Dialysate Temperature Research Articles

Dialysate temperature reduction for intradialytic hypotension for people with chronic kidney disease requiring haemodialysis.

Intradialytic hypotension (IDH) is a common complication of haemodialysis (HD), and a risk factor of cardiovascular morbidity and death. Several clinical studies suggested that reduction of dialysate temperature, such as fixed reduction of dialysate temperature or isothermal dialysate using a biofeedback system, might improve the IDH rate. This review aimed to evaluate the benefits and harms of dialysate temperature reduction for IDH among patients with chronic kidney disease requiring HD, compared with standard dialysate temperature. We searched Cochrane Kidney and Transplant's Specialised Register up to 14 May 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov. All randomised controlled trials (RCTs), cross-over RCTs, cluster RCTs and quasi-RCTs were included in the review. Two authors independently extracted information including participants, interventions, outcomes, methods of the study, and risks of bias. We used a random-effects model to perform quantitative synthesis of the evidence. We assessed the risks of bias for each study using the Cochrane 'Risk of bias' tool. We assessed the certainty of evidence using Grades of Recommendation, Assessment, Development and Evaluation (GRADE). We included 25 studies (712 participants). Three studies were parallel RCTs and the others were cross-over RCTs. Nineteen studies compared fixed reduction of dialysate temperature (below 36°C) and standard dialysate temperature (37°C to 37.5°C). Most studies were of unclear or high risk of bias. Compared with standard dialysate, it is uncertain whether fixed reduction of dialysate temperature improves IDH rate (8 studies, 153 participants: rate ratio 0.52, 95% CI 0.34 to 0.80; very low certainty evidence); however, it might increase the discomfort rate compared with standard dialysate (4 studies, 161 participants: rate ratio 8.31, 95% CI 1.86 to 37.12; very low certainty evidence). There were no reported dropouts due to adverse events. No study reported death, acute coronary syndrome or stroke.Three studies compared isothermal dialysate and thermoneutral dialysate. Isothermal dialysate might improve the IDH rate compared with thermoneutral dialysate (2 studies, 133 participants: rate ratio 0.68, 95% CI 0.60 to 0.76; I2 = 0%; very low certainty evidence). There were no reports of discomfort rate (1 study) or dropouts due to adverse events (2 studies). No study reported death, acute coronary syndrome or stroke. Reduction of dialysate temperature may prevent IDH, but the conclusion is uncertain. Larger studies that measure important outcomes for HD patients are required to assess the effect of reduction of dialysate temperature. Six ongoing studies may provide much-needed high quality evidence in the future.

Effect of Low Temperature Dialysis on The Functional Activity of Complement Activation Pathways during Hemodialysis Procedure

Background: low dialysate temperature dialysis has been used successfully in treatment of intradyalytic hypotension and resistant pruritus. In both conditions complement activation was proposed as one pathological mechanisms for their development. to our knowledge, no study has been done to assess the effect of low dialysate temperature on the individual complement activation pathway. Objective: to assess the effect of low dialysate temperature on complement activation pathways. Patients and Methods: this case control study included 20 patients, on regular hemodialysis at Alhusein University Hospital. Results: the mean age of our patients was 48.8±10 years, 11 males and 9 females, their mean BMI was 22±4 kg/m2 , their mean blood pressure 120/80± 20/20, all patients received hemodialysis via arterio-venous fistula. The main cause of hemodialysis is chronic renal failure due to hypertension in 8 patients, glomerulonephritis in 4 patients, polycystic kidney in 2 patients, hyperurecemic nephropathy in 2 patients, analgesic abuser in 1 patient, and chronic pyelonephritis in 1 patient. Conclusion: cold hemodialysis is associated with activation of complement system.

Renal Perfusion during Hemodialysis: Intradialytic Blood Flow Decline and Effects of Dialysate Cooling.

