Online Clearance Monitoring Research Articles

Real-Time Dialysis Dose: Ionic Dialysis Versus Classical Urea Kinetic Modeling Indices.

Introduction Worldwide, over 850 million people need renal replacement therapy, and over 80% of them are on hemodialysis. The term "dialysis adequacy" is most often associated with the achievement of minimally acceptable indices - single pool Kt/V (spKt/V) and urea reduction ratio (URR%) and largely does not take into account other clinical indicators in patients. In addition, it should be taken into account that in the conditions of clinical practice, their measurement is carried out according to standards controlled by the regulatory structures and is carried out with a frequency between one and three months, and not during each dialysis procedure. Accordingly, based on the obtained value, we assume that it refers to the urea clearance of the entire dialysis prescription. A new methodology for measuring dialysis adequacy through ionic dialysis allows dose estimation in real time without the need for additional blood testsby recording the difference in sodium ion conductivity at the dialyzer inlet and outlet. The latter corresponds to the dialysis dose delivered and can be measured at each dialysis session, enabling timely therapeutic intervention at minimal cost to the community. The aim of this original article is to present ion dialysis to the community as a reliable and inexpensive alternative to classical urea kinetic modeling (UKM), evaluating the comparability of the two methods and the possible sources of error in the result. Material and methods This was a retrospective study of 32 patients undergoing hemodialysis at the Clinic of Nephrology and Dialysis at the University Hospital St. Marina (Varna, Bulgaria) for the period between January and December 2020.For each of the patients, four measurements (every three months) of the delivered dialysis dose were performed by ion dialysis and classical urea kinetic modeling in order to assess the comparability and reliability of the two methods. Results The analysis of the results proved a high correlation between the validated indicators of dialysis adequacy (spKt/V; URR) and those registered with online monitoring (online clearance monitor) by ionic dialysis - online Kt/V (onKt/V)while at the same time reporting a significant difference in the two methods - primarily based on the anthropometric formulas used to estimate the volume. The established regression models confirmed the high predictive value of ionic dialysis in relation to the actually delivered dose. Discussion Despite the high bond strength, our recorded values ​​for onKt/V are 8% lower compared to results using UKM. Therefore, onKt/V as an assessment metric has the ability to underestimate the dialysis dose received. Various factors as a possible source of error and its cause have been reported by some authors. Several studies have reported differences of 2-5% in instantaneous conductance measurements, which they associate mainly with differences in the diffusion coefficients of urea and sodium, as well as different effects of dialysis membrane charge or inadequate ultrafiltration correction. Conclusions Our study confirms that online clearance monitoring (OCM) is a practical non-invasive tool for daily use that complements the classic performance of OCM by helping to deliver an adequate dialysis dose with increased patient benefit and minimal cost of financial resources.

Application of therapeutic ultrasonic waves across the dialyzer membrane: A pilot study on the impact on dialyzer clearance and safety.

Progressive clogging of the dialyzer membrane during hemodialysis can compromise solute removal efficiency. Existing solutions fall short in addressing intradialytic reduction of dialyzer clearance. This pilot study aims to assess the impact and safety of applying therapeutic ultrasonic waves to dialyzers for mitigating intradialytic clogging. In this pilot study, 15 stable maintenance hemodialysis patients (12 males and 3 females) were enrolled. Each patient served as their own control. They underwent one session of hemodialysis with the application of therapeutic ultrasonic waves (Ultrasonic session) and were crossed-over to a second session without the use of ultrasonic waves (Control session). All the study sessions operated at a fixed dialysate flow rate of 500 mL/min and a blood flow rate of 250 or 300 mL/min. The adequacy of dialysis achieved during each session was monitored using Online Clearance Monitoring of the dialysis machines, and clearance K values, varying between 135 and 209 mL/min, were recorded, and plotted. A direct comparison between Control and Ultrasonic sessions was performed to assess the impact and safety of using ultrasonic waves during hemodialysis. The mean percentage decline in dialyzer clearance values was 4.41% for Ultrasonic sessions (SD: 5.3) and 12.69% for Control sessions (SD: 6.35) (p-value <0.001). This indicates that the application of ultrasonic waves reduced the decline in clearance values. The mean differences of the blood component parameters were comparable between both Ultrasonic sessions and Control sessions, suggesting the safety of utilizing ultrasonic waves during dialysis. Microscopic membrane analysis corroborated the safety. Intradialytic clogging of dialyzer membranes is a significant problem that can cause dialysis inadequacy. Our study tackles this issue by introducing therapeutic ultrasonic waves to improve dialyzer clearance during hemodialysis sessions in patients.

Dialysis Adequacy: A Cross-Sectional Study to Assess the Reliability of the Online Clearance Monitor to Measure Dialysis Dose.

