Consecutive Hemodialysis Sessions Research Articles

#1762 Reduction in intradialytic glycemia and increased oxygen consumption as potential indicators of intradialytic parenchymal stress

Abstract Background and Aims Patients undergoing chronic hemodialysis (HD) face heightened all-cause and cardiovascular mortality due to various risk factors, with intradialytic stress playing a fundamental role. Recently, the assessment of intradialytic oxygen trends has emerged as a potential parameter for evaluating parenchymal stress. Specifically, an intradialytic increase in the oxygen extraction ratio (OER), derived from the ratio of peripherical oxygen saturation to central venous oxygen saturation, identifies patients at a greater risk of intradialytic events and increased clinical risk. In addition to OER, intradialytic consumption of glucose indicates higher tissue metabolic demand, likely indicative of parenchymal stress. We hypothesize that OER and intradialytic glucose consumption may be phenomena related to increased intradialytic parenchymal stress and, therefore, may be correlated. This study aimed to assess the potential correlation between intradialytic glycemia trends and oxygen extraction (OER). Method Patients in chronic HD treatment with a central venous catheter (CVC) for HD were enrolled from January 2019 to January 2020. The exclusion criteria were: ongoing acute pathology, diabetes mellitus, and undergoing hemodialysis for less than six months. OER and glycemia were measured during three consecutive HD sessions at baseline, 15, 30, 60, and 120 minutes into treatment, and post-HD. For statistical analysis, average values for each patient across the three dialysis sessions were considered. Results Twenty patients with a permanent CVC (10 males, 10 females; age 74 ± 13 years; HD vintage 46 ± 34 months) were enrolled. The pre-HD mean OER in the initial three HD sessions was 34 ± 7, increasing to 46 ± 9 post-HD, with a mean percentage delta OER of 39 ± 20%. Evaluating OER trends in the entire population revealed an increase in OER (∆OER) from the first 15 minutes of treatment (∆OER% 15’: 14 ± 7; ∆OER% 30’: 18 ± 22, p < 0.01). Patients' baseline glycemia was 120 ± 31 mg/dl at the start of the HD session and 111 ± 21 at the end, with a delta of −11 ± 21 mg/dl and a glucose delta percentage of 4%. Patients with higher oxygen consumption after 15 and 30 minutes of treatment experienced a greater decrease in glycemia. Specifically, ∆OER at 15’ negatively correlated with glycemia values at 15’ (r: −0.494, p < 0.05), 30’ (r: −0.521, p < 0.05), 60’ (r: −0.644, p < 0.01, Fig. 1), and 120’ (r: −0.714, p < 0.01), and post-HD (r: −0.634, p < 0.05). Patients were then divided based on the magnitude of mean O2 consumption measured post-HD into two groups: ΔOER ≤ mean and ΔOER > mean (threshold 40%). Patients with a higher ∆OER showed a more significant decrease in glycemia from the first 15 minutes of HD, confirmed at the end of HD (ΔOER ≤ 40%: Δglucose post-HD −2 ± 40; ΔOER > 40%: −22 ± 28, p < 0.05, Fig. 2). Conclusion The data confirm that oxygen extraction during hemodialysis progressively increases from the first 30 minutes of treatment. Changes in OER are associated with a reduction in glycemia, particularly patients with higher ΔOER have a more pronounced decrease in glycemia. This association between OER and glycemia supports the hypothesis that these two parameters are linked to the same pathophysiological phenomenon, such as increased intradialytic cellular metabolic activity. Studies with larger populations will help confirm this association and propose glycemia delta as an indicator of intradialytic parenchymal stress.

#2118 Monitoring hemodynamics in dialysis: on the feasibility of semi-continuous and multifrequency thoracic bioimpedance measurements by a wearable device

Abstract Background and Aims Hemodialysis patients face a high hemodynamic variability in blood pressure and fluid status, which contributes to their cardiovascular mortality. Currently, intradialytic hemodynamic monitoring has to rely on cuff-based blood pressure measurements. During the interdialytic interval, no monitoring system is applied. An interesting alternative to monitor hemodynamics continuously can be found in the bioimpedance technique, and more specifically in bioimpedance measurements of the thoracic segment. Repeated single-point measurements of thoracic bioimpedance at single (low)-frequency are strongly related to fluid changes during hemodialysis. Extension to semi-continuous measurements may provide longitudinal details in the time pattern of the bioimpedance signal, and multifrequency measurements may add in-depth information on the distribution between intra- and extracellular fluid. This study aims to investigate the feasibility of semi-continuous multifrequency thoracic bioimpedance measurements by a wearable device in hemodialysis patients. Method Thoracic bioimpedance was recorded semi-continuously (i.e. every ten minutes) at nine frequencies (8–160 kHz) in 68 patients during two consecutive hemodialysis sessions, complemented by an interdialytic single-point measurement at home. The wearable bioimpedance device was provided by imec, The Netherlands (Fig. 1). A linear mixed model was built to integrate all measurements at frequencies 8 and 160 kHz, incorporating the different dialysis sessions up until 240 minutes after the start of dialysis as well as the home measurement that was performed. Results On average, the thoracic resistance signals increased during the first hemodialysis session, decreased during the interdialytic interval, and increased again during the second hemodialysis session, at all frequencies. The average intradialytic increase was larger at 8 kHz (∆ 32.6 Ω during session 1 and ∆ 10 Ω during session 2) compared to 160 kHz (∆ 29.5 Ω during session 1 and ∆ 5.1 Ω during session 2). By measuring semi-continuously and at multiple frequencies, a different time pattern became clear within and between frequencies. The resistance at 8 kHz followed a linear time pattern, whereas the evolution of the resistance at 160 kHz showed a significant quadratic trend in the first dialysis session (p < 0.0001). During the first interdialytic interval (from the end of the first dialysis session towards the home measurement), the decrease in resistance was more distinct at 8 kHz (∆ −2.27 Ω) compared to a small increase of 0.84 Ω in 160 kHz. This finding reveals a certain inertia in the higher frequencies, mirroring the changes in intracellular volume. Finally, the statistical model could create individual predicting profiles over time, including as well the intradialytic as the interdialytic interval (Fig. 2). Conclusion In this study, we showed that it is feasible to perform semi-continuous and multifrequency bioimpedance measurements by a wearable device during hemodialysis. Semi-continuous and multifrequency measurements provided a broader, and respectively profounder knowledge on the trend of the bioimpedance signal during fluid changes compared to single-point and single-frequency measurements. Measuring thoracic bioimpedance semi-continuously and with a multifrequency current is a major step forward in the understanding of fluid dynamics in hemodialysis patients, by which the road is paved towards remote fluid monitoring and the prevention of hemodynamic instabilities.