Residual renal function (RRF) confers survival in patients with ESRD but declines after initiating hemodialysis. Previous research shows that dialysate cooling reduces hemodialysis-induced circulatory stress and protects the brain and heart from ischemic injury. Whether hemodialysis-induced circulatory stress affects renal perfusion, and if it can be ameliorated with dialysate cooling to potentially reduce RRF loss, is unknown. We used renal computed tomography perfusion imaging to scan 29 patients undergoing continuous dialysis under standard (36.5°C dialysate temperature) conditions; we also scanned another 15 patients under both standard and cooled (35.0°C) conditions. Imaging was performed immediately before, 3 hours into, and 15 minutes after hemodialysis sessions. We used perfusion maps to quantify renal perfusion. To provide a reference to another organ vulnerable to hemodialysis-induced ischemic injury, we also used echocardiography to assess intradialytic myocardial stunning. During standard hemodialysis, renal perfusion decreased 18.4% (P<0.005) and correlated with myocardial injury (r=-0.33; P<0.05). During sessions with dialysis cooling, patients experienced a 10.6% decrease in perfusion (not significantly different from the decline with standard hemodialysis), and ten of the 15 patients showed improved or no effect on myocardial stunning. This study shows an acute decrease in renal perfusion during hemodialysis, a first step toward pathophysiologic characterization of hemodialysis-mediated RRF decline. Dialysate cooling ameliorated this decline but this effect did not reach statistical significance. Further study is needed to explore the potential of dialysate cooling as a therapeutic approach to slow RRF decline.

The Effect of Reduced Dialysate Temperature on Dialysis Adequacy of Diabetic Patients Admitted to Ali-Ibn Abitaleb Hospital, Zahedan: A Clinical Trial

Background: Given that diabetes is the most prevalent cause of end-stage renal disease (ESRD) and that dialysis adequacy is an important factor in the survival of diabetic patients, prognosis of these individuals is predicated according to adequate and standard hemodialysis. Objectives: The present study aimed at investigating the effect of lowering dialysate solution temperature on dialysis adequacy. Methods: This was a clinical trial, in which 32 qualified patients were studied. The subjects were chosen by convenience sampling from patients, who had referred to Ali-Ibn Abitaleb Hospital of Zahedan in spring, 2018. Each patient underwent hemodialysis twice, in which the solution temperature was reduced by one temperature from 37°C to 36°C. Except for the temperature decrease, other conditions were identical during the study. To evaluate the adequacy of dialysis in each session, blood samples of patients were examined before and after dialysis. Data were analyzed in SPSS 21 using descriptive statistics and dependent t-test. The significance level was set below 0.05. Results: The mean and standard deviation of age was equal to 60.2 ± 9.2 (year), duration of diabetes was 12.07 ± 7.25 years, duration of hemodialysis was 27.7 ± 21.8 (months), and weight gain between two sessions of dialysis was 1.6 ± 0.68 (kg). The mean and standard deviation of dialysis adequacy index equaled 1.14 ± 0.34 in the two cold sessions and 0.98 ± 0.20 in the routine session, suggesting significantly higher value in the cold sessions (P < 0.001). Conclusions: Administering cold dialysis solution (36°C) positively influences dialysis adequacy. Therefore, if patients are not medically prohibited from using the cold solution, cold dialysis solution should be prescribed to hemodialysis patients.

Associations between Hemodialysis Facility Practices to Manage Fluid Volume and Intradialytic Hypotension and Patient Outcomes.