Background Frequent assessment of the dialysis dose delivered to hemodialysis patients might help improve morbidity and mortality. Daugirdas' second-generation formula is the recommended method for calculating dialysis doses. However, urea reduction ratios (URRs) and online clearance monitors (OCMs) are frequently used to assess dialysis adequacy due to their more straightforward concept and ease of use. This study was conducted to determine the most reliable method for measuring dialysis adequacy by comparing the correlation of urea reduction ratio and online clearance monitor measurements with the dialysis dose measured using the recommended Daugirdas' second-generation formula. Methods This study was an observational, cross-sectional, single-center study. The dialysis dose was measured as a urea reduction ratio and by an online clearance monitor simultaneously for 50 patients. It was compared to the dialysis dose measurements obtained using Daugirdas' second-generation formula. Results There was a statistically significant strong positive correlation (r = 0.929; p ≤ 0.001) of the urea reduction ratio and a poor concordance (ρC = 0.401; p ≤ 0.001) of online clearance monitor measurements with the dialysis dose measured using Daugirdas' second generation formula. Conclusion Our findings illustrate that the urea reduction ratio may be a more straightforward and reliable means for assessing the adequacy of intermittent hemodialysis with minimal errors in patients compared to online clearance monitors. Online clearance monitors offer easy estimation and practicality with minimal effort but are prone to multiple errors and may not be accurate in some settings.

#3179 PREDICTORS OF VASCULAR ACCESS THROMBOSIS IN MAINTENANCE HEMODIALYSIS PATIENTS – QA, KT/V AND CONVECTIVE VOLUME

Abstract Background and Aims Vascular access (VA) is vital for hemodialysis (HD) treatments and should allow to achieve the recommended dose of dialysis. Thrombosis is the primary cause of VA failure in grafts (AVG) and fistulas (AVF) and should be avoided as it can lead to significant patient morbidity and mortality. However, despite its importance, predictors of VA thrombosis are not completely established. Even if large randomized controlled trials are lacking to clearly identify the ideal surveillance strategies and benefits of surveillance, evidence suggests that when combined with preemptive interventions, prospective monitoring and surveillance and early detection of dysfunctional VA may reduce the thrombosis rate and improve its long-term patency. Several monitoring and surveillance techniques of VA can be used, from unexplained drop in dialysis adequacy (Kt/V and convective volume) to the noninvasive estimation of VA blood flow (Qa). The aim of this study was to assess whether these parameters can predict VA thrombosis. Method We retrospectively evaluated all episodes of VA thrombosis admitted in our Vascular Access Centre (VAC) between July 2019 and December 2022. Patient's demographics, VA characteristics and data from dialysis sessions were collected. Descriptive statistics were calculated and expressed as mean (standard deviation) or median (IQR) or count (%), as adequate. Values were compared using Mann-Whitney for independent samples and Pearson chi-squared test with 95% confidence intervals (CI). The predictors of VA thrombosis studied were Qa, Kt/V and convective volume (CV), in the case of the patients on hemodiafiltration. Qa was measured using the thermodilution method called blood temperature monitoring (BTM®), and Kt/V and CV with Online Clearance Monitoring (OCM®). In this study, we evaluated the ratio between the last measured value of Qa prior to the thrombosis episode and the average of the previous three months (Qa trend), and the ratio between the last measured value of Kt/V and CV before the thrombosis episode and the average of the previous month (Kt/V trend and CV trend, respectively) as predictors of VA thrombosis Results From July 2019 and December 2022, we treated, in our VAC, 386 VA thrombosis episodes in 226 patients. In our study population, mean age was 71.1 (± 13.2) years, 64% were male, 31% had diabetes. The dialysis vintage was 51 (69) months and the VA vintage was 42 (62) months. 70.2% of the VA thrombosis were on AVF. Prior to thrombosis the median of Qa obtained by BTM was 650 (495) mL/min, the median of kt/v was 1.43 (0.62) and the median of CV was 22.4 (6.3). The average of the previous values for Qa, Kt/V and CV were 658 (353) ml/min, 1.53 (0.35) and 23.5 (3.9) L. The median (IQR) of Qa trend, Kt/V trend and CV trend were -8,5 (33,3) %, -6,0 (28,2) % and -2,5 (17,0)%. We found no statistical significance for Qa trend and CV trend between AVF and AVG as predictors of VA thrombosis, but the reduction in Kt/V values was significantly more pronounced in AVF (-6.8%; Q1 -30.1% to Q3 0.7%) than in AVG (-3.8%; Q1 -18.0% to Q3 + 5.0%) (p = 0.007) as predictor of thrombosis. In 68.9% of VA thrombosis, we noticed a reduction in Kt/V value before the episode (73.8% in AVF and 57.5% in AVG, p = 0.002). We found no statistically significance in the reduction of Qa and CV values between AVF and AVG thrombosis episodes. Conclusion Our study showed that Kt/V trend was a better predictor of VA thrombosis than Qa trend and CV trend, especially in AVF.

