Effect of Lowering the Dialysate Temperature in Chronic Hemodialysis: A Systematic Review and Meta-Analysis

Association of frequent intradialytic hypotension with the clinical outcomes of patients on hemodialysis: a prospective cohort study

Intradialytic hypotension (IDH) is a common complication of hemodialysis (HD), but there is no consensus on its definition. In 2015, Flythe proposed a definition of IDH (Definition 1 in this study): nadir systolic blood pressure (SBP) <90 mmHg during hemodialysis for patients with pre-dialysis SBP <159 mmHg, and nadir SBP <100 mmHg during hemodialysis for patients with pre-dialysis SBP ≥160 mmHg. This prospective observational cohort study investigated the association of frequent IDH based on Definition 1 with clinical outcomes and compared Definition 1 with a commonly used definition (nadir SBP <90 mmHg during hemodialysis, Definition 2). The incidence of IDH was observed over a 3-month exposure assessment period. Patients with IDH events ≥30% were classified as 'frequent IDH'; the others were 'infrequent IDH'. All-cause mortality, cardiovascular mortality, and all-cause hospitalization events were followed up for 36 months. This study enrolled 163 HD patients. The incidence of IDH was 11.1% according to Definition 1 and 10.5% according to Definition 2. The Kaplan-Meier curves showed that frequent IDH patients had higher risks of all-cause mortality (p = 0.009, Definition 1; p = 0.002, Definition 2) and cardiovascular mortality (p = 0.021, Definition 1). Multivariable Cox regression analysis indicated that frequent IDH was independently associated with a higher risk of all-cause mortality (Model 1: HR = 2.553, 95%CI 1.334-4.886, p = 0.005; Model 2: HR = 2.406, 95%CI 1.253-4.621, p = 0.008). In conclusion, HD patients classified as frequent IDH are at a greater risk of all-cause mortality. This highlights the significance of acknowledging and proactively managing frequent IDH within the HD patients.

Use of Intravenous Albumin: A Guideline From the International Collaboration for Transfusion Medicine Guidelines

BACKGROUND

Albumin is used commonly across a wide range of clinical settings to improve hemodynamics, to facilitate fluid removal, and to manage complications of cirrhosis. The International Collaboration for Transfusion Medicine Guidelines developed guidelines for the use of albumin in patients requiring critical care, undergoing cardiovascular surgery, undergoing kidney replacement therapy, or experiencing complications of cirrhosis.

STUDY DESIGN AND METHODS

Cochairs oversaw the guideline development process and the panel included researchers, clinicians, methodologists, and a patient representative. The evidence informing this guideline arises from a systematic review of randomized clinical trials and systematic reviews, in which multiple databases were searched (inception through November 23, 2022). The panel reviewed the data and formulated the guideline recommendations using Grading of Recommendations Assessment, Development, and Evaluation methodology. The guidelines were revised after public consultation.

RESULTS

The panel made 14 recommendations on albumin use in adult critical care (three recommendations), pediatric critical care (one recommendation), neonatal critical care (two recommendations), cardiovascular surgery (two recommendations), kidney replacement therapy (one recommendation), and complications of cirrhosis (five recommendations). Of the 14 recommendations, two recommendations had moderate certainty of evidence, five recommendations had low certainty of evidence, and seven recommendations had very low certainty of evidence. Two of the 14 recommendations suggested conditional use of albumin for patients with cirrhosis undergoing large-volume paracentesis or with spontaneous bacterial peritonitis. Twelve of 14 recommendations did not suggest albumin use in a wide variety of clinical situations where albumin commonly is transfused.

INTERPRETATION

Currently, few evidence-based indications support the routine use of albumin in clinical practice to improve patient outcomes. These guidelines provide clinicians with actionable recommendations on the use of albumin.

Atomoxetine for Intradialytic Hypotension in a Patient on Hemodialysis: A Case Report

Intradialytic hypotension significantly affects patient safety and clinical outcomes during hemodialysis. Despite various pharmacological and nonpharmacological interventions, effective management remains elusive. In this report, we detail a case of intradialytic hypotension in a male patient in his 40s, undergoing hemodialysis with a history of polycystic kidney disease. Eight years ago, the patient underwent bilateral nephrectomy because of a severe cystic infection, after which his systolic blood pressure (BP) persistently remained at 50-70 mm Hg during dialysis sessions. The initial treatment strategy for hypotension included fludrocortisone, midodrine, and prednisolone, leading to a slight temporary increase in BP, which subsequently declined. As the patient's condition deteriorated, the administration of norepinephrine or dopamine became necessary to sustain BP during dialysis. Given the patient's resistance to these treatments, a daily dose of 25 mg of atomoxetine was introduced. Following this treatment, there was a gradual improvement in the patient's vertigo, weakness, and BP. This case illustrates that low-dose atomoxetine can alleviate symptoms and elevate BP in patients experiencing severe intradialytic hypotension during hemodialysis.

International renal interest society best practice consensus guidelines for intermittent hemodialysis in dogs and cats

Intermittent hemodialysis (IHD) is an advanced adjunctive standard of care for severe acute kidney injury (AKI) and other indications. Most animals with AKI are managed medically, however, when the disease is severe, medical management may not control the consequences of the disease, and animals with a potential for renal recovery may die from the consequences of uremia before recovery has occurred. Extracorporeal therapies aid the management of AKI by expanding the window of opportunity for recovery of sufficient kidney function to become dialysis independent. Intermittent hemodialysis (IHD) was introduced into veterinary medicine over 50 years ago, however, updated guidelines for the delivery of IHD have not been published for several decades. To that end, the International Renal Interest Society (IRIS) constituted a Working Group to establish best practice guidelines for the safe and effective delivery of IHD to animals with indications for dialytic intervention. The IRIS Working Group generated 60 consensus statements and supporting rational for a spectrum of prescription and management categories required for delivery of IHD on designated intermittent dialysis platforms (i.e., AKI, chronic hemodialysis and intoxications). A formal consensus method was used to validate the recommendations by a blinded jury of 12 veterinarians considered experts in extracorporeal therapies and actively performing IHD. Each vote provided a level of agreement for each recommendation proposed by the Working Group. To achieve a consensus, a minimum of 75% of the voting participants had to "strongly agree" or "agree" with the recommendation.

The Acute, Combined, and Separate Effects of Cold Hemodialysis and Intradialytic Exercise in Insulin Sensitivity and Glucose Disposal

Hemodialysis (HD) patients suffer from multiple health problems, including severe insulin resistance. Both cold dialysis and intradialytic exercise training could elicit health benefits; however, it is still unknown whether the combination of those two approaches could enhance overall health. The current study aimed to evaluate the separate and combined acute effects of a single session of cold dialysis and intradialytic exercise in parameters related to insulin sensitivity and glucose disposal. Ten HD patients (57.2 ± 14.9 years) participated in the study. Each patient participated in four different scenarios during HD: a) typical dialysis with dialysate temperature at 37°C (TD), b) cold dialysis with dialysate temperature at 35°C, c) typical HD combined with a single exercise bout, d) cold dialysis combined with a single exercise bout. Glucose disposal and insulin resistance were assessed immediately after the end of the HD session. None of the examined parameters significantly differed between the four scenarios ( p > 0.05). However, slight numerical changes and moderate to high effect size ( d : 0.50-0.85) were observed between TD versus cold dialysis and TD versus TD + exercise in glucose and insulin disposal rates. A single session of cold and TD with intradialytic exercise may provide an "acute" time-efficient stimulus for consecutively improving glucose disposal and insulin sensitivity.

