Association of intradialytic blood pressure changes with hospitalization and mortality rates in prevalent ESRD patients

The prevalence and risk of mortality associated with intradialytic hypertension among patients with end-stage kidney disease on haemodialysis: A systematic review and meta-analysis

INTRODUCTION

Intradialytic hypertension (IDHTN) is a common but less frequently recognised complication of haemodialysis. However, it is associated with increased overall mortality in patients on haemodialysis. This systematic review and meta-analysis aimed to determine the prevalence of IDHTN and associated mortality risk in the global haemodialysis population.

METHOD

A systematic search of PubMed and EMBASE was undertaken to identify articles with relevant data published between 1990 and 2023. The pooled prevalence of IDHTN in the global haemodialysis population was determined using the DerSimonian-Laird random-effects meta-analysis. The pooled hazards ratio for mortality in patients with IDHTN was also computed from the studies that reported mortality among haemodialysis patients with IDHTN. The study protocol was registered with PROSPERO (CRD42023388278).

RESULTS

Thirty-two articles from 17 countries were included, with a pooled population of 127,080 hemodialysis patients (median age 55.1 years, 38.2% females). Most studies had medium methodological quality (53.1%, n = 17). The overall pooled prevalence of IDHTN was 26.6% [(95% CI 20.2-33.4%), n = 27 studies, I2 = 99.3%, p<0.001 for heterogeneity], with significant differences depending on the definition used. The pooled proportion of haemodialysis sessions with IDHTN was 19.9% [(95% 12.5-28.6%, n = 8 studies, I2 = 99.3%, p<0.001 for heterogeneity)] with significant differences across the different definition criteria. The p-value for the Begg test was 0.85. The median pre-dialysis blood pressure was not significantly associated with IDHTN. The pooled hazard ratio for mortality was 1.37 (95% CI 1.09-1.65), n = 5 studies, I2 = 13.7%, and p-value for heterogeneity = 0.33.

CONCLUSION

The prevalence of IDHTN is high and varies widely according to the definition used. A consensus definition of IDHTN is needed to promote uniformity in research and management. The increased mortality risk forecasted by IDHTN highlights the need for optimal blood pressure control in patients on hemodialysis.

Association of Bioimpedance Parameters with Increases in Blood Pressure during Hemodialysis

BACKGROUND

Intradialytic hypertension, defined as an increase in BP from pre- to post-hemodialysis (HD), affects 5%-15% of patients receiving maintenance HD and is associated with cardiovascular and all-cause mortality. Hypervolemia is believed to be a major etiological factor, yet the association of more objective biomarkers of volume status with intradialytic hypertension is not well described.

METHODS

In a post hoc analysis of the Frequent Hemodialysis Network Daily Trial ( n =234), using data from baseline, 1-, 4-, and 12-month visits ( n =800), we used random-effects regression to assess the association of bioimpedance estimates of volume (vector length) with post-HD systolic BP (continuous) and any increase in systolic BP (categorical) from pre- to post-HD. We adjusted models for randomized group; age; sex; self-reported race; Quételet (body mass) index; vascular access; HD vintage; hypertension; history of heart failure; diabetes; residual kidney function (urea clearance); pre-HD systolic BP; ultrafiltration rate; serum-dialysate sodium gradient; and baseline values of hemoglobin, phosphate, and equilibrated Kt/V urea.

RESULTS

The mean age of participants was 50±14 years, 39% were female, and 43% were Black. In adjusted models, shorter vector length (per 50 Ω/m) was associated with higher post-HD systolic BP (2.9 mm Hg; 95% confidence interval [CI], 1.6 to 4.3) and higher odds of intradialytic hypertension (odds ratio 1.66; 95% CI, 1.07 to 2.55). Similar patterns of association were noted with a more stringent definition of intradialytic hypertension (>10 mm Hg increase from pre- to post-HD systolic BP), where shorter vector length (per 50 Ω/m) was associated with a higher odds of intradialytic hypertension (odds ratio 2.17; 95% CI, 0.88 to 5.36).

CONCLUSIONS

Shorter vector length, a bioimpedance-derived proxy of hypervolemia, was independently associated with higher post-HD systolic BP and risk of intradialytic hypertension.

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.

α-Blocker Use in Hemodialysis: The Japan Dialysis Outcomes and Practice Patterns Study

Rationale & Objective

Despite α-blockers' use for hypertension as add-on therapy in patients treated with hemodialysis, scant information is available on their association, particularly with safety, in these patients.

Study Design

Prospective cohort study.

Setting & Participants

patients treated with hemodialysis and receiving antihypertensive agents in the Japan Dialysis Outcomes and Practice Patterns Study, phases 4-6, were analyzed.

Exposure

Primary exposure was the prescription of α-blocking antihypertensive agents at baseline.

Outcomes

Incident fractures, falls, and all-cause mortality.

Analytical Approach

Multivariable Cox and modified Poisson regression analysis.

Results

Of 5,149 patients treated with hemodialysis (mean age, 65 years; 68% men) receiving antihypertensive drugs, 717 (14%) received α-blocking agents. During a mean follow-up period of 2.0 years, 247 fractures, 525 falls, and 498 deaths occurred. Multivariable analysis showed no significant association of α-blocker use and increased risk of fractures (hazard ratio [HR], 0.92 [95% confidence interval {CI}, 0.61-1.38]), falls (HR, 0.94 [95% CI, 0.74-1.20]), or all-cause deaths (HR, 0.87 [95% CI, 0.64-1.20]) compared with α-blocker nonuse. α-Blocker use was, however, significantly associated with a decreased risk of all-cause mortality in the subgroup analysis, for example, patients who were older (HR, 0.71 [95% CI, 0.51-0.99]), were women (HR, 0.68 [95% CI, 0.48-0.95]), or reported a history of cardiovascular disease (HR, 0.67 [95% CI, 0.48-0.95]) or a predialysis blood pressure of ≥140 mm Hg (HR, 0.69 [95% CI, 0.49-0.98]).