Fluid overload and intradialytic hypotension are associated with cardiovascular events and mortality in patients on hemodialysis. We investigated associations between hemodialysis facility practices related to fluid volume and intradialytic hypotension and patient outcomes. Data were analyzed from 10,250 patients in 273 facilities across 12 countries, from phase 4 of the Dialysis Outcomes and Practice Patterns Study (DOPPS; 2009-2012). Cox regression models (shared frailty) were used to estimate associations between facility practices reported by medical directors in response to the DOPPS Medical Directors Survey and all-cause and cardiovascular mortality and hospitalization, and cardiovascular events, adjusting for country, age, sex, dialysis vintage, predialysis systolic BP, cardiovascular comorbidities, diabetes, body mass index, smoking, residual kidney function, dialysis adequacy, and vascular access type. Of ten facility practices tested (chosen a priori), having a protocol that specifies how often to assess dry weight in most patients was associated with lower all-cause (hazard ratio [HR], 0.78; 99% confidence interval [99% CI], 0.64 to 0.94) and cardiovascular mortality (HR, 0.72; 99% CI, 0.55 to 0.95). Routine orthostatic BP measurement to assess dry weight was associated with lower all-cause hospitalization (HR, 0.86; 99% CI, 0.77 to 0.97) and cardiovascular events (HR, 0.85; 99% CI, 0.73 to 0.98). Routine use of lower dialysate temperature to limit or prevent intradialytic hypotension was associated with lower cardiovascular mortality (HR, 0.76; 99% CI, 0.58 to 0.98). Routine use of an online volume indicator to assess dry weight was associated with higher all-cause hospitalization (HR, 1.19; 99% CI, 1.02 to 1.38). Routine use of sodium modeling/profiling to limit or prevent intradialytic hypotension was associated with higher all-cause mortality (HR, 1.36; 99% CI, 1.14 to 1.63), cardiovascular mortality (HR, 1.34; 99% CI, 1.04 to 1.73), and cardiovascular events (HR, 1.21; 99% CI, 1.03 to 1.43). Hemodialysis facility practices relating to the management of fluid volume and intradialytic hypotension are associated with patient outcomes.

A Pilot Study Evaluating the Effect of Cooler Dialysate Temperature on Hemodynamic Stability During Prolonged Intermittent Renal Replacement Therapy in Acute Kidney Injury.

Acute kidney injury requiring renal replacement therapy is associated with high morbidity and mortality. Complications of renal replacement therapy include hemodynamic instability with ensuing shortened treatments, inadequate ultrafiltration, and delay in renal recovery. Studies have shown that lowering dialysate temperature in patients with end-stage renal disease is associated with a decrease in the frequency of intradialytic hypotension. However, data regarding mitigation of hypotension by lowering dialysate temperature in patients with acute kidney injury are scarce. We conducted a prospective, randomized, cross-over pilot study to evaluate the effect of lower dialysate temperature on hemodynamic status of critically ill patients with acute kidney injury during prolonged intermittent renal replacement therapy. Single-center prospective, randomized, cross-over study. ICUs and a step down unit in a tertiary referral center. Acute kidney injury patients undergoing prolonged intermittent renal replacement therapy. Participants were randomized to start prolonged intermittent renal replacement therapy with dialysate temperature of 35°C or dialysate temperature of 37°C. The primary endpoint was the number of hypotensive events, as defined by any of the following: decrease in systolic blood pressure greater than or equal to 20 mm Hg, decrease in mean arterial pressure greater than or equal to 10 mm Hg, decrease in ultrafiltration, or increase in vasopressor requirements. The number of events was analyzed by Poisson regression and other outcomes with repeated-measures analysis of variance. Twenty-one patients underwent a total of 78 prolonged intermittent renal replacement therapy sessions, 39 in each arm. The number of hypotensive events was twice as high during treatments with dialysate temperature of 37°C, compared with treatments with the cooler dialysate (1.49 ± 1.12 vs 0.72 ± 0.69; incidence rate ratio, 2.06; p ≤ 0.0001). Treatment sessions with cooler dialysate were more likely to reach prescribed ultrafiltration targets. Patients with acute kidney injury undergoing prolonged intermittent renal replacement therapy with cooler dialysate experienced significantly less hypotension during treatment. Prevention of hemodynamic instability during renal replacement therapy helped to achieve ultrafiltration goals and may help to prevent volume overload in critically ill patients.