Digital Health Support: Current Status and Future Development for Enhancing Dialysis Patient Care and Empowering Patients

Chronic kidney disease poses a growing global health concern, as an increasing number of patients progress to end-stage kidney disease requiring kidney replacement therapy, presenting various challenges including shortage of care givers and cost-related issues. In this narrative essay, we explore innovative strategies based on in-depth literature analysis that may help healthcare systems face these challenges, with a focus on digital health technologies (DHTs), to enhance removal and ensure better control of broader spectrum of uremic toxins, to optimize resources, improve care and outcomes, and empower patients. Therefore, alternative strategies, such as self-care dialysis, home-based dialysis with the support of teledialysis, need to be developed. Managing ESKD requires an improvement in patient management, emphasizing patient education, caregiver knowledge, and robust digital support systems. The solution involves leveraging DHTs to automate HD, implement automated algorithm-driven controlled HD, remotely monitor patients, provide health education, and enable caregivers with data-driven decision-making. These technologies, including artificial intelligence, aim to enhance care quality, reduce practice variations, and improve treatment outcomes whilst supporting personalized kidney replacement therapy. This narrative essay offers an update on currently available digital health technologies used in the management of HD patients and envisions future technologies that, through digital solutions, potentially empower patients and will more effectively support their HD treatments.

Cognitive Impairment and Brain Atrophy in Patients with Chronic Kidney Disease

In Japan, the aging of the population is rapidly accelerating, with an increase in patients with chronic kidney disease (CKD) and those undergoing dialysis. As a result, the number of individuals with cognitive impairment (CI) is rising, and addressing this issue has become an urgent problem. A notable feature of dementia in CKD patients is the high frequency of vascular dementia, making its prevention through the management of classical risk factors such as hypertension, diabetes mellitus, dyslipidemia, smoking, etc., associated with atherosclerosis and arteriosclerosis. Other effective measures, including the use of renin-angiotensin system inhibitors, addressing anemia, exercise therapy, and lifestyle improvements, have been reported. The incidence and progression of CI may also be influenced by the type of kidney replacement therapy, with reports suggesting that long-duration dialysis, low-temperature hemodialysis, peritoneal dialysis, and kidney transplantation can have a preferable effect on the preservation of cognitive function. In conclusion, patients with CKD are at a higher risk of developing CI, with brain atrophy being a contributing factor. Despite the identification of various preventive measures, the evidence substantiating their efficacy remains limited across all studies. Future expectations lie in large-scale randomized controlled trials.

Do patients dialysing with higher ultrafiltration rates report more intradialytic symptoms and longer postdialysis recovery times?

BACKGROUND

Many hemodialysis (HD) patients report intradialytic symptoms, and take time to recover postdialysis. To improve quality of life, patient groups have highlighted the need to reduce postdialysis fatigue and other peridialytic symptoms. As compartmental shifts of fluid during dialysis have been proposed to cause peridialytic symptoms we investigated whether patients dialysing with higher ultrafiltration rates (UFR) reported more intradialytic symptoms and recovery times.

METHODS

We reviewed the hospital records of HD patients who completed a self-reported intradialytic symptom questionnaire, using a visual analogue scale, who had contemporaneous midweek pre- and postdialysis segmental bioimpedance measurements.

RESULTS

Six hundred and five patients returned the peridialytic symptom questionnaire with pre- and postdialysis bioimpedance measurements. The majority were male (64.8%), mean age 64.2 ± 15.6 years, duration of dialysis treatment 26.8 (10.7-59.2) months, 85% treated by hemodiafiltration and mean dialysate temperature 35.4 ± 0.4°C. We divided patients into terciles according to UFR adjusted for weight, and there was a greater fall in the ratio of extracellular water (ECW) to total body water (TBW) postdialysis in the nonfistula arm from the lower to middle to higher tercile (0.8 (0-1.54) vs. 1.28 (0.52-1.85) vs. 1.54 (0.78-2.52)), trunk (1.5 (0.74-2.27) vs. 1.53 (0.99-2.2) vs. 1.98 (1.18-2.66)), left leg (1.56 (0.49-2.25) vs. 1.77 (1.24-2.43) vs. 2.08 (1.18-2.95)), lower versus higher tercile p < 0.05. However, no differences in intradialytic symptoms or postdialysis recovery times between the UFR terciles were observed.

CONCLUSION

There were no differences in self-reported intradialytic symptoms or postdialysis recovery times with differing UFRs, despite changes in intracompartmental fluid shifts as measured by changes in ECW/TBW.

Randomized trial comparing standard versus thermocontrolled haemodialysis using intradialytic cardiac, brain and renal magnetic resonance imaging

BACKGROUND

Ischaemic end-organ damage during haemodialysis (HD) is a significant problem that may be ameliorated by intradialytic cooling. A randomised trial was performed to compare standard HD (SHD; dialysate temperature 37°C) and programmed cooling of the dialysate [thermocontrolled HD (TCHD)] using multiparametric magnetic resonance imaging (MRI) to assess structural, functional and blood flow changes in the heart, brain and kidneys.

METHODS

Prevalent HD patients were randomly allocated to receive either SHD or TCHD for 2 weeks before undergoing serial MRI at four time points: pre-, during (30 min and 180 min) and post-dialysis. MRI measures include cardiac index, myocardial strain, longitudinal relaxation time (T1), myocardial perfusion, internal carotid and basilar artery flow, grey matter perfusion and total kidney volume. Participants then crossed to the other modality to repeat the study protocol.

RESULTS

Eleven participants completed the study. Separation in blood temperature between TCHD (-0.1 ± 0.3°C) and SHD (+0.3 ± 0.2°C; P = .022) was observed, although there was no difference in tympanic temperature changes between arms. There were significant intradialytic reductions in cardiac index, cardiac contractility (left ventricular strain), left carotid and basilar artery blood flow velocities, total kidney volume, longitudinal relaxation time (T1) of the renal cortex and transverse relaxation rate (T2*) of the renal cortex and medulla, but no differences between arms. Pre-dialysis T1 of the myocardium and left ventricular wall mass index were lower after 2 weeks of TCHD compared with SHD [1266 ms (interquartile range 1250-1291) versus 1311 ± 58 ms, P = .02; 66 ± 22 g/m2 versus 72 ± 23 g/m2, P = .004].

CONCLUSIONS

HD adversely affects cardiac function, reduces carotid and basilar artery blood flow and total kidney volume, but mild dialysate cooling using a biofeedback module did not result in differences in intradialytic MRI measures compared with SHD.

The effect of hemodialysis with cool dialysate on nausea in hemodialysis patients: A randomized clinical trial

Background and Aims

Experiencing nausea leads to decreased self-esteem and social isolation in hemodialysis patients and affects all aspects of their quality of life. Nausea and vomiting make hemodialysis unpleasant for patients leading to premature termination of hemodialysis. Therefore, based on this necessity, the present study was conducted to determine the effect of hemodialysis with cool dialysate on nausea in hemodialysis patients.

Methods

In this clinical trial, 60 eligible patients receiving hemodialysis were randomly assigned to the control (30 participants) and intervention (30 participants) groups. In the control group, the patients received standard hemodialysis (37°C) for three sessions. Simultaneously, patients in the intervention group received hemodialysis with a cold solution (of 36°C) for three sessions. The patients' nausea and shivering rates were measured using the visual analog scale and the shivering standard assessment scale, respectively. Both groups were evaluated before and after 1 week of intervention. The study did not include blinding. The trial has been registered in the Iranian Registry of Clinical Trials (IRCT) with the number IRCT20200530047597N1. The present study was financially supported by Kermanshah University of Medical Sciences, Kermanshah, Iran (no. 990220). Data were analyzed using SPSS-25 software.

Findings

The independent t test showed no statistically significant difference between the two control and experimental groups regarding the nausea rate in the three evaluation times (p < 0.05). Nevertheless, nausea severity decreased significantly after the intervention in the two groups. However, the rate of nausea in the intervention group with cold solution decreased more compared to the control group. Moreover, no patient in the intervention group experienced shivering during hemodialysis with a cool dialysate.

Conclusion

According to the results of this study, it can be stated that the use of cold hemodialysis to control nausea in patients undergoing hemodialysis requires further studies and can be recommended as a nonpharmacological treatment to manage the treatment costs in case of efficiency.

