I. NKF-K/DOQI Clinical Practice Guidelines for Hemodialysis Adequacy: update 2000

Safety and tolerability of the protein C activator AB002 in end-stage renal disease patients on hemodialysis: a randomized phase 2 trial

BACKGROUND

The protein C system regulates blood coagulation, inflammation, and vascular integrity. AB002 is an injectable protein C activating enzyme under investigation to safely prevent and treat thrombosis. In preclinical models, AB002 is antithrombotic, cytoprotective, and anti-inflammatory. Since prophylactic use of heparin is contraindicated during hemodialysis in some end-stage renal disease (ESRD) patients, we propose using AB002 as a short-acting alternative to safely limit blood loss due to clotting in the dialysis circuit.

METHODS

This phase 2, randomized, double-blind, placebo-controlled, single-dose study evaluates the safety and tolerability of AB002 administered into the hemodialysis line of ESRD patients during hemodialysis at one study center in the United States (ClinicalTrials.gov: NCT03963895). In this study, 36 patients were sequentially enrolled into two cohorts and randomized to AB002 or placebo in a 2:1 ratio. In cohort 1, patients received 1.5 µg/kg AB002 (n = 12) or placebo (n = 6); in cohort 2, patients received 3 µg/kg AB002 (n = 12) or placebo (n = 6). Patients underwent five heparin-free hemodialysis sessions over 10 days and were dosed with AB002 or placebo during session four.

RESULTS

Here we show that AB002 is safe and well-tolerated in ESRD patients, with no treatment-related adverse events. Clinically relevant bleeding did not occur in any patient, and the time to hemostasis at the vascular access sites is not affected by AB002.

CONCLUSIONS

As far as we are aware, this proof-of-concept study is the first clinical trial assessing the therapeutic potential of protein C activation. The results herein support additional investigation of AB002 to safely prevent and treat thrombosis in at-risk populations.

Phosphate Intake and Removal in Predominantly Vegetarian Patients on Twice-Weekly Hemodialysis

Background

Hyperphosphatemia is linked to increased mortality and morbidity in patients on hemodialysis. Currently, the phosphate intake and dialytic removal in predominantly vegetarian patients on twice-weekly dialysis is not well studied.

Materials and methods

This prospective, study recruited patients on twice-weekly dialysis of at least 3 months duration. Baseline clinical variables were measured. Dietary protein and phosphorus intake was assessed using a validated food frequency questionnaire. Phosphate binder use was assessed, hourly blood was collected for serum phosphorus during dialysis, and spent dialysate was collected to estimate cumulative phosphorus removal during the session.

Results

Forty (67%) of the 60 patients studied were vegetarians. Twenty-eight (48%) were hyperphosphatemic, and 15 (25%) had serum parathormone (PTH) >500 pg/ml. The mean phosphorus intake was 1247 (±312) mg/day, the mean serum phosphorus was 5.49 (±2.01) mg/dl, and the mean dialytic phosphorus removal was 910 (±383) mg/session. Up to 67% of the study population took calcium-based phosphate binders, 25% took sevelamer carbonate, and 40% took activated vitamin D preparation. The lowest tertiles of phosphorus intake correlated with low energy-adjusted protein intake and hypoalbuminemia. Hyperphosphatemic subjects had better nutritional indices (mid-upper arm circumference and body mass index). Dietary intake and serum phosphorus levels were not mutually associated, but both were strongly correlated with total phosphorus removal in the spent dialysate. Serum phosphorus levels fell by 32% by thefirst hour of hemodialysis.

Conclusion

Twice-weekly dialysis is often practised in resource-limited Asian countries. However, due to a predominantly vegetarian diet, hyperphosphatemia was noted only in up to half of the patients, despite twice-weekly hemodialysis schedules. This reinforces the fact that plant-based dietary phosphate is less well absorbed.

Plasma Nitrate and Nitrite Kinetics after Single Intake of Beetroot Juice in Adult Patients on Chronic Hemodialysis and in Healthy Volunteers: A Randomized, Single-Blind, Placebo-Controlled, Crossover Study

Nitric oxide (NO) contributes to maintaining normal cardiovascular and renal function. This bioactive signalling molecule is generally formed enzymatically by NO synthase in the vascular endothelium. NO bioactivity can also be attributed to dietary intake of inorganic nitrate, which is abundant in our diet, especially in green leafy vegetables and beets. Ingested nitrate is reduced to nitrite by oral commensal bacteria and further to NO systemically. Previous studies have shown that dialysis, by means of removing nitrate and nitrite from the body, can reduce NO bioactivity. Hence, dietary intervention approaches aimed to boost the nitrate-nitrite-NO pathway may be of benefit in dialysis patients. The purpose of this study was to examine the kinetics of plasma nitrate and nitrite after a single intake of nitrate-rich concentrated beetroot juice (BJ) in adult hemodialysis (HD) patients and in age-matched healthy volunteers (HV). Eight HD patients and seven HV participated in this single center, randomized, single-blind, placebo-controlled, crossover study. Each participant received a sequential single administration of active BJ (70 mL, 400 mg nitrate) and placebo BJ (70 mL, 0 mg nitrate) in a random order separated by a washout period of seven days. For the kinetic analysis, blood samples were collected at different time-points before and up to 44 h after BJ intake. Compared with placebo, active BJ significantly increased plasma nitrate and nitrite levels both in HD patients and HV. The area under the curve and the maximal concentration of plasma nitrate, but not of nitrite, were significantly higher in HD patients as compared with HV. In both groups, active BJ ingestion did not affect blood pressure or plasma potassium levels. Both BJs were well tolerated in all participants with no adverse events reported. Our data provide useful information in planning dietary nitrate supplementation efficacy studies in patients with reduced NO bioactivity.

Feeding during Dialysis Increases Intradialytic Blood Pressure Variability and Reduces Dialysis Adequacy

Whether hemodialysis patients should be allowed or even encouraged to eat during dialysis remains a controversial topic. This cross-over study aimed to evaluate the impact of feeding during dialysis on intradialytic blood pressure (BP) profile and dialysis adequacy in 26 patients receiving thrice-weekly, in-center hemodialysis. Over three consecutive mid-week dialysis sessions, intradialytic BP was monitored using the Mobil-O-Graph device (IEM, Stolberg, Germany). Blood samples were also obtained for the determination of the urea reduction ratio (URR). At baseline, patients underwent dialysis without the provision of a meal. In phases A and B, a meal with either high-protein (1.5 gr/kg of body weight) or low-protein (0.7 gr/kg of body weight) content was administered 1 h after the initiation of dialysis. The sequence of meals (high-protein and low-protein or vice versa) was randomized. Average intradialytic systolic BP (SBP) was similar on all three occasions. However, compared with baseline, the standard deviation (SD) (11.7 ± 4.1 vs. 15.6 ± 7.6 mmHg, p < 0.01), coefficient of variation (CV) (9.5 ± 3.7% vs. 12.4 ± 6.0%, p < 0.01) and average real variability (ARV) (9.4 ± 3.9 vs. 12.1 ± 5.2 mmHg, p < 0.01) of intradialytic SBP were higher in phase A. Similarly, compared with the baseline evaluation, all three indices of intradialytic SBP variability were higher in phase B (SD: 11.7 ± 4.1 vs. 14.1 ± 4.5 mmHg, p < 0.05; CV: 9.5 ± 3.7% vs. 11.1 ± 3.8%, p < 0.05; ARV: 9.4 ± 3.9 vs. 10.9 ± 3.9 mmHg, p < 0.05). Compared with dialysis without a meal, the consumption of a high-protein or low-protein meal resulted in a lower URR (73.4 ± 4.3% vs. 65.7 ± 10.7%, p < 0.001 in phase A and 73.4 ± 4.3% vs. 67.6 ± 4.3%, p < 0.001 in phase B, respectively). In conclusion, in the present study, feeding during dialysis was associated with higher intradialytic SBP variability and reduced adequacy of the delivered dialysis.

Assessment of volemia status using ultrasound examination of the inferior vena cava and spectroscopic bioimpendance in hemodialysis patients

Background/Aim. Hypervolemia is an important risk factor for the development of cardiovascular morbidity and mortality in patients treated with regular hemodialysis. There is still no reliable method for assessing the status of volemia in these patients. The aim of the study was to assess the status of volemia in patients treated with regular hemodialysis by measuring the parameters of the inferior vena cava (IVC) and bioimpedance. Methods. The effect of hemodialysis treatment on ultrasound parameters of the IVC, as well as on the parameters measured by bioimpedance, was examined before and after hemodialysis. The values of the N-terminal prohormone of brain natriuretic peptide (NT-proBNP) were measured both before and after hemodialysis. Forty-five patients were involved in this non-interventional cross-section study, including the patients treated with standard bicarbonate dialysis. According to the interdialytic yield, the patients were divided into three groups: I (up to 2,000 mL), II (2,000?3,000 mL), and III (over 3,000 mL). Results. The values of the IVC parameters and the parameters measured with bioimpedance were significantly lower after treatment with hemodialysis (p < 0.005). The third group of patients had a significantly higher total fluid volume in the body com-pared to the group I, as well as a significantly greater volume of extracellular fluid (p < 0.005). The significantly lower values of NT-proBNP in all groups (p < 0.005) were detected after hemodialysis. After treatment with hemodialysis, a positive correlation was observed between the concentration of NT-proBNP in the serum and the extracellular/intracellular water ratio. However, the correlation between NT-proBNP concentration and total fluid measured by bioimpedance spectroscopy did not reach statistical significance. Conclusion. Measurement of the IVC ultrasound parameters and volemia parameters using bioimpedance significantly contributes to the assessment of the status of volemia. Nevertheless, it cannot be used as a separate parameter, only in combination with all other methods.

