Volume Status In Hemodialysis Patients Research Articles

Monitorización hemodinámica no invasiva intradiálisis: utilidad de los valores de precarga cardiaca en la predicción de la inestabilidad hemodinámica

IntroductionAdequate control of patient blood volume in hemodialysis (HD) is essential as a modifiable risk factor for morbidity and mortality. In this study, we propose continuous non-invasive hemodynamic monitoring using bioreactance (Starling™ SV. Baxter) and real-time characterization of cardiac preload data to aid in the accurate assessment of volume status and improvement of tolerance in HD. MethodologyObservational and prospective study on the relationship between cardiac preload data and intradialytic hemodynamic instability. Forty-six stable HD patients were recruited. Clinical, analytical, and dialysis data were collected from all participants. The protocol included bioimpedance (BIVA), pre- and post-dialysis echocardiography and tissue Doppler, and monitoring of hemodynamic parameters during the session. ResultsAccording to the Fall20 definition, 24 patients (51.19%) experienced intradialytic hypotension (IDH). We found no relationship between IDH and analytical, echocardiographic, BIVA parameters, or relative blood volume measurement (BVM) values. Regarding hemodynamic monitoring, indexed systolic volume (ISV) was lower in patients with IDH (38.2±0.9 vs. 39.2±1.9; P<.001). Indexed systolic volume variation (ISVV) and heart rate (HR) were higher in the IDH group (14.1±0.7 vs. 13.5±0.7; P<.0001), (70.01±2.1 vs. 68.97±1.1; P<.0001), respectively. Indexed cardiac output (ICO) and indexed peripheral resistances (IPR) were also lower in the IDH group (2.62±0.09 vs. 2.65±0.13; P<.05) and (3201±325 vs. 3432±231; P<.05), respectively. Patients who started the session with lower preload (ΔSV after infusion of 250 cc ≥ 10%) more frequently developed IDH (P<.001). ConclusionsNon-invasive hemodynamic monitoring and preload data may constitute a valid tool in managing the volume status of HD patients and preventing IDH.

Lung Ultrasound to Assess Volume Status in Hemodialysis Patients: One-Center Experience

Lung Ultrasound to Assess Volume Status in Hemodialysis Patients: One-Center Experience

Prediction of Heart Function and Volume Status in End-Stage Kidney Disease Patients through N-Terminal Pro-Brain Natriuretic Peptide.

Background and Objectives: N-terminal pro-brain natriuretic peptide (NT-proBNP) is a biomarker used to predict heart failure and evaluate volume status in hemodialysis (HD) patients. However, it is difficult to determine the cutoff value for NT-proBNP in HD patients. In this study, we analyzed whether NT-proBNP helps predict heart function and volume status in HD patients. Materials and Methods: This prospective observational study enrolled 96 end-stage kidney disease patients with HD. All patients underwent echocardiography and bioimpedance spectroscopy (BIS) after an HD session. Overhydration (OH) was measured by BIS. Laboratory data were obtained preHD, while serum NT-proBNP was measured after HD. Interventions for blood pressure control and dry weight control were performed, and NT-proBNP was re-assessed after a month. Results: There was an inverse correlation between NT-proBNP and ejection fraction (EF) (β = −0.34, p = 0.001). OH (β = 0.331, p = 0.001) and diastolic dysfunction (β = 0.226, p = 0.027) were associated with elevated NT-proBNP. In a subgroup analysis of diastolic dysfunction grade, NT-proBNP increased according to dysfunction grade (normal, 4177 pg/mL [2637–10,391]; grade 1, 9736 pg/mL [5471–21,110]; and grades 2–3, 26,237 pg/mL [16,975–49,465]). NT-proBNP showed a tendency toward a decrease in the ‘reduced dry weight’ group and toward an increase in the ‘increased dry weight’ group compared to the control group (ΔNT-proBNP, −210 pg/mL [−12,899 to 3142], p = 0.104; 1575 pg/mL [−113 to 6439], p = 0.118). Conclusions: We confirmed that NT-proBNP is associated with volume status as well as heart function in HD patients.