Does cooled dialysate still have a role in reducing intradialytic stress? Implications of the MyTEMP trial

PURPOSE OF REVIEW

There is an excess of cardiovascular morbidity and mortality in the maintenance haemodialysis population. Targeting traditional risk factors (e.g. hypercholesterolaemia) do not improve cardiovascular outcomes. Repeated myocardial stunning during haemodialysis is an important nontraditional risk, resulting in pathological cardiac remodelling and fibrosis. This review explores dialysate cooling as a management strategy to promote haemodynamic stability, reduce myocardial injury, and improve cardiovascular disease outcomes for individuals receiving maintenance haemodialysis.

RECENT FINDINGS

Observational data and small interventional studies demonstrate dialysate cooling has the potential to reduce end-organ damage and provide cardioprotection, renal protection and neuroprotection compared with standard care. These data are limited by the small sample sizes, short follow-up times and lack of long-term patient important outcomes. The MyTEMP study, a multicentre pragmatic randomized controlled trial, demonstrated cooled dialysate (0.5°C below body temperature) vs. standard care did not improve cardiovascular outcomes for prevalent haemodialysis patients.

SUMMARY

Dialysate cooling has been widely adopted into routine clinical practice; the MyTEMP study challenges the unit-level approach to implementing dialysate cooling. Due to methodological limitations, the absence of other important patient outcome measures, and lack of granularity of patient-level data, dialysate cooling should not be hastily removed from all dialysis care and warrants further research.

Cognitive disorders in patients with chronic kidney disease: Approaches to prevention and treatment

BACKGROUND

Cognitive impairment is common in patients with chronic kidney disease (CKD), and early intervention may prevent the progression of this condition.

METHODS

Here, we review interventions for the complications of CKD (anemia, secondary hyperparathyroidism, metabolic acidosis, harmful effects of dialysis, the accumulation of uremic toxins) and for prevention of vascular events, interventions that may potentially be protective against cognitive impairment. Furthermore, we discuss nonpharmacological and pharmacological methods to prevent cognitive impairment and/or minimize the latter's impact on CKD patients' daily lives.

RESULTS

A particular attention on kidney function assessment is suggested during work-up for cognitive impairment. Different approaches are promising to reduce cognitive burden in patients with CKD but the availabe dedicated data are scarce.

CONCLUSIONS

There is a need for studies assessing the effect of interventions on the cognitive function of patients with CKD.

Archetypal sustained low-efficiency daily diafiltration (SLEDD-f) for critically ill patients requiring kidney replacement therapy: towards an adequate therapy

Sustained low-efficiency dialysis is a hybrid form of kidney replacement therapy that has gained increasing popularity as an alternative to continuous forms of kidney replacement therapy in intensive care unit settings. During the COVID-19 pandemic, the shortage of continuous kidney replacement therapy equipment led to increasing usage of sustained low-efficiency dialysis as an alternative treatment for acute kidney injury. Sustained low-efficiency dialysis is an efficient method for treating hemodynamically unstable patients and is quite widely available, making it especially useful in resource-limited settings. In this review, we aim to discuss the various attributes of sustained low-efficiency dialysis and how it is comparable to continuous kidney replacement therapy in efficacy, in terms of solute kinetics and urea clearance, and the various formulae used to compare intermittent and continuous forms of kidney replacement therapy, along with hemodynamic stability. During the COVID-19 pandemic, there was increased clotting of continuous kidney replacement therapy circuits, which led to increased use of sustained low-efficiency dialysis alone or together with extra corporeal membrane oxygenation circuits. Although sustained low-efficiency dialysis can be delivered with continuous kidney replacement therapy machines, most centers use standard hemodialysis machines or batch dialysis systems. Even though antibiotic dosing differs between continuous kidney replacement therapy and sustained low-efficiency dialysis, reports of patient survival and renal recovery are similar for continuous kidney replacement therapy and sustained low-efficiency dialysis. Health care studies indicate that sustained low-efficiency dialysis has emerged as a cost-effective alternative to continuous kidney replacement therapy. Although there is considerable data to support sustained low-efficiency dialysis treatments for critically ill adult patients with acute kidney injury, there are fewer pediatric data, even so, currently available studies support the use of sustained low-efficiency dialysis for pediatric patients, particularly in resource-limited settings.

Could cooling dialysate improve inflammatory and nutritional status of hemodialysis patients?

BACKGROUND

It has been shown that dialysate cooling (lowering the dialysate temperature to 0.5 °C below central body temperature) reduces the incidence of intradialytic hypotension. Other influences on hemodialysis patients, however, have not been adequately investigated. The purpose of this study was to determine the impact of individualized dialysate cooling on nutritional and inflammatory parameters in chronic hemodialysis (HD) patients.

METHODS

Seventy HD patients were separated into two groups: group A: (control group) standard dialysate temperature was 37 °C, and group B: (intervention group) dialysate temperature was 0.5 °C below core body temperature. In addition to routine laboratory tests, blood pressure, anthropometric measurements, inflammatory markers, and the malnutrition inflammation score (MIS) were calculated.

RESULTS

After six months of dialysate cooling, intradialytic hypotension episodes were much less prevalent in the intervention group (p = 0.001). Serum ferritin, transferrin saturation (TSAT), high sensitive C-reactive protein (HS-CRP), and Interleukin-6 (IL-6) reduced following dialysate cooling, whereas serum albumin rose. In the control group, IL-6 dropped but serum ferritin, TSAT, albumin, and HS-CRP rose. In both groups, hemoglobin levels dropped, and erythrocyte sedimentation rate (ESR) rose, both groups' midarm muscle circumference and MIS worsened.

CONCLUSION

Cold dialysate decreased intradialytic hypotension with no significant improvement of the nutritional and inflammatory surrogates. However, more studies including larger number of patients with longer duration of follow up are required to adequately assess its effect on inflammation and nutrition in chronic hemodialysis patients.

Prevention of Intradialytic Hypotension in Hemodialysis Patients: Current Challenges and Future Prospects

Intradialytic hypotension, defined as rapid decrease in systolic blood pressure of greater than or equal to 20 mmHg or in mean arterial pressure of greater than or equal to 10 mmHg that results in end-organ ischemia and requires countermeasures such as ultrafiltration reduction or saline infusion to increase blood pressure to improve patient's symptoms, is a known complication of hemodialysis and is associated with several potential adverse outcomes. Its pathogenesis is complex and involves both patient-related factors such as age and comorbidities, as well as factors related to the dialysis prescription itself. Key factors include the need for volume removal during hemodialysis and a suboptimal vascular response which compromises the ability to compensate for acute intravascular volume loss. Inadequate vascular refill, incorrect assessment or unaccounted changes of target weight, acute illnesses and medication interference are further potential contributors. Intradialytic hypotension can lead to compromised tissue perfusion and end-organ damage, both acutely and over time, resulting in repetitive injuries. To address these problems, a careful assessment of subjective symptoms, minimizing interdialytic weight gains, individualizing dialysis prescription and adjusting the dialysis procedure based on patients' risk factors can mitigate negative outcomes.

Management of Cardiovascular Diseases in Chronic Hemodialysis Patients

Hemodialysis (HD) is the main treatment modality for patients with end-stage kidney disease. Cardiovascular diseases (CVD) are highly prevalent in HD patients and are the leading cause of death in this population, with the mortality from CVD approximately 20 times higher than that of the general population. Traditional and non-traditional cardiovascular risk factors accelerate progression of CVD and exacerbate the prognosis in HD patients. This review provides a brief overview of the characteristics of CVD in HD patients, and a description of advances in its management.

Epidemiology, Pathophysiology, and Clinical Perspectives of Intradialytic Hypertension

BACKGROUND

Individuals with end-stage renal disease on chronic hemodialysis (HD) may encounter numerous HD-associated complications, including intradialytic hypertension (IDHYPER). Although blood pressure (BP) follows a predictable course in the post-HD period, BP levels during the session may vary across the individuals. Typically, a decline in BP is noted during HD, but a significant proportion of patients exhibit a paradoxical elevation.

