Volume Balance and Intradialytic Ultrafiltration Rate in the Hemodialysis Patient

Low muscle strength and physical function contribute to falls in hemodialysis patients, but not muscle mass

INTRODUCTION

Patients on hemodialysis (HD) have a higher incidence of fractures than the general population. Sarcopenia is frequently observed in patients on HD; however, the association of falls with sarcopenia and its diagnostic factors, including muscle mass, muscle strength, and physical function, are incompletely understood.

METHODS

This prospective cohort study was conducted at a single center. Sarcopenia was assessed according to the 2019 Asian Working Group for Sarcopenia diagnostic criteria. Muscle mass was measured the bioelectrical impedance method. Grip strength was evaluated to assess muscle strength, while the Short Physical Performance Battery (SPPB) was used to assess physical function. Falls and their detailed information were surveyed every other week.

RESULTS

This study analyzed 65 HD patients (median age, 74.5 [67.5-80.0] years; 33 women [49.2%]). Sarcopenia was diagnosed in 36 (55.4%) patients. During the 1-year observation period, 31 (47.7%) patients experienced accidental falls. The falls group had lower median grip strength than the non-falls group (14.7 [11.4-21.8] kg vs. 22.2 [17.9-27.6] kg; p < 0.001). The median SPPB score was also lower in the falls versus non-falls group (7.0 [5.0-11.0] vs. 11.0 [8.0-12.0]; p = 0.009). In adjusted multiple regression analysis, diagnostic factors, including grip strength (B = 0.96, p = 0.04, R2 = 0.19) and SPPB (B = 1.11, p = 0.006, R2 = 0.23), but not muscle mass, were independently associated with fall frequency.

CONCLUSIONS

The frequency of falls in HD patients was related to muscle strength and physical function, but not muscle mass.

Restless legs syndrome in chronic renal failure patients on dialysis

Background

Restless legs syndrome (RLS) occurs in patients with chronic renal failure (CRF).

Objectives

To determine the prevalence and morbidity of RLS in CRF patients on dialysis.

Methods

This cross-sectional questionnaire-based study included 100 dialysis patients (50 on haemodialysis [HD]; 50 on peritoneal dialysis [PD]). A focused lower limb examination was done. Patients were classified with RLS when reporting uncomfortable feelings in their legs that improved with movement and worsened when resting and at night.

Results

Gender distribution was equal. The median age was 43 (19-67) years. Six patients (HD and PD n=3 each) had international criteria-confirmed RLS. Twenty-four patients reported symptoms suggestive of RLS. Fourteen and 16 patients with RLS symptoms were on HD and PD, respectively. Sleep disturbances occurred in 43.3% (n=13) of patients with RLS symptoms, compared to 20.0% (n=20) of the large cohort. Sleep disturbances, peripheral sensory loss, chronic disease-related anaemia, increased urea and decreased albumin levels were more common among patients with RLS symptoms.

Conclusion

RLS symptoms occurred in 30.0% of the entire cohort, although only 6.0% met the international criteria. The type of dialysis had no impact on the incidence of symptoms. Identifying RLS in patients with CRF on dialysis will allow for early intervention.

A Randomized Trial Examining the Impact of Timing of Intradialytic Cycling on Intradialytic Hypotension

Introduction

Intradialytic cycling is often performed during the first half of hemodialysis because of concerns regarding increased frequency of intradialytic hypotension (IDH) late in hemodialysis. This increases exercise program resource needs and limits utility of intradialytic cycling to treat dialysis-related symptoms.

Methods

This multicenter, randomized, crossover trial compared IDH rate when cycling during the first half versus the second half of hemodialysis in 98 adults on maintenance hemodialysis. Group A cycled during the first half of hemodialysis for 2 weeks and subsequently during the second half for 2 weeks. In group B, the cycling schedule was reversed. Blood pressure (BP) was measured every 15 minutes throughout hemodialysis. Primary outcome was IDH rate (systolic BP [SBP] decrease of >20 mm Hg or SBP <90 mm Hg). Secondary outcomes included symptomatic IDH rate and time to recover post hemodialysis. Data were analyzed using negative binomial and gamma distribution mixed regression.