Limitations

Selection bias cannot be ruled out given the prevalent user analysis.

Conclusions

No significant association between α-blocker use and the risk of worse safety-related outcomes was seen, indicating that clinicians may safely prescribe α-blockers to patients receiving hemodialysis who require blood pressure lowering.

Plain-Language Summary

α-Blockers have been generally reserved for use as add-on therapy for resistant or refractory hypertension. However, little is known about the safety of α-blockers in patients treated by hemodialysis. We analyzed 5,149 patients receiving hemodialysis in Japan who were receiving antihypertensive drugs from the Japan Dialysis Outcomes and Practice Patterns Study. The results showed no significant increase in the risk of fractures, falls, or deaths for patients using α-blockers compared with those who did not, suggesting that α-blockers may be safely prescribed for patients receiving hemodialysis who need to lower their blood pressure.

Long-term peridialytic blood pressure changes are related to mortality

BACKGROUND

In chronic haemodialysis (HD) patients, the relationship between long-term peridialytic blood pressure (BP) changes and mortality has not been investigated.

METHODS

To evaluate whether long-term changes in peridialytic BP are related to mortality and whether treatment with HD or haemodiafiltration (HDF) differs in this respect, the combined individual participant data of three randomized controlled trials comparing HD with HDF were used. Time-varying Cox regression and joint models were applied.

RESULTS

During a median follow-up of 2.94 years, 609 of 2011 patients died. As for pre-dialytic systolic BP (pre-SBP), a severe decline (≥21 mmHg) in the preceding 6 months was independently related to increased mortality [hazard ratio (HR) 1.61, P = .01] when compared with a moderate increase. Likewise, a severe decline in post-dialytic diastolic BP (DBP) was associated with increased mortality (adjusted HR 1.96, P < .0005). In contrast, joint models showed that every 5-mmHg increase in pre-SBP and post-DBP during total follow-up was related to reduced mortality (adjusted HR 0.97, P = .01 and 0.94, P = .03, respectively). No interaction was observed between BP changes and treatment modality.

CONCLUSION

Severe declines in pre-SBP and post-DBP in the preceding 6 months were independently related to mortality. Therefore peridialytic BP values should be interpreted in the context of their changes and not solely as an absolute value.

Randomized Trial on the Effects of Dialysate Potassium Concentration on Intradialytic Hypertension

Introduction

Intradialytic hypertension is not an uncommon condition during chronic hemodialysis. It is associated with unfavorable cardiovascular outcomes, including hospitalization and mortality. Several small studies have demonstrated the contradictory effects of different dialysate potassium concentrations on intradialytic blood pressure. This study is a randomized crossover trial aiming to evaluate the effects of different dialysate potassium concentrations on intradialytic hypertension.

Methods

A 24-week, 2-treatment, 4-sequence, multicenter, double-blinded, randomized, crossover study was conducted at Maharaj Nakorn Chiang Mai Hospital and Lampang Hospital in Thailand among stable patients receiving chronic hemodialysis who experienced intradialytic hypertension >30% of their sessions over the past 3 months. Each participant was randomly assigned to 1 of 4 treatment sequences. During each intervention period, patients were dialyzed with dialysate potassium of either 2 mmol/l (D-K2) or 3 mmol/l (D-K3) for 4 weeks according to their preassigned sequence, separated by a 2-week washout period. The primary outcome was the incidence of intradialytic hypertension.

Results

Forty eligible patients were recruited. The mean age was 61.4 ± 14.2 years and the mean systolic blood pressure (SBP) was 146.6 ± 11.2 mm Hg. Of the 40 patients, 95.5% had hypertension and their average number of antihypertensive drugs was 2.8 ± 1.9. A total of 1380 dialysis sessions were included in the analysis (695 sessions for D-K2 and 685 sessions for D-K3). The incidence of intradialytic hypertension was not significantly different between different dialysate potassium concentrations (D-K2 54.7% vs. D-K3 53.1%, P = 0.788). The changes in SBP, diastolic blood pressure (DBP), and mean arterial pressure (MAP) were not different between the 2 dialysate potassium groups.

Conclusion

Dialysate potassium concentration of 2 or 3 mmol/l did not affect the incidence of intradialytic hypertension in patients receiving chronic hemodialysis who frequently developed intradialytic hypertension.

Association of Intradialytic Hypertension with Future Cardiovascular Events and Mortality in Hemodialysis Patients: Effects of Ambulatory Blood Pressure

INTRODUCTION

Intradialytic hypertension (IDHTN) is associated with increased risk of adverse outcomes. Patients with IDHTN have higher 44-h blood pressure (BP) than patients without this condition. Whether the excess risk in these patients is due to the BP rise during dialysis per se or on elevated 44-h BP or other comorbid conditions is uncertain. This study evaluated the association of IDHTN with cardiovascular events and mortality and the influence of ambulatory BP and other cardiovascular risk factors on these associations.

METHODS

242 hemodialysis patients with valid 48-h ABPM (Mobil-O-Graph-NG) were followed for a median of 45.7 months. IDHTN was defined as: systolic BP (SBP) rise ≥10 mm Hg from pre- to post-dialysis and post-dialysis SBP ≥150 mm Hg. The primary endpoint was all-cause mortality; the secondary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, resuscitation after cardiac arrest, heart failure hospitalization, coronary or peripheral revascularization.