SUMMARY

Several studies have been conducted to understand the complexity of IDHYPER, but much remains to be elucidated in the future. This review article aimed to present the current evidence regarding the proposed definitions, the pathophysiologic background, the extent and clinical implications of IDHYPER, as well as the possible therapeutic options that have emerged from clinical studies.

KEY MESSAGES

IDHYPER is noted in approximately 15% of individuals undergoing HD. Several definitions have been proposed, with a systolic BP rise >10 mm Hg from pre- to post-dialysis in the hypertensive range in at least four out of six consecutive HD treatments being suggested by the latest Kidney Disease: Improving Global Outcomes. Concerning its pathophysiology, extracellular fluid overload is a crucial determinant, with endothelial dysfunction, sympathetic nervous system overdrive, renin-angiotensin-aldosterone system activation, and electrolyte alterations being important contributors. Although its association with ambulatory BP in the interdialytic period is controversial, IDHYPER is associated with adverse cardiovascular events and mortality. Moving to its management, the antihypertensive drugs of choice should ideally be nondialyzable with proven cardiovascular and mortality benefits. Finally, rigorous clinical and objective assessment of extracellular fluid volume is essential. Volume-overloaded patients should be instructed about the importance of sodium restriction, while physicians ought to alter HD settings toward a greater dry weight reduction. The use of a low-sodium dialysate and isothermic HD could also be considered on a case-by-case basis since no randomized evidence is currently available.

Physical intradialytic patient-reported outcome measures in haemodialysis and haemodiafiltration: A cross-over study

AIM

Standard haemodialysis (sHD) is associated with a poor survival and marked adverse intradialytic patient-reported outcome measures (ID-PROMs). Whereas physical ID-PROMs (PID-PROMs) are alleviated by cool dialysate (cHD), survival is prolonged by haemodiafiltration (HDF). So far, PID-PROMs are not prospectively compared between HD and HDF.

METHODS

To assess whether PID-PROMs and thermal perception differ between sHD, cHD, low volume HDF (lvHDF) and high volume HDF (hvHDF), 40 patients were cross-over randomized to each modality for 2 weeks. Dialysate temperature (T_d ) was 36.5°C, except in cHD (T_d 35.5°C). Target convection volumes were 15 L in lvHDF and ≥ 23 L in hvHDF. PID-PROMs were evaluated with a modified Dialysis Symptom Index (mDSI) and thermal perception with the Visual Analogue Scale Thermal Perception (VAS-TP). T_b and room temperature were measured as well.

RESULTS

Except for the item 'feeling cold' during cHD (p = .01), PID-PROMs did not differ between modalities, but varied markedly between patients (11/13 items, p < .05). T_b increased in sHD, lvHDF, and hvHDF (+0.30, 0.35, 0.38°C, respectively, all p < .0005), but remained stable in cHD (+0.04°C, p = .43). Thermal perception remained unaltered in sHD and both HDF modalities, but shifted towards cold in cHD (p = .007).

CONCLUSION

(1) PID-PROMs did not differ between modalities, but varied markedly between patients. Hence, PID-PROMs are largely patient-dependent. (2) While T_b increased in sHD, lvHDF and hvHDF, thermal perception did not change. Yet, whereas T_b remained unaltered in cHD, cold perception emerged. Hence, as for bothersome cold sensations, cHD should be avoided in perceptive individuals.

Why is Intradialytic Hypotension the Commonest Complication of Outpatient Dialysis Treatments?

Intradialytic hypotension (IDH) is the most frequent complication of hemodialysis (HD) treatments with a frequency of 10% to 12% for patients with chronic kidney disease attending for outpatient treatments and is associated with both temporary ischemic stress to vital organs, including the heart and brain, and increased patient mortality. Although there have been many different definitions of IDH over the years, an absolute nadir systolic blood pressure (SBP) has the strongest association with patient outcomes. The unifying pathophysiology is one of reduced effective blood volume, resulting in lower plasma tonicity, and if this cannot be adequately compensated for by activation of neurohumeral systems, then arteriolar tone and blood pressure fall. The risk factors for developing IDH are numerous, ranging from patient-related factors, including age and comorbidity with reduced cardiac reserve, to patient compliance with dietary and lifestyle advice, to reactions with the extracorporeal circuit and medications, choice of dialysate composition and temperature, setting of postdialysis target weight, ultrafiltration rate, and profiling. Advances in dialysis machine technology by providing real time estimates of the effective circulating volume and adjusting dialysate composition to maintain vascular tonicity are being developed, but currently require more sophisticated biofeedback loops to be clinically effective in preventing IDH. While awaiting advances in artificial intelligence, the clinician continues to rely on patient education to limit interdialytic weight gains, frequent assessment of the postdialysis target weight, adjusting dialysate composition and temperature, introducing convective therapies to increase thermal losses, and altering dialysis session duration and frequency to reduce ultrafiltration rate requirements.

Management of Intermittent Hemodialysis in the Critically Ill Patient

Intermittent hemodialysis remains a cornerstone of extracorporeal KRT in the intensive care unit, either as a first-line therapy for AKI or a second-line therapy when patients transition from a continuous or prolonged intermittent therapy. Intermittent hemodialysis is usually provided 3 days per week in this setting on the basis that no clinical benefits have been demonstrated with more frequent hemodialysis. This should not detract from the importance of continually assessing and refining the hemodialysis prescription (including the need for extra treatments) according to dynamic changes in extracellular volume and other parameters, and ensuring that an adequate dose of hemodialysis is being delivered to the patient. Compared with other KRT modalities, the cardinal challenge encountered during intermittent hemodialysis is hemodynamic instability. This phenomenon occurs when reductions in intravascular volume, as a consequence of ultrafiltration and/or osmotic shifts, outpace compensatory plasma refilling from the extravascular space. Myocardial stunning, triggered by intermittent hemodialysis, and independent of ultrafiltration, may also contribute. The hemodynamic effect of intermittent hemodialysis is likely magnified in patients who are critically ill due to an inability to mount sufficient compensatory physiologic responses in the context of multiorgan dysfunction. Of the many interventions that have undergone testing to mitigate hemodynamic instability related to KRT, the best evidence exists for cooling the dialysate and raising the dialysate sodium concentration. Unfortunately, the evidence supporting routine use of these and other interventions is weak owing to poor study quality and limited sample sizes. Intermittent hemodialysis will continue to be an important and commonly used KRT modality for AKI in patients with critical illness, especially in jurisdictions where resources are limited. There is an urgent need to harmonize the definition of hemodynamic instability related to KRT in clinical trials and robustly test strategies to combat it in this vulnerable patient population.

Changes of Hemodynamic Parameters after Intradialytic Glucose Injection

BACKGROUND

Intradialytic hypotension (IDH) is a frequent complication of hemodialysis (HD). Current methods of IDH prevention are insufficient.

METHODS

We analyzed the intradialytic time course of systolic (SBP), diastolic (DBP), mean arterial (MAP), pulse pressure (PP), and heart rate (HR) in a group of chronic kidney disease (CKD) patients. First, 30 min into HD, a 40% glucose solution was injected into the venous line of the extracorporeal circulation at a dose of 0.5 g/kg of dry weight. Pressures and HR were measured in frequent intervals. Relative volume overload was determined by bioimpedance spectroscopy.

RESULTS

Thirty-five participants were studied. SBP increased after 5, 10, and 20 min of glucose infusion. DBP increased after 2 and 3 h and also at the end of HD. PP increased after 5, 10, and 20 min of glucose infusion and fell after the 2nd and 3rd hour and also at the end of HD. MAP increased after 2 and 3 h of glucose injection and at the end of HD. Significant interactions of the time course of SBP, DBP, MAP, with HR at baseline and of the time course of PP with fluid overload were observed. Symptomatic hypotensive episodes were absent.

CONCLUSIONS

Glucose infusions during HD prevent symptomatic IDH and do not cause severe hypertensive episodes.