Results

Mean age 64.7 (SD 12.0) and 64.7 (SD 14.2) years in group A (n = 52) and group B (n = 46), respectively. Proportions of females were 33% in group A and 43% in group B. Median time on hemodialysis was 4.1 (interquartile range [IQR] 2.5, 6.1]) years in group A and 3.9 years (IQR 2.5, 6.7) in group B. IDH rate per 100 hemodialysis hours (95% confidence interval [CI]) was 34.2 (26.4, 42.0) and 36.0 (28.9, 43.1) during early and late intradialytic cycling, respectively (P = 0.53). Timing of intradialytic cycling was not associated with symptomatic IDH (relative risk [RR]: 1.07 [0.75-1.53]) or time to recover post hemodialysis (odds ratio: 0.99 [0.79-1.23]).

Conclusion

We found no association between the rate of overall or symptomatic IDH and the timing of intradialytic cycling in patients enrolled in an intradialytic cycling program. Increased use of cycling late in hemodialysis may optimize intradialytic cycling program resource use and should be studied as a possible treatment for symptoms common in late hemodialysis.

Incidence of hospital admissions in bioimpedance-guided fluid management among maintenance hemodialysis patients-Results of a randomized controlled trial

INTRODUCTION

Hemodialysis is life-sustaining in kidney failure. However, proper regulation of body fluids depends on an accurate estimate of target weight. This trial aims to compare clinical endpoints between target weight estimation guided by bioimpedance spectroscopy and usual care in hemodialysis patients.

METHODS

This is an open-label, parallel-group, controlled trial that randomized, through a table of random numbers, adult patients on maintenance hemodialysis to target weight estimation based on monthly clinical evaluation alone or added to evaluation by bioimpedance twice a year. The primary outcome was survival, and the secondary outcomes were the rate of hospital admissions, change in blood pressure (BP), and antihypertensive drugs load. Participants were followed for 2 years. Survival analysis was performed using Kaplan-Meier estimator and Log-rank test, and hospital admissions were analyzed by the incidence-rate ratio.

FINDINGS

One hundred and ten patients were randomized to the usual care (52) or bioimpedance (58) groups, with a mean age of 57.4 (15.4) years, 64 (58%) males. There was no difference between the groups at baseline. Survival was not significantly different between groups (log-rank test p = 0.68), but the trial was underpowered for this outcome. There was also no difference between the groups in the change in systolic or diastolic BP or in the number of antihypertensive drugs being used. The incidence rate of hospital admissions was 3.1 and 2.1 per person-year in usual care and bioimpedance groups, respectively, with a time-adjusted incidence rate ratio of 1.48 (95% CI: 1.20-1.82, p = 0.0001) and attributable fraction of risk among exposed individuals of 0.32 (95% CI: 0.17-0.45).

DISCUSSION

The inclusion of bioimpedance data to guide the estimation of target weight in hemodialysis patients had no detectable impact on survival or BP control, but significantly reduced the incidence rate of hospital admissions. The study was registered at ClinicalTrials.gov Identifier: NCT05272800.

Relationship between Nutrition-Related Problems and Falls in Hemodialysis Patients: A Narrative Review

Falls are a social problem that increase healthcare costs. Hemodialysis (HD) patients need to avoid falling because fractures increase their risk of death. Nutritional problems such as frailty, sarcopenia, undernutrition, protein-energy wasting (PEW), and cachexia may increase the risk of falls and fractures in patients with HD. This review aimed to summarize the impact of frailty, sarcopenia, undernutrition, PEW, and cachexia on falls in HD patients. The reported global incidence of falls in HD patients is 0.85-1.60 falls per patient per year. HD patients fall frequently, but few reports have investigated the relationship between nutrition-related problems and falls. Several studies reported that frailty and undernutrition increase the risk of falls in HD patients. Nutritional therapy may help to prevent falls in HD patients. HD patients' falls are caused by nutritional problems such as iatrogenic and non-iatrogenic factors. Falls increase a person's fear of falling, reducing physical activity, which then causes muscle weakness and further decreased physical activity; this cycle can cause multiple falls. Further research is necessary to clarify the relationships between falls and sarcopenia, cachexia, and PEW. Routine clinical assessments of nutrition-related problems are crucial to prevent falls in HD patients.