Effect of isothermic dialysis on intradialytic hypertension

The primary outcome was incidence of intradialytic hypertension (IDH) during standard and cooler isothermic dialysate temperatures. Two pair of haemodialysis sessions were done at 37°C (SHD) and at isothermic temperature (IHD). All the four dialysis were done on the same time of the day to negate the changes due to circadian variation in body temperature. Axillary and tympanic temperatures were measured before start of the dialysis and dialysis temperature was adjusted as per axillary temperature. Sixty patients were enrolled and completed the study. The mean delivered dialysate temperature in the intervention group was 36.5 ± 0.2 achieving a 0.5 ± 0.2°C between-group separation. The incidence of IDH and intradialytic hypotension while on SHD and IHD were 79/120 (66%) vs 44/120 (37%), odds ratio (OR) 3.3, 95% confidence interval (CI) (1.96–5.65) and 45/120 (38%) vs 14/120 (12%), OR 4.5, 95% CI (2.3–8.7), respectively. The 4 h time averaged mean systolic blood pressure (SBP) at IHD and SHD were 154 ± 1.7 and 157.2 ± 1.1 mmHg, respectively, the mean difference in SBP being −3.4 mmHg to −3.1 mmHg, 95% CI, P < 0.001. The standard deviation, a measure of BP variability was lower at IHD than at SHD (P < 0.001). In a subgroup analysis during IHD there was a significant reduction of both SBP and diastolic BP during the entire duration of dialysis in 35 out of 60 patients (systolic 4 h mean 154.96 ± 2.22 vs 164.32 ± 1.99 mmHg), (diastolic 4 h mean 79.24 ± 0.82 vs 82.54 ± 0.68 mmHg) – (rANOVA for systolic and diastolic <0.001). This phenomenon of cooler dialysis causing reduction of BP was reproduced in the same group of patients when the IHD was repeated another time (systolic 4 h mean 157.95 ± 1.88 vs 160.65 ± 1.47), (diastolic 4 h mean 79.27 ± 0.74 vs 82.03 ± 1.07) rANOVA for systolic and diastolic <0.001. The incidence of IDH can be reduced significantly by reducing the dialysate temperature to patients' body temperature. Hypertension during dialysis is related to heat gain during dialysis.

The Effect of Dialysate Temperature on Urea Reduction Ratio among Patients Undergoing Maintenance Haemodialysis: A Case Control Study

The Effect of Dialysate Temperature on Urea Reduction Ratio among Patients Undergoing Maintenance Haemodialysis: A Case Control Study

Middle molecule elimination in expanded haemodialysis: only convective transport?

BackgroundNew high-retention onset dialysers have shown improved efficacy in the elimination of uraemic toxins, and their depurative capacity has been compared with high convective volumes of online haemodiafiltration. Haemodialysis (HD) using high-flux membranes leads to convective transport by internal filtration [direct filtration (DF)/backfiltration (BF)] and allows the removal of middle molecules (MMs). The aim of this study was to assess solute transport mechanisms in expanded HD (HDx).MethodsIn 14 4-h HDx sessions with Theranova-500 dialysers under similar dialysis conditions (blood flow 400 mL/min, dialysate flow 700 mL/min, dialysate temperature 35.5°C), pressures at the inlet and outlet of both dialyser compartments (Pbi, Pbo, Pdi and Pdo) were collected hourly to estimate DF/BF volumes by semi-empirical methods. Uraemic toxins with various molecular weights were measured pre-dialysis, at 1 h (pre-filter and post-filter) and post-dialysis to calculate molecules’ reduction over time and dialyser in vivo clearances.ResultsUltrafiltration was 1.47 ± 0.9 L and Kt/V 1.74 ± 0.3. Hydrodynamic data (Pbi: 259 ± 39, Pbo: 155 ± 27, Pdi: 271 ± 30, Pdo: 145 ± 29 mmHg and oncotic pressure 22.0 ± 3.5 mmHg) allowed the estimation of DF/BF rates. DF flow ranged from 29.5 ± 4.2 to 31.3 ± 3.9 mL/min and BF flow ranged from 25.1 ± 2.3 to 23.4 ± 2.6 mL/min. The highest calculated DF volume was 7506.8 ± 935.3 mL/session. Diffusive clearances (Kd) of all solutes were higher than their convective transport (all P < 0.001) except for prolactin (23 kDa) clearances, which showed no differences. Total clearances of all solutes were correlated with their Kd (ρ = 0.899–0.987, all P < 0.001) and Kt/V correlated with all reduction rates (ρ = 0.661–0.941, P = 0.010 to <0.001). DF flow was only associated with urea (ρ = −0.793, P = 0.001), creatinine (ρ = −0.675, P = 0.008) and myoglobin clearance (ρ = 0.653, P = 0.011).ConclusionResults suggest that diffusive transport is a main mechanism of MM elimination in HDx. HDx offers an efficient depuration of MM without the need for high convective volumes.