RESULTS

Cumulative freedom from both the primary and secondary endpoint was significantly lower for IDHTN patients (logrank-p = 0.048 and 0.022, respectively), corresponding to higher risks for all-cause mortality (hazard ratio (HR) = 1.566; 95% confidence interval (CI) [1.001, 2.450]) and the composite cardiovascular outcome (HR = 1.675; 95% CI [1.071, 2.620]) in these individuals. However, the observed associations lost statistical significance after adjustment for 44-h SBP (HR = 1.529; 95% CI [0.952, 2.457] and HR = 1.388; 95% CI [0.866, 2.225], respectively). In the final model after additional adjustment for 44-h SBP, interdialytic weight gain, age, history of coronary artery disease, heart failure, diabetes, and 44-h pulse wave velocity, the association of IDHTN with the outcomes was also not significant and the respective HRs were 1.377 (95% CI [0.836, 2.268]) and 1.451 (95% CI [0.891, 2.364]).

CONCLUSIONS

IDHTN patients had higher risk for mortality and cardiovascular outcomes but this risk is at least partly confounded by the elevated BP levels during the interdialytic period.

Home Pulse Pressure Predicts Death and Cardiovascular Events in Peritoneal Dialysis Patients

Increased arterial hypertension represents a prevalent condition in peritoneal dialysis patients that is often related to volume expansion. Pulse pressure is a robust predictor of mortality in dialysis patients, but its association with mortality is unknown in peritoneal patients. We investigated the relationship between home pulse pressure and survival in 140 PD patients. During a mean follow-up of 35 months, 62 patients died, and 66 experienced the combined event death/CV events. In a crude COX regression analysis, a five-unit increase in HPP was associated with a 17% increase in the hazard ratio of mortality (HR: 1.17, 95% CI 1.08-1.26 p < 0.001). This result was confirmed in a multiple Cox model adjusted for age, gender, diabetes, systolic arterial pressure, and dialysis adequacy (HR: 1.31, 95% CI 1.12-1.52, p = 0.001). Similar results were obtained considering the combined event death-CV events as an outcome. Home pulse pressure represents, in part, arterial stiffness, and it is strongly related to all-cause mortality in peritoneal patients. In these high cardiovascular risk populations, it is important to maintain optimal blood pressure control, but it is fundamental to consider all the other cardiovascular risk indicators, such as pulse pressure. Home pulse pressure measurement is easy and feasible and can add important information for the identification and management of high-risk patients.

Associations of Iron Sucrose and Intradialytic Blood Pressure

RATIONALE & OBJECTIVE

Intradialytic hypotension and intradialytic hypertension are associated with morbidity and mortality in hemodialysis (HD). Many factors can contribute to intra-HD blood pressure (BP) changes, such as drugs with vasoactive properties that can destabilize an already tenuous BP. Intravenous iron sucrose is commonly administered to correct iron deficiency; however, its reported associations with altered hemodynamics have not been consistent.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

950 outpatients receiving maintenance HD.

EXPOSURE

Iron sucrose administered during HD.

OUTCOME

Intradialytic hypotension, intradialytic hypertension, systolic blood pressure parameters.

ANALYTICAL APPROACH

Unadjusted and adjusted Poisson and linear repeated measures regression models.

RESULTS

The mean age of patients included in the study was 53±22 years, 43% were female, and 38% were Black. Mean pre-HD SBP was 152±26 (SD) mm Hg. At baseline, the patients who received higher doses of iron sucrose tended to have diabetes, have longer HD sessions, and have a higher frequency of erythropoiesis-stimulating agent use, compared with those who did not receive iron sucrose. In adjusted models, higher doses of iron sucrose were associated with an 11% lower rate of intradialytic hypotension (incidence rate ratio [IRR] for iron sucrose≥100mg vs 0 mg, 0.89 [95% CI, 0.85-0.94]). In adjusted analyses, the administration of higher doses of iron sucrose during HD was associated with intradialytic hypertension (IRR for iron sucrose≥100mg vs 0 mg, 1.07 [95% CI, 1.04-1.10]).

LIMITATIONS

Nonavailability of the precise iron sucrose formulation (volume), laboratory data for each HD session, and outpatient medications. Objective measures of volume status, home medications, and symptom data were not recorded in this study.

CONCLUSIONS

We observed an independent association of intravenous iron sucrose administration during HD with a lower risk of intradialytic hypotension and higher risk of intradialytic hypertension. Future studies to better understand the mechanisms underlying these associations are warranted.

PLAIN-LANGUAGE SUMMARY

Intradialytic hypotension and intradialytic hypertension are common among patients on hemodialysis, and they are associated with morbidity and mortality. Although many factors may contribute to these risks, medications administered during hemodialysis play an important role. We studied the significance of the intravenous iron sucrose used to treat iron deficiency and the impact it may have on blood pressure during dialysis. In our study of 950 outpatient hemodialysis patients, we observed that administration of iron sucrose was associated with higher systolic blood pressure (during and after hemodialysis sessions) as well as a lower risk of intradialytic hypotension. We also observed that higher doses of iron sucrose are associated with the development of intradialytic hypertension.

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.

Nitric Oxide Levels as a Marker of Intradialytic Hypertension in End-Stage Renal Disease Patients

Intradialytic hypertension (IDH) is an important emerging complication in hemodialysis patients. No study has examined the diagnostic markers of various risk factors for the occurrence of IDH in chronic hemodialysis patients. Therefore, our study aimed to assess the use of nitric oxide (NO) as a marker of IDH among end-stage renal disease patients. The patients were divided into two groups: Group I (40 patients) with IDH and Group II (40 patients) without IDH. For all participants, a full medical history was taken, followed by laboratory examinations to measure the level of NO and a clinical examination. The dose of erythropoietin per week, the level of intact parathyroid hormone, and platelet count were significantly higher in Group I than in Group II, whereas the mean level of NO (2.10 ± 1.23 pmol/L) was highly significantly lower in patients with IDH (P < 0.001). Multivariate analysis showed that hypertension (odds ratio: 1.824, 95% confidence interval: 1.273-2.982) and the level of NO (odds ratio: 1.68, 95% confidence interval: 1.13-2.97) were independent risk factors for IDH. The receiver operating characteristic curve showed that the cutoff point of NO was 2.52 μmol/L to differentiate between cases with and without IDH (area under the curve = 0.844). Our findings support previous research regarding the involvement of endothelial dysfunction and a higher sodium level in the pathogenesis of IDH. We also found that the NO level had a good diagnostic value for the occurrence of IDH at a cutoff of 2.52 μmol/L.