Sodium First Approach, to Reset Our Mind for Improving Management of Sodium, Water, Volume and Pressure in Hemodialysis Patients, and to Reduce Cardiovascular Burden and Improve Outcomes

New physiologic findings related to sodium homeostasis and pathophysiologic associations require a new vision for sodium, fluid and blood pressure management in dialysis-dependent chronic kidney disease patients. The traditional dry weight probing approach that has prevailed for many years must be reviewed in light of these findings and enriched by availability of new tools for monitoring and handling sodium and water imbalances. A comprehensive and integrated approach is needed to improve further cardiac health in hemodialysis (HD) patients. Adequate management of sodium, water, volume and hemodynamic control of HD patients relies on a stepwise approach: the first entails assessment and monitoring of fluid status and relies on clinical judgement supported by specific tools that are online embedded in the HD machine or devices used offline; the second consists of acting on correcting fluid imbalance mainly through dialysis prescription (treatment time, active tools embedded on HD machine) but also on guidance related to diet and thirst management; the third consist of fine tuning treatment prescription to patient responses and tolerance with the support of innovative tools such as artificial intelligence and remote pervasive health trackers. It is time to come back to sodium and water imbalance as the root cause of the problem and not to act primarily on their consequences (fluid overload, hypertension) or organ damage (heart; atherosclerosis, brain). We know the problem and have the tools to assess and manage in a more precise way sodium and fluid in HD patients. We strongly call for a sodium first approach to reduce disease burden and improve cardiac health in dialysis-dependent chronic kidney disease patients.

Dysfunction in dynamic, but not static balance is associated with risk of accidental falls in hemodialysis patients: a prospective cohort study

Background

Patients with chronic kidney disease undergoing hemodialysis (HD) have a high incidence of falls. Impairment of balance function is a risk factor for falls in the general elderly, and no report examining the association between balance dysfunction and fall incidence in HD patients exists.

Methods

This prospective cohort study was conducted at a single center. The timed-up-and-go test (TUG) as a dynamic balance function was performed and length of the center of pressure (CoP) as a static balance function was measured before and after the HD session at baseline. Data of the number and detailed information of accidental falls for 1 year were collected. Multiple regression analyses were performed to assess the relationships between the number of falls and balance function.

Results

Forty-three patients undergoing HD were enrolled in the study. During 1 year of observation, 24 (55.8%) patients experienced accidental falls. TUG time was longer, and CoP was shorter in the post-HD session than in the pre-HD session. Adjusted multiple regression analyses showed that the number of accidental falls was independently associated with TUG time in the pre-HD session (B 0.267, p < 0.001, R² 0.413) and that in the post-HD session (B 0.257, p < 0.001, R² 0.530), but not with CoP.

Conclusions

Dynamic balance was associated with fall incidence in maintenance HD patients. The evaluation and intervention of dynamic balance function might reduce the risk of falls in HD patients.

Trial registration

This study was carried out with the approval of the Niigata Rinko Hospital Ethics Committee (approval number 2005–92) (Registered on December 11, 2019) and registered in The University Hospital Medical Information Network (registration number 000040618).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02877-6.

Patient-centred approaches for the management of unpleasant symptoms in kidney disease

Patients with chronic kidney disease (CKD) frequently experience unpleasant symptoms. These can be gastrointestinal (constipation, nausea, vomiting and diarrhoea), psychological (anxiety and sadness), neurological (lightheadedness, headache and numbness), cardiopulmonary (shortness of breath and oedema), dermatological (pruritus and dry skin), painful (muscle cramps, chest pain and abdominal pain) or involve sexual dysfunction, sleep disorders and fatigue. These symptoms often occur in clusters, with one of them as the lead symptom and others as secondary symptoms. Uraemic toxins (also called uremic toxins) are often considered to be the main cause of CKD-associated symptom burden, but treatment of uraemia by dialysis often fails to resolve them and can engender additional symptoms. Indeed, symptoms can be exacerbated by comorbid conditions, pharmacotherapies, lifestyle and dietary regimens, kidney replacement therapy and ageing. Patients with kidney disease, including those who depend on dialysis or transplantation, should feel actively supported in their symptom management through the identification and targeting of unpleasant symptoms via a tailored palliative care approach. Such an approach may help minimize the burden and consequences of kidney disease, and lead to improved patient outcomes including health-related quality of life and better life participation.

Prevalence of fluid overload in an urban US hemodialysis population: A cross-sectional study

INTRODUCTION

Inadequate fluid status remains a key driver of cardiovascular morbidity and mortality in chronic hemodialysis (HD) patients. Quantification of fluid overload (FO) using bioimpedance spectroscopy (BIS) has become standard in many countries. To date, no BIS device has been approved in the United States for fluid status assessment in kidney patients. Therefore, no previous quantification of fluid status in US kidney patients using BIS has been reported. Our aim was to conduct a cross-sectional BIS-based assessment of fluid status in an urban US HD population.