Prediction of end-dialysis serum sodium concentration in severely hyponatremic kidney failure patients undergoing conventional hemodialysis using sodium kinetic equation

Background and ObjectivesConventional hemodialysis (HD) for kidney failure patients with severe hyponatremia may be complicated by rapid correction of hyponatremia, which increases the risk of osmotic demyelination syndrome. A simple sodium kinetic equation was effective in prediction of end-dialysis serum Na+ in severely hyponatremic kidney failure patient treated with continuous venovenous hemofiltration, but was not tested in conventional HD. The aim of this study was to assess the validity of this equation when used in conventional HD.MethodsTwenty conventional HD sessions were delivered to 12 kidney failure patients with severe hyponatremia (serum Na+ < 120 mEq/L). The target change in serum Na+ was 4 mEq/L. The DNa.t/V that obtained this change was predetermined according to the sodium kinetic equation and monitored in real time by online clearance monitoring software embedded in dialysis machine. The dialysis session was terminated once the target DNa.t/V was achieved.ResultsThe mean observed and predicted serum Na+ were 119.80 ± 3.42 mEq/L and 119.45 ± 3.12 mEq/L, respectively. Bland–Altman plot analysis revealed a mean difference ± SD of 0.33 ± 1.26 mEq/L, and 95% limits of agreement of − 2.13 to 2.83. The imprecision in prediction of end-dialysis serum Na+ was 2.52 mEq/L. The small difference and clinically insignificant 95% limits of agreement indicate a good agreement between the observed and predicted serum Na+.ConclusionThe sodium kinetic equation was effective in prediction of end-dialysis serum Na+ in kidney failure patients with severe hyponatremia.

Using the Intelligent System to Improve the Delivered Adequacy of Dialysis by Preventing Intradialytic Complications

Acute kidney failure patients while detoxificated by hemodialysis (HD) mostly or continuously faced regular problems such as low blood pressure (hypotension), muscle cramps, nausea, or vomiting. Higher intradialytic symptom leads to low-quality HD treatment. Although more known therapeutic interventions are used to relieve the HD side effects, this study was designed to investigate how intelligent systems can make highly beneficial alterations in dialysis facilities and equipment to ease intradialytic complications and help the staff deliver high-quality treatment. A search was performed among relevant research articles based on nonpharmacological intervention methods considered to prevent adverse effects of renal replacement therapy until 2020 in the PubMed databases using the terms “intradialytic complications,” “intradialytic complication interventions,” “nonpharmacological interventions,” “intradialytic exercises,” and “adequacy calculation methods.” Studies included the prevalence of intradialytic complications, different strategies with the aim of preventing complications, the outcome of intradialytic exercises on dialysis symptoms, and dialysis dose calculation methods. The results showed the incidence of hypotension varying between 5% and 30%, fatigue, muscular cramps, and vomiting as the most common complications during dialysis, which greatly affect the outcome of HD sessions. To prevent hypotension, ultrafiltration profiling, sodium modeling, low dialysate temperature, and changing the position to Trendelenburg are some strategies. Urea reduction ratio (URR), formal urea kinetic modeling (FUKM), formal single-pool urea kinetics, and online clearance monitoring (OCM) are methods for calculating the delivered dose of dialysis in which OCM is a low-cost and accessible way to monitor regularly the quality of dialysis delivered. Integration of the chair and HD machine which is in direct contact with the patient provides an intelligent system that improves the management of the dialysis session to enhance the quality of healthcare service.

Increasing Dialysate Flow Rate over 500 ml/min for Reused High-Flux Dialyzers do not Increase Delivered Dialysis Dose: A Prospective Randomized Cross Over Study

Objective: The primary objectives were: 1) to study the impact of Qd (500 vs 800 ml/min) on the delivered dose by reused dialyzers, and 2) to determine dialysis efficiency of a dialyzer reused 15 times.Materials and Methods: A prospective randomized-controlled crossover study was conducted in 42 thrice-weekly hemodialysis (HD) patients (630 HD sessions in each Qd). Delivered doses at both Qds were assessed by single-pool Kt/V (spKt/V), equilibrated Kt/V (eKt/V) and online clearance monitoring Kt/V (Kt/VOCM), measured at mid-week HD session using a new dialyzer and then again at every mid-week HD session.Results: Although the spKt/V in HD sessions using new dialyzers at Qd of 500 ml/min was slightly lower than spKt/V at Qd of 800 ml/min (2.19±0.08 vs. 2.34±0.08, respectively, P=0.04), when accounting for urea rebound as assessed by eKt/V and Kt/VOCM, there was no significant difference. The average delivered doses in dialyzers reused 15 times, with the mean average of spKt/V, eKt/V and Kt/VOCM at Qd 500 ml/min, were not significantly inferior to the delivered doses at Qd 800 ml/min. Reusing a dialyzer 15 times did not decrease dialysis efficiency and delivered doses in all HD sessions reached spKt/V &gt;1.4.Conclusion: Increasing Qd over 500 ml/min for modern dialyzers does not significantly increase delivered dose of dialysis. Dialyzer reuse does not affect dialysis efficiency and provides adequate dialysis therapy.