Frequency of Intradialytic Hypertension Using Kidney Disease: Improving Global Outcomes (KDIGO) Suggested Definition in a Single Hemodialysis Centre in Pakistan

OBJECTIVES

 To estimate the frequency of intradialytic hypertension (IDH) in our centre as per the definition suggested by Kidney Disease: Improving Global Outcomes (KDIGO).

METHODS

 A cross-sectional study was conducted at the dialysis department of The Kidney Centre Post Graduate Training Institute (PGTI) Karachi, Pakistan from August 2021 to October 2021 among 263 end-stage kidney disease (ESKD) patients on maintenance hemodialysis (MHD) aged ≥ 18 years of both genders. The study outcome was the frequency of IDH as per the latest KDIGO suggested definition i.e., systolic blood pressure (SBP) rise of > 10 mm Hg from pre- to post-dialysis within the hypertensive range in at least four out of six consecutive dialysis treatments. Frequencies (%) and mean (±SD) were calculated for categorical and continuous variables respectively, using SPSS version 21 (IBM Corp., Armonk, NY, USA).

RESULTS

 Among 263 patients, the mean age was 51.02 (±14.1) years and 56.3% were males. Around 30.8% of patients were dialysis-dependent for 1.1 to three years. The most common comorbidity was hypertension (88.6%). Standard dialysate calcium of 3mEq/l was received by 91.6% of study participants. About 78.7% of patients were using antihypertensive(s), out of which 85.5% were compliant and 37.6% were using a single antihypertensive. The most common antihypertensive in use was beta-blockers (78.3%). Around 16% of patients were found to have IDH. Age of the patients was significantly associated with IDH (p=0.038). The majority of the patients with IDH were those who were taking anti-hypertension medications as compared to the patients who were not taking them (p <0.004). Interdialytic weight gain was not a significant predictor for IDH.

CONCLUSION

 The frequency of IDH was 16% according to the latest suggested KDIGO definition. This is much lower than regional and global estimates according to earlier definitions. There is a dire need to establish a standardized definition of IDH in guidelines to diagnose, manage and compare data. Also, the association of IDH with fluid overload is not found in our study which emphasizes the need to evaluate other causative factors.

Ambulatory central BP and arterial stiffness in patients with and without intradialytic hypertension

BACKGROUND

Increased arterial stiffness is suggested to be involved in the pathogenesis of intradialytic-hypertension (IDH). Ambulatory pulse-wave-velocity (PWV) is an independent predictor for all-cause-mortality in haemodialysis and its prognostic power is better than office PWV. This is the first study examining ambulatory central blood pressure (BP) and arterial stiffness parameters in patients with and without IDH.

METHODS

This study examined 45 patients with IDH (SBP rise ≥10 mmHg from pre- to post-dialysis and post-dialysis SBP ≥150 mmHg) in comparison with 197 patients without IDH. All participants underwent 48-h ABPM with Mobil-O-Graph-NG; parameters of central haemodynamics, wave reflection and PWV were estimated.

RESULTS

Age, dialysis vintage and interdialytic weight gain did not differ between-groups. IDH patients had higher 48-h cSBP (131.7 ± 16.2 vs. 119.2 ± 15.2 mmHg, p < 0.001), 48-h cDBP (86.7 ± 12.7 vs. 79.6 ± 11.5 mmHg, p < 0.001) and 48-h cPP (45.5 ± 10.4 vs. 39.8 ± 10.0 mmHg, p = 0.001) compared to patients without IDH. Similarly, during day- and nighttime periods, cSBP/cDBP and cPP levels were higher in IDH-patients compared to non-IDH. Forty-eight-hour augmentation pressure and index, but not AIx(75) were higher in IDH patients; 48-h PWV (10.0 ± 2.0 vs. 9.2 ± 2.1 m/s, p = 0.017) was significantly higher in patients with IDH. The two study groups displayed different trajectories in central BP and PWV over the course of the recording; IDH patients had steadily high values of the above variables during the 2 days of the interdialytic-interval, whereas non-IDH patients showed a gradual elevation, with significant increases from the 1st to 2nd 24 h.

CONCLUSIONS

IDH patients have significantly higher levels of ambulatory central BP and arterial stiffness parameters and a different course over the 48-h period compared with non-IDH patients. Increased arterial stiffness could be a prominent factor associated with the high burden of cardiovascular disease in this population.

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.