METHODS

We determined fluid status in chronic HD patients using whole body BIS (Body Composition Monitor, BCM). The BCM reports FO in liters; negative FO denotes fluid depletion. Measurements were performed before dialysis. Post-HD FO was estimated by subtracting the intradialytic weight loss from the pre-HD FO.

FINDINGS

We studied 170 urban HD patients (age 61 ± 14 years, 60% male). Pre- and post-HD FO (mean ± SD), were 2.2 ± 2.4 and -0.2 ± 2.7 L, respectively. Pre-HD, 43% of patients were fluid overloaded, 53% normally hydrated, and 4% fluid depleted. Post-HD, 12% were fluid overloaded, 55% normohydrated and 32% fluid depleted. Only 48% of fluid overloaded patients were hypertensive, while 38% were normotensive and 14% hypotensive. Fluid status did not differ significantly between African Americans (N = 90) and Caucasians (N = 61).

DISCUSSION

While about half of the patients had normal fluid status pre-HD, a considerable proportion of patients was either fluid overloaded or depleted, indicating the need for tools to objectively quantify fluid status.

Shock Management Without Formal Fluid Responsiveness Assessment: A Retrospective Analysis of Fluid Responsiveness and Its Outcomes

BACKGROUND

In order to quantify fluid administration and evaluate the clinical consequences of conservative fluid management without hemodynamic monitoring in undifferentiated shock, we analyzed previously collected data from a study of carotid Doppler monitoring as a predictor of fluid responsiveness (FR).

METHODS

This study was a retrospective analysis of data collected from a single tertiary academic center from a previous study. Seventy-four patients were included for post-hoc analysis, and 52 of them were identified as fluid responsive (cardiac output increase > 10% with passive leg raise) according to NICOMTM bioreactance monitoring (Cheetah Medical, Newton Center, MA, USA). Treating teams provided standard of care conservative fluid resuscitation but were blinded to independently performed FR testing results. Outcomes were compared between fluid responsive and fluid non-responsive patients. Primary outcome measures were volume fluids administered and net fluid balance 24- and 72-hour post-FR assessment. Secondary outcome measures included change in vasopressor requirements, mean peak lactate levels, length of hospital/intensive care unit stay, acute respiratory failure, hemodialysis requirement, and durations of vasopressors and mechanical ventilation.

RESULTS

Mean fluids administered within 72 hours were similar between fluid non-responsive and fluid responsive patients (139 mL/kg [95% confidence interval [CI]: 102.00-175.00] vs. 136 mL/kg [95% CI: 113.00-158.00], p = 0.92, respectively). We observed an insignificant trend toward higher 28-day mortality among fluid non-responsive patients (36% vs. 19%, p = 0.14). Volume of fluids administered significantly correlated with adverse outcomes such as increased hemodialysis requirements (32 patients, 43%), (odds ratio [OR] = 1.7200, p = 0.0018). Subgroup analysis suggested administering ≥ 30 mL/kg fluids to fluid responsive patients had a trend toward increased mortality (25% vs. 0%, p = 0.09) and a significant increase in hemodialysis (55% vs. 17%, p = 0.024).

CONCLUSIONS

Without formal FR assessment, similar amounts of total fluids were administered in both fluid responsive and non-responsive patients. As greater volumes of intravenous fluids administered were associated with adverse outcomes, we suggest that dedicated FR assessment may be a beneficial utility in early shock resuscitation.

Multitargeted interventions to reduce dialysis-induced systemic stress

Hemodialysis (HD) is a life-sustaining therapy as well as an intermittent and repetitive stress condition for the patient. In ridding the blood of unwanted substances and excess fluid from the blood, the extracorporeal procedure simultaneously induces persistent physiological changes that adversely affect several organs. Dialysis patients experience this systemic stress condition usually thrice weekly and sometimes more frequently depending on the treatment schedule. Dialysis-induced systemic stress results from multifactorial components that include treatment schedule (i.e. modality, treatment time), hemodynamic management (i.e. ultrafiltration, weight loss), intensity of solute fluxes, osmotic and electrolytic shifts and interaction of blood with components of the extracorporeal circuit. Intradialytic morbidity (i.e. hypovolemia, intradialytic hypotension, hypoxia) is the clinical expression of this systemic stress that may act as a disease modifier, resulting in multiorgan injury and long-term morbidity. Thus, while lifesaving, HD exposes the patient to several systemic stressors, both hemodynamic and non-hemodynamic in origin. In addition, a combination of cardiocirculatory stress, greatly conditioned by the switch from hypervolemia to hypovolemia, hypoxemia and electrolyte changes may create pro-arrhythmogenic conditions. Moreover, contact of blood with components of the extracorporeal circuit directly activate circulating cells (i.e. macrophages-monocytes or platelets) and protein systems (i.e. coagulation, complement, contact phase kallikrein-kinin system), leading to induction of pro-inflammatory cytokines and resulting in chronic low-grade inflammation, further contributing to poor outcomes. The multifactorial, repetitive HD-induced stress that globally reduces tissue perfusion and oxygenation could have deleterious long-term consequences on the functionality of vital organs such as heart, brain, liver and kidney. In this article, we summarize the multisystemic pathophysiological consequences of the main circulatory stress factors. Strategies to mitigate their effects to provide more cardioprotective and personalized dialytic therapies are proposed to reduce the systemic burden of HD.