The Feasibility of Semi-Continuous and Multi-Frequency Thoracic Bioimpedance Measurements by a Wearable Device during Fluid Changes in Hemodialysis Patients.

Repeated single-point measurements of thoracic bioimpedance at a single (low) frequency are strongly related to fluid changes during hemodialysis. Extension to semi-continuous measurements may provide longitudinal details in the time pattern of the bioimpedance signal, and multi-frequency measurements may add in-depth information on the distribution between intra- and extracellular fluid. This study aimed to investigate the feasibility of semi-continuous multi-frequency thoracic bioimpedance measurements by a wearable device in hemodialysis patients. Therefore, thoracic bioimpedance was recorded semi-continuously (i.e., every ten minutes) at nine frequencies (8-160 kHz) in 68 patients during two consecutive hemodialysis sessions, complemented by a single-point measurement at home in-between both sessions. On average, the resistance signals increased during both hemodialysis sessions and decreased during the interdialytic interval. The increase during dialysis was larger at 8 kHz (∆ 32.6 Ω during session 1 and ∆ 10 Ω during session 2), compared to 160 kHz (∆ 29.5 Ω during session 1 and ∆ 5.1 Ω during session 2). Whereas the resistance at 8 kHz showed a linear time pattern, the evolution of the resistance at 160 kHz was significantly different (p < 0.0001). Measuring bioimpedance semi-continuously and with a multi-frequency current is a major step forward in the understanding of fluid dynamics in hemodialysis patients. This study paves the road towards remote fluid monitoring.

Pulmonary congestion and systemic congestion in hemodialysis: dynamics and correlations.

Systemic congestion and pulmonary congestion (PC) are common in hemodialysis (HD) patients. However, the relationship between these two entities is not quite clear. We study this relationship and attempt to uncover the factors that may affect it considering different inter-dialytic intervals. A prospective pilot observational and interventional study including 18 HD patients was conducted. The following were obtained: i) B-line score (BLS) by lung ultrasound (LUS) (reflecting significant pulmonary congestion if BLS > 5), ii) echocardiography, iii) bioelectrical impedance analysis (BIA) (reflecting global volume status), and iv) inferior vena cava (IVC) dynamics (reflecting systemic congestion) before and after the first two consecutive HD sessions of the week, with different inter-dialytic intervals (68 hours and 44 hours). Serum N-terminal pro-brain natriuretic peptide type B (NT-proBNP) levels were obtained before each session. Then, patients were randomized into two groups: the active group, where dry weight was reduced according to BLS + standard of care, and the control group, where dry weight was modified according to standard of care. All the measures were repeated on day 30. We found no correlation between pulmonary congestion represented by BLS and IVC dimensions and dynamics reflecting systemic congestion, independent of different inter-dialytic intervals. Pulmonary congestion was quite prevalent, as mean pre- and post-dialysis BLSs were quite elevated (16 ± 5.53 and 15.3 ± 6.63, respectively) in the first session compared with the second session (16.3 ± 5.26 and 13.6 ± 5.83, respectively). Systolic (left ventricular ejection fraction) and diastolic cardiac function (e/è ratio) parameters from one side and pulmonary congestion (BLS) from the other were not always correlated. BLS was correlated to e/è ratio before HD (session 1) (R 2 = 0.476, p = 0.002) and after HD (session 2) (R 2 = 0.193, p = 0.034). Pulmonary congestion reflected by BLS was correlated to the global volume state reflected by BIA only in the second HD session (HD2) (R 2 = 0.374, p = 0.007). NT-proBNP levels and BLS were correlated before both sessions (R 2 = 0.421, p = 0.004, and R 2 = 0.505, p = 0.001, respectively). Systemic congestion was quite prevalent, as mean pre- and post-dialysis IVC dimensions and dynamics were quite elevated in both sessions, with a higher level of systemic congestion in the first HD session (diameter and collapsibility of 2.1 cm and 23%, and 2.01 cm and 19%, respectively) compared with the second session (1.98 cm and 17.5%, and 1.9 cm and 22%, respectively) without reaching statistical significance. IVC dimensions and global volume status measured by BIA were correlated in the second dialysis session (R 2 = 0.260, p = 0.031). No correlation was found between IVC dimensions and diastolic cardiac function (e/è ratio) parameters or with NT-proBNP levels. On day 30, BLS was significantly reduced in the active group, whereas no difference was found in the control group. However, no real impact was observed on IVC dimensions and dynamics or in total volume status by BIA. Pulmonary congestion is common in HD patients even after reaching their dry weight at the end of two consecutive sessions, and it is not correlated to systemic congestion, suggesting a complex multifactorial pathophysiology origin. Global volume status reflected by BIA and cardiac function are not always related to either systemic congestion represented by IVC dimensions or pulmonary congestion represented by BLS. Fluid redistribution anomalies may allow pulmonary congestion accumulation independently from systemic congestion and global volume status (non-cardiogenic pulmonary congestion). We recommend a personalised approach when managing HD patients by integrating systemic and pulmonary congestion parameters. Dry weight modification guided by repeat LUS may safely reduce pulmonary congestion. However, no impact was observed on systemic congestion or global volume status.