Comparison between different methods of calculating Kt/V as the marker of adequacy of dialysis

ABSTRACTObjectives:To compare different methods of calculating adequacy of hemodialysis in terms of Kt/V.Methods:This was an observational, quantitative study undertaken after the approval of Internal Review Board at the Hemodialysis Unit of Nephrology department, Mayo Hospital, Lahore from 1st December 2018 to 30th June 2019. Sixty hemodynamically stable patients of end stage renal disease undergoing hemodialysis for more than three months with age 18 to 70 years were included in the study by convenience non probability sampling. Critically ill patients with multiple co-morbidities like sepsis (i.e. total leukocyte count >11000 or <4000 x 109/L), ischemic heart disease, pace- makers, malignancies, cirrhosis etc. were excluded. Patients who were not adherent to dialysis prescription or hemodynamically unstable were also excluded. One way ANOVA and Pearson’s correlation were used to find correlation between three methods of measuring Kt/V.Results:Mean ultrafiltration was 2.1+ 0.76 liter/session. Pre dialysis weight was 64.7 +14.7 kgs, mean post dialysis weight was 62.5 + 14.7 kgs. For every patient blood flow rate was 300 ml/m and dialysis flow rate was 500 ml/min. The mean values of Kt/V measured by Daugirdas formula was 1.35 ± 0.33, mean online clearance monitoring (OCM) value was 1.17 ± 0.29 and by normogram was 1.36 ± 0.33. There was positive significant correlation between values of Daugirdas formula, Normogram and online clearance monitoring (OCM) i.e. r = 0.897 (p-value < 0.001) measured by Pearson’s correlation and one way-ANOVA.Conclusion:Online clearance monitoring can be used for measuring adequacy of hemodialysis, but OCM slightly underestimates Kt/V as compared to Daugirdas formula and Normogram.

Assessment of hemodialysis adequacy: Correlation between online clearance monitoring and single pool Kt/V.

Objectives: The aim of this study is to correlate the dose of dialysis delivered by both methods in the dialysis population in our developing country. Study Design: Cross Sectional study. Setting: Dialysis Centre at Doctor’s Hospital and Medical Center Lahore. Period: February 1, 2018 to April 30, 2018. Material &amp; Methods: Using Fresenius 4008S machines equipped with OCM, we prospectively studied 41 hemodialysis patients. All patients were on hemodialysis for more than three months. Pre and post dialysis urea samples were collected for estimation of single pool Kt/V and compared with OCM. Results: The average age of the patients was 56.46 ± 13.82 years and the mean duration of dialysis was 28.9 ±35.22 months. Mean blood flow rate was 309.27 ±46.06 mL/min. The mean Kt/V was 1.51 ±0.216 (&lt;p=0.001) and the mean OCM was 1.47 ±0.191 (&lt;p=0.001). We found a positive correlation between the two parameters i.e a Pearson’s Correlation: 0.83 (&lt;p=0.001) and an R square value of 0.645.We found that OCM is a good indicator of Kt/V. However, it underestimated Kt/V by 2.07%±8.53%. Conclusion: Online Kt/V calculated by ionic dialysance is a useful method to estimate dialysis dose without the need of blood samples. In clinical practice Kt/V is done on a monthly basis. Any change in the dialysis prescription would entail repeat labs. OCM can be performed at each dialysis session at no extra cost and in real time. Thus, it can prove to be a helpful and economical tool in the assessment of dialysis adequacy in the low income countries with limited resources.

Getting the basics right: the monitoring of arteriovenous fistulae, a review of the evidence

Despite being the preferred vascular access for haemodialysis, the arteriovenous fistula (AVF) remains prone to a number of complications, the most common of these being thrombosis secondary to stenosis. This has resulted in the widespread use of monitoring and surveillance programmes. Surveillance uses more resources than monitoring and has not been convincingly shown to improve outcomes. The evidence supporting the use of the various monitoring tools has been relatively neglected and has not been the focus of literature review. This narrative review is the first to appraise the evidence for the use of physical examination, access recirculation, Kt/V and dynamic venous pressures (DVP) as monitoring tools in mature AVF. The vastly increased number of data points for access recirculation, Kt/V and DVP produced as standard by online clearance monitoring (OCM) on modern dialysis machines is likely to have significantly changed the utility of these metrics in the prediction of AVF failure. Algorithms have been developed to highlight those of highest risk of failure. The evidence supporting the use of monitoring in the prediction of AVF failure is predominantly observational, underpowered and more than 20 years old. Access recirculation and Kt/V appears to have higher utility in AVF than in arteriovenous grafts. We suggest that the development of OCM necessitates the reevaluation of these tools.