Fear of falling and physical activity in hemodialysis patients: a pilot study

Background

Hemodialysis (HD) patients are at a high risk of falls and fractures. The amount of physical activity (PA) they perform may be limited by psychosomatic factors associated with fear of falling, leading to frailty progression. This study aimed to clarify the relationship between fear of falling and PA in patients undergoing HD.

Methods

This cross-sectional study included 46 HD patients. Fear of falling was evaluated using the Modified Falls Efficacy Scale (MFES). A 3-axis accelerometer was used to measure PA, including number of steps; 1 to 1.9 METs = static PA, 2 to 2.9 = light PA, and 3 or more = moderate to vigorous PA (MVPA). We examined correlation of MFES with each type of PA. Factors affecting fear of falling were determined using multiple regression analysis.

Results

The median MFES was 9.2 (7.4, 10.0). MFES was associated with the number of steps (r = 0.608, p < 0.001), light PA (r = 0.421, p = 0.004), and MVPA (r = 0.546, p < 0.001). Eighteen participants (39.1%) experienced at least one fall in a year and had lower MFES than the non-fall group (fall group: 7.4 [5.1, 9.0] vs. non-fall group: 9.7 [8.5, 10.0], p < 0.001). Multiple regression analysis showed that MFES was independently associated with the number of steps (B = 279.7, 95% confidence interval [CI] = 90.5–469.0, p = 0.005) and MVPA (B = 3.52, 95% CI = 1.14–5.90, p = 0.005), respectively.

Conclusions

Fear of falling was associated with amount of PA among patients undergoing HD. Interventions that target the fear of falling may be effective in reducing HD patients’ fall risk by enhancing PA.

Assessment of pleth variability index in volume changes during ultrafiltration process

OBJECTIVES:

Pleth variability index (PVI) has been studied mostly in mechanically ventilated patients, and the role of PVI in predicting volume status and volume changes among spontaneously breathing patients is not clear in the literature. We hypothesized that hemodialysis (HD) can be a valid model for a simulation that can be evaluated the correlation of PVI with fluid changes in various volume states. The aim of this study was to investigate the utility of PVI for assessing volume changes in HD patients who are breathing spontaneously.

METHODS:

This prospective, observational study included patients aged 18 years or older who had end-stage renal failure and presented for routine HD between December 2019 and January 2020. PVI values were measured before and after HD session. Changes in PVI levels were compared according to the amount of ultrafiltration.

RESULTS:

A total of sixty patients were included. Mean PVI level before HD (20.7% ± 5%) showed a statistically significant increase to 27.7% ± 6% after HD session (P < 0.001). According to the amount of fluid removed during HD, the changes in PVI were statistically significant (P = 0.015). There was a strong correlation between ΔPVI and ultrafiltrated volume (r = 0.744, P < 0.001).

CONCLUSION:

The fluid removed by HD caused increase in PVI, and the increase was strongly correlated with the amount of volume change. Bedside monitoring of PVI may provide the clinicians with useful information for monitoring the volume status in critically ill patients with spontaneous breathing.

Effects of Caffeinated and Decaffeinated Coffee on Hemodialysis-Related Headache (CoffeeHD): A Randomized Multicenter Clinical Trial

OBJECTIVES

Historically, headache was reported in up to 76% of hemodialysis patients. Some authors suggested that headache resulted from caffeine withdrawal. This study aims to compare the incidence of headache and hypotension between patients drinking regular or decaffeinated coffee during dialysis.

METHODS

One-hundred fifty-six patients were enrolled in this randomized, double-blind, placebo-controlled, multicenter study. Patients with atrial fibrillation were excluded. Group A was given 80 mL of regular coffee and group B 80 mL of decaffeinated coffee (placebo) in the middle of the session for 12 consecutive sessions. Ultrafiltration rate was fixed to a maximum of 13 mL/kg/hour. The primary outcome was the incidence of headache during dialysis.