Size-adjustment techniques of lumbar spine dual energy X-ray absorptiometry measurements in assessing bone mineralization in children on maintenance hemodialysis

OBJECTIVES

Growing skeleton is uniquely vulnerable to impaired mineralization in chronic kidney disease (CKD). Continued debate exists about the optimal method to adjust for body size when interpreting dual energy X-ray absorptiometry (DXA) scans in children with CKD given the burden of poor growth. The study aimed to evaluate the clinical usefulness of size-adjustment techniques of lumber-spine DXA measurements in assessing bone mineralization in children with kidney failure on maintenance hemodialysis (HD).

METHODS

Case-control study included 93 children on maintenance HD (9-18 years; 48 males). Participants were subjected to spinal-DXA-scan to obtain areal bone mineral density (aBMD; g/cm²). Volumetric-BMD (vBMD; g/cm³) was mathematically estimated. Z-scores of aBMD for chronological age (aBMD_Z-CA), aBMD adjusted for height age (aBMD_Z-HA), and vBMD_Z-score were calculated using mean and SD values of age subgroups of 442 healthy controls (7-18 years).

RESULTS

In short-for-age CKD patients, aBMD_Z-CA was significantly lower than vBMD_Z-score, while aBMD_Z-HA was significantly higher than aBMD_Z-CA and vBMD_Z-score. In normal height-for-age CKD patients, no significant difference between aBMD_Z-scores and vBMD_Z-score was detected. aBMD_Z-CA was significantly lower and aBMD_Z-HA was significantly higher in short-for-age compared to normal height-for-age patients without significant differences in vBMD_Z-score. We observed age-related decrements in the percentage of HD patients with normal densitometric Z-scores, the effect of age was less pronounced in aBMD_Z-HA than vBMD_Z-score. vBMD_Z-score correlated negatively with age, but not with height_Z-score.

CONCLUSIONS

Estimated vBMD seems to be a convenient size-adjustment approach of spinal-DXA measurements in assessing BMD especially in older short-for-age children with CKD. aBMD_Z-CA underestimates, while aBMD_Z-HA overestimates BMD in such patients.

Telavancin pharmacokinetics in patients with chronic kidney disease receiving haemodialysis

BACKGROUND

Telavancin is a lipoglycopeptide antibiotic with limited pharmacokinetic data to guide drug dosing in patients receiving haemodialysis.

OBJECTIVES

This study characterized telavancin pharmacokinetics in patients receiving haemodialysis.

PATIENTS AND METHODS

This was a Phase IV, prospective, open-label, single-centre, crossover pharmacokinetic study (ClinicalTrials.gov: NCT02392208). Eight subjects with end-stage kidney disease requiring maintenance haemodialysis (mean ± SD: 47 ± 20 years, 69.5 ± 17.1 kg) received 5 mg/kg telavancin IV 3 h before starting a 3.5 hour haemodialysis treatment with a high-permeability haemodialyser (haemodialysis period). After a 14 day washout period, a second 5 mg/kg dose was administered post-haemodialysis (control period). Telavancin plasma concentrations were measured over a 2 day period after each dose and non-compartmental pharmacokinetic analyses were performed.

RESULTS

The geometric mean (GM) of telavancin overall clearance was 11.2 mL/h/kg (intrinsic clearance and dialytic clearance) in the haemodialysis period and 5.9 mL/h/kg (off-haemodialysis clearance) in the control period [GM ratio (GMR) = 1.89; 90% CI: 1.70-2.10; P < 0.01]. The GM t½ was 13.1 h when haemodialysis occurred 3 h post-dosing in the haemodialysis period but extended to 20.9 h with post-haemodialysis dosing in the control period (GMR = 0.63; 90% CI: 0.54-0.73; P < 0.01). The GM of telavancin plasma concentrations removed by haemodialysis was 27.7%. The GMR of peak plasma concentration and volume of distribution of the haemodialysis period and the control period were 0.88 (90% CI: 0.79-0.98; P = 0.08) and 1.17 (90% CI: 1.05-1.30; P = 0.048), respectively.

CONCLUSIONS

Haemodialysis with high-permeability haemodialysers removes telavancin considerably (∼⅓ of body load). Telavancin 5 mg/kg every 48 h post-haemodialysis dosing is recommended, but dose adjustments may be warranted if haemodialysis starts within 3 h of telavancin administration.

Low hand grip strength is associated with worse functional capacity and higher inflammation in people receiving maintenance hemodialysis

OBJECTIVES

To evaluate the associations of hand grip strength (HGS) with body composition, functional capacity, muscle quality, and inflammatory markers in people receiving maintenance hemodialysis.

METHODS

This is a cross-sectional study in people receiving maintenance hemodialysis. HGS was measured by hydraulic dynamometer on the upper limb without fistula. Participants were stratified into low or adequate HGS, based on population-specific cutoff points. Body composition was assessed by dual-energy X-ray absorptiometry, and functional capacity by the Short Physical Performance Battery and timed up-and-go tests. In addition, serum creatinine, interleukin-6 (IL-6), IL-10, tumor necrosis factor-α, and ultra-sensitive C-reactive protein (us-CRP) were measured before the dialysis session.

RESULTS

A total of 67 participants (41.8% women, 58.2% male; ages 54.1 ± 11.7 y) were included. Those with low HGS had worse functional capacity than those with adequate HGS (timed up-and-go test, 10.7 ± 1.0 versus 8.5 ± 0.8 sec, respectively; P < 0.001). IL-6 and us-CRP were higher in those with low HGS than their counterparts (IL-6: 2.7 ± 0.3 versus 1.9 pg/mL, P = 0.03; us-CRP: 14.8 ± 3.0 versus 4.7 ± 1.9 mg/L, P = 0.03). Multiple linear regression analysis showed that appendicular lean mass, us-CRP, age, sex, and seven-point subjective global assessment score were associated with HGS.

CONCLUSIONS

Participants with low HGS showed higher inflammation and lower functional capacity. In addition to muscle mass, inflammation and nutritional status also affect HGS.<END ABSTRACT>.

Automatic real-time analysis and interpretation of arterial blood gas sample for Point-of-care testing: Clinical validation

Background

Point-of-care arterial blood gas (ABG) is a blood measurement test and a useful diagnostic tool that assists with treatment and therefore improves clinical outcomes. However, numerically reported test results make rapid interpretation difficult or open to interpretation. The arterial blood gas algorithm (ABG-a) is a new digital diagnostics solution that can provide clinicians with real-time interpretation of preliminary data on safety features, oxygenation, acid-base disturbances and renal profile. The main aim of this study was to clinically validate the algorithm against senior experienced clinicians, for acid-base interpretation, in a clinical context.

Methods

We conducted a prospective international multicentre observational cross-sectional study. 346 sample sets and 64 inpatients eligible for ABG met strict sampling criteria. Agreement was evaluated using Cohen’s kappa index, diagnostic accuracy was evaluated with sensitivity, specificity, efficiency or global accuracy and positive predictive values (PPV) and negative predictive values (NPV) for the prevalence in the study population.

Results

The concordance rates between the interpretations of the clinicians and the ABG-a for acid-base disorders were an observed global agreement of 84,3% with a Cohen’s kappa coefficient 0.81; 95% CI 0.77 to 0.86; p < 0.001. For detecting accuracy normal acid-base status the algorithm has a sensitivity of 90.0% (95% CI 79.9 to 95.3), a specificity 97.2% (95% CI 94.5 to 98.6) and a global accuracy of 95.9% (95% CI 93.3 to 97.6). For the four simple acid-base disorders, respiratory alkalosis: sensitivity of 91.2 (77.0 to 97.0), a specificity 100.0 (98.8 to 100.0) and global accuracy of 99.1 (97.5 to 99.7); respiratory acidosis: sensitivity of 61.1 (38.6 to 79.7), a specificity of 100.0 (98.8 to 100.0) and global accuracy of 98.0 (95.9 to 99.0); metabolic acidosis: sensitivity of 75.8 (59.0 to 87.2), a specificity of 99.7 (98.2 to 99.9) and a global accuracy of 97.4 (95.1 to 98.6); metabolic alkalosis sensitivity of 72.2 (56.0 to 84.2), a specificity of 95.5 (92.5 to 97.3) and a global accuracy of 93.0 (88.8 to 95.3); the four complex acid-base disorders, respiratory and metabolic alkalosis, respiratory and metabolic acidosis, respiratory alkalosis and metabolic acidosis, respiratory acidosis and metabolic alkalosis, the sensitivity, specificity and global accuracy was also high. For normal acid-base status the algorithm has PPV 87.1 (95% CI 76.6 to 93.3) %, and NPV 97.9 (95% CI 95.4 to 99.0) for a prevalence of 17.4 (95% CI 13.8 to 21.8). For the four-simple acid-base disorders and the four complex acid-base disorders the PPV and NPV were also statistically significant.