P1363ON-LINE SURVEILLANCE OF ESTABLISHED HAEMODIALYSIS ARTERIOVENOUS FISTULA UTILISING FRESENIUS THERAPY MONITORING SYSTEM AND EUROPEAN CLINICAL DATA SYSTEM (EUCLID): THE SHUNT STUDY- BASELINE DEMOGRAPHICS OF PARTICIPANTS

Abstract Background and Aims The arteriovenous fistula (AVF) is well established as the preferred vascular access for haemodialysis (HD). However AVF remain prone to a number of complications, the most common of these being thrombosis, which usually occurs on the background of a developing stenosis. The development of stenosis can be detected and the lesion treated before thrombosis occurs; this forms the rationale behind monitoring and surveillance programs. Surveillance uses more resources than monitoring and has not been convincingly shown to improve outcomes such as access loss. The evidence supporting the use of the various monitoring techniques in AVF is in the main observational, under-powered, out of date and based on studies populations of predominantly arteriovenous grafts (AVG). Monitoring techniques have been shown in multiple studies to have higher utility in AVF than AVG. The modern, high efficiency dialysis machine with integrated on-line clearance monitoring (OCM) necessitates the reconsideration of the performance and utility of monitoring metrics such as Kt/V and access recirculation (AR). The lack of evidence surrounding monitoring techniques is recognised by KDOQI who recommend that further research is required to validate these indicators. In this study we aim to examine if changes in AR and Kt/V values obtained through OCM during HD can help predict AVF failure. Method SHUNT is a UK single-centre prospective cohort study with a 1-year follow-up of all study participants. The 100 participants are aged over 18 years receiving in-centre maintenance HD with through an established AVF. We use the Fresenius Therapy Data Monitoring System (F-TDMS) and EuCliD system to capture all dialysis treatment data from Fresenius 5008 machines. This will allow trend analysis for AR and Kt/V to assess the accuracy of these parameters in predicting access failure. The primary outcome measure is to determine whether changes in AR and Kt/V trends are able to predict AVF failure. Secondary outcome measures include assessment of the utility of AR and Kt/V alone to predict AVF failure, the comparison of AR and Kt/V trends pre- and post-intervention and the assessment of the number of patients referred for fistulograms, requiring AVF intervention and suffering access failure, VA related hospitalization and central line use. Results The planned 100 AVF patients have been recruited. Participants’ mean and median age is 63.07 and 63.32 years respectively with a standard deviation of 14.21. The patients are 59% male and the mean BMI is 28.27kg/m2. The mean vintage on HD is 3.41 years with a median of 2.32 years. The AVF are 37% brachiocephalic, 35% radiocephalic (65% of which are at the wrist), and 13% brachiobasilic transposition. Aetiology of primary renal disease is diabetic nephropathy in 22%, glomerulonephritis in 19%, unknown in 19%, obstructive in 15%, polycystic kidney disease in 11%, renovascular/hypertensive in 9% and assorted other pathology (eg. ATN, TIN) in 5%. Conclusion Our study participants are broadly representative of the UK’s AVF population as a whole. We hope that the SHUNT STUDY will provide representative, up-to-date and robust evidence for the utility of these basic monitoring tools in the prediction of AVF stenosis in the age of OCM.

SAT-213 Relationship of Cardiovascular disease with dialysis dosage

Cardiovascular Disease (CVD) is the leading cause of death in End Stage Renal Disease (ESRD) patients on Maintenance Hemodialysis (MHD). The accumulation of uremic toxins play a part in the pathophysiology of cardiovascular disease that may progress to myocardial fibrosis, cardiomyopathy, left ventricular hypertrophy, vascular calcification and atherosclerosis. Thus, morbidity and mortality in hemodialysis patients is closely correlated to the delivered dialysis dose. The delivered dose is measured in MHD patients either by blood samples to calculate single pool Kt/V or by measuring the ionic dialysance in real time using online clearance monitoring (OCM). The aim of our study is to evaluate the influence of dialysis dose on the presence of CVD and to assess its relationship with echocardiographic parameters. 34 ESRD patients on MHD were included in the study from June 2019 to September 2019. Patients’ record, pre- and post- dialysis labs, Kt/V,OCM,URR, echocardiographic parameters including Left Atrial Volume Index (LAVI), Ejection Fraction (EF), Pulmonary Artery Systolic Pressure (PASP), presence of diastolic dysfunction and Left Ventricular Hypertrophy (LVH) were studied. Patients with a history of any cardiac event, a reduced EF or segmental wall motion abnormality on echocardiography were labelled as having CVD. Baseline echocardiographic measurements for each patient were analyzed. Data was analyzed using Statistical Package for Social Sciences (SPSS) version 25. Of the 34 hemodialysis patients there were 16 females and 18 males with age ranging from 17 to 87 years and mean age of 59.6 years (table 1). Patients had MHD vintage ranging from half a month to 79 months with a mean vintage of 33.9 months. 55.9% of patients had CVD. 14.7%(5) patients had a Kt/V of <1.4 and 85.3% (29) had Kt/V of >1.4. Average EF of patients with CVD was 46.9% and without CVD was 55.1%. Presence of CVD correlated negatively with EF (r = -0.541, p=0.001). Mean LAVI was 40.3ml/m2. 82.4% patients had a LAVI of >34ml/m2. Markers of dialysis dose OCM (r= -0.467, p=0.005), KT/V (r= -0.405, p=0.017), URR (r= -0.364, p=0.034) correlated negatively with the presence of CVD. Patients with a Kt/V of <1.4 had a higher prevalence of CVD and diastolic dysfunction. as compared to patients with Kt/V of >1.4 (table 3). A higher PASP was prevalent in patients with lower Kt/V as compared to those with high Kt/V. Patients with a Kt/V of <1.4 had a higher prevalence of moderately enlarged LAVI (42-48 ml/m2). OCM had a significant negative correlation with LAVI (r= -0.359, p=0.037). However, there was no statistically significant correlation of Kt/V with any of the parameters on echocardiography.View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT) The presence of Cardiovascular disease is related to dialysis dose. Sub-optimal dialysis is associated with CVD. Many echocardiographic parameters were related to the dose of dialysis. Patients with a lower Kt/V had higher LAVI and PASP. There was also an increased presence of diastolic dysfunction in patients with lower Kt/V. Thus, clearance during dialysis can influence cardiac clinical and echocardiographic parameters.

