropriate. Although blood volume response to UF and the interrelation between blood volume changes and changes in hemodynamic parameters are highly individual, certain principles of this response and interrelation can be identified and exploited for effective use of CBVM. The present work summarizes the authors' findings from practical CBVM application over the past 5 years and their opinions on the future development of this method. Four distinct types of blood volume response to constant UF rate were identified: Type 1, flat line throughout the whole session; Type 2, flat line during the first part of dialysis, followed by a linear decrease during the remaining time; Type 3, linear decrease right from dialysis start; and Type 4, linear decrease first, followed by a flat line during the remaining time. The possibility of a shift from one type to the other was verified. Blood volume reduction due to UF was found to have a static and a dynamic component. The most important factors affecting both components were found to be, by sensitivity analysis of a three-pool kinetic model, degree of overhydration, vascular system compliance, and UF volume (for the static component); and UF coefficient of the capillary wall and UF rate (for the dynamic component). Type 3 response, induced by more vigorous UF, was found to significantly decrease the volume of residual daily diuresis on the first postdialysis day. If confirmed, this finding may serve as a basis for the response type choice in patients with still significant residual renal function. Exploitation of the existence of dynamic blood volume reduction component for the first generation of automated biofeedback UF controllers may be complemented by automated identification of patient's plasma refilling capacity and/or position of his/her point on the Guytonian pressure/volume characteristics curves, and thus may more advanced "intelligent" UF controllers be constructed in the future.

Dialysis schedule-related fluid state and cardiovascular effects.

[2]. Furthermore, a paradoxical increase in blood Introduction pressure during ultrafiltration in HD patients can occur in the presence of overhydration [3]. Overhydration The oscillation of the fluid state in anuric patients is can lead to a wide spectrum of cardiac changes dependent on the type of dialysis, which has to mimic depending on the pre-existing cardiac state: hypercirexcretory renal function. Typically, in haemodialysis culation, characterized by an increased cardiac output, (HD), patients’ fluid state is in a continuous disequilibcan be one sequela. Another reaction pattern can be rium characterized by a rapid reduction during dialysis cardiac dilatation, characterized by increases in the and a slow increase between dialysis sessions. Maxima diameters of the vena cava, right atrium, left atrium and minima of the cyclic fluctuations of body water and right and left ventricles [4]. (and sodium) are determined by the physician’s preIn some patients with end-stage renal failure, cardiac scription (target weight) and by the drinking and enlargement associated with a reduced left ventricle eating habits of the patients (pre-dialysis weight). Both (LV ) function can be present without other evidence extremes of fluid state have to be compensated by the of hyperhydration. Initiation of dialysis and water cardiovascular system of dialysis patients, which freremoval to normovolaemia can regress cardiac quently is in an abnormal state. Typical cardiovascular dilatation and restore normal cardiac function. complications can occur originating from all three Symptoms of hypovolaemia most frequently occur determinants: dialysis target weight can be erroneous during or immediately post-haemodialysis and ultraand the mode of the dialysis technique can be inadfiltration. Although plasma volume is an integral part equate; the fluid intake of the patients may overwork of the extracellular volume and the equilibrium the cardiovascular compensation capacity; and, finally, between the two compartments establishes eventually, a pathological cardiovascular system responds refilling of plasma volume takes some time and clearly differently to the stress of fluid fluctuation. depends on the degree of overhydration [5,6 ]. Primarily with high ultrafiltration rates, as necessitated Fluid-dependent signs and symptoms in short dialysis sessions, vascular underfilling can lead to ventricular underfilling and eventually to dialysis hypotension [7]. Thus, dialysis hypotension need not In chronic dialysis patients without acute disease, some necessarily be a consequence of hypovolaemia and an signs and symptoms occur at distinct phases of the incorrectly defined dialysis target weight. The same is fluid cycle. However, all signs and symptoms can have true for symptoms such as muscle cramps. On the a multi-factorial origin, and only in the case of other hand, suddenly occurring fatigue, low blood regression after fluid correction do they appear to be pressure, cramps and hypotension can be taken as specifically volume related. In the pre-dialysis phase, hypovolaemic signs when the dialysis schedule has not a patient frequently is hyperhydrated, which can been altered and has been tolerated without symptoms translate into sudden dyspnoea during exercise, while during preceding sessions. recumbent or while sitting, and this can culminate in The incidence of dysvolaemic periods in dialysis pulmonary oedema. Ankle or tibial oedema can be patients is virtually unknown. By clinical standards, present. Hypervolaemia is not the only cause of arterial only about half of the patients are in a state of hypertension in dialysis patients, albeit that it is the normohydration, about one-third are hypovolaemic most important and most frequent. It has been shown that salt loading increases the arterial pressure of and a quarter are hypervolaemic (Table 1). Whether patients with renal failure in contrast to healthy persons dysvolaemia is an independent risk factor in the pro[1], and that systolic blood pressure is significantly gnosis of dialysis patients still awaits further elucidaincreased during hypervolaemic periods in HD patients tion. There are three lines of indirect evidence that this may well be the case: Kramer et al. published data from the (at that time still incomplete) EDTA registry Correspondence and offprint requests to: Dr V. Wizemann, J.-S. Bachstrasse 40, D-35392, Giessen, Germany. of increased mortality in dialysis patients with excess

