Effect of low dialysate sodium in the management of intradialytic hypertension in maintenance hemodialysis patients: A single-center Indian experience

Interdialytic weight gain and low dialysate sodium concentration in patients on chronic hemodialysis: a systematic review and meta-analysis

PURPOSE

The present systematic review and meta-analysis aimed at evaluating the effect of low dialysate sodium concentration on interdialytic weight gain (IDWG) in chronic hemodialysis patients.

METHODS

Studies were eligible for inclusion if they were English language papers published in a peer-reviewed journal and met the following inclusion criteria: (1) studies in adult patients (over 18 years of age), (2) included patients on chronic hemodialysis since at least 6 months; (3) compared standard (138-140 mmol/l) or high (> 140 mmol/l) dialysate sodium concentration with low (< 138 mmol/l) dialysate sodium concentration; (4) Included one outcome of interest: interdialytic weight gain. Medline, PubMed, Web of Science, and the Cochrane Library were searched for the quality of reporting for each study was performed using the Quality Assessment Tool of Controlled Intervention Studies of the National Institutes of Health. The quality of reporting of each cross-over study was performed using the Revised Cochrane Risk of Bias (RoB) tool for cross-over trials as proposed by Ding et al. RESULTS: Nineteen studies (710 patients) were included in the analysis: 15 were cross-over and 4 parallel randomized controlled studies. In cross-over studies, pooled analysis revealed that dialysate sodium concentration reduced IDWG with a pooled MD of - 0.40 kg (95% CI - 0.50 to - 0.30; p < 0.001). The systematic review of four parallel, randomized, studies revealed that the use of a low dialysate sodium concentration was associated with a significant reduction of the IDWG in two studies, sustained and almost significant (p = 0.05) reduction in one study, and not significant reduction in one study.

CONCLUSION

Low dialysate sodium concentration reduces the IDWG in prevalent patients on chronic hemodialysis.

Real-time dual prediction of intradialytic hypotension and hypertension using an explainable deep learning model

Both intradialytic hypotension (IDH) and hypertension (IDHTN) are associated with poor outcomes in hemodialysis patients, but a model predicting dual outcomes in real-time has never been developed. Herein, we developed an explainable deep learning model with a sequence-to-sequence-based attention network to predict both of these events simultaneously. We retrieved 302,774 hemodialysis sessions from the electronic health records of 11,110 patients, and these sessions were split into training (70%), validation (10%), and test (20%) datasets through patient randomization. The outcomes were defined when nadir systolic blood pressure (BP) < 90 mmHg (termed IDH-1), a decrease in systolic BP ≥ 20 mmHg and/or a decrease in mean arterial pressure ≥ 10 mmHg (termed IDH-2), or an increase in systolic BP ≥ 10 mmHg (i.e., IDHTN) occurred within 1 h. We developed a temporal fusion transformer (TFT)-based model and compared its performance in the test dataset, including receiver operating characteristic curve (AUROC) and area under the precision-recall curves (AUPRC), with those of other machine learning models, such as recurrent neural network, light gradient boosting machine, random forest, and logistic regression. Among all models, the TFT-based model achieved the highest AUROCs of 0.953 (0.952-0.954), 0.892 (0.891-0.893), and 0.889 (0.888-0.890) in predicting IDH-1, IDH-2, and IDHTN, respectively. The AUPRCs in the TFT-based model for these outcomes were higher than the other models. The factors that contributed the most to the prediction were age and previous session, which were time-invariant variables, as well as systolic BP and elapsed time, which were time-varying variables. The present TFT-based model predicts both IDH and IDHTN in real time and offers explainable variable importance.

Epidemiology, Pathophysiology, and Clinical Perspectives of Intradialytic Hypertension

BACKGROUND

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

SUMMARY

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

KEY MESSAGES

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

Management of intradialytic hypertension: current evidence and future perspectives

Intradialytic hypertension (IDH), that is, a paradoxical rise in blood pressure (BP) during or immediately after a hemodialysis session, affects approximately 10-15% of the hemodialysis population. It is currently recognized as a phenomenon of major clinical significance as recent studies have shown that BP elevation extends to the whole interdialytic interval and associates with increased cardiovascular and all-cause mortality. The pathophysiology of IDH is complex involving volume and sodium overload, endothelial dysfunction, excess renin-angiotensin-aldosterone system and sympathetic nervous system activation, and other mechanisms. For several years, there was a scarcity of studies regarding IDH treatment; recently, however, several attempts to examine the effect of nonpharmacological and pharmacological measures on BP levels in IDH are made. This review attempts to summarize this latest evidence in the field of management of IDH and discuss areas for future research.

Intradialytic hypertension: epidemiology and pathophysiology of a silent killer

The term intradialytic hypertension (IDH) describes a paradoxical rise in blood pressure (BP) during or immediately after the hemodialysis session. Although it was formerly considered a phenomenon without clinical implications, current evidence suggests that IDH may affect up to 15% of hemodialysis patients and exhibit independent associations with future cardiovascular events and all-cause mortality. Furthermore, during the last decade, several studies have tried to elucidate the complex pathophysiological mechanisms responsible for this phenomenon. Volume overload, intradialytic sodium gain, overactivity of the sympathetic-nervous-system and renin-angiotensin-aldosterone system, endothelial dysfunction and dialysis-related electrolyte disturbances have been proposed to be involved in the pathogenesis of the BP increase during hemodialysis. This review attempts to summarize existing evidence on the epidemiology, pathophysiology and clinical characteristics of the distinct phenomenon of IDH.