Recovery Time after Hemodialysis Is Inversely Associated with the Ultrafiltration Rate

Introduction: The present study aimed to determine the variables that are associated with a longer dialysis recovery time (DRT) and to define the relationship that exists between DRT and the ultrafiltration rate (UFR) in prevalent chronic hemodialysis (CHD) patients. Methods: We studied 210 prevalent CHD of 5 hemodialysis units in Central Italy. Patients were invited to answer to the question: “How long does it take you to recover from a dialysis session?” Answers to this question were subsequently converted into minutes. Demographic, clinical and laboratory parameters were recorded for each patient as well as the UFR (mL/kg/h), the dialysate sodium concentration and temperature. Results: Median DRT was 180 min (60–420). Ninety five (45%) patients had a DRT ≥ the median value. Mean UFR was 9.2 ± 3.0 mL/kg/h. Patients with a lower DRT had a less prevalent disability in the instrumental activities daily living, had a higher UFR, and a lower dialysate temperature, as compared with subjects with higher DRT. According to the logistic regression model, UFR was associated with a DRT below the median (i.e., 180) in the unadjusted model (OR 1.12; 95% CI 1.02–1.23; p = 0.019), after adjusting for age and sex (OR 1.11; 95% CI 1.01–1.22; p = 0.025), and in the fully adjusted model (OR 1.11; 95% CI 1.04–1.22; p = 0.040). UFR increase was associated with increasing probability of DRT below the median (p for trend = 0.035). The highest tertile of DRT was associated with UFR below the mean value (i.e., 9.2 mL/kg/h) in multinomial logistic regression having the lowest DRT tertile as reference. DRT was significantly lower in patients with UFR > 13 mL/kg/h than in patients with UFR 10–13 or < 10 mL/kg/h. Conclusion: DRT is inversely associated with UFR in CHD patients. Whether a high UFR should be recommended to reduce the DRT needs to be elucidated through an adequate prospective randomized study.

Prevalence and Severity of Postdialysis Fatigue Are Higher in Patients on Chronic Hemodialysis With Functional Disability.

The aim of the present study was to determine the intensity, duration, frequency and prevalence of postdialysis fatigue (PDF) in patients on chronic hemodialysis (PCD) with and without functional disability. Patients underwent assessment of functional ability by the Katz ADL (activity daily living) questionnaire and the Lawton and Brody scale for the instrumental activity daily living (IADL) fatigue using the SF-36 Vitality Subscale, comorbidity through the Charlson comorbidity score index (CDI), and time of recovery after hemodialysis (TIRD). We studied 271 PCD. ADL and IADL disabilities were present in 75 (27.6%) and 168 (62%) patients, respectively. Patients with ADL disability were significantly older and showed higher CDI scores, and lower levels of serum albumin and Kt/V. Prevalence of PDF was significantly higher in patients with ADL disability as well as its severity, intensity, duration and frequency. Patients with IADL disability were significantly older, had a higher CCI score, had lower levels of serum albumin and Kt/V, and had a higher severity, intensity, duration and frequency of PDF. At multivariate regression analysis, ADL disability was positively associated with age, prevalence and severity of PDF, and dialysate temperature and inversely associated with serum albumin levels. IADL disability was instead positively associated with age and dialysate temperature and inversely associated with serum albumin levels. In conclusion, prevalence and severity of PDF are significantly higher in PCD with ADL disability than in those without it. This knowledge may have important implications for the development of interventions to reduce PDF in PCD.