#5667 PULMONARY CONGESTION IN HEMODIALYSIS: PREVALENCE, DYNAMICS AND ASSOCIATED FACTORS

Abstract Background and Aims Lung ultrasound (LUS) helps detecting pulmonary congestion (PC) among haemodialysis (HD) patients. This study investigated the relation between PC, cardiac function parameters, volume status and ultrafiltration, as well as chronic inflammation in two consecutive HD sessions with different inter-dialytic intervals. Method Prospective observational study, where 18 HD patients underwent LUS to calculate the B Lines Score (BLS) using the 8 zone method, inferior vena cava (IVC) dimensions measurement, and echocardiography before and after their regular first (S1) and second (S2) HD sessions of the week. The cut-off for BLS was fixed as 0.54 line per zone. Total body volume using Bio-electrical Impedance Analysis (BIA) was measured before both HD sessions besides serum NT-pro BNP (N-Terminal Pro-Brain Natriuretic Peptide Type B) levels. Moreover, circulating markers of inflammation (soluble urokinase Plasminogen Activator Receptor [suPAR] and soluble Suppression of Tumorigenicity 2 [sST2]) were measured before each session. Results Interdialytic interval did not impact BLS, which was high before and after both sessions. There was no significant difference in BLS before and after S1, whereas the difference was significant in S2 (P: 0.03, ES: 0.54). BIA was correlated to PC only before S2 (R² = 0.374, P = 0.007). BLS and the systolic cardiac function represented by the ejection fraction were correlated only after S2. Nt-ProBNP levels and BLS were correlated before both sessions (R²: 0.421, P: 0.004; R² = 0.505, P = 0.001), respectively. Cardiac diastolic function was correlated with BLS before S1 (R² = 0.476, P = 0.002) and after S2 (R² = 0.193, P = 0.034). Mean levels (± SD, ng/ml) of suPAR (7.88 ± 3.07), (7.78 ± 3.02) remained significantly above the normal range (&amp;lt; 4 ng/ml), while sST2 levels reached 2-fold the upper normal value in some patients (27.4 ± 17.8). Conclusion PC is common in HD patients even after reaching their dry weight at the end of their two consecutive sessions. It is not only correlated to volume status and cardiac function. Chronic inflammation may be involved in PC pathophysiology. A better management strategy is thus needed to better reduce PC in HD patients.

Comparing Effects of Rhythmic Breathing and Lidocaine Spray on Pain Intensity During Needle Insertion Into Arteriovenous Fistula in Hemodialysis Patients: A Randomized Controlled Trial.

Hemodialysis patients suffer from pain caused by needle insertion into the fistula site. Non-pharmacological methods may be associated with acceptable effects. The present study aimed to compare the effects of two interventions on pain intensity during needle insertion into the arteriovenous fistula in hemodialysis patients. This self-controlled, single-blind clinical trial was conducted on 54 hemodialysis subjects with arteriovenous fistula in Mashhad in 2021. In this regard, the patients were selected according to the inclusion criteria and randomly assigned to two groups (lidocaine spray and rhythmic breathing). In each group, pain intensity was assessed based on the visual analogue scale (VAS) before the intervention, followed by measuring the post-intervention pain intensity during three consecutive hemodialysis sessions every other day. Regarding the lidocaine spray group, two puffs of 10% lidocaine spray (20 mg) were sprayed on the needle insertion site five minutes before cannulation. However, the patients in another group took a long deep breath through the nose with three numbers, held their breath in the lungs for three numbers, and slowly exhaled through the mouth with three numbers two minutes before cannulation. The data were analyzed using SPSS software version 20, and Mann-Whitney U, Wilcoxon, chi-squared, and paired t-tests were run. In this study, P < 0.05 was considered significant. The results represented a significant decrease in the pain severity scores of both rhythmic breathing (P = 0.023) and lidocaine spray (P < 0.001) groups after the intervention. Moreover, a more significant difference was observed between pre-and post-intervention pain intensity scores in the group treated with lidocaine spray (1.16 ± 1.56) compared to the other group (0.508 ± 1.25). The lidocaine spray group had a larger difference in the pre-and post-intervention pain intensity scores than the rhythmic group; however, the difference was not significant. The rhythmic breathing can be used by nurses as a non-pharmacological method with low complications in hemodialysis departments because of declining pain.

Sodium flux during hemodialysis and hemodiafiltration treatment of acute kidney injury: Effects of dialysate and infusate sodium concentration at 140 and 145 mmol/L.

A higher sodium (Na) dialysate concentration is recommended during renal replacement therapy (RRT) of acute kidney injury (AKI) to improve intradialytic hemodynamic tolerance, but it may lead to Na loading to the patient. We aimed to evaluate Na flux according to Na dialysate and infusate concentrations at 140 and 145 mmol/L during hemodialysis (HD) and hemodiafiltration (HDF). Fourteen AKI patients that underwent consecutive HD or HDF sessions with Na dialysate/infusate at 140 and 145 mmol/L were included. Per-dialytic flux of Na was estimated using mean sodium logarithmic concentration including diffusive and convective influx. We compared the flux of sodium between HD140 and 145, and between HDF140 and 145. Nine HD140, ten HDF140, nine HD145, and 11 HDF145 sessions were analyzed. A Na gradient from the dialysate/replacement fluid to the patient was observed with dialysate/infusate Na at 145 mmol/L in both HD and HDF (p=0.01). The comparison of HD145 to HD140 showed that higher Na dialysate induced a diffusive Na gradient to the patient (163 mmol vs. -25 mmol, p=0.004) and that of HDF145 to -140 (211 vs. 36 mmol, p=0.03) as well. Intradialytic hemodynamic tolerance was similar across all RRT sessions. During both HD and HDF, a substantial Na loading occurred with a Na dialysate and infusate at 145 mmol/L. This Na loading is smaller in HDF with Na dialysate and infusate concentration at 140 mmol/L and inversed with HD140. Clinical and intradialytic hemodynamic tolerance was fair regardless of Na dialysate and infusate.