Diagnostic Utility of Thoracic Ultrasound in Assessment of Volume Status of Haemodialysis Patients

Background: Optimizing volume status of hemodialysis patients is an important clinical challenge because volume expansion is a critical deadly complication of chronic kidney disease. The use of thoracic ultrasound to detect cases of volume overload and depletion has gained great attention by several studies that are because of its advantage as a rapid, available, non-invasive and free of radiation imaging method. Aim: To evaluate the usefulness of thoracic ultrasound for the assessment of extravascular lung water and intravascular volume in hemodialysis patients. Patients and Methods: This prospective observational study was conducted on 30 patients on regular hemodialysis. Assessment of extravascular lung water (EVLW) by number of B –lines, and intravascular volume by measurement of inferior vena cava (IVC) diameter and collapsibility index, was done pre- and post-dialysis. Results: There was statistically highly significant reduction in number of B-lines and highly significant decrease of IVC minimum and maximum diameters post-dialysis (P value < 0.001). There was also highly significant increase in IVC collapse index following hemodialysis (P value < 0.001). Conclusion: Lung ultrasound is a useful method for the assessment of both EVLW and intravascular volume. EVLW as represented by B-lines number was highly significantly reduced post-hemodialysis. Intravascular volume assessed by IVC ultrasound was improved by 53% following hemodialysis.

NT-ProBNP for Heart Function and Volume Status in Hemodialysis Patients

NT-ProBNP for Heart Function and Volume Status in Hemodialysis Patients

Association of Pulmonary Hypertension With Inflammatory Markers and Volume Status in Hemodialysis Patients of End-Stage Renal Disease.

Background and objectivesPulmonary hypertension (PH) is an independent risk factor for increased mortality, especially in patients undergoing hemodialysis (HD), but the mechanism of its development is unknown. This study aimed at evaluating volume overload and inflammation as potential variables to cause its development in patients undergoing maintenance hemodialysis.Materials and methodsThis was an observational cross-sectional study conducted on patients undergoing hemodialysis at a tertiary hospital in northern India. Patients of end-stage renal disease, aged 18 years or more, on maintenance hemodialysis for over two months were included in the study. The patients were divided into two groups based on the presence or absence of PH, determined by measuring systolic pulmonary arterial pressure (SPAP). The severity of PH was defined as: mild (SPAP 35-45 mmHg), moderate (SPAP 46-55 mmHg), and severe (SPAP> 55mmHg). The two groups were evaluated for demographic variables, type of vascular access, biochemical parameters, and markers of inflammation and fluid overload. Data between the two groups were compared statistically.ResultsThis study included a total of 82 patients showing the prevalence of PH to be 25.6% with a men-to-women ratio of 2:1. Out of 21 cases of PH, mild PH was found in seven (33.3%) cases, moderate in 14 (66.7%), and cases with severe PH were none. The two groups differed significantly in ejection fraction and markers of inflammation and volume status. Laboratory data associated with PH were alpha-1-acid glycoprotein (p<0.05) and pro-b-type natriuretic peptide (p <0.05).ConclusionThe present study showed higher levels of inflammatory markers alpha-1-acid glycoprotein and pro-b-type natriuretic peptide and lower levels of ejection fraction in patients undergoing HD, indicating a significant association with PH.

Association between Ultrafiltration Rate and Clinical Outcome Is Modified by Muscle Mass in Hemodialysis Patients

Background: The association between ultrafiltration rate (UFR) and mortality may be affected by the muscle mass or volume status in hemodialysis (HD) patients. However, there is an absence of data regarding this association. Methods: We performed an observational study on patients (≥18 years old) who had been on HD for at least 3 months. A body composition monitor (BCM) was used for baseline bioimpedance analysis measurement. The primary composite outcome was defined as the time to death or the first cardiovascular event. Results: The median (interquartile range) UFR, volume excess measured by the BCM, and lean tissue index (LTI) (calculated as lean tissue mass/height²) were 11.4 (8.0–15.0) mL/h/kg, 2.4 (1.4–4.1) L, and 12.5 (10.4–14.4) kg/m², respectively. During 284 person-years of follow-up, the primary outcome occurred in 44 of the 167 patients (26%). Higher UFR was associated with an increased outcome of death or cardiovascular event; the adjusted hazard ratio (HR) was 1.044 (95% confidence interval [CI]: 1.006–1.083). This association remained consistent even after adjusting for volume excess. However, the association between UFR and the primary outcome was modified by LTI (p_interaction = 0.027); the association was significant in patients with LTI < 12.5 kg/m², and the HR (95% CI) was 1.050 (1.001–1.102). Conclusion: Higher UFR was associated with an increased risk of a composite outcome of death or cardiovascular event regardless of volume status in HD patients. However, muscle mass may modify the association between higher UFR and increased risk of a composite outcome.