Conclusions

The ABG-a showed very high agreement and diagnostic accuracy with experienced senior clinicians in the acid-base disorders in a clinical context. The method also provides refinement and deep complex analysis at the point-of-care that a clinician could have at the bedside on a day-to-day basis. The ABG-a method could also have the potential to reduce human errors by checking for imminent life-threatening situations, analysing the internal consistency of the results, the oxygenation and renal status of the patient.

Evaluating dialysis adequacy: Origins, evolution, and future directions

The expansion and transformation over time of dialysis therapies have been inexorably linked to the concept of adequacy. While initially the goal of dialysis was simple survival of patients until their next treatment, this changed with the publication of the National Cooperative Dialysis Study. It brought about a focus on defining adequate dialysis through measurements of the removal of small solutes, in particular urea. This spurred significant improvements in patient outcomes by standardizing therapy and providing benchmarks for each center to achieve. Over time, however, further research has found this narrow definition of adequacy to be insufficient to encompass the complexities of dialysis therapies. Factors such as residual kidney function (RKF), nutritional and volume status, and cardiovascular control all contribute to the outcomes for dialysis patients. We propose that an optimal definition of adequacy should not only focus on one factor but rather the interconnection and contribution to our patient's individual specific goals and their overall quality of life.

Blood temperature monitoring-guided vascular access intervention improved dialysis adequacy

OBJECTIVES

The aim of this study was to investigate whether blood temperature monitoring-guided vascular access intervention could improve dialysis adequacy.

METHODS

We retrospectively evaluated all patients who received outpatient-based prevalent hemodialysis patients (n = 84) in our artificial kidney room between January 2019 and October 2019. Through blood temperature monitoring, access blood flow was calculated every month and Kt/V was calculated every 3 months. The reference point was set at the time of vascular intervention in the patients (n = 27) who underwent intervention or at the middle of the study period in patients (n = 57) who did not undergo intervention. The mean blood temperature monitoring-estimated access flow and Kt/V before and after the reference point were calculated and compared.

RESULTS

Among 84 patients, 30 (35.7%) showed access flow rates of <500 mL/min, calculated by blood temperature monitoring during the study period. Twenty-seven patients (32.1%) underwent vascular intervention, of whom 24 (28.6%) showed access flow rates of <500 mL/min, 2 (2.4%) showed weak bruit or thrill incapable of needling, and 1 (1.2%) presented acute occlusion. Six patients (7.1%) whose access flow rates were <500 mL/min refused to undergo intervention. All angiographies in the patients whose access flow rates were <500 mL/min who underwent intervention showed a significant stenosis. The mean change in blood temperature monitoring-estimated access flow and Kt/V before and after vascular intervention was 483.3 ± 490.6 and 0.19 ± 0.21, respectively, which showed significant differences (all p < 0.05). A weak positive correlation between the mean change in blood temperature monitoring-estimated access flow and Kt/V was shown in all study patients by Pearson's correlation analysis (r = 0.234, p = 0.033).

CONCLUSION

Access flow estimation by blood temperature monitoring might identify candidates who require vascular intervention. Blood temperature monitoring-guided vascular intervention significantly improved access flow and dialysis adequacy.

The potassium regulator patiromer affects serum and stool electrolytes in patients receiving hemodialysis

Hyperkalemia is a common and an important cause of death in maintenance hemodialysis patients. Here we investigated the effect of patiromer, a synthetic cation exchanger, to regulate potassium homeostasis. Serum and stool electrolytes were measured in 27 anuric patients with hyperkalemia receiving hemodialysis (mainly 2 mEq/L dialysate) during consecutive two weeks of no-treatment, 12 weeks of treatment with patiromer (16.8g once daily), and six weeks of no treatment. The serum potassium decreased from a mean of 5.7 mEq/L pre-treatment to 5.1 mEq/L during treatment and rebounded to 5.4 mEq/L post-treatment. During the treatment phase, serum calcium significantly increased (from 8.9 to 9.1 mg/dL) and serum magnesium significantly decreased (from 2.6 to 2.4 mg/dL) compared to pre-treatment levels. For each one mEg/L increase in serum magnesium, serum potassium increased by 1.07 mEq/L. Stool potassium significantly increased during treatment phase from pre-treatment levels (4132 to 5923 μg/g) and significantly decreased post-treatment to 4246 μg/g. For each one μg/g increase in stool potassium, serum potassium significantly declined by 0.05 mEq/L. Stool calcium was significantly higher during the treatment phase (13017 μg/g) compared to pre-treatment (7874 μg/g) and post-treatment (7635 μg/g) phases. We estimated that 16.8 g of patiromer will increase fecal potassium by 1880 μg/g and reduce serum potassium by 0.5 mEq/L. Thus, there is a complex interaction between stool and blood potassium, calcium and magnesium during patiromer treatment. Long term consequence of patiromer-induced changes in serum calcium and magnesium remains to be studied.

Sodium-Based Osmotherapy in Continuous Renal Replacement Therapy: a Mathematical Approach

Cerebral edema, in a variety of circumstances, may be accompanied by states of hyponatremia. The threat of brain injury from hypotonic stress-induced astrocyte demyelination is more common when vulnerable patients with hyponatremia who have end stage liver disease, traumatic brain injury, heart failure, or other conditions undergo overly rapid correction of hyponatremia. These scenarios, in the context of declining urinary output from CKD and/or AKI, may require controlled elevations of plasma tonicity vis-à-vis increases of the plasma sodium concentration. We offer a strategic solution to this problem via sodium-based osmotherapy applied through a conventional continuous RRT modality: predilution continuous venovenous hemofiltration.

Do Transferrin Levels Predict Haemodialysis Adequacy in Patients with End-Stage Renal Disease?

BACKGROUND

Since haemodialysis is a lifesaving therapy, adequate control measures are necessary to evaluate its adequacy and to constantly adjust the dose to reduce hospitalisation and prolong patient survival. Malnutrition is common in haemodialysis patients and closely related to morbidity and mortality. Patients undergoing haemodialysis have a high prevalence of protein-energy malnutrition and inflammation, along with abnormal iron status. The haemodialysis dose delivered is an important predictor of patient outcome.

AIM

To evaluate through haemodialysis adequacy, which parameter(s), if any, better predict Kt/V, among those used to assess nutritional status, inflammation response, and iron status.

METHODS

We retrospectively studied 78 patients undergoing haemodialysis due to end-stage renal disease. As parameters of nutritional status, geriatric nutritional risk index (GNRI), transferrin levels, lymphocyte count, and albumin concentration were analysed. As signs of inflammation, C reactive protein (CRP) levels and ferritin concentrations were studied as well. Iron status was evaluated by both transferrin and ferritin levels, as well as by haemoglobin (Hb) concentration.

RESULTS

The core finding of our retrospective study is that transferrin levels predict the adequacy of haemodialysis expressed as Kt/V; the latter is the only predictor (P = 0.001) when adjusting for CRP concentrations, a solid marker of inflammation, and for ferritin levels considered an iron-storage protein, but also a parameter of inflammatory response.

DISCUSSION AND CONCLUSION

In keeping with the results of this study, we underline that the use of transferrin levels to assess haemodialysis quality combine into a single test the evaluation of the three most important factors of protein-energy wasting.

Incremental hemodialysis, a valuable option for the frail elderly patient

Management of older people on dialysis requires focus on the wider aspects of aging as well as dialysis. Recognition and assessment of frailty is vital in changing our approach in elderly patients. Current guidelines in dialysis have a limited evidence base across all age group, but particularly the elderly. We need to focus on new priorities of care when we design guidelines "for people not diseases". Patient-centered goal-directed therapy, arising from shared decision-making between physician and patient, should allow adaption of the dialysis regime. Hemodialysis (HD) in the older age group can be complicated by intradialytic hypotension, prolonged time to recovery, and access-related problems. There is increasing evidence relating to the harm associated with the delivery of standard thrice-weekly HD. Incremental HD has a lower burden of treatment. There appears to be no adverse clinical effects during the first years of dialysis in presence of a significant residual kidney function. The advantages of incremental HD might be particularly important for elderly patients with short life expectancy. There is a need for more research into specific topics such as the assessment of the course of frailty with progression of chronic kidney disease and after dialysis initiation, the choice of dialysis modality impacting on the trajectory of frailty, the timing of dialysis initiation impacting on frailty or on other outcomes. In conclusion, understanding each individual's goals of care in the context of his or her life experience is particularly important in the elderly, when overall life expectancy is relatively short, and life experience or quality of life may be the priority.