Circumferential Strain as a Marker of Vessel Reactivity in Patients with Intradialytic Hypotension

Background and Objectives: Intradialytic hypotension (IDH) complicates 4 to 39.9% of hemodialysis (HD) sessions. Vessels' reactivity disturbances may be responsible for this complication. Two-dimensional speckle tracking is used to assess arterial circumferential strain (CS) as a marker of the effectiveness of the cardiovascular response to the reduction of circulating plasma. Materials and Methods: The common carotid artery (CCA) and common iliac artery (CIA) CSs were recorded using ultrasonography in 68 chronically dialyzed patients before and after one HD session. Results: In patients with IDH episodes (n = 26), the CCA-CS was significantly lower both before (6.28 ± 2.34 vs. 4.63 ± 1.74 p = 0.003) and after HD (5.00 (3.53-6.78) vs. 3.79 ± 1.47 p = 0.010) than it was in patients without this complication. No relationship was observed between CIA-CS and IDH. IDH patients had a significantly higher UF rate; however, they did not differ compared to complication-free patients either in anthropometric or laboratory parameters. Conclusions: Patients with IDH were characterized by lower pre- and post-HD circumferential strain of the common carotid artery. The lower CCA-CS showed that impaired vascular reactivity is one of the most important risk factors for this complication's occurrence.

Personalised cooler dialysate for patients receiving maintenance haemodialysis (MyTEMP): a pragmatic, cluster-randomised trial

BACKGROUND

Haemodialysis centres have conventionally provided maintenance haemodialysis using a standard dialysate temperature (eg, 36·5°C) for all patients. Many centres now use cooler dialysate (eg, 36·0°C or lower) for potential cardiovascular benefits. We aimed to assess whether personalised cooler dialysate, implemented as centre-wide policy, reduced the risk of cardiovascular-related death or hospital admission compared with standard temperature dialysate.

METHODS

MyTEMP was a pragmatic, two-arm, parallel-group, registry-based, open-label, cluster-randomised, superiority trial done at haemodialysis centres in Ontario, Canada. Eligible centres provided maintenance haemodialysis to at least 15 patients a week, and the medical director of each centre had to confirm that their centre would deliver the assigned intervention. Using covariate-constrained randomisation, we allocated 84 centres (1:1) to use either personalised cooler dialysate (nurses set the dialysate temperature 0·5-0·9°C below each patient's measured pre-dialysis body temperature, with a lowest recommended dialysate temperature of 35·5°C), or standard temperature dialysate (36·5°C for all patients and treatments). Patients and health-care providers were not masked to the group assignment; however, the primary outcome was recorded in provincial databases by medical coders who were unaware of the trial or the centres' group assignment. The primary composite outcome was cardiovascular-related death or hospital admission with myocardial infarction, ischaemic stroke, or congestive heart failure during the 4-year trial period. Analysis was by intention to treat. The study is registered at ClinicalTrials.gov, NCT02628366.

FINDINGS

We assessed all of Ontario's 97 centres for inclusion into the study. Nine centres had less than 15 patients and one director requested that four of their seven centres not participate. 84 centres were recruited and on Feb 1, 2017, these centres were randomly assigned to administer personalised cooler dialysate (42 centres) or standard temperature dialysate (42 centres). The intervention period was from April 3, 2017, to March 31, 2021, and during this time the trial centres provided outpatient maintenance haemodialysis to 15 413 patients (about 4·3 million haemodialysis treatments). The mean dialysate temperature was 35·8°C in the cooler dialysate group and 36·4°C in the standard temperature group. The primary outcome occurred in 1711 (21·4%) of 8000 patients in the cooler dialysate group versus 1658 (22·4%) of 7413 patients in the standard temperature group (adjusted hazard ratio 1·00, 96% CI 0·89 to 1·11; p=0·93). The mean drop in intradialytic systolic blood pressure was 26·6 mm Hg in the cooler dialysate group and 27·1 mm Hg in the standard temperature group (mean difference -0·5 mm Hg, 99% CI -1·4 to 0·4; p=0·14).

INTERPRETATION

Centre-wide delivery of personalised cooler dialysate did not significantly reduce the risk of major cardiovascular events compared with standard temperature dialysate. The rising popularity of cooler dialysate is called into question by this study, and the risks and benefits of cooler dialysate in some patient populations should be clarified in future trials.

FUNDING

Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Ontario Renal Network, Ontario Strategy for Patient-Oriented Research Support Unit, Dialysis Clinic, Inc., ICES (formerly known as the Institute for Clinical Evaluative Sciences), Lawson Health Research Institute, and Western University.

High-Volume Hemodiafiltration and Cool Hemodialysis Have a Beneficial Effect on Intradialytic Hemodynamics: A Randomized Cross-Over Trial of Four Intermittent Dialysis Strategies

Introduction

Compared to standard hemodialysis (S-HD), postdilution hemodiafiltration (HDF) has been associated with improved survival.

Methods

To assess whether intradialytic hemodynamics may play a role in this respect, 40 chronic dialysis patients were cross-over randomized to S-HD (dialysate temperature [Td] 36.5 °C), cooled HD (C-HD; Td 35.5 °C), and HDF (low-volume [LV-HDF)] and high-volume [HV-HDF], both Td 36.5 °C, convection volume 15 liters, and at least 23 liters per session, respectively), each for 2 weeks. Blood pressure (BP) was measured every 15 minutes. The primary endpoint was the number of intradialytic hypotensive (IDH) episodes per session. IDH was defined as systolic BP (SBP) less than 90 mmHg for predialysis SBP less than 160 mmHg and less than 100 mmHg for predialysis SBP greater than or equal to 160 mmHg, independent of symptoms and interventions. A post hoc analysis on early-onset IDH was performed as well. Secondary endpoints included intradialytic courses of SBP, diastolic BP (DBP) and mean arterial pressure (MAP).

Results

During S-HD, IDH occurred 0.68 episodes per session, which was 3.2 and 2.5 times higher than during C-HD (0.21 per session, P < 0.0005) and HV-HDF (0.27 per session, P < 0.0005), respectively. Whereas the latter 2 strategies showed similar frequencies, HV-HDF differed significantly from LV-HDF (P = 0.02). A comparable trend was observed for early-onset IDH: S-HD (0.32 per session), C-HD (0.07 per session, P < 0.0005) and HV-HDF (0.10 per session, P = 0.001). SBP, DBP, and MAP declined during S-HD (−6.8, −5.2, −5.2 mmHg per session; P = 0.004, P < 0.0005, P = 0.002 respectively), which was markedly different from C-HD (P < 0.01).

Conclusion

Though C-HD and HV-HDF showed the lowest IDH frequency and the best intradialytic hemodynamic stability, all parameters were most disrupted in S-HD. Therefore, the survival benefit of HV-HDF over S-HD may be partly caused by a more beneficial intradialytic BP profile.

A methodologic survey on use of the GRADE approach in evidence syntheses published in high-impact factor urology and nephrology journals

Background

To identify and describe the use of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach for rating the certainty of systematic reviews (SRs) evidence published in urology and nephrology journals.

Methods

SRs that were published in the top ten "urology and nephrology" journals with the highest impact factor according to the 2020 Journal Citation Reports (covering 2016–2020) were systematically searched and evaluated using the GRADE approach.

Results

A total of 445 SRs were researched. Sixty SRs of randomized control trials (RCTs) and/or non-randomized studies (NRSs) were evaluated using the GRADE approach. Forty-nine SRs (11%) rated the outcome-specific certainty of evidence (n = 29 in 2019–2020). We identified 811 certainty of evidence outcome ratings (n = 544 RCT ratings) as follows: very low (33.0%); low (32.1%); moderate (24.5%); and high (10.4%). Very low and high certainty of evidence ratings accounted for 55.0% and 0.4% of ratings in SRs of NRSs compared to 23.0% and 15.3% in SRs of RCTs. The certainty of evidence for RCTs and NRSs was downgraded most often for risk of bias and imprecision.

Conclusions

We recommend increased emphasis on acceptance of the GRADE approach, as well as optimal use of the GRADE approach, in the synthesis of urinary tract evidence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01701-x.