Chest Ultrasound as a New Tool for Assessment of Volume Status in Hemodialysis Patients.

Accurate assessment of volume status (VS) in hemodialysis (HD) patients is challenging. The use of chest ultrasound (CUS) for detection of extravascular lung water has recently gained wide acceptance. The aim of this study was to evaluate the use of CUS in VS assessment in HD patients in comparison to clinical and inferior vena cava (IVC) indices and to assess their relation with volume displacement after ultrafiltration. This prospective cohort study was carried out on 38 patients on regular HD. VS was assessed using a 13-point clinical score, and IVC indices and CUS score were measured pre- and post-ultrafiltration. Correlation between these parameters and with ultrafiltration volume was tested. There was a statistically significant reduction in post-ultrafiltration CUS score and the 13-point clinical score (P < 0.01). Moreover, reduction in all the IVC indices (inspiratory and expiratory diameters and collapsing index) was detected, but did not reach statistical significance (P = 0.185, P = 0.296, and P = 0.194, respectively). CUS score had statistically significant correlations with ultrafiltration volume and New York Heart Association classes (P < 0.001 and <0.001, respectively). Neither clinical signs nor IVC indices can be used independently for the assessment of VS in HD patients. CUS is a useful guide in VS assessment, and we recommend its routine use in the management of HD patients. Concomitant use of bio- impedance analysis (BIA) may be needed in addition to CUS for more accurate assessment of VS in HD patients.

Lung ultrasound for volume status assessment in chronic hemodialysis patients

Backoground/Aim. Assessing volume status in chronic hemodialysis (HD) patients is difficult despite several techniques have been developed. The aim of this study was to demonstrate the adequacy and efficacy of lung ultrasound (LUS) and B line score (BLS) in the assessment of volume status in patients on HD in comparison to other techniques: ultrasonographic determination of inferior vena cava diameter (IVCD), echocardiography (ECHO) and B-type natriuretic peptide (BNP) determination. Methods. LUS, ECHO, ultrasonography of inferior vena cava in inspiration (IVCDi) and expiration (IVCDe), and BNP sampling were performed before and after HD in 83 patients. Results. A significant reduction of BLS, IVCDi, IVCDe, BNP and several ECHO parameters such as left atrium diameter (LA), left ventricular internal dimension in diastole and systole (LVIDd and LVIDs, respectively), and left atrial volume in systole (LAVs), was registered (p &lt; 0.001). There was a significant correlation between BLS and BNP before (p = 0.01) and after HD (p = 0.05), and a weaker but significant correlation between BLS and IVCDi and IVCDe before HD (p = 0.05). Conclusion. All techniques assessed hypervolemia before and after HD successfully. BNP correlated with LUS before and after HD, and IVCDi and IVCDe correlated with LUS only before HD. LUS is cheap and simple to perform, can be performed bedside and can be reliably used for assessing volume status in HD patients.

Knee-to-knee Bioimpedance Measurements to Monitor Changes in Extracellular Fluid in Haemodynamic-unstable Patients During Dialysis.