Facility size and mortality in hospital-based and freestanding haemodialysis units: A nationwide retrospective cohort study

AIM

Existing studies on the association between haemodialysis facility size/volume and patient survival are mostly limited to freestanding dialysis units in the United States. This study in Taiwan explored the facility size - mortality association in both hospital-based and freestanding haemodialysis (HD) units.

METHODS

In this nationwide population-based retrospective cohort study, we used the Taiwan National Health Insurance Research Database to include patients who began maintenance (HD) between 2008 and 2012. Facility size was categorized according to the number of stations in the HD unit. The 5 years mortality rate was analyzed using a frailty model for Cox regression. The patients in hospital-based and freestanding HD units were examined separately.

RESULTS

Among the 39 506 patients, 24 597 (62.3%) and 14 909 (37.7%) patients received HD in hospital-based and freestanding facilities, respectively. After the 4th month of dialysis initiation, the 5 years survival rates of patients in hospital-based and freestanding HD units were 50.7% and 52.3%, respectively. When patient and other facility characteristics were adjusted, patients in the smallest facility category (1-15 stations) showed the highest mortality risk (hazard ratio, 1.36; 95% confidence interval, 1.11-1.67) among all the patients treated in hospital-based units. The patients treated in freestanding units with 1-15, 16-30 and 31-45 stations showed 31%, 33% and 36%, respectively, higher mortality risks than those of patients treated in units with more than 45 stations.

CONCLUSION

A small facility size was associated with an increased mortality risk in HD patients, and the threshold size was higher in freestanding units.

A need for a paradigm shift in focus: From Kt/Vurea to appropriate removal of sodium (the ignored uremic toxin)

Hemodialysis for chronic renal failure was introduced and developed in Seattle, WA, in the 1960s. Using Kiil dialyzers, weekly dialysis time and frequency were established to be about 30 hours on 3 time weekly dialysis. This dialysis time and frequency was associated with 10% yearly mortality in the United States in 1970s. Later in 1970s, newer and more efficient dialyzers were developed and it was felt that dialysis time could be shortened. An additional incentive to shorten dialysis was felt to be lower cost and higher convenience. Additional support for shortening dialysis time was provided by a randomized prospective trial performed by National Cooperative Dialysis Study (NCDS). This study committed a Type II statistical error rejecting the time of dialysis as an important factor in determining the quality of dialysis. This study also provided the basis for the establishment of the Kt/V_urea index as a measure of dialysis adequacy. This index having been established in a sacrosanct randomized controlled trial (RCT), was readily accepted by the HD community, and led to shorter dialysis, and higher mortality in the United States. Kt/V_urea is a poor measure of dialysis quality because it combines three unrelated variables into a single formula. These variables influence the clinical status of the patient independent of each other. It is impossible to compensate short dialysis duration (t) with the increased clearance of urea (K), because the tolerance of ultrafiltration depends on the plasma-refilling rate, which has nothing in common with urea clearance. Later, another RCT (the HEMO study) committed a Type III statistical error by asking the wrong research question, thus not yielding any valuable results. Fortunately, it did not lead to deterioration of dialysis outcomes in the United States. The third RCT in this field ("in-center hemodialysis 6 times per week versus 3 times per week") did not bring forth any valuable results, but at least confirmed what was already known. The fourth such trial ("The effects of frequent nocturnal home hemodialysis") too did not show any positive results primarily due to significant subject recruitment issues leading to inappropriate selection of patients. Comparison of the value of peritoneal dialysis and HD in RCTs could not be completed because of recruitment problems. Randomized controlled trials have therefore failed to yield any meaningful information in the area of dose and or frequency of hemodialysis.

Effects of Listening to Live Singing in Patients Undergoing Hemodialysis: A Randomized Controlled Crossover Study

Background:

Participation in music therapy is associated with improved psychological and physical indices among chronically ill patients. Listening to music during hemodialysis treatments positively affects patients’ hemodynamics, laboratory values, quality of life, and physical symptoms. The effect of live singing during hemodialysis treatments, however, has not previously been studied.

Methods:

A total of 24 participants with a diagnosis of end-stage kidney disease participated in the study. The vocalist was a musically trained dialysis nurse. Twelve of the patients listened to 15 min of live singing during 6 consecutive hemodialysis sessions, while the other 12 underwent standard hemodialysis. After a washout period of 2 days, the two groups were reversed.

Results:

Listening to live music was associated with improvements in systolic and diastolic blood pressure, better quality of sleep, fewer cramps, and reduced anxiety/depression, pain, and itching ( p < .05, all values).

Conclusions:

Listening to live music during hemodialysis is an effective and potentially low-cost therapy for the dialysis care team to employ during hemodialysis treatments.

The forearm basilic vein looped transposition fistula as a tertiary option for upper limb vascular access

Introduction:

The forearm basilic vein can serve as an option for haemodialysis access but may not be possible in cases where the wrist arteries are unsuitable. In this setting, the forearm basilic vein can be used in a looped transposition with a brachial artery anastomosis.

Aims:

The aims of this study were to assess the outcome of forearm basilic vein looped transposition as an option for vascular access.

Material and methods:

Data from January 2007 to December 2010 were prospectively collected and analysed. Outcome measures were operative success, complications, maturation and primary and secondary patency following 5 years of follow-up.

Results:

From a total of 583 patients receiving autologous vascular access for haemodialysis, 24 (4.1%) underwent a forearm basilic vein looped transposition. The median age was 60 years (range, 27–80 years), with a slight male predominance (13 male:11 female). Mean follow-up was 34 months (1–60 months). Two patients died and other three were transplanted with subsequent fistula closure. All procedures were successful (100%); however, maturation failure occurred in one case (4.2%). No serious perioperative complications were observed. In two cases, we observed late false aneurysm formation requiring intervention. Primary patency at 1, 2, 3 and 5 years was the following: 77%, 62%, 21% and 10%, whereas secondary patency was the following: 81%, 71%, 61% and 32%, respectively.

Conclusion:

Autologous forearm basilic vein looped transposition is an effective surgical procedure for the creation of access for haemodialysis. This may be a useful option in patients with compromised peripheral arterial diameter or flow and should be considered in patients with a suitable forearm basilic vein.

Aryl hydrocarbon receptor is activated in patients and mice with chronic kidney disease

Patients with chronic kidney disease (CKD) are exposed to uremic toxins and have an increased risk of cardiovascular disease. Some uremic toxins, like indoxyl sulfate, are agonists of the transcription factor aryl hydrocarbon receptor (AHR). These toxins induce a vascular procoagulant phenotype. Here we investigated AHR activation in patients with CKD and in a murine model of CKD. We performed a prospective study in 116 patients with CKD stage 3 to 5D and measured the AHR-Activating Potential of serum by bioassay. Compared to sera from healthy controls, sera from CKD patients displayed a strong AHR-Activating Potential; strongly correlated with eGFR and with the indoxyl sulfate concentration. The expression of the AHR target genes Cyp1A1 and AHRR was up-regulated in whole blood from patients with CKD. Survival analyses revealed that cardiovascular events were more frequent in CKD patients with an AHR-Activating Potential above the median. In mice with 5/6 nephrectomy, there was an increased serum AHR-Activating Potential, and an induction of Cyp1a1 mRNA in the aorta and heart, absent in AhR^-/- CKD mice. After serial indoxyl sulfate injections, we observed an increase in serum AHR-AP and in expression of Cyp1a1 mRNA in aorta and heart in WT mice, but not in AhR^-/- mice. Thus, the AHR pathway is activated both in patients and mice with CKD. Hence, AHR activation could be a key mechanism involved in the deleterious cardiovascular effects observed in CKD.

Efficacy and Safety of a Retrograde Tunneled Hemodialysis Catheter: 6-Month Clinical Experience with the Cannon Catheter™ Chronic Hemodialysis Catheter

Purpose

Tunneled catheters play an important role in the delivery of hemodialysis, for both temporary and long-term vascular access. Proper catheter tip positioning is critical for optimal blood flow and performance. The modular Cannon Catheter™ II Chronic Hemodialysis Catheter is placed tip first, then tunneled back to the exit site, in a simple technique (retrograde tunneling) that provides precise tip placement within the right atrium. This retrospective study evaluated 6-month efficacy and safety of the Cannon catheter in 38 patients.

Methods

Monthly mean flow, pressure, Kt/V, and URR were determined. Safety parameters included early and late device-related complications, device removals, and device survival.

Results

87% of subjects had history of vascular access failure. Cannon catheters were inserted via an internal jugular vein with retrograde tunneling in all patients without insertional complication. Mean flow ranged from 369.0 to 404.8 ml/min, with a trend for increasing flow over time. High flow allowed delivery of correspondingly high clearance. Mean URR remained ≥71%; mean weekly Kt/V ranged between 1.55 and 1.60, above current K/DOQI adequacy guidelines. There were no device-related hospitalizations or deaths. Catheter-related bacteremia occurred in 3 patients over the 6 months (0.62 bacteremias/1,000 patient-days), resolving through outpatient treatment. The Cannon catheter provided extended high flow vascular access (≥6 months or until hemodialysis catheter-based access was no longer needed) in 95% of patients.