Restless Leg Syndrome in Hemodialysis Patients: A Narrative Review

BACKGROUND

Restless legs syndrome (RLS) is a clinical entity characterized by sensory-motor manifestations commonly observed in end-stage renal illness. Evidence suggests that RLS is a multifactorial phenomenon that can be influenced by many critical factors, including genetic predisposition, dietary patterns, and deficiency in some vitamins. Iron metabolism disorders and metabolic derangements have been generally accepted as predisposing elements in RLS. Furthermore, both pharmacological and neuroimaging studies demonstrated dopamine deficiency and dopamine receptors decrease in basal ganglia during RLS.

REVIEW SUMMARY

A literature search was done in three databases (PubMed, Google Scholar, and Cochrane) to identify the pertinent articles discussing the epidemiology, pathogenesis, and management of RLS in hemodialysis patients. RLS can affect the morbidity and mortality of patients treated with dialysis. It also has significant impacts on the quality of life since it can lead to insomnia, increased fatigue, mental health troubles, and other movement problems. Appropriate measures should be considered in this particular population so to prevent and treat RLS. Many drugs and other nonpharmacological methods have been investigated to attenuate the disease's severity. No treatment, however, could offer long-term effects.

CONCLUSION

Further efforts are still required to improve the understanding of RLS pathogenic trends to find more specific and efficient therapies. A wide range of treatment options is available. However, it can be individualized according to the patients' several factors.

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.

Dialysis-Associated Nonarteritic Anterior Ischemic Optic Neuropathy: A Case Series and Review

BACKGROUND

Dialysis-associated nonarteritic ischemic optic neuropathy (DA-NAION) occurs secondary to intradialytic hypotension often with catastrophic consequences and is one of the rare situations where NAION can recur in the same eye. We describe 3 cases of DA-NAION associated with hypotension, review the current literature on DA-NAION, and provide recommendations for decreasing the risk of intradialytic hypotension.

METHODS

In addition to describing 3 cases of DA-NAION, PubMed was searched for all reports of DA-NAION in adults with documented episodes of hypotension preceding the onset of NAION. A total of 50 eyes of 31 patients were included. Age, visual acuity at presentation, rate of bilateral involvement at presentation, sequential involvement of the fellow eye, and recurrence of NAION in the same eye were analyzed.

RESULTS

We found that most cases of DA-NAION occur in relatively young patients (47.7 ± 14.7 years) with a high rate of bilateral involvement at presentation (23%) and bilateral sequential involvement (39%). Vision loss is severe with 64% of patients presenting with 20/200 acuity or worse in the involved eye and 19% of patients with final visual acuity of 20/200 or worse in both eyes. 3 patients (9.7%) had recurrence of NAION in the previously affected eye.

CONCLUSIONS

Neuro-ophthalmologists have an important role in identifying patients who have suffered DA-NAION and communicating their findings to nephrologists to minimize the chance of involvement of the fellow eye and recurrence in the same eye. Intradialytic blood pressure must be closely monitored, and fluid balance, dialysate composition, and dialysis protocol must be optimized to prevent occurrence of intradialytic hypotension, which is the culprit for DA-NAION.

Effect of Cold Dialysis Solution on the Sexual Dysfunction of Patients with Chronic Renal Failure Undergoing Hemodialysis: A Randomized Clinical Trial

Background: The present study aimed to evaluate the effect of cold dialysis solution on the sexual dysfunction of patients with chronic renal failure undergoing hemodialysis. Methods: This randomized clinical trial was conducted with a before and after parallel design among 60 hemodialysis patients diagnosed with sexual dysfunction. The selected subjects were randomly allocated to the two groups of experimental and control (30 per each). Patients in the experimental and control groups underwent hemodialysis for one month using 35.5°C and 37°C dialysis solutions, respectively. Following the procedure, male and female sexual function was assessed in the study groups. Data were collected using the International Index of Erectile Functions, the female sexual function index (FSFI), and a demographic questionnaire. Data analysis was performed using Chi-square, Fisher's exact test, Mann-Whitney U test, t-test, paired t-test, and Wilcoxon test at 95% confidence interval. Results: No significant difference was observed between the experimental and control groups regarding male sexual function before and after the intervention (P > 0.05). However, the Mann-Whitney U test indicated a significant difference in the female subjects’ arousal in the experimental group before (3.68 ± 0.38) and after the intervention (3.98 ± 0.46; z = 2.216; P = 0.027). Conclusions: Cold dialysis solution could only increase the sexual arousal of the women in the experimental group, and no changes were observed in other sexual function domains of the male and female patients. Given the short duration of our intervention, it is recommended that further longitudinal studies be performed on larger cohorts of patients in different geographical regions.

The Effects of Cool Dialysate on Vital Signs, Adequacy and Complications during Hemodialysis

BACKGROUND

Cooling the dialysate is an important factor that contributes to the hemodynamic stability in patients during hemodialysis. The aim of this study was to determine the effect of cool dialysate on vital signs, and the adequacy and common complications of hemodialysis.

MATERIALS AND METHODS

The present crossover, triple-blind, clinical trial was performed on 62 dialysis patients, who were selected through stratified block randomization. First, one group underwent hemodialysis using a cool dialysate (35°C), and the other received routine hemodialysis (36.5°C). Each patient received a total of eight hemodialysis sessions. Then, treatment methods were swapped, and each group received the other group's method. The patients' blood pressure, pulse rate, and temperature were measured before dialysis, and in the first, second, third, and fourth hours of dialysis. The frequency of common complications of hemodialysis and dialysis efficacy were measured. The marginal model and Generalized Estimating Equations (GEE) were used to analyze the data.

RESULTS

The participants' systolic (p = 0.01) and diastolic blood pressures significantly increased with a decrease in temperature (p = 0.005). The patients' pulse rate (p = 0.143), adequacy of dialysis (p = 0.922), and common complications of hemodialysis did not significantly differ between the two temperatures (p > 0.05).

CONCLUSIONS

Reducing dialysate temperature from 36.5 to 35°C led to hemodynamic stability; the blood pressure of the patients undergoing hemodialysis was more stable with the cool dialysate method and the number of drops in the blood pressure during the hemodialysis was reduced.

Hemodiafiltration maintains a sustained improvement in blood pressure compared to conventional hemodialysis in children-the HDF, heart and height (3H) study

BACKGROUND

Hypertension is prevalent in children on dialysis and associated with cardiovascular disease. We studied the blood pressure (BP) trends and the evolution of BP over 1 year in children on conventional hemodialysis (HD) vs. hemodiafiltration (HDF).

METHODS

This is a post hoc analysis of the "3H - HDF-Hearts-Height" dataset, a multicenter, parallel-arm observational study. Seventy-eight children on HD and 55 on HDF who had three 24-h ambulatory BP monitoring (ABPM) measures over 1 year were included. Mean arterial pressure (MAP) was calculated and hypertension defined as 24-h MAP standard deviation score (SDS) ≥95th percentile.

RESULTS

Poor agreement between pre-dialysis systolic BP-SDS and 24-h MAP was found (mean difference - 0.6; 95% limits of agreement -4.9-3.8). At baseline, 82% on HD and 44% on HDF were hypertensive, with uncontrolled hypertension in 88% vs. 25% respectively; p < 0.001. At 12 months, children on HDF had consistently lower MAP-SDS compared to those on HD (p < 0.001). Over 1-year follow-up, the HD group had mean MAP-SDS increase of +0.98 (95%CI 0.77-1.20; p < 0.0001), whereas the HDF group had a non-significant increase of +0.15 (95%CI -0.10-0.40; p = 0.23). Significant predictors of MAP-SDS were dialysis modality (β = +0.83 [95%CI +0.51 - +1.15] HD vs. HDF, p < 0.0001) and higher inter-dialytic-weight-gain (IDWG)% (β = 0.13 [95%CI 0.06-0.19]; p = 0.0003).