Using the Intelligent System to Improve the Delivered Adequacy of Dialysis by Preventing Intradialytic Complications

Acute kidney failure patients while detoxificated by hemodialysis (HD) mostly or continuously faced regular problems such as low blood pressure (hypotension), muscle cramps, nausea, or vomiting. Higher intradialytic symptom leads to low-quality HD treatment. Although more known therapeutic interventions are used to relieve the HD side effects, this study was designed to investigate how intelligent systems can make highly beneficial alterations in dialysis facilities and equipment to ease intradialytic complications and help the staff deliver high-quality treatment. A search was performed among relevant research articles based on nonpharmacological intervention methods considered to prevent adverse effects of renal replacement therapy until 2020 in the PubMed databases using the terms “intradialytic complications,” “intradialytic complication interventions,” “nonpharmacological interventions,” “intradialytic exercises,” and “adequacy calculation methods.” Studies included the prevalence of intradialytic complications, different strategies with the aim of preventing complications, the outcome of intradialytic exercises on dialysis symptoms, and dialysis dose calculation methods. The results showed the incidence of hypotension varying between 5% and 30%, fatigue, muscular cramps, and vomiting as the most common complications during dialysis, which greatly affect the outcome of HD sessions. To prevent hypotension, ultrafiltration profiling, sodium modeling, low dialysate temperature, and changing the position to Trendelenburg are some strategies. Urea reduction ratio (URR), formal urea kinetic modeling (FUKM), formal single-pool urea kinetics, and online clearance monitoring (OCM) are methods for calculating the delivered dose of dialysis in which OCM is a low-cost and accessible way to monitor regularly the quality of dialysis delivered. Integration of the chair and HD machine which is in direct contact with the patient provides an intelligent system that improves the management of the dialysis session to enhance the quality of healthcare service.

Seasonal Variation: A Non-negligible Factor Associated With Blood Pressure in Patients Undergoing Hemodialysis

Objective

To investigate a seasonal variation in blood pressure (BP) for patients undergoing hemodialysis (HD).

Methods

In this retrospective study, we exported all BP measurements from the information system to investigate a seasonal variation of BP. We also investigated a seasonal variation in BP for patients of different gender types, of different age groups, with diabetic nephropathy (DN), and with non-DN having HD. Multiple linear regression models were used to explore the associations between BP and climatic parameters.

Results

In 2019, a total of 367 patients had received HD therapy in the Longwen HD unit. We included nearly 40,000 pre-dialysis BP measurements. The result of our study demonstrated a clear seasonal variation in pre-dialysis BP in general patients with HD, in male and female patients, and patients with DN and non-DN. December seemed to be a peak in the values of pre-dialysis systolic BP (SBP) and diastolic BP (DBP). The nadir values of pre-dialysis SBP and DBP were observed in June and July, respectively. A difference between peak and nadir values of BP is 3.81/2.20 mmHg in patients undergoing HD. Maximal seasonal variation in BP is 9.03/5.08 mmHg for patients with DN. A significant association of SBP and DBP with climatic parameters was found in this study. Pre-dialysis BP was inversely correlated with outdoor temperature, daytime length, and relative humidity.

Conclusion

A clear seasonal variation in BP is observed for patients with HD. Pre-dialysis SBP and DBP are inversely associated with outdoor temperature, daytime length, and relative humidity. The magnitude of a seasonal variation in BP increases in patients with DN.

Association of Different Definitions of Intradialytic Hypertension With Long-Term Mortality in Hemodialysis

BACKGROUND

Hypertension is common in hemodialysis patients. A subset of patients experience systolic blood pressure increases from prehemodialysis to posthemodialysis (intradialytic hypertension), which are associated with adverse outcomes. However, little consensus exists on an evidence-based definition.

METHODS

In 3198 hemodialysis patients, Cox models were fit to examine the association of various definitions of intradialytic hypertension (≥30% of baseline sessions with an increase in prehemodialysis to posthemodialysis systolic blood pressure of (1) ≥0 mm Hg [Hyper0]; (2) ≥10 mm Hg [Hyper10], or (3) ≥20 mm Hg increase [Hyper20]) with all-cause mortality. Effect modification was assessed using interaction terms according to prespecified variables.

RESULTS

At baseline, mean age was 62±15 years, 57% were male, and 14% were Black. During the baseline period, 47% of individuals met the Hyper0 definition and experienced 32% (hazard ratio, 1.32 [95% CI, 1.05-1.66]) higher adjusted risk of death, compared with no systolic blood pressure increase. Hyper10 was present in 21.2% and associated with 18% higher adjusted risk of death (hazard ratio, 1.18 [95% CI, 0.94-1.48]). Hyper20 was present in 6.8% and associated with 3% higher adjusted risk of death (hazard ratio 1.03 [95% CI, 0.74-1.44]). Effect modification by age and peripheral vascular disease was observed (P interaction=0.04 for age and 0.02 for peripheral vascular disease), with higher associated risk of death for those aged 45 to 70 years and those without peripheral vascular disease.

CONCLUSIONS

Individuals with any systolic blood pressure increase from prehemodialysis to posthemodialysis had the highest adjusted risk of mortality, compared with other threshold-based definitions.

Comparison of intradialytic blood pressure metrics as predictors of all-cause mortality

Background

Intradialytic hypotension (IDH) has been reported to be an important prognostic factor in hemodialysis patients. However, a standard definition of IDH has not yet been determined.

Methods

We retrospectively analyzed blood pressure (BP) metrics obtained during serial dialysis sessions over a 90-day period from a single dialysis center from 2016 to 2017. The mean values and the frequency of specific values of BP were analyzed as predictors of 3-year mortality.

Results

A total of 430 patients who underwent maintenance dialysis were included. The mean age was 63.3 ± 12.4 years and 58.6% were male. A low minimum systolic blood pressure (SBP) <110 mmHg during dialysis was significantly associated with increased all-cause mortality. The frequency of a minimum SBP <100 mmHg was the most significant predictor of 3-year mortality, with an area under the curve (AUC) of 0.722. Furthermore, the frequency of a minimum SBP <100 mmHg significantly increased the predictability of mortality when combined with the presence of other clinical factors including age, body mass index and vascular access type (AUC 0.786 vs. 0.835; p = 0.005).

Conclusion

Among the various intradialytic BP metrics, the frequency of a minimum SBP <100 mmHg is the most significant factor related to all-cause mortality. The guidelines for the management of blood pressure in dialysis patients should consider including a minimum SBP <100 mmHg as a definition for IDH.