Conclusion

Retrograde tunneling of the Cannon Catheter™ II Chronic Hemodialysis Catheter allowed optimal tip placement and high flow rates, as well as safe, reliable, extended use.

Measuring Central Venous Structures in Humans: Implications for Central-Vein Catheter Dimensions

The tip of a central vein catheter for hemodialysis should be located in the upper right atrium for the best performance. Hemodialysis catheters do have internal diameter unadjusted to the catheter length; however, the longer the catheter the slower the flow at the same pressure difference. On the other hand, the catheter diameter cannot be so large as to fill the vein too tightly as it predisposes to the damage of the vein wall, thrombosis and stenosis. Therefore, the catheter length and diameter should be appropriate for the patient. For this purpose, the exact dimensions of the venous system in vivo should be known. In this study we correlated the anthropometric measurements and the dimensions of the large upper body veins in 31 adult volunteers.

After deep inspiration, magnetic resonance imaging of the chest was performed in three planes; the positions of specific points in the three-dimensional coordinate system were measured, and the distance to adjacent points was calculated according to the analytic geometry formula. The total length from the catheter entry point to the right atrium was the sum of distances between the adjacent points. The lengths of the veins were correlated with the body anthropometric measurements (height, weight, body surface area, biacromion span, and height plus biacromion span).

The best overall correlations of the lengths and diameters of the large upper body veins are with the body surface area. A table is included to guide the selection of the total catheter length and diameter in relation to the body surface area and insertion site.

Is β2-Microglobulin-Related Amyloidosis of Hemodialysis Patients a Multifactorial Disease? a New Pathogenetic Approach

Purpose

β2-microglobulin amyloidosis (Aβ2M) is one of the main long-term complications of dialysis treatment. The incidence and the onset of Aβ2M has been related to membrane composition and/or dialysis technique, with non-homogeneous results. This study was carried out to detect: i) the incidence of bone cysts and CTS from Aβ2M; ii) the difference in Aβ2M onset between cellulosic and synthetic membranes; iii) other risk factors besides the membrane.

Methods

480 HD patients were selected between 1986 to 2005 and grouped according to the 4 types of membranes used (cellulose, synthetically modified cellulose, synthetic low-flux, synthetic high-flux). The patients were analyzed before and after 1995, when the reverse osmosis treatment for dialysis water was started at our center, and the incidence of Aβ2M was compared between the two periods. Routine plain radiography, computer tomography (CT) and nuclear magnetic resonance imaging (MRI) as well as electromyography were used to investigate the clinical symptoms.

Results

Bone cysts occurred in 29.2% of patients before 1995 vs. 12.2% after 1995 (p<0.0001). CTS occurred in 24% of patients before 1995 vs. 7.1% after 1995 (p<0.0001). Bone cysts and CTS occurred in older patients, who began dialysis at a late age, with high CRP, low albumin, low residual GFR, and low Hb. Cox regression analysis showed that the risk factor for bone cysts was high CRP (RR 1.3, p<0.01), while albumin (RR 0.14, p<0.0001) and residual GFR (RR 0.81, p<0.0001) were revealed to be protective factors. Cox analysis for CTS confirmed CRP as a risk factor (RR 1.2, p<0.01), and albumin (RR 0.59, p<0.0001) and residual GFR (RR 0.75, p<0.0001) as protective factors. The comparison obtained between membranes did not suggest any protective effect on Aβ2M.

Conclusions

The findings that the inflammatory status as well as low albumin and the residual GFR of the uremic patient are predictive of Aβ2M lesions suggests that Aβ2M has a multifactorial origin rather than being solely a membrane- or technique-related side effect.

Short, Thrice-Weekly Hemodialysis is Inadequate Regardless of Small Molecule Clearance

Chronic hemodialysis sessions, as developed in Seattle in the 1960s, were long procedures with minimal intra- and interdialytic symptoms. Over the next three decades, financial and logistical pressures related to the overwhelming number of patients requiring hemodialysis created an incentive to shorten dialysis time to four, three, and even two hours per session in a thrice weekly schedule. This method spread rapidly, particularly in the United States, after the National Cooperative Dialysis Study suggested that time of dialysis is of minor importance as long as urea clearance multiplied by dialysis time and scaled to total body water (Kt/Vurea) equals 0.95–1.0. This number was later increased to 1.3, but the assumption that hemodialysis time is of minimal importance, as long as it is compensated by increased urea clearance, remained unchanged. Patients accepted short dialysis as a godsend, believing that it would not be detrimental to their well being and longevity.

However, Kt/Vurea measures only removal of low molecular weight substances and does not consider removal of larger molecules. Nor does it correlate with the other important function of hemodialysis, namely ultrafiltration. Whereas patients with substantial residual renal function may tolerate short dialysis sessions, patients with little or no urine output tolerate short dialyses poorly because at a given interdialytic weight gain the ultrafiltration rate is inversely proportional to dialysis time. Rapid ultrafiltration is associated with cramps, nausea, vomiting, headache, fatigue, hypotensive episodes during dialysis, and hangover after dialysis; patients remain fluid overloaded with subsequent poor blood pressure control leading to left ventricular hypertrophy, diastolic dysfunction, and high cardiovascular mortality.

Short, high-efficiency dialysis requires high blood flow, which increases demands on blood access. The classic, wrist arteriovenous fistula, the access with the best longevity and lowest complication rates, provides “insufficient” blood flow and is replaced with an arteriovenous graft fistula or an intravenous catheter. Moreover, to achieve high blood flows, large diameter intravenous catheters are used; these fit veins “too tightly” and so predispose to central-vein thrombosis.

Longer hemodialysis sessions (5–8 hours, thrice weekly), as practiced in some centers, are associated with lower complication rates and better outcomes. Frequent dialyses (four or more sessions per week) with total weekly dialysis time sufficient to allow gentle ultrafiltration rates provide the best clinical results, but are associated with increased costs which are not properly reimbursed in the USA at present. Therefore, it is my strong belief that before a more appropriate reimbursement is available, a wide acceptance of longer, gentler dialysis sessions, in the current thrice weekly schedule, would improve overall hemodialysis results, decrease access complications, hospitalizations and mortality, particularly in anuric patients.

Kt/Vurea should be abandoned as a measure of dialysis quality. The formula suggests that it is possible to decrease t as long as K is proportionately increased, but this is not true. The use of rigid, quantitative guidelines (e.g., spKt/Vurea of 1.3 per dialysis) assumes that all patients behave identically in response to therapeutic maneuvers, like the mean of the group, but this is also not true. The individual, clinical approach assumes that there are differences among patients, which require adjustment of dialysis schedule for each patient.

Factors affecting responsiveness to hepatitis B immunization in dialysis patients

BACKGROUND

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are widespread health problems all over the world and have high morbidity and mortality. Hemodialysis patients are more frequently exposed to these viruses as they have poor immune system and frequently undergo parenteral interventions. The vaccination against HBV prevents infection and it has been recommended for the prevention of HBV infection in all susceptible dialysis patients. This study aimed to determine the seroprevalence of HBV and HCV infections and analyzed the factors affecting inadequate response to HBV vaccine in dialysis patients.

METHODS

The data for 584 dialysis patients that were followed up at seven dialysis centers were analyzed. The patients received four doses of 40 μg recombinant hepatitis B vaccine at 0, 1, 2, and 6 months and were tested for anti-HBs titer after one month of completion of vaccination. If patients showed a titer of anti-HBs <10 IU/mL, an additional 40 μg in four vaccine doses was administered immediately and they were retested for the anti-HBs following the same schedule. The patients were divided into two groups: responders and non-responders.

RESULTS

HBsAg and anti-HCV seroprevalence was 3.4% and 10.3%, respectively. After vaccination schedule, 264 (83.5%) patients had antibody response to HBV vaccine and 52 (16.5%) had no response. Hepatitis B vaccine unresponsiveness is more common in the patients with hepatitis C positivity (p = 0.011), BMI >30 (p = 0.019), over the age of 65 years (p = 0.009), and duration of dialysis treatment >5 years (p = 0.001). There was no statistically significant difference between gender, causes of renal disease, erythropoietin treatment, and the type of dialysis.

CONCLUSION

Hepatitis C infection, obesity, being elderly, and having long hemodialysis period reduced the hepatitis B vaccination response in hemodialysis patients.

The Effects of e-interventions on the Medical Outcomes of Hemodialysis Patients: A Retrospective Matched Patient Cohort Study

Aggressively applying e-interventions in the health care industry has become a global trend to improve the quality of medical care. The present retrospective study evaluated the effect of electronic information systems on the quality of medical care provide to hemodialysis (HD) patients. In total, 600 patients (300 patients each in the e-intervention and non-e-intervention groups, were matched for sex, age, HD duration, diabetes, and hypertension) receiving HD at the study institute for four years were included in this study. The e-intervention group had significantly fewer hospitalization days than the non-e-intervention group. Cox regression analysis demonstrated that the non-e-intervention group had a significantly higher mortality rate than the e-intervention group. Stratified analysis revealed significant differences between the e-intervention and non-e-intervention groups in their serum albumin levels, urea reduction ratios, and cardiothoracic ratios at 1-year follow-up. The patients in the e-intervention group had a significantly higher HD blood flow rate, fewer hospitalization days and a lower 4-year all-cause mortality rate than those in the non-e-intervention group. The implementation of the e-intervention improved patient outcomes, but additional studies are required to evaluate the cost effectiveness of such implementations.