RESULTS

A total of 139 patients completed the trial (6.4% vs. 15.4% of withdrawal in Groups A and B, respectively). The number of sessions with headache was not significantly different between Group A and B (33.3% vs. 37.1% respectively, P = .522), nor the number of sessions with hypotension (27% vs. 26% respectively, P = .539). In a subgroup analysis, headache tended to be more frequent in Group B (P = .06) in 2 categories of patients: those with the highest potassium dialysate (K = 2) and the non-hypertensive patients.

CONCLUSIONS

Headache occurred in 35% of patients during their chronic hemodialysis sessions. Caffeine intake did not prevent headache occurrence in these patients.

Effects of diuretics on intradialytic hypotension in maintenance dialysis patients: a systematic review and meta-analysis

PURPOSE

Intradialytic hypotension (IDH) is a serious complication in dialysis patients. Diuretics might reduce the incidence of IDH by decreasing ultrafiltration. However, the effect of diuretics on IDH in maintenance dialysis patients is still unclear.

METHODS

We searched Medline, Embase, the Cochrane Library, China National Knowledge Infrastructure and clinical trials registries from 1945 to May 2019. Randomized controlled trials (RCTs) or observational studies about IDH in maintenance dialysis with diuretics were included.

RESULTS

Seven studies including 28,226 patients were included, of which 4 were RCTs involving mineralocorticoid receptor antagonists (MRAs) and 3 were observational studies involving loop diuretics. There was a trend that a lower incidence rate of IDH in maintenance dialysis patients who used loop diuretics than control, although the result was not statistically significant (OR 0.65, 95% CI 0.34-1.22, P = 0.18). Similarly, lower incidence rate of all-cause mortality (OR 0.92, 95% CI 0.87-0.99; P = 0.02) and cardiovascular (CV) mortality (OR 0.86, 95% CI 0.75-0.99, P = 0.03) in dialysis patients who used loop diuretics than control. On the contrary, there were no significant difference in the incidence of IDH (OR 1.35, 95% CI 0.78-2.34, P = 0.29) and all-cause mortality (OR 0.73, 95% CI 0.26-2.01; P = 0.54) and CV mortality (OR 0.57, 95% CI 0.14-2.25; P = 0.42) in maintenance dialysis patients who used MRAs compared with control.

CONCLUSION

Loop diuretics, but not MRAs, might have a potential benefit to reduce the incidence rate of IDH, all-cause mortality and CV mortality. More high-quality studies are needed to strengthen the arguments.

Predicting the Appearance of Hypotension During Hemodialysis Sessions Using Machine Learning Classifiers

A patient suffering from advanced chronic renal disease undergoes several dialysis sessions on different dates. Several clinical parameters are monitored during the different hours of any of these sessions. These parameters, together with the information provided by other parameters of analytical nature, can be very useful to determine the probability that a patient may suffer from hypotension during the session, which should be specially watched since it represents a proven factor of possible mortality. However, the analytical information is not always available to the healthcare personnel, or it is far in time, so the clinical parameters monitored during the session become key to the prevention of hypotension. This article presents an investigation to predict the appearance of hypotension during a dialysis session, using predictive models trained from a large dialysis database, which contains the clinical information of 98,015 sessions corresponding to 758 patients. The prediction model takes into account up to 22 clinical parameters measured five times during the session, as well as the gender and age of the patient. This model was trained by means of machine learning classifiers, providing a success in the prediction higher than 80%.

Volume overload in hemodialysis: diagnosis, cardiovascular consequences, and management

Volume overload in haemodialysis (HD) patients associates with hypertension and cardiac dysfunction and is a major risk factor for all-cause and cardiovascular mortality in this population. The diagnosis of volume excess and estimation of dry weight is based largely on clinical criteria and has a notoriously poor diagnostic accuracy. The search for accurate and objective methods to evaluate dry weight and to diagnose subclinical volume overload has been intensively pursued over the last 3 decades. Most methods have not been tested in appropriate clinical trials and their usefulness in clinical practice remains uncertain, except for bioimpedance spectroscopy and lung ultrasound (US). Bioimpedance spectroscopy is possibly the most widely used method to subjectively quantify fluid distributions over body compartments and produces reliable and reproducible results. Lung US provides reliable estimates of extravascular water in the lung, a critical parameter of the central circulation that in large part reflects the left ventricular end-diastolic pressure. To maximize cardiovascular tolerance, fluid removal in volume-expanded HD patients should be gradual and distributed over a sufficiently long time window. This review summarizes current knowledge about the diagnosis, prognosis and treatment of volume overload in HD patients.