Interventions to prevent hemodynamic instability during renal replacement therapy in critically ill patients: a systematic review

BackgroundHemodynamic instability related to renal replacement therapy (HIRRT) may increase the risk of death and limit renal recovery. Studies in end-stage renal disease populations on maintenance hemodialysis suggest that some renal replacement therapy (RRT)-related interventions (e.g., cool dialysate) may reduce the occurrence of HIRRT, but less is known about interventions to prevent HIRRT in critically ill patients receiving RRT for acute kidney injury (AKI). We sought to evaluate the effectiveness of RRT-related interventions for reducing HIRRT in such patients across RRT modalities.MethodsA systematic review of publications was undertaken using MEDLINE, MEDLINE in Process, EMBASE, and Cochrane’s Central Registry for Randomized Controlled Trials (RCTs). Studies that assessed any intervention’s effect on HIRRT (the primary outcome) in critically ill patients with AKI were included. HIRRT was variably defined according to each study’s definition. Two reviewers independently screened abstracts, identified articles for inclusion, extracted data, and evaluated study quality using validated assessment tools.ResultsFive RCTs and four observational studies were included (n = 9; 623 patients in total). Studies were small, and the quality was mostly low. Interventions included dialysate sodium modeling (n = 3), ultrafiltration profiling (n = 2), blood volume (n = 2) and temperature control (n = 3), duration of RRT (n = 1), and slow blood flow rate at initiation (n = 1). Some studies applied more than one strategy simultaneously (n = 5). Interventions shown to reduce HIRRT from three studies (two RCTs and one observational study) included higher dialysate sodium concentration, lower dialysate temperature, variable ultrafiltration rates, or a combination of strategies. Interventions not found to have an effect included blood volume and temperature control, extended duration of intermittent RRT, and slower blood flow rates during continuous RRT initiation. How HIRRT was defined and its frequency of occurrence varied widely across studies, including those involving the same RRT modality. Pooled analysis was not possible due to study heterogeneity.ConclusionsSmall clinical studies suggest that higher dialysate sodium, lower temperature, individualized ultrafiltration rates, or a combination of these strategies may reduce the risk of HIRRT. Overall, for all RRT modalities, there is a paucity of high-quality data regarding interventions to reduce the occurrence of HIRRT in critically ill patients.

The Effect of Cold Dialysis in Motor and Sensory Symptoms of RLS/WED Occurring During Hemodialysis: A Double-Blind Study.

Restless legs syndrome/Willis-Ekbom disease (RLS/WED) is a common sensorimotory disorder affecting almost 30% of hemodialysis (HD) patients. RLS/WED induces discomfort during rest hours, and its symptoms have also been observed during HD sessions. Anecdotal reports suggest that cooling the dialysate solution during dialysis could help patients overcome those symptoms and improve restlessness. The aim of this double-blind study was to assess whether a reduction of the dialysate temperature by 1°C could reduce motor and sensory symptoms of RLS/WED occurring during HD. Thirty-two HD patients participated in the study. Patients were divided into two groups: the RLS (N=16) and the non-RLS groups (N=16). Patients were studied on two different scenarios for two consecutive HD sessions, 1 week apart: 1) standard temperature of the dialysate (37°C) and 2) low temperature of the dialysate (36°C cold dialysis scenario). In all sessions, motor (leg movement per hour of HD [LM/hHD]) and sensory symptoms were assessed. The reduction of dialysate temperature by 1°C was effective in reducing motor symptoms as they assessed the LM/hHD by 36% only in patients with RLS, while a significant interaction was found between "LM/hHD affected by temperature" and "RLS status" (p = 0.039). Sensory symptoms also reduced by 10% after the reduction of the dialysate temperature. The reduction of the dialysate temperature by 1°C reduced motor symptoms by 36-54% and sensory symptoms by 10% in HD patients with RLS/WED. Cold dialysis could be considered a safe nonpharmacological approach for the amelioration of RLS/WED symptoms occurring during HD.

Investigation and analysis of hemodialysis blood tubing vein pot particle formation and related factors

Objective To investigate the composition of particulate matter in hemodialysis and to explore the influencing factors of particulate matter formation. Methods The composition of the particles was determined by chemical experiments and electron microscopy. Fifty-four outpatients in hemodialysis centers were divided into pellets and non - particulate groups (34 and 20 cases). Thirty-four variables were collected by literature review and their influencing factors were analyzed. Results The particles were white thrombus, formed by aggregated platelets and fibrin aggregates, and embedded in a small amount of red blood cells. Logistic regression analysis showed that low molecular weight heparin was statistically significant (OR = 1.001, P <0.01). In addition, male, smoking, dry weight, hypersensitive C-reactive protein, venous pressure, dialysate temperature, blood vessel thrombosis and granule formation were statistically significant (P < 0.05). Conclusions To improve the degree of attention to white thrombosis, the injection of low molecular weight heparin sodium into the machine before the vascular access intravenous injection, for the analysis of the results to take appropriate care measures to reduce the production of white thrombosis is important, and can be white thrombosis. The repeated formation is seen as a sign of blood vessel thrombosis Key words: Hemodialysis; Particulate matter; Intravenous pot; White thrombus; Scanning electron microscope

To cool, or too cool: Is reducing dialysate temperature the optimal approach to preventing intradialytic hypotension?