Is incremental hemodialysis ready to return on the scene? From empiricism to kinetic modelling

Most people who make the transition to maintenance dialysis therapy are treated with a fixed dose thrice-weekly hemodialysis regimen without considering their residual kidney function (RKF). The RKF provides effective and naturally continuous clearance of both small and middle molecules, plays a major role in metabolic homeostasis, nutritional status, and cardiovascular health, and aids in fluid management. The RKF is associated with better patient survival and greater health-related quality of life, although these effects may be confounded by patient comorbidities. Preservation of the RKF requires a careful approach, including regular monitoring, avoidance of nephrotoxins, gentle control of blood pressure to avoid intradialytic hypotension, and an individualized dialysis prescription including the consideration of incremental hemodialysis. There is currently no standardized method for applying incremental hemodialysis in practice. Infrequent (once- to twice-weekly) hemodialysis regimens are often used arbitrarily, without knowing which patients would benefit the most from them or how to escalate the dialysis dose as RKF declines over time. The recently heightened interest in incremental hemodialysis has been hindered by the current limitations of the urea kinetic models (UKM) which tend to overestimate the dialysis dose required in the presence of substantial RKF. This is due to an erroneous extrapolation of the equivalence between renal urea clearance (Kru) and dialyser urea clearance (Kd), correctly assumed by the UKM, to the clinical domain. In this context, each ml/min of Kd clears the urea from the blood just as 1 ml/min of Kru does. By no means should such kinetic equivalence imply that 1 ml/min of Kd is clinically equivalent to 1 ml/min of urea clearance provided by the native kidneys. A recent paper by Casino and Basile suggested a variable target model (VTM) as opposed to the fixed model, because the VTM gives more clinical weight to the RKF and allows less frequent hemodialysis treatments at lower RKF. The potentially important clinical and financial implications of incremental hemodialysis render it highly promising and warrant randomized controlled trials.

Upper Arm Basilic Vein Transposition for Hemodialysis: A Single Center Study for 300 Cases

Purpose:

The population of end-stage renal failure patients dependent on hemodialysis continues to expand with an increasing number of patients having an unsuitable cephalic vein or failed radio- and brachio-cephalic fistula. In these patients, the transposed basilic vein to brachial artery arteriovenous fistula (BaVT) provides autologous choice for hemodialysis. The results of basilic vein transposition arteriovenous fistula were assessed.

Materials and Methods:

Three hundred cases of BaVT performed at a single center during the period of January 2005 to December 2011 were reviewed retrospectively. Data including demographics and postoperative complications were collected. Primary and secondary patency rates were determined by using Kaplan-Meier methods.

Results:

The median age of patients was 57.4±13.1 years, and 154 patients were male. Renal failure was associated with hypertension in 88.7%, and with diabetes in 34.0%. The mean follow-up was 27.4±20.0 (12 to 72) months. There was no operation-related death. Eighteen patients required prosthetic graft interposition because of short vein. Thirty-five postoperative complications developed in 41 patients (148 cases), including thrombosis, stenosis, hematoma, seroma, arm swelling, steal syndrome, infection and aneurysm formation. Primary patency of BaVT was 69%, 60%, 53%, 52%, 44%, and 22% at 1, 2, 3, 4, 5, and 6 years, respectively. Secondary patency was 99%, 97%, 97%, 97%, 95%, and 95%, respectively.

Conclusion:

Chronic renal failure patients with hemodialysis may benefit from BaVT, because of high patency, less radiologic procedure, and less infection rate. The BaVT fistula should be used in preference to polytetrafluoroethylene grafts for secondary access.

Adequacy of twice weekly hemodialysis in end stage renal disease patients at a tertiary care dialysis centre

Hemodialysis has improved the morbidity and mortality associated with end stage renal disease. In India, hemodialysis prescription is empiric, which leads to complications related to under-dialysis. Hence, adequacy of hemodialysis in Indian setting was analyzed in this study. A total of 50 patients on twice per week hemodialysis were assessed for 1 month. The number of sessions meeting standards laid out by Kidney Diseases Outcome Quality Initiatives (KDOQI) guidelines were calculated. They were divided into two groups: one in whom dialysis was monitored and session length enhanced to meet the minimum standard Kt/V of 2 and second control group; where Kt/V was not monitored. Hemoglobin (Hb) levels, albumin levels, mean arterial pressure and World Health Organization (WHO) quality of life (QoL) score were compared in the two groups after 6 months. Only 28% of hemodialysis sessions were adequate as per KDOQI guidelines. There was significant improvement in Hb levels (1.47 vs. 0.15 g/dl), mean arterial pressure levels (15.2 vs. 3.16 mm Hg), serum albumin levels (0.82 vs. 0.11 g/dl) and WHO QoL score (17.2 vs. 2.24) in study group as compared to control group. Standard Kt/V can be used as an important tool to modify twice weekly dialysis sessions to provide better QoL to the patients. However, studies with larger sample size are required to conclusively prove our results.

Relationship between dialysis adequacy and sleep quality in haemodialysis patients

AIM AND OBJECTIVES

The aim of this study is to examine the relationship between dialysis adequacy and sleep quality in haemodialysis patients.

BACKGROUND

Sleep problems are common in haemodialysis patients. Dialysis adequacy is one of the factors associated with sleep quality. Studies evaluating the association between dialysis adequacy and sleep quality in haemodialysis patients present different results.

DESIGN

Descriptive and cross-sectional study.

METHODS

This study was performed with a total of 119 patients who had applied to dialysis centres for haemodialysis treatment between January and March 2014. The data collection form consists of socio-demographic and medical characteristics as well as laboratory parameters. A modified Post-Sleep Inventory was used to examine sleep quality in the research.

RESULTS

There were no statistically significant relationship between sleep quality and dialysis adequacy (p > 0·05). When the Post-Sleep Inventory scores were evaluated according to sleep quality, 63·0% of patients had poor sleep quality, and 37·0% had good sleep quality. Sleep quality was worse in unemployed patients (X(2) = 4·852; p = 0·025) and patients who smoked heavily (Z = 2·289; p = 0·022).

CONCLUSIONS

In this study, there is no statistically significant relationship between dialysis adequacy and sleep quality. However, it was found that the majority of haemodialysis patients had poor sleep quality.

RELEVANCE TO CLINICAL PRACTICE

Even if the dialysis adequacy of patients is at the recommended level, their sleep qualities may be poor. Therefore, evaluations of the sleep quality of haemodialysis patients during the clinical practice must be taken into consideration.

Trends in the Timing and Clinical Context of Maintenance Dialysis Initiation

Whether secular trends in eGFR at dialysis initiation reflect changes in clinical presentation over time is unknown. We reviewed the medical records of a random sample of patients who initiated maintenance dialysis in the Department of Veterans Affairs (VA) in fiscal years 2000-2009 (n=1691) to characterize trends in clinical presentation in relation to eGFR at initiation. Between fiscal years 2000-2004 and 2005-2009, mean eGFR at initiation increased from 9.8±5.8 to 11.0±5.5 ml/min per 1.73 m(2) (P<0.001), the percentage of patients with an eGFR of 10-15 ml/min per 1.73 m(2) increased from 23.4% to 29.9% (P=0.002), and the percentage of patients with an eGFR>15 ml/min per 1.73 m(2) increased from 12.1% to 16.3% (P=0.01). The proportion of patients who were acutely ill at the time of initiation and the proportion of patients for whom the decision to initiate dialysis was based only on level of kidney function did not change over time. Frequencies of documented clinical signs and/or symptoms were similar during both time periods. The adjusted odds of initiating dialysis at an eGFR of 10-15 or >15 ml/min per 1.73 m(2) (versus <10 ml/min per 1.73 m(2)) during the later versus earlier time period were 1.43 (95% confidence interval [95% CI], 1.13 to 1.81) and 1.46 (95% CI, 1.09 to 1.97), respectively. In conclusion, trends in eGFR at dialysis initiation at VA medical centers do not seem to reflect changes in the clinical context in which dialysis is initiated.

The incremental treatment of ESRD: a low-protein diet combined with weekly hemodialysis may be beneficial for selected patients

BACKGROUND

Infrequent dialysis, namely once-a-week session combined with very low-protein, low-phosphorus diet supplemented with ketoacids was reported as a useful treatment schedule for ESRD patients with markedly reduced residual renal function but preserved urine output. This study reports our findings from the application of a weekly dialysis schedule plus less severe protein restriction (standard low-protein low-phosphorus diet) in stage 5 CKD patients with consistent dietary discipline.