The feasibility of bioimpedance spectroscopy (BIS) techniques for monitoring intradialytic changes in body fluids is advancing. The aim of this study was to compare the knee-to-knee (kkBIS) with the traditional whole-body (whBIS) with respect to continuous assessment of fluid volume status in hemodialysis patients. Twenty patients divided into two groups, hemodynamically stable and unstable, were recruited. Bioimpedance data from two different electrodes configurations (hand-to-foot and knee-to-knee) were collected and retrospectively analysed. A good correlation between the two methods with respect to changes in extracellular resistance (Re) and Re normalized for ultrafiltration volume (ΔRe/UFV) with p < 0.001 was observed. The relationship between relative change (%) in ΔRe and that in patient weight was most notable with kkBIS (4.82 ± 3.31 %/kg) in comparison to whBIS (3.69 ± 2.90 %/kg) in unstable patients. Furthermore, results based on kkBIS showed a reduced ability of the thigh compartments to keep up with the volume changes in the trunk for unstable patients. kkBIS provided a comparable sensitivity to whBIS even in patients at risk of intradialytic hypotension while avoiding the need for the complex implementation imposed by whBIS or other configurations.

Does the intravascular volume status in haemodialysis patients measured by inferior vena cava ultrasound correlate with bioimpedance spectroscopy?

To evaluate the accuracy of traditional clinical predialytic fluid assessment by renal nurses and the efficacy of 2 additional fluid assessment methods focussing on the potential preventative effect for intradialytic hypotension (IDH). Predialytic fluid assessment remains a daily challenge for renal nurses, when aiming for adverse event free haemodialysis treatments. Adding further objective parameters obtained through noninvasive methods into pre- and intradialytic fluid assessment could potentially improve health outcomes for haemodialysis patients. Comparative, observational study of three fluid assessment methods on their reliability on volume status and correlation to clinical outcomes. Clinical predialytic nursing fluid assessments in 30 haemodialysis patients were compared with additional initial bioimpedance spectroscopy (BIS) measurements, and 3 serial intradialytic ultrasound scans of the inferior vena cava (IVC-US) performed by a second renal nurse concurrently during the same session. A retrospective data analysis compared all measurements in each individual for the predictive value for IDH. A STROBE checklist for observational cohort studies was used for the reporting of results. Seven subjects experienced episodes of symptomatic intradialytic hypotension (S-IDH), which would have been anticipated by IVC-US or by BIS in 5 patients (71%). Using an algorithm to predict IDH would have provided a sensitivity of 100% and specificity of 95%. Both additional fluid assessment methods would have provided critical information before and during each haemodialysis session. Therefore, we consider them as being potentially effective for the prevention of intradialytic hypotension, with IVC-US being similar to BIS. Traditional clinical nursing fluid assessment methods in haemodialysis patients do not provide sufficient information to prevent episodes of IDH. Additional objective fluid assessment methods are useful and likely to lead to improved health outcomes in HD patients when applied by renal nurses. A combination of IVC-US, MAP and BIS has potential to reduce the risk of IDH events in HD patients significantly.

Does fibroblast growth factor 23 correlates with volume status in hemodialysis patients?

Introduction: Volume overload is a known risk factor for cardiovascular disease and stroke in hemodialysis patients. The use of fibroblast growth factor 23 (FGF23) as a volume overload marker has been validated in multiple studies. Objectives: This is a prospective cross-sectional study considering the association between FGF23 and bioimpedance-measured volume overload in hemodialysis patients. Patients and Methods: Bioimpedance analysis was performed on 43 hemodialysis patients at the end of hemodialysis to evaluate the remaining volume overload and serum FGF23 was measured before hemodialysis. Results: The results indicated no significant correlation between mean serum FGF23 levels and volume overload in hemodialysis patients (P=0.824). Conclusion: Although this study did not show any association between volume overload and FGF23, further studies are needed to define the role of FGF23 as a volume overload marker.

Plasma syndecan-1 in hemodialysis patients associates with survival and lower markers of volume status.

