What Is the Optimal Sodium Concentration in the Dialysate?

Based on our experience in our hemodiafiltration unit we would recommend a personalized isonatremic dialysate bath. We currently prescribe 137 meq (isonatremic) or delta dialysate Na/serum Na less than 2 meq. In addition to the sodium prescribed in the dialysate, for the majority of our patients we do not restrict dietary sodium or water intake. The average sodium intake is 2775 mg per day and blood pressure is maintained without hypertensive medications. We acknowledge that part of the success for achieving dry weight may not be attributable only to the dialysate sodium but is likely the result of a combination of multiple factors such as convection therapy, cooling of dialysate, close monitoring of volume status during sessions with relative blood volume, presence of a nephrologist during all sessions and assessing volume status regularly with lung ultrasound and bioimpedance. In our experience, exercising during hemodialysis has additionally been associated with better hemodynamic status and less intradialytic hypotension. Moreover, we acknowledge there is little evidence to support a gradient dialysate to serum sodium of less than 2 meq and that our approach may not be optimal.

How Would You Prescribe the Dialysate Sodium Concentration for Your Patients?

Low sodium dialysate was commonly used in the early year of hemodialysis to enhance diffusive sodium removal beyond its convective removal by ultrafiltration. However, disequilibrium syndrome was common, particularly when dialysis sessions were reduced to 4 h. The recent trend of lowering the DNa from the most common level of 140 mEq/L has been associated with intradialytic hypotension and increased risk of hospitalization and mortality. Higher DNa also has disadvantages, such as higher blood pressure and greater interdialytic weight gain, likely due to increased thirst. My assessment of the evidence leads me to choose DNa at the 140 level for most patients and to avoid DNa below 138. Patients with intradialytic symptoms may benefit from DNa 142 mEq/L, if they can avoid excessive fluid weight gains.

Hemodynamic and Metabolic Tolerance of Acetate-Free Biofiltration in Mechanically Ventilated Critically Ill Patients: A Real-Life Study

Intradialytic hypotension can lead to superimposed organ hypoperfusion and ultimately worsens long-term kidney outcomes in critically ill patients requiring kidney replacement therapy. Acetate-free biofiltration (AFB), an alternative technique to bicarbonate-based hemodialysis (B-IHD) that does not require dialysate acidification, may improve hemodynamic and metabolic tolerance of dialysis. In this study, we included 49 mechanically ventilated patients requiring 4 h dialysis (AFB sessions n = 66; B-IHD sessions n = 62). Whereas more AFB sessions were performed in patients at risk of hemodynamic intolerance, episodes of intradialytic hypotension were significantly less frequent during AFB compared to B-IHD, whatever the classification used (decrease in mean blood pressure ≥ 10 mmHg; systolic blood pressure decrease >20 mmHg or absolute value below 95 mmHg) and after adjustment on the use of vasoactive agent. Diastolic blood pressure readily increased throughout the dialysis session. The use of a bicarbonate zero dialysate allowed the removal of 113 ± 25 mL/min of CO2 by the hemofilter. After bicarbonate reinjection, the global CO2 load induced by AFB was +25 ± 6 compared to +80 ± 12 mL/min with B-IHD (p = 0.0002). Thus, notwithstanding the non-controlled design of this study, hemodynamic tolerance of AFB appears superior to B-IHD in mechanically ventilated patients. Its use as a platform for CO2 removal also warrants further research.

Dynamic Echocardiographic Assessments Reveal Septal E/e’ Ratio as Independent Predictor of Intradialytic Hypotension in Maintenance for Hemodialysis Patients with Preserved Ejection Fraction

Background: Intradialytic hypotension (IDH) is a frequent and grave complication of hemodialysis (HD). However, the dynamic hemodynamic changes and cardiac performances during each dialytic session have been rarely explored in patients having IDH. Methods: Seventy-six HD patients (IDH = 40, controls = 36) were enrolled. Echocardiography examinations were performed in all patients at the pre-HD, during-HD and post-HD phases of a single HD session. A two-way analysis of variance was applied to compare differences of echocardiographic parameters between IDH and controls over time. The risk association was estimated by using a logistic regression analysis. Results: The IDH patients had a higher ejection fraction during HD followed by a greater reduction at the post-HD phase than the controls. Significant decreases in septal ratios of transmitral flow velocity to annular velocity (E/e’) over times were detected between IDH patients and controls after adjusting for gender, age and ultrafiltration (p = 0.016). A lower septal E/e’ ratio was independently associated with IDH (OR = 0.040; 95% CI = 0.003–0.606; p = 0.02). In contrast, significant systolic and diastolic dysfunctions over time were found in diabetic IDH compared to non-diabetic counterparts. Conclusion: The septal E/e’ ratio was a significant predictor for IDH.