METHODS

This is a multicenter, prospective controlled study, including 68 incident CKD patients followed in a pre-dialysis clinic with Glomerular Filtration Rate 5 to 10 ml/min/1.73/ m2 who became unstable on the only medical treatment. They were offered to begin a Combined Diet Dialysis Program (CDDP) or a standard thrice-a-week hemodialysis (THD): 38 patients joined the CDDP, whereas 30 patients chose THD. Patients were studied at baseline, 6 and 12 months; hospitalization and survival rate were followed-up for 24 months.

RESULTS

Volume output and residual renal function were maintained in the CDDP Group while those features dropped quickly in THD Group. Throughout the study, CDDP patients had a lower erythropoietin resistance index, lower β2 microglobulin levels and lower need for cinacalcet of phosphate binders than THD, and stable parameters of nutritional status. At 24 month follow-up, 39.4% of patients were still on CDDP; survival rates were 94.7% and 86.8% for CDDP and THD patients, respectively, but hospitalization rate was much higher in THD than in CDDP patients. The cost per patient per year resulted significantly lower in CDDP than in THD Group.

CONCLUSIONS

This study shows that a CDDP served to protect the residual renal function, to maintain urine volume output and to preserve a good nutritional status. CDDP also blunted the rapid β2 microglobulin increase and resulted in better control of anemia and calcium-phosphate abnormalities. CDDP was also associated with a lower hospitalization rate and reduced need of erythropoietin, as well as of drugs used for treatment of calcium-phosphate abnormalities, thus leading to a significant cost-saving. We concluded that in selected ESRD patients with preserved urine output attitude to protein restriction, CDDP may be a beneficial choice for an incremental hemodialysis program.

Association of peroxisome proliferator-activated receptorγ gene Pro12Ala and C161T polymorphisms with cardiovascular risk factors in maintenance hemodialysis patients

The Pro12Ala and C161T polymorphisms in peroxisome proliferator-activated receptor γ (PPARγ) have been shown to be associated with carotid artery atherosclerosis. It remains unclear whether these two polymorphisms are associated with risk factors for cardiovascular disease (CVD) in hemodialysis (HD) patients. Therefore, the PPARγ genotypes in 99 HD patients and 149 controls were determined, and clinical characteristics among the different genotypes were compared. We found that the frequency of the Pro12Ala and C161T polymorphisms in HD patients was similar to that in healthy controls, but C161T polymorphism and T allele frequencies in HD patients with CVD were lower than that in HD patients without CVD. Carotid artery plaque (CAP) and carotid intima-media thickness (CIMT) in HD patients with CT + TT or Pro12Ala genotypes were also less than that in patients with CCor Pro12Pro genotypes, respectively. HD patients with CT + TT genotype had lower serum C reactive protein (CRP) levels, as well as higher triceps skin fold (TSF) thickness, mid arm circumference (MAC) and mean mid arm circumference (MMAC) than HD patients with CC genotype (P < 0.05). Moreover, CIMT of the Pro12Ala-CT161 subgroup was less than the Pro12Pro-CC161 and Pro12Pro-CT161 subgroup, and, CAP amounts of the Pro12Ala-CT161 subgroup was less than the Pro12Pro-CC161 subgroup. Our results indicate that the Pro12Ala and C161T polymorphisms were associated with some important risk factors for CVD in HD patients in the Han Chinese population.

Patient clearance time (tp) with different vascular access types

BACKGROUND/AIMS

The dialysis delivered dose is limited by the rate at which urea can be transferred from the different body compartments. The time needed to clear the peripheral compartments of the body has been called the patient clearance time (tp). The aim of the study was to compare delivered dialysis dose using the tp index between patients dialyzed through a permanent central venous catheter (CVC) and patients with an arteriovenous fistula (AVF).

METHODS

The study included 48 stable hemodialyzed patients. Patients were classified into two groups according to their vascular access type. The first group included 24 patients dialyzed through a permanent CVC and the second group consisted of 24 patients with a mature AVF. The following parameters were calculated twice for each patient: tp, Kt/V adjusted for the tp.

RESULTS

tp was lower in the AVF dialysis modality than in CVC (26 ± 7 vs. 42 ± 14 min, p<0.001) while the (eqKt/V)tp was higher in AVF than in CVC dialysis (1.36 ± 0.11 vs. 1.19 ± 0.13, p<0.001).

CONCLUSIONS

The patient clearance time is lower in AVF than in CVC dialysis, and this is accompanied by a higher delivered dialysis dose.

Changes in dialysis treatment modalities during institution of flat rate reimbursement and quality assurance programs

Dialysis procedure rates in Germany were changed in 2002 from per-session to weekly flat rate payments, and quality assurance was introduced in 2009 with defined treatment targets for spKt/V, dialysis frequency, treatment time, and hemoglobin. In order to understand trends in treatment parameters before and after the introduction of these changes, we analyzed data from 407 to 618 prevalent patients each year (hemodialysis over 90 days) in 14-21 centers in cross-sections of the Dialysis Outcomes and Practice Patterns Study (phases 1-4, 1998-2011). Descriptive statistics were used to report differences over time in the four quality assurance parameters along with erythropoietin-stimulating agent (ESA) and intravenous iron doses. Time trends were analyzed using linear mixed models adjusted for patient demographics and comorbidities. The proportion of patients with short treatment times (less than 4 h) and low spKt/V (below 1.2) improved throughout the study and was lowest after implementation of quality assurance. Hemoglobin levels have increased since 1998 and remained consistent since 2005, with only 8-10% of patients below 10 g/dl. About 90% of patients were prescribed ESAs, with the dose declining since peaking in 2006. Intravenous iron use was highest in 2011. Hence, trends to improve quality metrics for hemodialysis have been established in Germany even after introduction of flat rate reimbursement. Thus, analysis of facility practice patterns is needed to maintain quality of care in a cost-containment environment.

A review article: access recirculation among end stage renal disease patients undergoing maintenance hemodialysis

BACKGROUND

The presence of arterio-venous (A-V) fistula recirculation among hemodialysis (HD) patients markedly decrease adequacy of dialysis.

OBJECTIVES

The present article summarize some of observations about clinical significance, causes, the most common techniques for measurement, and main source of pitfall in calculation of access recirculation.

MATERIALS AND METHODS

A variety of literature sources such as PubMed, Current Content, Scopus, Embase, and Iranmedex; with key words such as inadequate dialysis and arterio-venous fistula access recirculation were used to collect current data. Manuscripts published in English language as full-text articles or as abstract form were included in our review study.

RESULTS

Any access recirculation among HD patients should be considered abnormal and if it presents prompt investigation should be performed for its causes. There are two most common techniques for accurate assessment of access recirculation: Urea (or chemical) and nonurea-based method by ultrasound dilution technique. The most common causes of access recirculation are the presence of high-grade venous stenosis, inadequate arterial blood flow rate, close proximity, or misdirection of arterial and venous needles placement by HD staff especially in new vascular accesses due to a lack of familiarity with the access anatomy.

CONCLUSIONS

The presence of access recirculation among HD patients can lead to significant inadequate dialysis thereby resulting in reducing the survival of these patients. Therefore, periodic assessment of access recirculation should be performed in HD wards.

Ionic Dialysance and Determination of Kt/V in on-line Hemodiafiltration with Simultaneous Pre- and Post-dilution

Purpose

A direct determination of Kt/V using ionic dialysance for estimating K and bio-impedancemetry for estimating V is compared with the usual indirect estimation based on the second generation Daugirdas equation during a new technique of hemodiafiltration with simultaneous pre- and postdilution (mixed-HDF).

Methods

In 31 informed consented patients, the urea distribution volume (V) is estimated by total body water (VBCM) measured by the Body Composition Monitor (BCM; Fresenius Medical Care, Bad Homburg, Germany) based on bio-impedance spectroscopy. The value (KOCM t)/VBCM is calculated during 114 mixed-HDF sessions (duration 4 hours) from the measurement of ionic dialysance KOCM by the OCM module, standard on the 5008 dialysis monitor (Fresenius Medical Care, Germany). The single pool (Kt/V)sp is determined from blood urea concentration measurements using the Daugirdas equation.

Results

Mixed-HDF is a very high-efficiency hemodialysis with a delivered dialysis dose Kt/V near from 2 per 4-hour session. (KOCM t)/VBCM (1.97 ± 0.28) is consistent with (Kt/V)sp (2.01 ± 0.34) with a correlation coefficient at 0.72.

Conclusions

Direct calculation of Kt/V from estimating K by OCM and V by BCM is consistent with the usual indirect estimation by the second generation Daugirdas equation. Therefore, the regular determination of V by BCM allows the estimation of single-pool Kt/V at each session without the need of blood sampling.