Knowledge and practices about hemodialysis among dialysis technicians in western part of India

Introduction: Chronic kidney disease (CKD) is a global health burden with a high economic cost to health systems. Objectives: To determine the knowledge and practices regarding end-stage renal disease and hemodialysis (HD) among dialysis technicians. Patients and Methods: Total of 157 technicians participated in a study carried out at Ahmedabad city of Gujrat state. A validated written questionnaire was distributed among dialysis technicians who gave their consent to participate in the study and responded questionnaires were analyzed. Data entry was made in Excel software in codes and analysis was conducted by SPSS software version 17.0 Results: Out of 157, 113 participants were routinely using online clearance monitoring. Around, 19.1% carried out disinfection of water loop once per week, while 23.6% and 28% were doing it once in 15 days and 30 days respectively. Reverse osmosis (RO) plant parameters like pH, hardness of water, chlorine content were checked once daily by 46.5% of technicians while 17.8% and 24.2% technicians were doing it once a week and once a month respectively. About 87.3% of technicians said that dialyzer was reused at their center. Accordingly, 33.8% and 51.6% of technicians were using formalin and per-acetic based disinfectants for dialyzer reprocessing. Additionally 7.6% of technicians were using hypochlorite as disinfectant at their center. Around 63.7% of technicians said they were not reprocessing dialyzers of HCV positive patients. They preferred to use single dialyzers in these subsets of patients at their center. Around, 79.6% of technicians said that endotoxin filter was installed in their dialysis unit. Likewise, 45.9% knew correctly the permissible level of endotoxin in RO water used for HD. Only 15.3% of technicians had correct knowledge of permissible level of bacteria in treated RO water as per association for the advancement of medical instrumentation (AAMI) standards. Conclusion: Better knowledge and awareness about dialysis standards among dialysis technicians will help in better patient’s care. Effective dialysis education campaign needs to be driven at regular intervals with relevant information among dialysis technicians to address the knowledge gap.

Severe suicidal self-poisoning with massive dose of potassium ferricyanide(III): hyperkalemia but not free cyanide may cause death

Potassium ferricyanide(III), K3[Fe(CN)6], has a widespread use in blueprint drawing, photography, chemical industry, and metallurgy. In mice, the oral lethal dose 50 (LD50) is 1600 mg kg−1. We report the case of a suicide attempt in a 37-year-old male by intentional ingestion of 80 g of potassium ferricyanide(III) dissolved in water. The estimated ingested dose was 770 mg kg−1. The patient reported vertigo as the first sign of poisoning and six episodes of diarrhea with dark-colored stool 2 h after ingestion. The patient was transported by ambulance to the intensive care unit 8 h after ingestion. He was conscious and spontaneously ventilating, with a Glasgow Coma Scale (GCS) score of 15. On ECG performed at admission, tall “tented” T waves in V3–V6 and progressive flattering of P waves were registered. Serum concentrations of potassium of 7.2 mmol dm−3, urea of 7.1 mmol dm−3, and creatinine of 162 µmol dm−3 indicated development of acute renal failure. Despite the administration of intravenous insulin and 10% glucose infusion during the first hours after admission, there was a further elevation of serum potassium to 7.4 mmol dm−3 suggesting acute renal failure. For this reason, intermittent hemodialysis was performed [duration 200 min, blood flow rate 147 cm3 min−1, online clearance monitoring (OCM) clearance rate 100 cm3 min−1, and substitution fluid volume 5.8 dm3]. The condition of the patient stabilized and he was discharged from hospital on the fourth day after admission. This case report demonstrates the risks of life-threatening hyperkalemia and acute renal failure as complications of massive ingestion of potassium ferricyanide(III).