CONCLUSIONS

Children on HD had a significant and sustained increase in BP over 1 year compared to a stable BP in those on HDF, despite an equivalent dialysis dose. Higher IDWG% was associated with higher 24-h MAP-SDS in both groups.

Evolution and change in paradigm of hemodialysis in children: a systematic review

BACKGROUND

There are similarities in hemodialysis (HD) between adults and children and also unique pediatric aspects. In this systematic review, we evaluated the existing HD literature, including vascular access, indications, parameters, and outcomes as a reflection on real-life HD practices.

METHODS

Medline, Embase, CINAHL, Web of Science, and Cochrane Library were systematically searched for literature on HD in children (1-20 years). Two reviewers independently assessed the literature and data on indications; vascular access, outcomes, and specific parameters for HD were extracted.

RESULTS

Fifty-four studies (8751 patients) were included in this review. Studies were stratified into age groups 1-5, 6-12, and 13-20 years based on median/mean age reported in the study, as well as era of publication (1990-2000, 2001-2010, and 2011-2019). Across all age groups, both arteriovenous fistulas and central venous catheters were utilized for vascular access. Congenital abnormalities and glomerulopathy were the most common HD indications. HD parameters including HD session duration, dialysate and blood flow rates, urea reduction ratio, and ultrafiltration were characterized for each age group, as well as common complications including catheter dysfunction and intradialytic hypotension. Median mortality rates were 23.3% (3.3), 7.6% (14.5), and 2.0% (3.0) in ages 1-5, 6-12, and 13-20 years, respectively. Median transplantation rates were 41.6% (38.3), 52.0% (32.0), and 21% (25.6) in ages 1-5, 6-12, and 13-20, respectively.

CONCLUSION

This comprehensive systematic review summarizes available literature on HD in children and young adults, including best vascular access, indications, technical aspects, and outcomes, and reflects on HD practices over the last three decades.

Effect of various dialysis modalities on intradialytic hemodynamics, tissue injury and patient discomfort in chronic dialysis patients: design of a randomized cross-over study (HOLLANT)

BACKGROUND

From a recent meta-analysis it appeared that online post-dilution hemodiafiltration (HDF), especially with a high convection volume (HV-HDF), is associated with superior overall and cardiovascular survival, if compared to standard hemodialysis (HD). The mechanism(s) behind this effect, however, is (are) still unclear. In this respect, a lower incidence of intradialytic hypotension (IDH), and hence less tissue injury, may play a role. To address these items, the HOLLANT study was designed.

METHODS

HOLLANT is a Dutch multicentre randomized controlled cross-over trial. In total, 40 prevalent dialysis patients will be included and, after a run-in phase, exposed to standard HD, HD with cooled dialysate, low-volume HDF and high-volume HDF (Dialog iQ® machine) in a randomized fashion. The primary endpoint is an intradialytic nadir in systolic blood pressure (SBP) of < 90 and < 100 mmHg for patients with predialysis SBP < 159 and ≥ 160 mmHg, respectively. The main secondary outcomes are 1) intradialytic left ventricle (LV) chamber quantification and deformation, 2) intradialytic hemodynamic profile of SBP, diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP), 3) organ and tissue damage, such as the release of specific cellular components, and 4) patient reported symptoms and thermal perceptions during each modality.

DISCUSSION

The current trial is primarily designed to test the hypothesis that a lower incidence of intradialytic hypotension contributes to the superior survival of (HV)-HDF. A secondary objective of this investigation is the question whether changes in the intradialytic blood pressure profile correlate with organ dysfunction and tissue damage, and/or patient discomfort.

TRIAL REGISTRATION

Registered Report Identifier: NCT03249532 # ( ClinicalTrials.gov ). Date of registration: 2017/08/15.

The time of onset of intradialytic hypotension during a hemodialysis session associates with clinical parameters and mortality

Intradialytic hypotension (IDH) is a common complication of hemodialysis, but there is no data about the time of onset during treatment. Here we describe the incidence of IDH throughout hemodialysis and associations of time of hypotension with clinical parameters and survival by analyzing data from 21 dialysis clinics in the United States to include 785682 treatments from 4348 patients. IDH was defined as a systolic blood pressure of 90 mmHg or under while IDH incidence was calculated in 30-minute intervals throughout the hemodialysis session. Associations of time of IDH with clinical and treatment parameters were explored using logistic regression and with survival using Cox-regression. Sensitivity analysis considered further IDH definitions. IDH occurred in 12% of sessions at a median time interval of 120-149 minutes. There was no notable change in IDH incidence across hemodialysis intervals (range: 2.6-3.2 episodes per 100 session-intervals). Relative blood volume and ultrafiltration volume did not notably associate with IDH in the first 90 minutes but did thereafter. Associations between central venous but not arterial oxygen saturation and IDH were present throughout hemodialysis. Patients prone to IDH early as compared to late in a session had worse survival. Sensitivity analyses suggested IDH definition affects time of onset but other analyses were comparable. Thus, our study highlights the incidence of IDH during the early part of hemodialysis which, when compared to later episodes, associates with clinical parameters and mortality.

Updates on hemodialysis techniques with a common denominator: The personalization of the dialytic therapy

Hemodialysis (HD) is a life-saving therapy for patients with end-stage renal disease. In dialyzed patients, the prevalence of multi-morbidity is rising driven by various factors, such as the population aging, the incomplete correction of uremia, and the side effects of the dialysis therapy itself. Each dialyzed patient has their own specific clinical and biochemical problems. It is therefore unthinkable that the same dialysis procedure can be able to meet the needs of every patient on chronic dialysis. We have very sophisticated dialysis machines and different dialysis techniques and procedures beyond conventional HD, such as hemodiafiltration (HDF) with pre- and post-dilution, acetate-free biofiltration (AFB), hemofiltration (HF), and expanded HD. Each of these techniques has its own specific characteristics. To solve some intradialytic clinical issues, such as arterial hypotension and arrhythmias, we have biofeedback systems with automatic regulation of the blood volume, body temperature, arterial pressure, as well as potassium profiling techniques in the dialysis bath. New technical innovations, such as citrate-containing dialysate or heparin-coated membranes, could reduce the risk of bleeding. To better address to patient needs, the strengths and weaknesses of each of these systems must be well-known, in order to have a personalized dialysis prescription for each patient.

Management of acute intradialytic cardiovascular complications: Updated overview (Review)

An increasing number of patients require renal replacement therapy through dialysis and renal transplantation. Chronic kidney disease (CKD) affects a large percentage of the world's population and has evolved into a major public health concern. Diabetes mellitus, high blood pressure and a family history of kidney failure are all major risk factors for CKD. Patients in advanced stages of CKD have varying degrees of cardiovascular damage. Comorbidities of these patients, include, on the one hand, hypertension, hyperlipidemia, hyperglycemia, hyperuricemia and, on the other hand, the presence of mineral-bone disorders associated with CKD and chronic inflammation, which contribute to cardiovascular involvement. Acute complications occur quite frequently during dialysis. Among these, the most important are cardiovascular complications, which influence the morbidity and mortality rates of this group of patients. Chronic hemodialysis patients manifest acute cardiovascular complications such as intradialytic hypotension, intradialytic hypertension, arrhythmias, acute coronary syndromes and sudden death. Thus, proper management is extremely important.

Predictive modeling of blood pressure during hemodialysis: a comparison of linear model, random forest, support vector regression, XGBoost, LASSO regression and ensemble method

BACKGROUND

Intradialytic hypotension (IDH) is commonly occurred and links to higher mortality among patients undergoing hemodialysis (HD). Its early prediction and prevention will dramatically improve the quality of life. However, predicting the occurrence of IDH clinically is not simple. The aims of this study are to develop an intelligent system with capability of predicting blood pressure (BP) during HD, and to further compare different machine learning algorithms for next systolic BP (SBP) prediction.