Acute hemodialysis therapy in neonates with inborn errors of metabolism.

Inborn errors of metabolism (IEM), including organic acidemias and urea cycle defects, are characterized by systemic accumulation of toxic metabolites with deleterious effect on the developing brain. While hemodialysis (HD) is most efficient in clearing IEM-induced metabolic toxins, data regarding its use during the neonatal period is scarce. We retrospectively summarize our experience with HD in 20 neonates with IEM-induced metabolic intoxication (seven with maple syrup urine disease, 13 with primary hyperammonia), over a 16-year period, between 2004 and 2020. All patients presented with IEM-induced neurologic deterioration at 48h to 14days post-delivery, and were managed with HD in a pediatric intensive care setting. HD was performed through an internal jugular acute double-lumen catheter (6.5-7.0 French), using an AK-200S (Gambro, Sweden) dialysis machine and tubing, with F3 or FXpaed (Fresenius, Germany) dialyzers. Median (interquartile range) age and weight at presentation were 5 (3-8) days and 2830 (2725-3115) g, respectively. Two consecutive HD sessions decreased the mean leucine levels from 2281 ± 631 to 179 ± 91μmol/L (92.1% reduction) in MSUD patients, and the mean ammonia levels from 955 ± 444 to 129 ± 55μmol/L (86.5% reduction), in patients with hyperammonemia. HD was uneventful in all patients, and led to marked clinical improvement in 17 patients (85%). Three patients (15%) died during the neonatal period, and four died during long-term follow-up. Taken together, our results indicate that HD is safe, effective, and life-saving for most neonates with severe IEM-induced metabolic intoxication, when promptly performed by an experienced and multidisciplinary team. A higher resolution version of the Graphical abstract is available as Supplementary information.

INFERR-Iron infusion in haemodialysis study: INtravenous iron polymaltose for First Nations Australian patients with high FERRitin levels on haemodialysis\u2014a protocol for a prospective open-label blinded endpoint randomised controlled trial

BackgroundThe effectiveness of erythropoiesis-stimulating agents, which are the main stay of managing anaemia of chronic kidney disease (CKD), is largely dependent on adequate body iron stores. The iron stores are determined by the levels of serum ferritin concentration and transferrin saturation. These two surrogate markers of iron stores are used to guide iron replacement therapy. Most Aboriginal and/or Torres Islander Australians of the Northern Territory (herein respectfully referred to as First Nations Australians) with end-stage kidney disease have ferritin levels higher than current guideline recommendations for iron therapy. There is no clear evidence to guide safe and effective treatment with iron in these patients. We aim to assess the impact of intravenous iron treatment on all-cause death and hospitalisation with a principal diagnosis of all-cause infection in First Nations patients on haemodialysis with anaemia, high ferritin levels and low transferrin saturationMethodsIn a prospective open-label blinded endpoint randomised controlled trial, a total of 576 participants on maintenance haemodialysis with high ferritin (> 700 μg/L and ≤ 2000 μg/L) and low transferrin saturation (< 40%) from all the 7 renal units across the Northern Territory of Australia will be randomised 1:1 to receive intravenous iron polymaltose 400 mg once monthly (200 mg during 2 consecutive haemodialysis sessions) (Arm A) or no IV iron treatment (standard treatment) (Arm B). Rescue therapy will be administered when the ferritin levels fall below 700 μg/L or when clinically indicated. The primary outcome will be the differences between the two study arms in the risk of hospitalisation with all-cause infection or death. An economic analysis and several secondary and tertiary outcomes analyses will also be performed.DiscussionThe INFERR clinical trial will address significant uncertainty on the safety and efficacy of iron therapy in First Nations Australians with CKD with hyperferritinaemia and evidence of iron deficiency. This will hopefully lead to the development of evidence-based guidelines. It will also provide the opportunity to explore the causes of hyperferritinaemia in First Nations Australians from the Northern Territory.Trial registrationThis trial is registered with The Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12620000705987. Registered 29 June 2020.

A Prospective Study on Anxiety and Blood Pressure Levels in Hemodialysis Patients During COVID-19 Pandemic

Objective: The coronavirus disease 2019 (COVID-19) pandemic has currently been one of the leading causes of psychosocial stress throughout the world. We hypothesized that possible changes in anxiety status during the COVID-19 pandemic might affect blood pressure in hemodialysis (HD) patients. Methods: This is an observational cross-sectional study. The Hospital Anxiety and Depression Scale (HADS) and State-Trait Anxiety Inventory (STAI) were applied to 71 prevalent HD patients. Pre-dialysis blood pressure was measured, and the systolic blood pressure measurements of 6 consecutive HD sessions were averaged. All assessments were performed both at the beginning (March) and after the end (June) of the partial lockdown, which was officially instituted by the Government in Turkey. Results: The mean age (+/- SD) was 59.2 +/- 14.8 years and 52% of the patients were female. The STAI-State score was higher in March than in June (44.6 +/- 12.6 vs. 42.3 +/- 11.5, respectively, P =.047), whereas the HADS-Anxiety, HADS-Depression, and STAI-Trait scores were not different. The pre-dialysis systolic blood pressure was significantly higher in March than in June (127.9 +/- 20.3 vs. 124.8 +/- 22.8 mmHg, respectively, P =.029). The change in state anxiety score from March to June was remarkable, particularly in patients not taking a beta-blocker (49.3 +/- 9.6 to 43.8 +/- 11.1, P =.001) and in patients younger than the median age of 64 years (48.6 +/- 12.8 to 45.3 +/- 12.5, P =.029). The change in blood pressure level from March to June was found to be significant only in patients not taking a beta-blocker (123.4 +/- 20.2 to 118.2 +/- 20.6 mmHg, P <.001), while it did not reach a statistically significant level in the others. Conclusion: Our findings revealed an association between a higher state of anxiety and a higher blood pressure level in HD patients during the COVID-19 pandemic, which was remarkable particularly in patients not taking a beta-blocker.