Análisis de la ultrafiltración media por sesión de los pacientes en una unidad de hemodiálisis

Introducción: En los pacientes en hemodiálisis (HD), el ajuste erróneo del peso ideal puede llevarlos a la sobrecarga de líquido que puede desembocar en episodios de insuficiencia cardiaca o a la inversa, a una situación de bajo peso generando hipotensiones que pueden originar cardiopatía isquémica. Se estima como adecuada una ultrafiltración (UF) máxima de 10 ml/kg/h, valor por encima del cual está demostrado el aumento de la mortalidad. Objetivos: Analizar que tasa de ultrafiltración media usamos en nuestra unidad, y conocer qué porcentaje de pacientes sobrepasaban la ultrafiltración máxima recomendada. Material y Método: Realizamos un estudio observacional, prospectivo, en 58 pacientes en hemodiálisis, analizando la tasa de ultrafiltración expresada en ml/kg/h por sesión durante 6 meses. Se definió una tasa de UF>10 ml/kg/h como punto de corte para, según los criterios actuales de tasa adecuada, determinar que pacientes presentaban una UF superior a 10 ml/Kg/h en más de un 25% de las sesiones. Resultados: Durante el periodo de estudio la tasa media de UF de todos los pacientes fue de 8,78±2,76 ml/kg/h, aunque el porcentaje de sesiones por paciente con tasa de UF superior a 10 ml/kg/h fue de un 35,9±29,74%. Conclusión: Un porcentaje alto de pacientes presentan tasas de UF por encima de los valores recomendados. Se han de buscar estrategias para minimizar esta situación, donde la educación sanitaria sobre alimentación y el ajuste individualizado de las sesiones de diálisis son aspectos fundamentales.

Systematic Fluid Assessment in Haemodialysis: Development and Validation of A Decision Aid

BACKGROUND

About a third of patients undergoing haemodialysis have poorly controlled fluid status, which may affect survival. Clinical assessment is subjective and imprecise, which has led to the increasing use of devices based on bioimpedance spectroscopy (BIS). However, BIS cannot provide a simple target applicable to all patients. Our aim was to develop and validate a decision aid combining clinical assessment of fluid status with information from BIS in target weight determination.

METHODS

The decision aid was based on empirical experience and a literature review identifying physiological parameters already used in the clinical assessment of fluid status. Content validity was established by patient representatives, interdisciplinary stakeholders and external experts, who assessed item relevance and comprehensiveness. Reliability was assessed by inter-rater agreement analysis between nurses assessing typical patient cases.

RESULTS

The decision aid for Recognition and Correction of Volume Alterations (RECOVA) consists of three parts (1) a scoring system; (2) thresholds and triggers; (3) a decision aid algorithm. Agreement between raters in the assessment of symptoms was almost perfect, with Intraclass Correlation Coefficient > 0.90. Agreement in clinical response was only fair, but increased to moderate, with training and self-reported confidence.

CONCLUSION

RECOVA may enable systematic clinical assessment of fluid status, facilitating early recognition of fluid alterations, and incorporation of bioimpedance into target weight management. However, implementation into clinical practice will require training of staff. Clinical intervention studies are required to evaluate if RECOVA facilitates response to and correction of recognised fluid alterations.

Intermittent pneumatic compression in patients with ESRD. A systematic review

INTRODUCTION

Patients with end-stage renal disease (ESRD) experience frequent hemodialysis (HD) complications. Intradialytic hypotension (IDH) is a common complication presenting in approximately between 20 and 50% of HD sessions. Available interventions such as volume replacement or vasoactive medications are associated with significant side effects. Intermittent pneumatic compression (IPC) has been proposed as a feasible intervention for the prevention of IDH, treatment of peripheral arterial disease and venous ulcers. These devices apply intermittent pressure to the legs improving arterial blood flow, mobilization of pooled blood with an increase in venous return increasing the effective circulatory volume. Our goal was to identify the published clinical evidence on whether IPC has a circulatory benefit and is it well-tolerated among patients receiving HD.

METHODS

We conducted a systematic review to identify studies assessing the efficacy and safety of IPC in patients with ESRD. Our primary outcome was IDH. Secondary outcomes such as HD comfort, ultrafiltration volume, and physical activity were collected. No restrictions where used and we included all observational and interventional studies. Two reviewers performed screening and study quality assessment.