Syndecan-1, a transmembrane heparan sulfate proteoglycan, associates with renal and cardiovascular functioning. We earlier reported syndecan-1 to be involved in renal tubular regeneration. We now examined plasma values of syndecan-1 in a hemodialysis cohort and its association with volume and inflammatory and endothelial markers in addition to outcome. Eighty-four prevalent hemodialysis patients were evaluated for their plasma syndecan-1 levels by ELISA before the start of hemodialysis, as well as 60, 180, and 240 min after start of dialysis. Patients were divided into sex-stratified tertiles based on predialysis plasma syndecan-1 levels. We studied the association between plasma levels of syndecan-1 and volume, inflammation, and endothelial markers and its association with cardiovascular events and all-cause mortality using Kaplan-Meier curves and Cox regression analyses with adjustments for gender, age, diabetes, and dialysis vintage. Predialysis syndecan-1 levels were twofold higher in men compared with women ( P = 0.0003). Patients in the highest predialysis plasma syndecan-1 tertile had a significantly higher ultrafiltration rate ( P = 0.034) and lower plasma values of BNP ( P = 0.019), pro-ANP ( P = 0.024), and endothelin ( P < 0.0001) compared with the two lower predialysis syndecan-1 tertiles. No significant associations with inflammatory markers were found. Cox regression analysis showed that patients in the highest syndecan-1 tertile had significantly less cardiovascular events and better survival compared with the lowest syndecan-1 tertile ( P = 0.02 and P = 0.005, respectively). In hemodialysis patients, higher plasma syndecan-1 levels were associated with lower concentrations of BNP, pro-ANP, and endothelin and with better patient survival. This may suggest that control of volume status in hemodialysis patients allows an adaptive tissue regenerative response as reflected by higher plasma syndecan-1 levels.

Corrected carotid flow time and passive leg raise as a measure of volume status

BackgroundThe aim of this study was to investigate the value of corrected carotid flow time (FTc) with passive leg raise (PLR) as a non-invasive marker of volume status in end stage renal disease (ESRD) patients. MethodsProspective observational study of ESRD patients presenting to the Emergency department requiring hemodialysis. The common carotid artery was evaluated in long axis. Flow time measurements pre- and post-dialysis as well as before and after PLR were recorded. Results54 patients were enrolled, of which, 30 (55%) were male. The mean age was 47.4 years. The mean volume of fluid removed was 3.89 ± 0.91 L. In the pre-dialysis cohort, the mean FTc was 340.16 ms (95% CI, 330.36–349.95). Following PLR, the mean FTc was 341.34 ms (95% CI 331.74–350.94). In the post hemodialysis cohort, the mean FTc was 302.48 ms (95% CI, 293.63–311.32). Following the PLR maneuver, the mean FTc was 340.49 ms (95% CI 331.97–349.02). The mean decrease in corrected carotid flow time was 19.15 ms (95% CI, 22.86–41.17), 32.02 ms (95% CI 4.05–34.25) and 41.17 ms (95% CI, 36.47–54.76) for patients who had <3 L, 3-4 L and >4 L removed, respectively. In patients without CHF, the mean decrease in FTc after hemodialysis was 38.80 ms (95% CI, 30.12–47.49) whereas for CHF patients the mean decrease was 35.60 ms (95% CI, 25.05–46.15). ConclusionCorrected flow time in conjunction with passive leg raise seem to correlate with volume status in hemodialysis patients.

Lung ultrasound and bioimpedance in assessment of volume status of hemodialysis patients

Lung ultrasound and bioimpedance in assessment of volume status of hemodialysis patients

Which echocardiographic parameter is a better marker of volume status in hemodialysis patients?

Aim: Bio-impedance analysis (BIA) is a preferred method for estimating the volume status. However, it cannot be utilized in daily practice. Since the assessment of the volume status is important and challenging for hemodialysis (HD) patients, the aim of study was to determine the volume status in chronic HD patients using echocardiographic parameters and assess its correlation with BIA.Methods: In this cross-sectional analysis, echocardiography and BIA were performed on 30 chronic HD patients 30 min before and 30 min after dialysis. All the cases of dialysis were performed in the middle of the week. This study also assessed the correlation between echocardiographic parameters and BIA parameters.Results: There were significant differences between ECW, TBW, and TBW% (TBW/W) before and after HD. Significant differences were observed between echocardiographic parameters of IVCD, IVCDimin, IVCDimax before and after the HD. LVEDD, LVESD, LA area, mitral valve inflow, E/E′, and IVRT, were improved after dialysis, too. There was a significant correlation between IVCDimin as an index of volume status, ECW% and TBW% before HD and IVCDimin change after dialysis had a significant correlation with %ECW change after dialysis. Comparison between hypertensive and non-hypertensive groups indicated IVCDimin was significantly lower in non-hypertensive group after dialysis.Conclusion: Our results showed a correlation between IVCDimin and BIA parameters before HD. So, it seems that IVCDimin can be a good parameter for determining the volume status of HD patients. However, further studies, with larger sample size and with a prospective study design, are required to confirm these results.