Blood Pressure Control and Antihypertensive Treatment among Hemodialysis Patients-Retrospective Single Center Experience.

Background and Objectives: Hypertension affects at least 80% of hemodialysis patients. Inappropriate control of blood pressure is mentioned as one of the essential cardiovascular risk factors associated with development of cardiovascular events in dialysis populations. The aim of the cross-sectional, retrospective study was the evaluation of the antihypertensive treatment schedule and control of blood pressure in relation to the guidelines in the group of hemodialysis patients. Additionally, we assessed the level of decrease in blood pressure by each group of hypotensive agents. Materials and Methods: 222 patients hemodialyzed in a single Dialysis Unit in three distinct periods of time—2006, 2011, and 2016—with a diagnosis of hypertension were enrolled in the study. The analysis of the antihypertensive treatment was based on the medical files and it consisted of a comparison of the mean blood pressure results reported during the six consecutive hemodialysis sessions. Results: The mean values of blood pressure before hemodialysis were as follows: 134/77, 130/74, and 140/76 mmHg, after hemodialysis 124/74, 126/73, and 139/77 mmHg in 2006, 2011, and 2016 respectively. The goal of predialysis blood pressure control (<140/90) was achieved by up to 64.3% of participants in 2006 as compared to 49.4% in 2016. Additionally, the postdialysis goal (<130/90) reached 57.1% of the study population in 2006 as compared to 27.1% of patients in 2016. The differences in percentage of patients using single, double, triple, and multidrug therapy during observation were not statistically significant. The most often used drugs were ß-blockers, diuretics, and calcium channel blockers in all points of the study. Blockades of the renin–angiotensin–aldosterone system in 2006 and calcium channel blockers in 2011 and 2016 were the drugs with highest impact on lowering blood pressure. Conclusions: The goal of predialysis or postdialysis blood pressure control was achieved in a lower percentage of patients during the period of the study. Blockade of renin–angiotensin–aldosterone system and calcium channel blockers decrease the blood pressure significantly. It is necessary to achieve better control of blood pressure in prevention of cardiovascular incidents.

MO106A PROSPECTIVE STUDY ON ANXIETY AND BLOOD PRESSURE LEVELS IN HAEMODIALYSIS PATIENTS DURING COVID-19 PANDEMIC

Background and AimsCoronavirus Disease-19 (COVID-19) pandemic has currently been one of the leading causes of psychosocial stress worldwide. We hypothesized that possible changes in anxiety status might affect blood pressure in haemodialysis (HD) patients during COVID-19 pandemic.MethodSeventy one prevalent HD patients were included in this prospective study. Hospital Anxiety and Depression Scale (HADS) and State-Trait Anxiety Inventory (STAI) were applied to assess psychological status of the patients. Peridialysis blood pressure measurements were performed and average of 6 consecutive HD sessions’ pre-dialysis systolic blood pressure measurements were used for statistical analyses. All assessments were performed both at the beginning (March) and after ending (June) of the partial lock-down, which was officially instituted by the Government in parallel with the status of the pandemic in Turkey.ResultsMean age (±SD) was 59.2±14.8 years and 52% of the patients were female. Dose of medications including antihypertensives, dry weight, interdialytic weight gain, and Kt/Vurea were stable during the study period. STAI-state score was higher in March than that in June (44.6±12.6 vs 42.3±11.5, respectively, p=0.047), whereas HADS-anxiety, HADS-depression, and STAI-trait scores were not different. Pre-dialysis systolic blood pressure was significantly higher in March than in June (127.9±20.3 vs 124.8±22.8 mmHg, respectively, p=0.029). Change in state anxiety score from March to June was remarkable particularly in patients not taking a beta-blocker (49.3±9.6 to 43.8±11.1, p=0.001) and in patients younger than the median age of 64 years (48.6±12.8 to 45.3±12.5, p=0.029). Change in blood pressure level from March to June was found to be significant only in patients not taking a beta-blocker (123.4±20.2 to 118.2±20.6 mmHg, p<0.001), while did not reach a statistically significant level in the others.ConclusionOur findings, though need to be confirmed by further studies, revealed an association between a higher state of anxiety and a higher blood pressure level in HD patients in COVID-19 pandemic era, which was remarkable particularly in patients not taking a beta-blocker.