High ultrafiltration rate induced intradialytic hypotension is a predictor for cardiac remodeling: a 5-year cohort study

BACKGROUND

Intradialytic-hypotension (IDH) is a common complication of hemodialysis. High ultrafiltration rate (UFR) might lead to IDH. However, the relationships between UFR, IDH, and cardiac remodeling among hemodialysis patients in the long-term have not been deeply explored.

METHODS

This retrospective cohort study collected clinical and echocardiographic data. Patients were enrolled from 1 January 2014 to 31 March 2014 and were followed-up for 5-year. Those who suffered from more than four hypotensive events during three months (10% of dialysis treatments) were defined as the IDH group. Subgroup analysis was done according to the UFR of 10 ml/h/kg. Associations between UFR, IDH, and alterations of cardiac structure/function were analyzed.

RESULTS

Among 209 patients, 96 were identified with IDH (45.9%). The survival rate of IDH patients was lower than that of no-IDH patients (65.5% vs. 81.4%, p = .005). In IDH group, decreased ejection fraction (EF), larger left atrium diameter index (LADI), and left ventricular mass index (LVMI) (p < .05) were observed at the end of the follow-up. In multivariate logistic model, the interaction between UFR and IDH was notably associated with LVMI variation (OR = 1.37). After adjusting covariates, UFR was still an independent risk factor of LVMI variation (OR = 1.52) in IDH group. In subsequent analysis, we divided patients according to UFR 10 ml/h/kg. For IDH-prone patients, decreased EF, larger LADI, and LVMI (p < .05) were observed at the end of the study only in high-UFR group.

CONCLUSIONS

UFR and IDH have interactions on cardiac remodeling. High ultrafiltration rate induced IDH is a predictor for cardiac remodeling in long-term follow-up.

Weekly pattern of dialysis unit blood pressure is a promising marker for prognosis evaluation in hemodialysis population

BACKGROUND

Dialysis unit blood pressure (BP) pattern showed superiority in prognostic evaluation and interdialytic BP burden assessment. However previous studies mainly focused on the recurrent BP pattern within a session (intradialytic BP change or intradialytic BP slope), the clinical value of the weekly pattern of dialysis unit BP is unknown.

METHODS

We performed a prospective cohort study in adult end stage renal disease (ESRD) patients on thrice weekly hemodialysis (HD). The slope and the change of the postdialysis systolic BP (SBP) in the course of a week (post-SBP slope and post-SBP change) were used to characterize the weekly pattern of dialysis unit BP. Outcomes included all-cause mortality, cardiovascular mortality, and first cardiovascular event. We also measured the home BP in our cohort.

RESULTS

One hundred and twenty-nine subjects were followed over a median of 31 months. Higher post-SBP slope (≥0.185) was independently associated with increased risk of all-cause mortality, cardiovascular mortality, and first cardiovascular event. Results were similar for increased post-SBP change. HD patients with a higher post-SBP slope or an increased post-SBP change also had significant increased interdialytic BP burden measured by home SBP on both dialysis days and non-dialysis days.

CONCLUSIONS

Post-SBP slope and post-SBP change might be promising dialysis unit BP markers for prognostic evaluation and interdialytic BP burden assessment.

Machine Learning Analysis of Time-Dependent Features for Predicting Adverse Events During Hemodialysis Therapy: Model Development and Validation Study

BACKGROUND

Hemodialysis (HD) therapy is an indispensable tool used in critical care management. Patients undergoing HD are at risk for intradialytic adverse events, ranging from muscle cramps to cardiac arrest. So far, there is no effective HD device-integrated algorithm to assist medical staff in response to these adverse events a step earlier during HD.

OBJECTIVE

We aimed to develop machine learning algorithms to predict intradialytic adverse events in an unbiased manner.

METHODS

Three-month dialysis and physiological time-series data were collected from all patients who underwent maintenance HD therapy at a tertiary care referral center. Dialysis data were collected automatically by HD devices, and physiological data were recorded by medical staff. Intradialytic adverse events were documented by medical staff according to patient complaints. Features extracted from the time series data sets by linear and differential analyses were used for machine learning to predict adverse events during HD.

RESULTS

Time series dialysis data were collected during the 4-hour HD session in 108 patients who underwent maintenance HD therapy. There were a total of 4221 HD sessions, 406 of which involved at least one intradialytic adverse event. Models were built by classification algorithms and evaluated by four-fold cross-validation. The developed algorithm predicted overall intradialytic adverse events, with an area under the curve (AUC) of 0.83, sensitivity of 0.53, and specificity of 0.96. The algorithm also predicted muscle cramps, with an AUC of 0.85, and blood pressure elevation, with an AUC of 0.93. In addition, the model built based on ultrafiltration-unrelated features predicted all types of adverse events, with an AUC of 0.81, indicating that ultrafiltration-unrelated factors also contribute to the onset of adverse events.

CONCLUSIONS

Our results demonstrated that algorithms combining linear and differential analyses with two-class classification machine learning can predict intradialytic adverse events in quasi-real time with high AUCs. Such a methodology implemented with local cloud computation and real-time optimization by personalized HD data could warn clinicians to take timely actions in advance.