The Kt/V by ionic dialysance: Interpretation limits

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

Effect of sertraline on uremic pruritus improvement in ESRD patients

Background. Although uremic pruritus is a common and upsetting problem of chronic kidney disease, there is no approved treatment for it. This study was undertaken to find the efficiency of sertraline as a possible treatment for uremic pruritus. Methods. 19 ESRD patients under hemodialysis with severe chronic pruritus were randomly selected to participate in this before-after clinical trial. Before and after starting treatment with sertraline, a detailed pruritus history was obtained and pruritus graded by the 30-item inventory of pruritus that patients based on priorities grade allocated to 3 classes. Subjects were treated with sertraline 50 mg oral daily for four months, with monthly assessments of pruritus symptoms. Results. Before treatment with sertraline, the grade of pruritus in 9 (47.4%) patients was moderate and severe in 10 (52.6%) patients. After treatment, grade of pruritus in 11 (57.8%) patients was weak, 6 (31.5%) have moderate and only 2 (10.7%) patients have severe pruritus. Of 10 patients with severe pruritus, 5 (50%) patients experiencing weak pruritus, and 4 (40%) patients have moderate pruritus after treatment. Based on Wilcoxon signed-rank test, the difference between the grade of pruritus before and after treatment with sertraline was significant (P = 0.001). Conclusions. Although no definitive recommendation can be made regarding treatment of uremic pruritus, we found an increased antipruritic effect of sertraline in ESRD patients.

Pictorial essay: Interventional radiology in the management of hemodialysis vascular access - A single-center experience

Chronic kidney disease (CKD) is a worldwide public health problem and is associated with high morbidity and mortality. The majority of patients with CKD stage 5 (CKD-5), who cannot undergo renal transplant, depend on maintenance hemodialysis by surgically created access sites. Native fistulae are preferred over grafts due to their longevity. More than half of these vital portals for dialysis access will fail over time. Screening procedures to select high-risk patients before thrombosis or stenosis appears have resulted in aggressive management. These patients are referred for angiographic evaluation and/or therapy. We present the patterns of dialysis-related interventions done in our institution.

Hemodynamically significant arterial inflow stenosis in dysfunctional hemodialysis arteriovenous fistulae and grafts

PURPOSE

Hemodynamically significant arterial inflow stenosis in dysfunctional fistulae and grafts is poorly understood. No reliable clinical methods exist to detect arterial inflow stenosis. In this study, we assessed the accuracy of a novel screening method to detect arterial inflow stenosis in dysfunctional fistulae and grafts following successful juxta-anastomotic and venous outflow intervention.

METHODS

We prospectively evaluated all patients (N= 204) referred to our academic center for angiographic evaluation of a dysfunctional dialysis fistula/graft from May 1, 2006 to June 30, 2007. Following successful angioplasty/stenting of the venous outflow and juxta-anastomotic areas, patients were screened for arterial inflow stenosis. The screening method involved detection of 1) weak thrill, or sluggish blood flow on the post-intervention angiogram, 2) low mean arterial blood pressures in the dialysis access arm compared to the contralateral arm, and 3) inadequate blood flow at the first hemodialysis session post-intervention. If patients screened positive for any of these, they were further evaluated for arterial inflow stenosis.

RESULTS

Fifteen patients (15/204) were positive for arterial inflow stenosis on screening study. Eleven of those 15 had arterial stenosis on angiography, giving our screening method a positive predictive value of 73.3%. Eight patients were successfully treated by angioplasty/stenting. Two patients successfully underwent surgical intervention. Two year patency of revascularization was 91% (10/11).

CONCLUSIONS

Hemodynamically significant arterial inflow stenosis occurs and can be detected by simple clinical methods. Interventions for correction of the arterial inflow stenosis are successful.

Use of online blood volume and blood temperature monitoring during haemodialysis in critically ill patients with acute kidney injury: a single-centre randomized controlled trial

BACKGROUND

Little is known about the clinical impact on cardiovascular stability during intermittent haemodialysis (IHD) for acute kidney injury (AKI) of online monitoring devices that control blood volume (BV) and blood temperature in the intensive care unit (ICU) setting. We compared different dialysis treatment modalities with or without these new systems among critically ill patients requiring IHD.

METHODS

In a prospective single-centre three-arm randomized controlled trial, 600 dialysis sessions in 74 consecutive AKI critically ill patients were involved to assess intradialytic hypotension. Standard dialysis therapy with constant ultrafiltration (UF) rate, cool dialysate and high sodium conductivity (Treatment A) was compared to regimens with adjunctive interventions including BV control (Treatment B) and the combination of BV and active blood temperature control (Treatment C). Each dialysis session was randomly assigned to one of the three treatment arms and served as statistical unit.

RESULTS

Five hundred and seventy-two dialysis sessions were analysed (188, 190 and 194 in Treatments A, B and C, respectively). Hypotension occurred in 16.6% treatments, with similar rates among the arms. Haemodynamic parameters and dialysis-related complications did not differ between therapies. Based on generalized estimating equation adjusted to dialysate sodium conductivity, higher Sequential Organ Failure Assessment the day of dialysis session, the need for vasopressors and lower systolic blood pressure at the onset of the session were identified as independent predictors of hypotensive episodes, whereas regimens containing the new online monitors were not.

CONCLUSIONS

These results suggest that both actively controlled body temperature and UF profiled by online monitoring systems have no significant impact on the incidence of intradialytic hypotension in the ICU setting. Further research is needed before the use of these new sophisticated automatic methods can be applied routinely to the ICU setting.

Trends in timing of initiation of chronic dialysis in the United States

BACKGROUND

During the past decade, a trend has been observed in the United States toward initiation of chronic dialysis at higher levels of estimated glomerular filtration rate. This likely reflects secular trends in the composition of the dialysis population and a tendency toward initiation of dialysis earlier in the course of kidney disease.

METHODS

The goal of this study was to generate model-based estimates of the magnitude of changes in the timing of dialysis initiation between 1997 and 2007. We used information from a national registry for end-stage renal disease on estimated glomerular filtration rate at initiation among patients who received their first chronic dialysis treatment in 1997 or 2007. We used information regarding predialysis estimated glomerular filtration rate slope from an integrated health care system.

RESULTS

After accounting for changes in the characteristics of new US dialysis patients from 1997 to 2007, we estimate that chronic dialysis was initiated a mean of 147 days earlier (95% confidence interval, 134-160) in the later compared with the earlier year. Differences in timing were consistent across a range of patient subgroups but were most pronounced for those aged 75 years or older; the mean difference in timing in that subgroup was 233 days (95% confidence interval, 206-267).

CONCLUSIONS

Chronic dialysis appears to have been initiated substantially earlier in the course of kidney disease in 2007 compared with 1997. In the absence of strong evidence to suggest that earlier initiation of chronic dialysis is beneficial, these findings call for careful evaluation of contemporary dialysis initiation practices in the United States.

Provision and quality of dialysis services in Libya

Dialysis is entirely funded by the public health care sector in Libya. Access to treatment is unrestricted for citizens but there is a lack of local information and no renal registry to gather national data. This cross-sectional study aimed to investigate dialysis provision and practice in Libyan dialysis facilities in 2009. A structured interview regarding dialysis capacity, staffing and methods of assessment of dialysis patients, and infection control measures was conducted with the medical directors of all 40 dialysis centers and 28 centers were visited. A total of 2417 adult patients were receiving maintenance dialysis in 40 centers, giving a population prevalence of approximately 624 per million. Most dialysis units were located in the northern part of the country and only 12.5% were free-standing units. Only three centers offered peritoneal dialysis. One hundred ninety-two hemodialysis rooms hosted 713 functioning hemodialysis stations, giving a ratio of one machine to 3.4 patients. Around half of centers operated only two dialysis shifts per day. Nephrologist/internist to patient ratio was 1:40 and nurse to patient ratio was 1:3.7. We found a wide variation in monitoring of dialysis patients, with dialysis adequacy assessed only in a minority. Separate rooms were allocated for chronic viral infection seropositive patients in 92.5% of the units. In general, the provision of dialysis is adequate but several areas for improvement have been identified, including a need for implementation of guidelines, recruitment of more nephrologists, and the development of more cost-effective alternatives such as peritoneal dialysis and transplantation.

The risks of high ultrafiltration rate in chronic hemodialysis: implications for patient care

As dialytic practice has evolved, hemodialysis (HD) adequacy has come to be defined in terms of small molecule clearance. A growing body of evidence suggests that fluid dynamics, specifically ultrafiltration rate (UFR), bear clinical and physiological significance and should perhaps play a more central role in titrating HD therapy. Three recent studies have shown an independent association between higher UFR and mortality. Further work is needed to determine whether this relationship represents a direct toxic effect of rapid fluid perturbations or whether this association is a consequence of confounding on the basis of large interdialytic weight gain, as each would prompt a different therapeutic response. This mounting evidence builds the case that fluid management should play a more central role in the dialytic prescription and that more individualized approaches to fluid management should be encouraged.

Renal replacement therapy review: past, present and future

Support of renal function in modern times encompasses a wide array of methods and clinical scenarios, from the ambulatory patient to the critically ill. The ability to safely and routinely deliver ongoing organ support in the outpatient setting has until recently separated renal replacement therapy from other organ support. Renal replacement therapy (RRT) can be applied intermittently or continuously using extracorporeal (hemodialysis) or paracorporeal (peritoneal dialysis) methods. The purpose of this article is to familiarize the reader with the history, physiology, mode, dose, equipment and future of renal replacement therapy and not to detail the technical methods employed for blood purification.