FC 057SALIVARY POTASSIUM FOLLOWS PLASMA POTASSIUM DYNAMICS IN HEMODIALYSIS PATIENTS

Abstract Background and Aims Hyperkalemia is common in patients on hemodialysis (HD) and in cardiorenal patients on RAAS inhibitors. Frequently, hyperkalemia is a leading reason to withdraw potentially lifesaving therapy in cardiorenal patients. Out-patient monitoring of plasma K+ levels due to preanalytical problems has proven problematic. The present pilot-study examined salivary K+ levels and kinetics based on plasma K+ measurements in HD patients employing a novel class of genetically-encoded fluorescent potassium-ion indicators, the GEPIIs (Bischof et al. Nat. Commun. 2017). HD patients represent a unique population in whom significant K+ derangements and rapid K+ level changes predictably occur and where these phenomena can be safely investigated. Method K+ assessments were performed in healthy individuals (n=20) and HD patients (n=30). Study-related procedures were approved by the local Institutional Review Board. Healthy individuals were recruited on a voluntary basis and provided only saliva samples. HD patients were recruited from our HD unit. Blood and saliva samples for K+ assessment were collected simultaneously during three consecutive HD sessions (HD1-3) prior to and directly after each session (pre/post HD). Blood was drawn in a standardized procedure directly from the HD access line and plasma K+ was measured immediately using standardized ion-selective electrodes (ISE). Saliva samples were gathered in a standardized procedure using a commercially available collection device (SuperSALTM). Of note, gaining adequate amounts of saliva from chronic HD patients, who frequently suffer from xerostomia, has proven challenging in some cases. The K+ content of saliva samples was measured by ISE and GEPII-technique. For the latter, samples were mixed with purified GEPIIs and were inserted into a fluorescent plate-reader. Probes were illuminated at 430 nm and emission light were collected at 475 nm and 525 nm, respectively. The ratio of the fluorescent intensities (F535/F480) after appropriate calibration is a direct measure of the K+ concentration sensed by GEPIIs. Results K+ determination in saliva samples using the GEPII-technique and ISE showed a strong agreement ((Figure 1A), Bias 0,71; 95% limits of agreement from -2.79 to 4.40). Pre-dialytic [K+]saliva of HD patients compared to healthy individuals, was higher (40,64±1,50 vs. 23,15±0,76 mmol/l, p&amp;lt;0.05). As expected, each HD session (HD1-3) led to a significant reduction in [K+]plasma, which is followed by a similar, significant reduction of [K+]saliva (Figure 1B). Dynamics of plasma and salivary [K+] showed a very similar pattern: strong reduction during a HD session followed by a marked increase in the dialysis-free period until the next session 48-72h later (Figure 1C). Although basal [K+]saliva shows individual variations, [K+]Saliva and [K+]plasma exhibited a tendency of linear association (Figure 1D). Correlation analysis in each HD session (HD1-3 pre/post) revealed however no or weak correlation of pre- and post-dialytic saliva and plasma K+ values (Figure 1E). Conclusion The GEPII-technique is an easy to use, reliable and suitable method for salivary K+ determination in healthy individuals and in HD patients with accuracy and precision comparable to that of ISE. Despite heterogeneous baselines, changes of [K+]saliva represent a sensitive marker of K+ derangements as well as hyper- and normokalemia in HD patients. Although we observed that [K+]saliva dynamically follows [K+]plasma , an exact quantification - most likely due to the low number of cases per HD sessions in this pilot-study – was not possible. Additionally, how closely [K+]saliva tracks [K+]plasma in patients with hypokalemia was not addressed in this study. To confidently answer whether [K+]saliva measurement can potentially be used in the care of patients at increased risk of hyperkalemia, further studies in a larger number of patients need to be conducted.

MO730THORACIC BIOIMPEDANCE AS AN INNOVATIVE TOOL TO DETECT CHANGES IN BLOOD PRESSURE DURING HEMODIALYSIS

Abstract Background and Aims Blood pressure (BP) variability is an important cardiovascular risk factor that contributes to the high burden of cardiovascular mortality in hemodialysis (HD) patients. Ultrafiltration rate (UFR) and plasma refill rate modify the extracellular volume (ECV), which is a major determinant of the systolic BP. Segmental bioimpedance of the thoracic region addresses the central volume compartment of the body. We hypothesize that changes in bioimpedance reflect changes in BP and that thoracic measurements are more accurately in detecting intradialytic BP changes compared to whole body bioimpedance. Method During two consecutive short-term interval HD sessions, thoracic bioimpedance signal was registered continuously from predialysis until the end of the session. Corresponding BP, whole body bioimpedance and ultrafiltration volume (UFV) after the start and at the end of dialysis was registered. After outlier detection, valid raw bioimpedance data [Ohm] at 8 and 160 kHz for thoracic measurements, and 5 and 200 kHz for whole body measurements, were taken into further analysis. Dialysis sessions were divided into 3 groups according to the development of the systolic BP: a drop ≥ than 20 mmHg was defined as a hypotensive session, an increase ≥ 10 mmHg was considered as a hypertensive session. Pearson correlation analysis was applied (r, p-value) to the relative data, calculated as a percentage from the start value. Results From 2 dialysis centres, a total of 46 HD patients were enrolled in the study (65.2% male, mean age 71 ± 12.6 years, mean dialysis vintage 4 ± 3.9 years), which resulted in 89 dialysis sessions to analyse. Mean systolic BP after start of dialysis was 133.2 ± 20.7 mmHg and mean UF volume was 1817.5 ± 801.5 mL. 23 sessions showed a hypotensive gradient from the start till the end of dialysis, and 13 sessions progressed with an increase of more than 10 mmHg. When the 8 kHz curve was plotted according to the 3 BP groups, a more plane increase in thoracic bioimpedance signal was observed in the group with a normal tension course (Figure 1). There was a significant relationship between UFR and changes in relative bioimpedance data, as well as thoracic (r = .49 at 8 kHz, r = .46 at 160 kHz, all ps &amp;lt; .001), as whole body bioimpedance (r = .58 at 5 kHz, r = .52 at 200 kHz, all ps &amp;lt; .001). UFV correlated with changes in systolic BP (r = -.31, p &amp;lt; .01). Both bioimpedance techniques correlated with each other (r = .38, p = .001 for low frequencies; r = .29, p &amp;lt; .01 for high frequencies). Where the relative thoracic bioimpedance signal correlated with changes in systolic BP (r = -.35 at 8kHz, -.32 at 160 kHz, all ps &amp;lt; .01) (Figure 2), whole body did not. Conclusion Thoracic bioimpedance is associated with intradialytic BP changes, whereas whole body bioimpedance is not. Thoracic bioimpedance has the potential to function as an important diagnostic and predictive tool in BP variability during HD.