FINDINGS

We included seven studies. Out of the seven studies, five addressed IDH, and the rest were included for secondary outcomes such as physical capacity and HD comfort. In one randomized crossover trial comparing exercise against IPC, 21 patients were randomized to 3 different arms (no intervention, cycling, IPC) a decrease in the rates of IDH with IPC was described (43%, 38%, and 24% respectively P = 0.014). The smaller studies corroborated these results. All studies where at high risk of bias.

DISCUSSION

IPC might offer significant benefits for patients undergoing HD not limited to prevention of IDH but also improvement of hemodialysis comfort and physical capacity. However, our results should be interpreted in the context of its limitations.

Extracellular mass to body cell mass ratio as a potential index of wasting and fluid overload in hemodialysis patients. A case-control study

BACKGROUND & AIMS

Extracellular mass-to-body cell mass ratio (ECM/BCM ratio) which differentiates the proportion between intraextracellular compartments, could be a nutrition index of being wasted overloaded in hemodialysis (HD) patients. This study aimed to describe a cut-off point of the ECM/BCM ratio and, to find out the relationship between the nutritional-hydration status and this ratio in HD patients.

METHODS

A case-control study was carried out in 64 HD patients individually age-gender-matched to controls. Demographic, clinical and laboratory parameters were recorded. Bioelectrical impedance analysis was used to estimate ECM/BCM ratio as an indicator of the nutritional hydration status. Receiver operator characteristic (ROC) curve analysis was applied to determine the optimal cut-off point for identification of ECM/BCM ratio. An univariate and multivariate conditional logistic regression for the ECM/BCM ratio ≥1.20 was performed.

RESULTS

Median of ECM/BCM ratio was 1.50 (IQR:0.66) in HD patients, whereas 0.87 (IQR: 0.35) was found in controls (p < 0.001). HD-patients had lower body weight, serum albumin (s-albumin) and higher serum C-reactive protein (s-CRP) than controls. By ROC curve analysis, a cut-off point of 1.20 for the ECM/BCM ratio best discriminates to be wasted-overhydrated (sensitivity: 81.2%; specificity: 87.5%). Conditional logistic regression showed that for each 10%, ECM/BCM ratio increase the probability of developing fluid overload was increased 63% (OR: 1.63; 95% CI, 1.15-2.29), whereas an inverse association with s-albumin (OR: 0.15; 95% CI, 0.03-0.61) and other nutritional indicators were found.

CONCLUSIONS

The ECM/BCM ratio appears as a sensitive index that discriminates nutritional and/or hydration status in HD patients compared with age-gender-matched-controls. ECM/BCM ratios ≥1.20 are indicators of wasting and fluid overload in HD patients.

Dialysis Prescription and Sudden Death

In the United States, end-stage renal disease patients receiving hemodialysis have an exceedingly high risk of sudden cardiac death (SCD), accounting for 29% of death events, likely relating to their uremic milieu, recurring exposure to fluid and electrolyte fluxes, and underlying cardiovascular pathology. Furthermore, epidemiologic studies have shown that SCD events, as well as mortality and hospitalizations, occur most frequently on the first dialysis day after the long interdialytic gap, suggesting that abrupt fluctuations in the accumulation and removal of electrolytes, fluid, and uremic toxins over the dialysis cycle may be contributory. Some population-based observational studies have suggested that lower dialysate potassium concentrations appear to be associated with a heightened risk of postdialysis cardiac arrest in hemodialysis patients, although the optimal serum-to-dialysate potassium gradient remains unclear. Some observational studies have suggested that low dialysate calcium concentrations and high serum-to-dialysate calcium gradients may predispose patients to SCD. There is ongoing controversy about an association between higher dialysate bicarbonate concentrations and higher risk of cardiac arrest, likely owing to confounding by indication. Some observational studies also have shown that large interdialytic weight gains, fluid retention, and high ultrafiltration rates are linked with higher risk of SCD and mortality. However, there remains considerable controversy regarding the pros and cons of designating a specific upper ultrafiltration limit with extended treatment times as a clinical practice measure, and further studies are needed to define the optimal tools, metrics, targets, and implementation measures for volume control in the hemodialysis population. In this review, we highlight the epidemiology and pathophysiology of how specific aspects of the hemodialysis procedure may relate to the risk of SCD, as well as preventative strategies and future research directions that can address this risk.