Do Bioimpedance Measurements of Over-Hydration Accurately Reflect Post-Haemodialysis Weight Changes?

Introduction: Bioelectrical impedance spectroscopy (BIS) devices are being used to determine ultrafiltration requirements to achieve target weight for haemodialysis (HD) patients. Pre-dialysis measurements are more convenient for both patients and staff. We wished to compare the changes in pre- and post-dialysis hydration measured by BIS with actual weight loss. Methods: We compared paired BIS measurements made pre and post HD using a BIS device based on a 3-compartmental model, designed to provide information on extracellular water (ECW) excess. Results: BIS was measured in 49 HD patients, 35 male (71.4%) with mean age 67.6 ± 14.2. Weight fell significantly from 69.2 ± 17.8 to 67.6 ± 17.4 kg, and BIS over hydration (OH) from 4.5 ± 3.3.4 to 3.4 ± 2.9 litres, and ECW from 16.8 ± 4.8 to 15.5 ± 4.4 litres, but there was no change in the amount of intracellular water. Weight loss correlated positively with the change in ECW, but exceeded the fall in OH; mean bias -0.58 (95% confidence limits -3.6 to 4.8 kg). Summary: We measured OH pre and post HD, but did not find that the change in OH correlated with changes in body weight. Although there was a correlation between changes in OH and ECW, there was none for weight. Our findings do not support total reliance on pre-dialysis BIS alone for assessing volume status in HD patients, but rather BIS should be considered an aid to clinical assessment of volume status.

Combining Inferior Vena Cava Diameter and Right Atrial Volume Index with Pro-BNP in Assessment of Volume Status in Haemodialysis Patients

1.1.Background: The need for a concept of dry weight derives from an awareness of the dangers of being fluid overloaded. Which reflected by strain on the heart also abnormal low fluid load is also harmful and it might be associated with unacceptable degrees of low blood pressure and consequently of ischemia of vital organs. To judge excess volume, there are no gold standards, but its assessment has been done using a variety of tools. Physical examination which based on patient’s interdialytic weight gain and clinical signs, the assessment of volume is made poorly by physical examination. The assessment of inferior vena cava (IVC) diameter and its collapse with inspiration have been the most commonly used echocardiographic techniques to assess intravascular volume. Right atrial volume index which is noninvasive echocardiographic tool for assessment of volume overload but not widely used due to lack of data about right atrial volume even in normal population. NT-pro BNP is one of natriuretic peptides which secreted mainly upon mechanical stretching of cardiomyocytes, Both BNP and NT-proBNP are eliminated during hemodialysis, but they show different behaviors depending on the chosen dialysis membrane. 1.2.Methods: The study was conducted on two groups group I include 20 ESRD patients maintained on regular HD three times/week, four hour/session which they subdivided into two subgroups. The 1st subgroup included ten patients using high flux dialyzers and the 2nd subgroup included ten patients using low flux dialyzers. Group II: include ten healthy subjects as a control group. We estimate Urea, Cr, Hg and NT pro BNP by enzyme linked immune-sorbent assay (ELISA), trans-thoracic echocardiography stressing on inferior vena cava diameter and collapsibility index, right atrial volume index to the patients before and after HD and also in 2nd group. 1.3.Results: There was statistical significant difference between the pre HD and post HD in mean BP, Rt. at volume index, IVC diameter, and IVC collapsibility index. There were statistical significant difference between the Pro BNP low flux in pre HD and post HD, the Pro BNP high flux in pre HD and post HD. 1.4.Conclusion: Mean BP, Rt. at volume index, IVC diameter and pro BNP high flux were significantly decreased post HD session, and IVC collapsibility index, and proBNP low flux were increased post HD. So we can combine these parameters for effected evaluation of dry weight.