METHODS

This study presented comprehensive comparisons among linear regression model, least absolute shrinkage and selection operator (LASSO), tree-based ensemble machine learning models (random forest [RF] and extreme gradient boosting [XGBoost]), and support vector regression to predict the BP during HD treatment based on 200 and 48 maintenance HD patients containing a total of 7,180 and 2,065 BP records for the training and test dataset, respectively. Ensemble method also was computed to obtain better predictive performance. We compared the developed models based on R², root mean square error (RMSE) and mean absolute error (MAE).

RESULTS

We found that RF (R²=0.95, RMSE=6.64, MAE=4.90) and XGBoost (R²=1.00, RMSE=1.83, MAE=1.29) had comparable predictive performance on the training dataset. However, RF (R²=0.49, RMSE=16.24, MAE=12.14) had more accurate than XGBoost (R²=0.41, RMSE=17.65, MAE=13.47) on testing dataset. Among these models, the ensemble method (R²=0.50, RMSE=16.01, MAE=11.97) had the best performance on testing dataset for next SBP prediction.

CONCLUSIONS

We compared five machine learning and an ensemble method for next SBP prediction. Among all studied algorithms, the RF and the ensemble method have the better predictive performance. The prediction models using ensemble method for intradialytic BP profiling may be able to assist the HD staff or physicians in individualized care and prompt intervention for patients' safety and improve care of HD patients.

Evaluation of the effect of Cooled HaEmodialysis on Cognitive function in patients suffering with end-stage KidnEy Disease (E-CHECKED): feasibility randomised control trial protocol

BACKGROUND

Cognitive impairment is common in haemodialysis (HD) patients and is associated independently with depression and mortality. This association is poorly understood, and no intervention is proven to slow cognitive decline. There is evidence that cooler dialysis fluid (dialysate) may slow white matter changes in the brain, but no study has investigated the effect of cooler dialysate on cognition. This study addresses whether cooler dialysate can prevent the decline in cognition and improve quality of life (QOL) in HD patients.

METHODS

This is a multi-site prospective randomised, double-blinded feasibility trial.

SETTING

Four HD units in the UK.

PARTICIPANTS AND INTERVENTIONS

Ninety HD patients randomised (1:1) to standard care (dialysate temperature 36.5 °C) or intervention (dialysate temperature 35 °C) for 12 months.

PRIMARY OUTCOME MEASURE

Change in cognition using the Montreal Cognitive Assessment (MoCA).

SECONDARY OUTCOME MEASURES

Recruitment and attrition rates, reasons for non-recruitment, frequency of intradialytic hypotension, depressive symptom scores, patient and carers burden, a detailed computerised cognitive test and QOL assessments.

ANALYSIS

mixed method approach, utilising measurement of cognition, questionnaires, physiological measurements and semi-structured interviews.

DISCUSSION

The results of this feasibility trial will inform the design of a future adequately powered substantive trial investigating the effect of dialysate cooling on prevention and/or slowing in cognitive decline in patients undergoing haemodialysis using a computerised battery of neuro-cognitive tests. The main hypothesis that would be tested in this future trial is that patients treated with regular conventional haemodialysis will have a lesser decline in cognitive function and a better quality of life over 1 year by using cooler dialysis fluid at 35 °C, versus a standard dialysis fluid temperature of 36.5 °C. This also should reflect in improvements in their abilities for activities of daily living and therefore reduce carers' burden. If successful, the treatment could be universally applied at no extra cost.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03645733 . Registered retrospectively on 24 August 2018.

Ultrafiltration rates and intradialytic hypotension: A case-control sampling of pooled haemodialysis data

BACKGROUND

Intradialytic hypotension (IDH) is one of the most critical adverse events during maintenance haemodialysis. Previous studies reported the association of fluid removal rate with the occurrence of IDH.

OBJECTIVE

We aimed to identify the optimal threshold of ultrafiltration rate to prevent the occurrence of IDH events. DESIGN, PARTICIPANTS AND MEASUREMENTS: Prognostic factor research with a retrospective case-control design was conducted. Patient data were gathered from four haemodialysis units from January to December 2017. All the haemodialysis records were independently justified, whether IDH occurred or not, based on the standard definition. A total of 10 haemodialysis sessions were sampled from each patient's pool based on the incidence of events. The association of ultrafiltration rates and IDH events was explored by multivariable multilevel logistic regression.

RESULTS

A total of 1080 haemodialysis sessions from 108 patients were included: 149 (13.8%) with IDH and 931 (86.2%) without IDH. After adjusting for all pre-specified risk factors and imbalance baselines, the odds ratio of IDH were 1.22 (95% confidence interval [CI]: 0.59, 2.52) for rate 10-12 ml/kg/h; 2.52 (95% CI: 1.20, 5.29) for rate 12-14 ml/kg/h; 4.02 (95% CI: 1.61, 10.03) for rate 14-16 ml/kg/h; and 7.41 (95% CI: 2.53, 21.68) for rate >16 ml/kg/h comparing to the referent rate of <10 ml/kg/h.

CONCLUSION

The ultrafiltration rate should be limited to 12 ml/kg/h. If a higher rate of fluid removal was indicated, it should not exceed 16 ml/kg/h to avoid the occurrence of IDH.

Monitoring for intradialytic hypotension: An audit of nursing practice

BACKGROUND

Intradialytic hypotension (IDH) is one of the most common complications associated with haemodialysis (HD), yet the frequency of patient assessment by nurses varies in practice. We sought to measure the frequency of nursing assessments before, during and after HD and to identify any predictors of IDH.

OBJECTIVES

To audit the frequency, nursing management and contributing factors of IDH.

DESIGN

A prospective clinical audit was undertaken over 4 weeks.

PARTICIPANTS

Nurses completed audit sheets on 132 patients at three chronic HD units.

MEASUREMENTS

The audit tool consisted of 34 questions related to demographics, HD prescription, frequency of monitoring and nursing interventions.

RESULTS

A total of 1584 sessions were performed with 876 (55.3%) audits returned, of which 452 were useable. There were 74 actual episodes of IDH, and a further 72 potential episodes may have been prevented due to nursing intervention. Most nurses reported assessing patients before starting HD and as required before an actual or potential IDH event (n = 85; 63%); few hourly assessments were performed. Predictors of IDH were systolic blood pressure ≤140 mmHg, having more than four comorbidities, dialysate temperature > 36°C, calcium < 1.3 mmol/L and a shorter dialysis session (3.0-4.5 h). These predictors explained 14.1% of the variance in hypotensive episodes during HD.

CONCLUSION

This clinical audit highlighted the importance of assessing blood pressure trends during HD to preemptively intervene before IDH developing. The audit has resulted in a practice change to hourly assessments. Follow-up audits of practice should occur.

An update review of intradialytic hypotension: concept, risk factors, clinical implications and management

Intradialytic hypotension (IDH) is a frequent and serious complication of chronic haemodialysis, linked to adverse long-term outcomes including increased cardiovascular and all-cause mortality. IDH is the end result of the interaction between ultrafiltration rate (UFR), cardiac output and arteriolar tone. Thus excessive ultrafiltration may decrease the cardiac output, especially when compensatory mechanisms (heart rate, myocardial contractility, vascular tone and splanchnic flow shifts) fail to be optimally recruited. The repeated disruption of end-organ perfusion in IDH may lead to various adverse clinical outcomes affecting the heart, central nervous system, kidney and gastrointestinal system. Potential interventions to decrease the incidence or severity of IDH include optimization of the dialysis prescription (cool dialysate, UFR, sodium profiling and high-flux haemofiltration), interventions during the dialysis session (midodrine, mannitol, food intake, intradialytic exercise and intermittent pneumatic compression of the lower limbs) and interventions in the interdialysis period (lower interdialytic weight gain and blood pressure–lowering drugs). However, the evidence base for many of these interventions is thin and optimal prevention and management of IDH awaits further clinical investigation. Developing a consensus definition of IDH will facilitate clinical research. We review the most recent findings on risk factors, pathophysiology and management of IDH and, based on this, we call for a new consensus definition of IDH based on clinical outcomes and define a roadmap for IDH research.