Lower Levels of Blood Zinc Associated with Intradialytic Hypertension in Maintenance Hemodialysis Patients

Intradialytic hypertension (iHTN) has been related with an increased risk of mortality, with imbalances in trace elements being frequent in maintenance hemodialysis (MHD) patients. The aim of this study was to analyze the relationships between the levels of blood trace elements and iHTN in MHD patients. A total of 144 MHD patients were enrolled in September, 2019 (66 females; 5616 hemodialysis treatments), with a mean age of 64.33 ± 13.39 years and median vintage of 33.50 (16.25-57.50) months. Patients exhibited an average peridialytic systolic blood pressure (SBP) change of - 4.18 ± 20.22 mm Hg in the next 3 months. Thirty-four (23.6%) patients had persistent iHTN (piHTN). These patients were characterized by older age, higher rate of hypozincemia, and modified Charlson comorbidity score, whereas lower blood zinc and hemoglobin, at the time of their recruitment. No significant difference in the levels of other blood trace elements was observed between groups. A general linear mixed (GLM) model showed that with every mg/L point lower mean blood zinc at baseline, the peridialytic SBP change was increased by 4.524 mm Hg (P < 0.001). Binary logistic model in modulate of the GLM model revealed that the lower level of blood zinc was associated with piHTN (OR = 0.433, 95 % CI 0.295 to 0.637, P < 0.001). Multivariate analysis confirmed both above results. Our study indicated that lower blood zinc was independently associated with piHTN in patients undergoing MHD, but prospective studies with larger population are still needed.

Endothelin-1 and Parameters of Systolic Blood Pressure in Hemodialysis

BACKGROUND

Hypertension is common in hemodialysis (HD) patients. Increased blood pressure (BP) variability, particularly higher and lower extremes, is associated with adverse outcomes. We explored the association of endothelin-1 (ET-1), a potent vasoconstrictor, with different BP parameters (pre-HD, intra-HD, and post-HD) during HD in a contemporary patient cohort.

METHODS

This study uses the DaVita Biorepository, a longitudinal prospective cohort study with quarterly collection of clinical data and biospecimens. Unadjusted and adjusted linear mixed effects regression models were fit to determine association of pre-HD ET-1 (log-transformed and quartiles) with HD-related systolic BP (SBP) parameters (pre-HD, nadir intra-HD, and post-HD). As ET-1 was measured at baseline, analyses were restricted to 1 year of follow-up.

RESULTS

Among 769 participants, mean age was 52 years, 42% were females, and 41% were Black. Mean pre-HD SBP was 152 (±28) mm Hg and mean ET-1 concentration was 2.3 (±1.2) ng/ml. In fully adjusted models, each unit increase in SD of log-transformed ET-1 was associated with a 2.7 (95% confidence interval [CI] 1.5, 4.0) mm Hg higher pre-SBP; 1.6 (95% CI 0.9, 2.3) mm Hg higher nadir SBP; and 2.0 (95% CI 1.1, 2.9) mm Hg higher post-SBP. Each SD increase in log-transformed ET-1 was associated with 21% higher odds of experiencing intradialytic hypertension (odds ratio 1.21; 95% CI 1.10-1.34).

CONCLUSIONS

Higher baseline ET-1 levels are independently associated with higher SBP and higher odds of intradialytic hypertension. These results highlight a potential role for ET-1 in BP control in HD patients and raise the possibility of ET-1 antagonism as a therapeutic target.

Serum sodium variation is a major determinant of peridialytic blood pressure trends in haemodialysis outpatients

Intradialytic hypotension (IDH) and peridialytic blood pressure (BP) trends are associated with morbidity and mortality in haemodialysis (HD) patients. We aimed to characterise the respective influence of volume status and small solutes variation on peridialytic systolic BP (SBP) trends during HD. We retrospectively analysed the relative peridialytic SBP decrease in 647 prevalent outpatients attending for their mid-week session with corresponding pre- and post-HD bioelectrical impedance analysis. Mean SBP decreased by 10.5 ± 23.6 mmHg. Factors positively associated with the relative decrease in SBP were: serum sodium (Na) decrease, body mass index, serum albumin, dialysis vintage, ultrafiltration rate and urea Kt/V (p < 0.05 for all). Antihypertensive medications and higher dialysate calcium were negatively associated with the relative decrease in SBP (p < 0.05 for both). Age had a quadratic relationship with SBP trends (p < 0.05). Pre-HD volume status measured by extracellular to total body water ratio was not associated with SBP variation (p = 0.216). Peridialytic SBP trends represent a continuum with serum Na variation being a major determinant while volume status has negligible influence. Middle-aged and overweight patients are particularly prone to SBP decline. Tailoring Na and calcium dialysate concentrations could influence haemodynamic stability during HD and improve patient experience and outcomes.

Diastolic blood pressure is associated with brain atrophy in hemodialysis patients: A single center case-control study

Brain atrophy (BA) is often found in neuroimaging of hemodialysis patients, representing parenchymal cerebral damage. Likely contributing factors to BA are age, chronic hypertension, diabetes mellitus and other cardiovascular risk factors of atherosclerosis that are also common among hemodialysis patients. BA may also occur due to focal ischemia and hypoperfusion during hemodialysis. However, data on optimal blood pressure (BP) in these patients are limited. The goal of this study was to determine whether the prevalence and severity of BA would be higher among hemodialysis patients with lower BP. A blinded neuroradiologist graded BA of all hemodialysis patients who underwent brain non-contrast computerized tomography (CT) from 2015 to 2017 in our institution. Age- and sex-matched patients with normal kidney function who underwent brain CT during the same period and technique served as the control group. A total of 280 patients were included in this retrospective study, with average BP of 140/70 mmHg among hemodialysis patients and 142/75 mmHg in the control group. BA was more common in dialysis patients and its severity increased with age and traditional cardiovascular risk factors. We observed a significant negative correlation between diastolic BP (DBP) at dialysis initiation and BA. Average DBP decreased with increasing severity of BA. These findings were observed in both hemodialysis and non-CKD patients. BA was associated with lower DBP, which may induce cerebral hypoperfusion and ischemia. This finding should discourage over-treatment of hypertension among hemodialysis patients.

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

BACKGROUND

High dialysate sodium is a significant contributor to intradialytic hypertension (IDH) in maintenance hemodialysis patients. In this study, we aimed to study the effect of low dialysate sodium on IDH in Indian hemodialysis patients.