40. THE RELATION BETWEEN INTERDIALYTIC WEIGHT GAIN AND INTRADIALYTIC HYPERTENSION IN PATIENTS WITH CHRONIC KIDNEY DISEASE WITH ROUTINE HEMODIALYSIS IN PROF. DR. R.D. KANDOU GENERAL HOSPITAL MANADO

Background: Chronic kidney disease (CKD) is a pathological process hallmarked by progressive decline of kidney function and most likely end up in kidney failure state. Hemodialysis (HD) is one of the main therapy for CKD, where the goal is to replace renal function in maintaining fluid and acid-base-electrolyte balance, excreting metabolism waste and controlling blood pressure. Intradialytic hypertension (IDH) is a possible complication during HD. Interdialytic Weight Gain (IDWG) is a risk factor of IDH. Objective: To acknowledge relation between IDWG and IDH incidence in CKD patients. Method: This is analytic observational cross sectional study that was carried out from November–December 2020. Patients with CKD aged ≥18 years old and had routine HD twice a week for at least 3 months. IDWG = [(current pre dialysis weight – previous post dialysis weight)/dry weight × 100%]. Dry weight was defined by body weight without clinical sign of fluid retention. IDWG were categorized into 3 groups: &lt;3% (group I); 3.1–3.9% (group II); &gt;3.9% (group III). IDH was defined by increasing in systolic blood pressure &gt;10 mmHg after at least 4 of 6 consecutive HD sessions. Blood pressure was measured 30 minutes before and after HD. Patients who did not finish at least 4 HD sessions, refused informed consent, and whose body weight unobtainable were excluded. Data was analyzed using chi square with significance level of p &lt; 0.05 and confidence interval (CI) 95%. Result: 140 patients were included in this study (70 male, 70 female). IDH were found in all 3 IDWG groups: group I 37%, group II 80%, and group III 93.1%. Data analysis showed a significant relation between IDWG and IDH (p = 0.0001). Conclusion: There is a significant relation between IDWG and incidence of IDH.

Asymptomatic Supraventricular Arrhythmias in Patients Undergoing Dialysis

Aim. Supraventricular arrhythmias (SVA) are associated with high morbidity and mortality. However, little attention is paid to this condition in patients undergoing hemodialysis. The aim of this study was to analyze the long-term relationship of intradialytic SVA, including asymptomatic arrhythmias, with adverse events in a cohort of patients undergoing hemodialysis.Material and methods. An observational prospective study was conducted in a group of patients on hemodialysis with a 10-year follow-up. The study involved 77 patients (42 men and 35 women; mean age 58±15 years) with sinus rhythm, then they were monitored for ECG for six consecutive hemodialysis sessions during recruitment.Results. Arterial hypertension was present in 68.8% of patients, diabetes mellitus in 29.9% of patients. SVA were reported in 38 patients (49.3%); they all had a short-term, asymptomatic character and were terminated independently. Age (hazard ratio [HR] 1.04 per year; 95% confidence interval [CI] 1.00-1.08) and an increase of the atrium (HR 4.29; 95%CI 1.30-14.09) were associated with supraventricular arrhythmia in multidimensional analysis. During an average follow-up of 40 months, 57 patients died, and cardiovascular diseases were the main cause of death (52.6%). Variables associated with all-cause mortality in the Cox model were age (HR 1.04 per year; 95%CI 1.00-1.08), C-reactive protein (HR 1.04 per 1 mg/l; 95%CI 1.00-1.08) and supraventricular arrhythmias (HR 3.21; 95%CI 1.29-7.96). Patients with supraventricular arrhythmias also had a higher risk of nonfatal cardiovascular events (HR 4.32; 95%CI 2.11-8.83) and symptomatic atrial fibrillation during observation (HR 17.19; 95%CI 2.03-145.15).Conclusions. Strong relationships have been established between the presence of supraventricular arrhythmias recorded during ECG during dialysis and symptomatic AF developing in the future. Patients with supraventricular arrhythmias had a larger right atrium. Age and supraventricular arrhythmias are the main variables associated with mortality in dialysis patients.

Oxygen extraction ratio to identify patients at increased risk of intradialytic hypotension

Intradialytic hypotension (IDH) is a hemodynamic phenomenon recently associated with decreased blood oxygen saturation (SO2). The ratio between peripheral oxygen saturation (SpO2) and central venous SO2 (ScvO2) or Oxygen Extraction Ratio (OER), which represents a roughly estimate of the amount of oxygen claimed by peripheral tissues, might be used to estimate haemodialysis (HD) related hypoxic stress. Aim of this pilot study was to evaluate the relationship between OER increments during dialysis sessions (ΔOER) and episodes of IDH. We enrolled chronic HD patients with permanent central venous catheter (CVC) and no fistula, in whom ScvO2 measurement is at hand. OER ([(SpO2 − ScvO2)/SpO2] × 100) was measured in three consecutive HD sessions (HD OER sessions) before HD, after 15′, 30′ and 60′ min and at the end of HD. Then, a one-year follow-up was planned to record the number of IDH episodes. In the 28 enrolled patients (age 74 ± 2.6 years), during 12 ± 1.2 months of follow up, incidence of IDH was 3.6%. We divided patients into two groups, above or below the median value of ΔOER at the end of HD, which was 36%. In these groups, the average incidence of IDH was 7% and 2% respectively (p < 0.01), while OER values before HD were not different. Notably, in the high ΔOER group the OER increment was evident since after 15′ and was significantly higher than in the low ∆OER group (∆OER-15′ = 19 ± 3.0% vs. 9.0 ± 3.0%; p < 0.05). By comparison, blood volume changes overlapped in the two groups (average change − 9 ± 0.8%). Values of ∆OER > 19% after only 15′ of HD treatment or > 36% at the end of the session characterize patients with higher rates of hypotension. Intradialytic ∆OER, a parameter of tissue hypoxic stress, identifies more fragile patients at greater risk of IDH.