Abnormal decreases in blood pressure during hemodialysis are frequent in end stage renal disease (ESRD) patients treated with hemodialysis, and thought to be largely due to an inadequate cardiovascular response to the rapid blood volume decline. Intradialytic hypotension (IDH) and cardiac instability during dialysis can increase risks for negative health consequences and is possibly preventable though several types of interventions. One intervention that holds promise for prevention of IDH in hemodialysis patients is to reduce the temperature of the dialysate to or below the patient's core temperature. A considerable number of randomized studies have demonstrated a short term benefit of using a cooler dialysate temperature for the prevention of IDH and improved cardiac stability. Despite this, a key observational study was not able to show long term improvements with lower dialysate temperatures utilized in routine clinical practice, albeit possibly confounded by indication. It appears that cooling the dialysate may be reasonable to consider on an individual basis for patients who suffer from persistent IDH if they can tolerate the adjustment and it is effective. However, careful assessment of the etiology of IDH should be performed when considering treatment options. In this review, we detail the current body of evidence on the effectiveness of using low dialysate temperatures for prevention of IDH in ESRD patients, and suggest areas where further research is needed.

A brief review of intradialytic hypotension with a focus on survival.

Intradialytic hypotension (IDH), a common complication of ultrafiltration during hemodialysis therapy, is associated with high mortality and morbidity. IDH, defined as a nadir systolic blood pressure of less than 90 mm Hg on more than 30% of treatments, is a relevant definition and is correlated with mortality. Risk factors for IDH include patient demographics, anti-hypertensive medication use, larger interdialytic weight gain, and dialysis prescription features as dialysate sodium, high ultrafiltration rate, and dialysate temperature. A high frequency of IDH events carries a substantial death risk. An ultrafiltration rate >10 mL/h/kg, and even more so >13 mL/h/kg, is highly predictive of cardiovascular and all-cause mortality. Evidence suggests that IDH causes acute reversible segmental myocardial hypoperfusion and contractile dysfunction (myocardial stunning), which can result in long-term loss of myocardial contractility, leading to premature death. IDH also has negative end-organ effects on the brain and gut, contributing to mortality through stroke, and endotoxin translocation with associated inflammation and protein-energy wasting. Given strong association of IDH and dialysis mortality, a paradigm shift to its approach is urgently needed. Randomized controlled trials are required to prospectively test drugs and monitoring devices which may reduce IDH.

Barriers and facilitators to healthcare professional behaviour change in clinical trials using the Theoretical Domains Framework: a case study of a trial of individualized temperature-reduced haemodialysis