Application of on-line clearance monitoring in evaluating Kt/V of dialysis patients

Objective To evaluate the role of monitoring hemodialysis Kt/V by online clearance monitoring(OCM) in assessing dialysis sufficiency of maintenance hemodialysis (MHD) patients by different dialysis modes. Methods This is a prospective single-centre study in china. In this study, 46 patients with MHD were assessed including 30 males. The study was conducted over a period of 4 weeks. All patients were dialysed with conventional bicarbonate heamodialysis and three sessions per week. In the first and second week, blood flow rate was 250 mL/min, dialysate flow rate was performed at 500 mL/min and 800 mL/min, respectively. In the third and forth week, blood flow rate was 300 mL/min, dialysate flow rate was performed at 500 mL/min and 800 mL/min, respectively. The type and size of dialyzer was kept constant. The treatment time was 4 hours. Delivered dose of dialysis, measured by Kt/Vocm, was determined from serial measurements of ionic dialysance made throughout each treatment. Meanwhile, blood urea nitrogen(BUN) of pre-and post- dialysis were examined. Then Kt/V was calculated according to the equation Daugirdas and the correlation between Kt/V by OCM and by calculation in different blood flow rates or dialysate flow rates was evaluated. Results There was no statistical differences between ultrafiltration volumes per week. From 1 to 4 week, the correlation coefficient of linear regression analysis was γ1=0.895, γ2=0.919, γ3=0.913 and γ4=0.940, respectively(P<0.001). The value for Kt/Ve minus Kt/Vocm was (0.176±0.111), (0.209±0.110), (0.182±0.091) and (0.193±0.105) , respectively(P<0.05). The ROC curve for the Kt/Vocm was formed for dialysis adequancy: AUC=0.900, 95%CI(0.835, 0.966) , P<0.001. The marginal value of Kt/Vocm1.1 was the absolute criterion for the minimum dialysis dose. Conclusions OCM can display the Kt/V data conveniently and accurately, don’t need blood sample. It is very useful in monitoring the adequacy of dialysis and the correlation between Kt/Ve and Kt/Vocm is not be affected by increasing Qd or Qb. Key words: Renal Dialysis; Urea; Metabolic Clearance Rate

Online measurement of hemodialysis adequacy using effective ionic dialysance of sodium-a review of its principles, applications, benefits, and risks.

Dialysis dose is an important determinant of clinical outcomes in patients with end stage renal disease on maintenance dialysis. In clinical practice dialysis dose is monitored at least monthly by urea clearance based on Urea Kinetic Modeling. Online clearance monitoring using effective ionic dialysance (EID) of sodium (Na+ ) is available on some hemodialysis machines. This paper reviews the background, methodology, additional applications, and potential risks associated with EID. Effective ionic dialysance provides a reliable, real-time, noninvasive, and inexpensive measurement of dialysis dose during an ongoing hemodialysis (HD) session to allow interventions and assess the impact of these changes on clearance. Surveillance of vascular access flow rates can be used to screen for access dysfunction and refer for interventions. There is a concern that EID measurements may cause Na+ loading because of high dialysate Na+ used during these measurements, however, mathematical models, in vitro experiments, and clinical studies in patients on maintenance HD do not show any evidence of Na+ loading during EID measurements. We cannot rule out the possibility of nonosmotic Na+ accumulation in the skin because no published literature exists on this topic as it pertains to clearance measurements based on EID of Na+ .

Quantification of Hemodialysis Dose: What Kt/V to Choose?

Quantification of hemodialysis became more accurate and easier after the advent of ionic dialysance and the use of methods for estimating urea distribution volume (V). The aim of this study was to compare different methods of hemodialysis dose assessment: Kt/VDau (Daugirdas 2nd generation), Kt/VOCM (Kt by OCM (Online Clearance Monitor) and V by Watson), and Kt/VBCM (Kt by OCM and V by bio-impedance); and to assess the dialysis adequacy, defined by a Kt/V>1.4. Prospective, observational study. 35 hemodialysis sessions were evaluated in 35 chronic hemodialysis patients. During each session, we measured simultaneously, Kt/VOCM, Kt/VBCM and calculated Kt/VDau by performing blood samples before and after each session. 35 patients, gender (M/F: 19/16), mean age of 50.49 years, were evaluated. We noted a difference between the three methods of evaluating Kt/V index: Kt/VDau, Kt/VOCM and Kt/VBCM (1.82 ± 0.29; 1.45 ± 0.23; 1.8 ± 0.33, p<0.001). Comparison of Kt/VOCM with Kt/VDau and Kt/VBCM leads to a significant systematic underestimate of Kt/V by 22% and 20.5% respectively. Better agreement between Kt/VDau and Kt/VBCM was observed. The adequate hemodialysis was achieved, according to three methods: Kt/VDau, Kt/VOCM and Kt/VBCM respectively in 100%, 57,1% and 88.6% of the cases. The Kt/V index is different depending on the method used for its evaluation. The three methods can be used for quantification of hemodialysis with a better agreement between Kt/VDau and Kt/VBCM. In this study, Kt/VOCM results underestimate hemodialysis efficiency. This difference has to be considered when applying quantification of hemodialysis to clinical practice.

Factors determining a low dose of haemodialysis as measured by ionic dialysance in critical patients with acute kidney injury.