Computational Analysis of Blood Volume Dynamics during Hemodialysis

The recently introduced continuous blood volume monitoring (CBVM) technique enables real time observation of the blood volume (BV) response to ultrafiltration. This response differs quite widely among patients even under otherwise comparable conditions. Assessing the clinical recordings of over 100 CBVM measurements, identification of a static and a dynamic component of the overall BV reduction was made. Computational analysis of the factors that influence BV response variability was then performed by means of a three-pool model of sodium, potassium, and urea kinetics with the following results. The blood volume profile contains clinically highly interesting yet cumulative information. Except for the small change and flat BV profiles the static component is predominant. From the external factors, the static component of BV reduction during hemodialysis is influenced by the total ultrafiltered volume and by the degree of overhydration. From the patient's internal factors, compliance of his cardiovascular system is dominant. BV is also more reduced in patients with lower values of total plasma protein content and/or lower hematocrit. The BV reduction dynamic component is primarily influenced by the applied ultrafiltration rate. A certain influence is also exerted by the ultrafiltration coefficient of the capillary wall which may vary in different individuals.

Characteristic Profiles of Circulating Blood Volume During Dialysis Therapy

From continuous measurements of the hemoglobin concentration in the arterial blood line during 50 hemodialysis sessions in 20 stable dialysis patients, the influence of the amount of ultrafiltered fluid, the ultrafiltration rate, and overhydration of the patient upon the circulating blood volume was derived. If ultrafiltration is stopped, blood volume increases until equilibrium is obtained. The amount of refilling is proportional to the ultrafiltration rate [2.5%/(L/hr)]. The decrease of blood volume after re-equilibration depends upon the ultrafiltered amount and the degree of overhydration. The mean decrease of blood volume per liter of ultrafiltrate was found to be 5.5% for an average overhydration of 3 L.

Characteristic profiles of circulating blood volume during dialysis therapy.

From continuous measurements of the hemoglobin concentration in the arterial blood line during 50 hemodialysis sessions in 20 stable dialysis patients, the influence of the amount of ultrafiltered fluid, the ultrafiltration rate, and overhydration of the patient upon the circulating blood volume was derived. If ultrafiltration is stopped, blood volume increases until equilibrium is obtained. The amount of refilling is proportional to the ultrafiltration rate [2.5%/(L/hr)]. The decrease of blood volume after re-equilibration depends upon the ultrafiltered amount and the degree of overhydration. The mean decrease of blood volume per liter of ultrafiltrate was found to be 5.5% for an average overhydration of 3 L.