Sodium in Hemodialysis Fluid

The principal aim of dialysis in relation to sodium is that dialysate sodium should not be low enough to cause intradialytic hypotension and cramps, and should not be high enough to cause interdialytic weight gain and hypertension. Dialysis sodium at 138 meq/L is supposed to be neutral and for most patients, this remains the standard sodium level for regular long-term dialysis. In my opinion, sodium should be changed temporarily from this level to 142 meq/L in selected patients only for a few dialysis sessions, where the cause of intradialytic hypotension is not obvious. In patients who regularly go into intradialytic hypotension and whose cause of intradialytic hypotension is unclear or cannot be corrected, sodium profiling should be used for maintenance dialysis. There is no consensus on the level of sodium, although I think 142 meq/L for the initial hour followed by a decrease to 138 meq/L in the last hour is sensible.

Development and Validation of a Nomogram for Predicting the 6-Month Survival Rate in Incident Hemodialysis Patients

Background The all-cause mortality in hemodialysis(HD) patients is higher than in the general population and the first 6 months after initiating dialysis is an important transitional period for new HD patients. The aim of this study was to develop and validate a nomogram for predicting the 6-month survival rate among HD patients. Methods We developed a prediction model based on a training cohort of 679 HD patients. Multivariate Cox regression analyses were performed to identify predictive factors, followed by establishment of a nomogram. Next, performance of the nomogram was assessed using the C-index and calibration plots. The nomogram was validated through applying discrimination and calibration to an additional cohort of 173 HD patients. Results During a follow-up period of six months, there were 47 and 12 deaths in the training cohort and validation cohort, respectively, with a mortality rate of 7.3% and 6.9%, respectively. The score included five commonly available predictors: age, temporary dialysis catheter, intradialytic hypotension, use of ACEi or ARB, and use of loop diuretics. The score revealed good discrimination in the training cohort [C-index 0.775(0.693-0.857)] and validation cohort [C-index 0.758(0.677-0.836)], whereas the calibration plots showed good calibration, indicating suitable performance of the nomogram model. The total score point was then divided into two risk classifications: low risk (0-90 points) and high risk (≥ 91 points). Results showed that all-cause mortality was significantly different in HD patients in the high-risk group compared to the low-risk group. Conclusions This nomogram can accurately predict the 6-month survival rate for HD patients, and thus it can be used in clinical decision-making.

Prognostic factors for acute ischemic stroke in patients undergoing hemodialysis

Background Acute ischemic stroke (AIS) is a critical complication in patients undergoing dialysis. Although the improvement of AIS management is an urgent requirement, few studies have evaluated the prognostic factors of AIS in these patients. This study aimed to assess the relationship between clinical factors in patients undergoing dialysis and the prognosis of AIS. Methods Among 1267 patients who were hospitalized for AIS in Sendai City Hospital from January 2015 to June 2020, 81 patients undergoing hemodialysis were retrospectively enrolled. Multivariate analysis was performed to evaluate the effect of baseline characteristics, dialysis factors, and neurological severity of patients at admission [National Institutes of Health Stroke Scale (NIHSS) score] on in-hospital mortality, physical disability, and the need for rehabilitation transfer. Results A higher NIHSS score was a critical risk factor for each outcome and the only significant factor for in-hospital mortality [odds ratio (OR)/point 1.156, 95% confidence interval (CI) 1.054–1.267]. The risk factors of physical disability were NIHSS score (OR/point 1.458, 95% CI 1.064–1.998), older age (OR/year 1.141, 95% CI 1.022–1.274), diabetic nephropathy (OR 7.096, 95% CI 1.066–47.218), and higher premorbid modified Rankin scale (mRS) score (OR/grade 2.144, 95% CI 1.155–3.978); while those of rehabilitation transfer were a higher NIHSS score (OR/point 1.253, 95% CI 1.080–1.455), dialysis vintage (OR/year 1.175, 95% CI 1.024–1.349), and intradialytic hypotension before onset (OR 5.430, 95% CI 1.320–22.338). Conclusions Along with neurological severity, dialysis vintage, intradialytic hypotension, and diabetic nephropathy could worsen the prognosis of patients with AIS undergoing hemodialysis.

Effects of ivabradine on the prevention of intradialytic hypotension in a dialytic patient with heart failure with reduced ejection fraction

A 65-year-old man with a history of heart failure with reduced ejection fraction (HFrEF) and renal failure was admitted due to difficulty in fluid volume control during haemodialysis. He had frequent episodes of intradialytic hypotension (IDH) with presyncope during haemodialysis despite using a vasopressor agent. Before haemodialysis, his blood pressure was 130–150/60–70 mm Hg, and his heart rate was 80–100 beats/min. There were no specific causes of IDH. For refractory IDH, he was treated with oral ivabradine (2.5 mg two times per day), which resulted in reduced heart rate and decreased occurrence of IDH. This is the first report to describe a dialysis case with HFrEF presenting with an elevated heart rate and impaired fluid management as manifested by recurring IDH, which improved after ivabradine treatment. Ivabradine therapy may assist in increasing stroke volume by lowering the sinus heart rate, thus resulting in the prevention of IDH.