Fibroblast growth factor 23 correlates with volume status in haemodialysis patients and is not reduced by haemodialysis.

Recent data suggest a role for fibroblast growth factor 23 (FGF-23) in volume regulation. In haemodialysis patients, a large ultrafiltration volume (UFV) reflects poor volume control, and both FGF-23 and a large UFV are risk factors for mortality in this population. We studied the association between FGF-23 and markers of volume status including UFV, as well as the intradialytic course of FGF-23, in a cohort of haemodialysis patients. We carried out observational, post hoc analysis of 109 prevalent haemodialysis patients who underwent a standardized, low-flux, haemodialysis session with constant ultrafiltration rate. We measured UFV, plasma copeptinand echocardiographic parameters including cardiac output, end-diastolic volumeand left ventricular mass index at the onset of the haemodialysis session. We measured the intradialytic course of plasma C-terminal FGF-23 (corrected for haemoconcentration) and serum phosphate levels at 0, 1, 3and 4 h after onset of haemodialysis and analysed changes with linear mixed effect model. Median age was 66 (interquartile range: 51-75) years, 65% were male with a weekly Kt/V 4.3 ± 0.7 and dialysis vintage of 25.4 (8.5-52.5) months. In univariable analysis, pre-dialysis plasma FGF-23 was associated with UFV, end-diastolic volume, cardiac output, early diastolic velocity e' and plasma copeptin. In multivariable regression analysis, UFV correlated with FGF-23 (standardized β: 0.373, P < 0.001, model R(2): 57%), independent of serum calcium and phosphate. The association between FGF-23 and echocardiographic volume markers was lost for all but cardiac output upon adjustment for UFV. Overall, FGF-23 levels did not change during dialysis [7627 (3300-13 514) to 7503 (3109-14 433) RU/mL; P = 0.98], whereas phosphate decreased (1.71 ± 0.50 to 0.88 ± 0.26 mmol/L; P < 0.001). FGF-23 was associated with volume status in haemodialysis patients. The strong association with UFV suggests that optimization of volume status, for example by more intensive haemodialysis regimens, may also benefit mineral homeostasis. A single dialysis session did not lower FGF-23 levels.

Abstract 19931: Echocardiographic Assessment of Volume Status in Hemodialysis Patients: a Study Based on Inferior Vena Cava Diameter and Ventricular Interdependence

Background: It is difficult to assess volume status in patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD). The euvolemic state (dry weight) in ESRD patients is determined clinically but has limitations. We hypothesized that a combination of ventricular interdependence (VI)_the physiologic phenomenon whereby filling of one ventricle is affected by filling of the contralateral ventricle during different phases of the respiratory cycle_and inferior vena cava diameter (IVCd) predicts volume status in ESRD patients undergoing HD. Methods: Echocardiograms were performed in 20 patients immediately pre- and post-HD. Clinical assessment of volume status was performed by a single nephrologist blinded to echocardiographic data. VI was defined as peak expiratory to inspiratory mitral inflow E velocity ratio. Hypovolemia was defined as IVCd 20 mm and VI &gt;15%. Results: 65% of patients were men, and 60% had a history of heart failure. A total of 40 volume clinical assessments were performed (20 pre- and 20 post-HD): 23 were categorized as hypovolemic, 5 euvolemic, and 12 hypervolemic. 21 of 23 (91%) hypovolemic assessments met echo definition for hypovolemia. None of 5 (0%) euvolemic assessments met echo definition of euvolemia. 12 of 12 (100%) hypervolemic assessments met echo definition of hypervolemia. (Figure. Columns and error bars represent mean +/- standard error of mean. P=0.007, Kruskal-Wallis equality-of-populations rank test.) Conclusions: In ESRD patients undergoing HD, echocardiographic definition of volume status using IVCd and VI accurately predicts hypo- and hypervolemia. There was poor correlation between echo and clinical volume assessment for euvolemia. This is the first study to examine volume status in HD patients with concomitant cardiac disease using IVCd, and VI. Further studies are needed to determine whether clinical or echo assessment of euvolemia is accurate.