Estimating the dialysis dose is a requirement commonly used to assess the quality of renal replacement therapy (RRT) in patients with chronic kidney disease (CKD). In patients with acute kidney injury (AKI), this value is not always evaluated and it has been estimated that the prescribed dose is seldom obtained. Reports addressing this issue in AKI individuals are scarce and most have not included an adequate number of patients or treatments, nor were patients treated with extended therapies. Kt values obtained by the ionic dialysance method have been validated for the evaluation of the dialysis dose and it has also been shown that, compared with Kt/V, this is the most sensitive strategy for revealing inadequate dialysis treatment in critically ill AKI individuals. The main aim of this study was to assess the difference between the prescribed and the administered dialysis dose in critically ill AKI patients, and to evaluate what factors determine this gap using Kt values assessed through ionic dialisance. Data from 394 sessions of renal replacement therapy in 105 adult haemodialysis (HD) patients with oliguric acute kidney injury and admitted to ICU were included in this analysis. RRT was carried out with Fresenius 4008E dialysis machines equipped with on-line clearance monitoring (OCM® Fresenius), which use non-invasive techniques to monitor the effective ionic dialysance, equivalent to urea clearance. The baseline characteristics of the study population as well as the prescription and outcome of RRT were analysed. These variables were included in a multivariate model in which the dependent variable was the failure to obtain the threshold dose (TD). The main baseline characteristics of the study population/treatments were: age 66 ± 15 years, 37% female, most frequent cause of AKI: sepsis (70%). Low BP and/or vasoactive drug requirement (71%), mechanical ventilation (70%) and average individual severity index: 0.7 ± 0.26. Two hundred and one intermittent HD (IHD) and 193 extended HD (EHD) sessions were performed; the most frequently used temporary vascular access was the femoral vein catheter (79%). Prescribed Kt was 53.5 ± 14L and 21% of prescriptions fell below the TD. Sixty-one percent of treatments did not fulfill the TD (31 ± 8L) compared with 56 ± 12L obtained in the subgroup that achieved the target. Compared to IHD, EHD provided a significantly larger Kt (46 ± 16L vs 33L ± 9L). Univariate analysis showed that inadequate compliance was associated with age (>65y), male gender, intra-dialytic hypotension, low Qb, catheter line reversal, and IHD. The same variables with the exception of age and gender were independently associated in the multivariate analysis. The dialysis dose obtained was significantly lower than that prescribed. EHD achieved values closer to the prescribed KT and significantly higher than in IHD. Ionic Kt measurement facilitates monitoring and allows HD treatments to be extended based upon a previously established TD. Besides the chosen strategy to dispense the dose of dialysis, a well-functioning vascular access allowing for optimal blood flow and other approaches aimed at avoiding hemodynamic instability during RRT are the most important factors to achieve TD, mainly in elderly male patients. The dialysis dose should be prescribed and monitored for all critically ill AKI patients.

Cálculo de Kt/V em hemodiálise: comparação entre fórmulas

The quality of delivered dialysis can be measured by the Kt/V ratio, which can be calculated in various ways. To compare the Kt/V ratio obtained with the formulas of Lowrie (L) and Daugirdas (D) with the results measured by an Online Clearance Monitor (OCM). Observational, cross-sectional study of 59 patients on hemodialysis (HD). Data were collected in the same dialysis session (predialysis and postdialysis urea) and Kt/V was calculated by the OCM of the Fresenius 4008S machine (Fresenius Medical Care AG, Bad Homburg, Germany). A total of 95 sessions were assessed, with a predominance of males 56% (33), and a sample mean age of 57 + 14 years. Hypertension (42%; n = 25), diabetes (12%; n = 7) and glomerulonephritides (8%; n = 5) were the most frequent causes of chronic kidney disease (CKD). Mean Kt/V values obtained with the L and D formulas and the OCM were 1.31, 1.41 and 1.32, respectively. Comparison between the L and D formulas showed a statistically significant difference (p = 0.008), with a Pearson's correlation of 0.950. The difference between the D formula and the OCM was also significant (p = 0.011 and r = 0.346), probably due to convective loss, estimated by the D formula but not by the OCM and L formula. The difference between the L formula and the OCM was not significant (p = 0.999 and r = 0.577). These data suggest that the OCM can be used as a guide to the real-time adjustment of the dialysis dose.

The Kt/V by ionic dialysance: Interpretation limits

The availability of hemodialysis machines equipped with online clearance monitoring (OCM) allows frequent assessment of dialysis efficiency and adequacy without the need for blood samples. Accurate estimation of the urea distribution volume (V) is required for Kt/V calculated from OCM to be consistent with conventional blood sample-based methods. A total of 35 patients were studied. Ionic dialysance was measured by conductivity monitoring. The second-generation Daugirdas formula was used to calculate the Kt/V single-pool (Kt/VD). Values of V to allow comparison between OCM and blood-based Kt/V were determined using Watson formula (VWa), bioimpedance spectroscopy (Vimp), and blood-based kinetic data (Vukm). Comparison of Kt/Vw ocm calculated by the ionic dialysance and Vw (Kt/Vw ocm) with Kt/VD shows that using VW leads to significant systematic underestimation of dialysis dose by 24%. Better agreement between Kt/V ocm and Kt/VD was observed when using Vimp and Vukm. Bio-impedancemetry and the indirect method using the second-generation Daugirdas equation are two methods of clinical interest for estimating V to ensure greater agreement between OCM and blood-based Kt/V.