BackgroundImplementing the treatment arm of a clinical trial often requires changes to healthcare practices. Barriers to such changes may undermine the delivery of the treatment making it more likely that the trial will demonstrate no treatment effect. The ‘Major outcomes with personalized dialysate temperature’ (MyTEMP) is a cluster-randomised trial to be conducted in 84 haemodialysis centres across Ontario, Canada to investigate whether there is a difference in major outcomes with an individualized dialysis temperature (IDT) of 0.5 °C below a patient’s body temperature measured at the beginning of each haemodialysis session, compared to a standard dialysis temperature of 36.5 °C. To inform how to deploy the IDT across many haemodialysis centres, we assessed haemodialysis physicians’ and nurses’ perceived barriers and enablers to IDT use.MethodsWe developed two topic guides using the Theoretical Domains Framework (TDF) to assess perceived barriers and enablers to IDT ordering and IDT setting (physician and nurse behaviours, respectively). We recruited a purposive sample of haemodialysis physicians and nurses from across Ontario and conducted in-person or telephone interviews. We used directed content analysis to double-code transcribed utterances into TDF domains, and inductive thematic analysis to develop themes.ResultsWe interviewed nine physicians and nine nurses from 11 Ontario haemodialysis centres. We identified seven themes of potential barriers and facilitators to implementing IDTs: (1) awareness of clinical guidelines and how IDT fits with local policies (knowledge; goals), (2) benefits and motivation to use IDT (beliefs about consequences; optimism; reinforcement; intention; goals), (3) alignment of IDTs with usual practice and roles (social/professional role and identity; nature of the behaviour; beliefs about capabilities), (4) thermometer availability/accuracy and dialysis machine characteristics (environmental context and resources), (5) impact on workload (beliefs about consequences; beliefs about capabilities), (6) patient comfort (behavioural regulation; beliefs about consequences; emotion), and (7) forgetting to prescribe or set IDT (memory, attention, decision making processes; emotion).ConclusionsThere are anticipatable barriers to changing healthcare professionals’ behaviours to effectively deliver an intervention within a randomised clinical trial. A behaviour change framework can help to systematically identify such barriers to inform better delivery and evaluation of the treatment, therefore potentially increasing the fidelity of the intervention to increase the internal validity of the trial. These findings will be used to optimise the delivery of IDT in the MyTEMP trial and demonstrate how this approach can be used to plan intervention delivery in other clinical trials.Trial registrationClinicalTrials.gov NCT02628366. Registered November 16 2015.

Dialysate temperature reduction for intradialytic hypotension for people with chronic kidney disease requiring haemodialysis

Dialysate temperature reduction for intradialytic hypotension for people with chronic kidney disease requiring haemodialysis

Sudden Cardiac Death Among Hemodialysis Patients

Hemodialysis patients carry a large burden of cardiovascular disease; most onerous is the high risk for sudden cardiac death. Defining sudden cardiac death among hemodialysis patients and understanding its pathogenesis are challenging, but inferences from the existing literature reveal differences between sudden cardiac death among hemodialysis patients and the general population. Vascular calcifications and left ventricular hypertrophy may play a role in the pathophysiology of sudden cardiac death, whereas traditional cardiovascular risk factors seem to have a more muted effect. Arrhythmic triggers also differ in this group as compared to the general population, with some arising uniquely from the hemodialysis procedure. Combined, these factors may alter the types of terminal arrhythmias that lead to sudden cardiac death among hemodialysis patients, having important implications for prevention strategies. This review highlights current knowledge on the epidemiology, pathophysiology, and risk factors for sudden cardiac death among hemodialysis patients. We then examine strategies for prevention, including the use of specific cardiac medications and device-based therapies such as implantable defibrillators. We also discuss dialysis-specific prevention strategies, including minimizing exposure to low potassium and calcium dialysate concentrations, extending dialysis treatment times or adding sessions to avoid rapid ultrafiltration, and lowering dialysate temperature.

Effects of Sodium Concentration and Dialysate Temperature Changes on Blood Pressure in Hemodialysis Patients: A Randomized, Triple-Blind Crossover Clinical Trial.

The present study investigated the effects of different temperatures and sodium dialysate concentration on blood pressure in hemodialysis patients. Following Williams' design, hemodialysis patients were randomly assigned into four dialysis modes. Dialysate temperature was set at 37°C for modes A and C and, 35°C for modes B and D. Sodium concentration was set at 138mmol/L in modes A and B, while it changed from 150mmol/L to 138mmol/L in modes C and D. Using analysis of variance for repeated measures, the mean values of systolic and diastolic blood pressure were investigated. The mean values of systolic and diastolic blood pressure in modes C and D had a significant difference with the values in mode A. The mean values of systolic and diastolic blood pressure in patients dialyzed with mode B had a significant difference with the values in those dialyzed with mode D. Moreover, there were significant differences in the incidence of hypotension between A and other modes and between B and modes C and D, but this difference was not significant between modes C and D. In order to reduce intradialytic blood pressure fluctuations and hypotension, the nursing staff are recommended to gradually reduce dialysate sodium concentration.