Management of iron deficiency anemia in hemodialysis patients based on mean corpuscular volume

BackgroundTo manage the anemic status in hemodialysis (HD) patients, a well-balanced combination therapy based on the use of erythropoiesis-stimulating agents (ESAs) and iron supplementation is essential. Serum ferritin level and transferrin saturation rate (TSAT) are the current standard tests for screening iron deficiency status. However, these are not included in frequently checked regular blood measurements in many HD centers. Other parameters that could predict a hemoglobin (Hb) increase response from iron supplementation have yet to be established. To determine a frequently checked and regularly measured biomarker for predicting iron deficiency status, this study investigated the value of mean corpuscular volume (MCV) as a clinical parameter for HD patients receiving intravenous iron supplementation (Fe-IV) therapy.Methods and resultsOne hundred thirty four HD patients, 88 non-HD patients with anemia, and 50 HD patients on Fe-IV therapy from the Nozatomon clinic were assessed. Comparison of MCV values of anemic HD patients and anemic non-chronic kidney disease (CKD) patients showed that anemic HD patients had significantly higher MCV values (93.9 ± 7.3 fL) compared with anemic non-CKD patients (82.8 ± 8.8fL). Fifty HD patients, who received Fe-IV therapy at ten consecutive HD sessions (inclusion criteria: Hb ≤ 12.0 g/dL, TSAT < 20%, and serum ferritin < 100 ng/mL) showed a rapid increase during the Fe-IV period in MCV, Hb, and TSAT levels. After the completion of the Fe-IV therapy, MCV persisted at the increased levels, whereas Hb levels further increased and peaked at 1 month with a gradual decline after, largely influenced by ESA dosage reductions. The 50 patients were divided into three groups according to the MCV levels obtained immediately prior to the Fe-IV therapy (MCV ≤ 85 fL, 85 fL < MCV ≤ 90 fL, MCV > 90 fL), and Hb changes at 50 days after the initiation of the Fe-IV therapy were compared. All the patients in the MCV ≤ 85 fL group and most of the patients in the 85 fL < MCV ≤ 90 fL group showed linear and consistent Hb increase during the 50-day period. In marked contrast, patients in the MCV > 90 fL group showed dispersed trends in their Hb increase. The present study also revealed that successful ESA dosage reduction could be achieved after the Fe-IV therapy in both the MCV ≤ 85 fL and 85 fL < MCV ≤ 90 fL groups.ConclusionsThe present study underscored the value of MCV in perceiving iron deficiency status as well as predicting iron-based therapeutic response in HD patients.

ACUTE RENAL FAILURE IN INTRAOPERATIVE LESION OF BOTH URETERS FOLLOWING HYSTEROADNEXECTOMY- CASE REPORT

Intraoperative injury of the ureters and the bladder during hysterectomy is not uncommon. Lesion of both ureters is much rarer condition and it occurs in 5% to 10% of injury cases. Acute renal failure develops in case of ligation of both ureters. Diagnosis of this condition, intraoperatively or in the first seven postoperative days at the latest, allows complete recovery of the renal function. A 44-year-old women was admitted at the Department of Nephrology at Acibadem Sistina Hospital in Skopje due to anuria, lower abdominal pain and nausea. On admission the patient had increased creatinine levels and sonography finding of grade 3 hydronephrosis bilaterally. Two days earlier the patient underwent hysterectomy and adnexectomy by Pfannensteil due to myoma. MRI of lesser pelvis without contrast and retrograde urethrocystography were performed for diagnostic purposes. A bilateral prevesical lesion of the ureters was found. Upon the admission, the patient underwent two consecutive haemodialysis sessions. On the fourth day after the first surgery (hysterectomy) the patient was transferred to the Department of Urology where a surgery: bilateral ureterocystoneostomy (sec. Litch-Gregoire) was performed the same day. Following surgery the patient went in to polyuria with rapid normalization of the renal function. On the sixth postoperative day, the patient was discharged from the hospital in good general condition. In case of anuria following hysterectomy, a mechanical lesion of the ureters should be suspected. Early diagnosis allows for complete rehabilitation without consequences to the renal function. Keywords: acute renal failure, intraoperative ureteral lesion, hysterectomy, haemodialysis.

Cohort Study of Outpatient Hemodialysis Management Strategies for COVID-19 in North-West London

BackgroundDialysis patients are at risk of severe coronavirus disease 2019 (COVID-19). We managed COVID-19 hemodialysis outpatients in dedicated satellite dialysis units. This provided rare opportunity to study early disease progress in community-based patients. We aimed to (i) understand COVID-19 progression, (ii) identify markers of future clinical severity, and (iii) assess associations between dialysis management strategies and COVID-19 clinical outcomes.MethodsWe conducted a cohort study of all outpatients managed at a COVID-19 hemodialysis unit. We analyzed data recorded as part of providing COVID-19 clinical care. We analyzed associations between features at diagnosis and the first 3 consecutive hemodialysis sessions in patients who required future hospital admission, and those who had died at 28 days.ResultsIsolated outpatient hemodialysis was provided to 106 patients over 8 weeks. No patients received antiviral medication or hydroxychloroquine. Twenty-one patients (20%) were admitted at COVID-19 diagnosis; 29 of 85 patients (34%) were admitted after initial outpatient management; 16 patients (15%) died. By multivariate analysis, nonactive transplant list status, use of institutional transport, and increased white cell count associated with future hospitalization and increased age associated with death. Oxygen saturations progressively decreased over the first 3 dialysis sessions in the cohorts that progressed to future hospital admission or death. Mean ultrafiltration volume of the first 3 hemodialysis sessions was reduced in the same cohorts.ConclusionsOutpatient hemodialysis in patients with COVID-19 is safe for patients and staff. Features at the first 3 dialysis sessions can identify individuals at risk of future hospitalization and death from COVID-19.