MATERIALS AND METHODS

Fifty patients on maintenance hemodialysis for atleast 3 months with episodes of IDH were enrolled in this study. The study was performed in two different stages. In the first phase, patients were dialyzed with standard dialysate sodium (140 mEq/L) for eight consecutive sessions and in the second phase, they were dialyzed with low sodium dialysate (136 mEq/L) for eight consecutive sessions. Differences in pre, intradialytic, and post-HD blood pressure, interdialytic weight gain, mean serum sodium, intradialytic adverse events, and number of IDH episodes requiring intervention between the two phases were assessed.

RESULTS

The mean age of the study population was 52 years (36 males,14 females). The mean post-HD systolic and diastolic BP was 163.26 ± 9.58 mmHg and 88.60 ± 5.27 mmHg in the standard dialysate phase and 142.38 ± 14.09 mmHg and 84.58 ± 4.276 mmHg, respectively, in the low dialysate phase (p < 0.01). Interdialytic weight gain was 3.34 ± 0.9 and 3.11 ± 0.86 in the standard and low sodium dialysate phases, respectively (p = 0.19).The mean pre-HD plasma sodium level was 138.48 ± 3.69 and 135.80 ± 1.35 mEq/dl, respectively, in standard and low dialysate phases (p = 0.01). There was significant reduction in number of IDH episodes requiring intervention. There was no difference in hypotensive episodes, adverse events between the two phases.

CONCLUSION

In patients with intradialytic hypertension, low dialysate sodium significantly reduces the post-HD blood pressure and intradialytic hypertensive episodes, when compared with standard sodium dialysate.

Intradialysis hypotension and hypertension in patients with end stage kidney disease in Nigeria: risk factors and clinical correlates

Background

Many shortcomings associated with haemodialysis for instance, intradialysis blood pressure changes, often lead to inadequate dialysis dose. Measures are needed to improve on this.

Objectives

To determine the risk factors and clinical correlates of intradialysis blood pressure variations.

Methods

Maintenance haemodialysis sessions for 232 consented patients with end stage kidney disease who had 1248 sessions were studied. Data collected was from history, examination findings, serum electrolytes and hematocrit. Blood pressure reading was taken manually at rest. Statistical analysis was with SPSS 22. Chi square and t-test were used to compare proportions and means respectively while regression analysis was used to determine predictors of blood pressure changes.

Results

The mean age of participants was 49.9 ± 4.6. More participants (38.8%) had hypertension associated CKD, than chronic glomerulonephritis, (37.9%). Majority (60.7%) had internal jugular catheter. Intradialysis hypertension was commoner than intradialysis hypotension (24.4% versus 19.4%). Intradialysis hypotension was commoner in females, diabetics and with less frequent dialysis while intradialysis hypertension was commoner in males, frequent erythropoietin use. The mean dialysis dose (Kt/V) was 1.02 ± 0.4, with 0.68 ± 0.1 for intradialysis hypotension and 0.84 ± 0.2 for intradialysis hypertension.

Conclusion

Risk factors for intradialysis hypertension were males, frequent erythropoietin use while for intradialysis hypotension, were female gender and less frequent dialysis. Effective intra and inter-dialytic blood pressure control with adequate pre dialysis work up should be carried out to lessen the degree, burden and outcome of these variations.

Funding

None declared.

Association of all-cause mortality with pre-dialysis systolic blood pressure and its peridialytic change in chronic hemodialysis patients

Background

Pre-dialysis systolic blood pressure (pre-HD SBP) and peridialytic SBP change have been associated with morbidity and mortality among hemodialysis (HD) patients in previous studies, but the nature of their interaction is not well understood.

Methods

We analyzed pre-HD SBP and peridialytic SBP change (calculated as post-HD SBP minus pre-HD SBP) between January 2001 and December 2012 in HD patients treated in US Fresenius Medical Care facilities. The baseline period was defined as Months 4–6 after HD initiation, and all-cause mortality was noted during follow-up. Only patients who survived baseline and had no missing covariates were included. Censoring events were renal transplantation, modality change or study end. We fitted a Cox proportional hazard model with a bivariate spline functions for the primary predictors (pre-HD SBP and peridialytic SBP change) with adjustment for age, gender, race, diabetes, access-type, relative interdialytic weight gain, body mass index, albumin, equilibrated normalized protein catabolic rate and ultrafiltration rate.

Results

A total of 172 199 patients were included. Mean age was 62.1 years, 61.6% were white and 55% were male. During a median follow-up of 25.0 months, 73 529 patients (42.7%) died. We found that a peridialytic SBP rise combined with high pre-HD SBP was associated with higher mortality. In contrast, when concurrent with low pre-HD SBP, a peridialytic SBP rise was associated with better survival.

Conclusion

The association of pre-HD and peridialytic SBP change with mortality is complex. Our findings call for a joint, not isolated, interpretation of pre-HD SBP and peridialytic SBP change.

Frequency of Intradialytic Complications in Patients of End-Stage Renal Disease on Maintenance Hemodialysis

Introduction

Hemodialysis is a vital management option for end-stage renal disease (ESRD) patients. With adequate hemodialysis, patients can have a good quality of life but complications do occur during the session, which can be minor to life-threatening. The objective of this study was to assess the frequency of acute complications during this procedure.

Material and methods

An observational, cross-sectional study was conducted at Jinnah Postgraduate Medical Centre, Karachi, Pakistan. Patient data were collected about access, comorbid conditions, frequency and duration of hemodialysis, and intradialytic complications. Those with acute kidney injury were excluded.

Results

There was a total of 94 patients, with a mean age of 45.51±13.29 years, of which 62 (66%) were males and 32 (34%) were females. Diabetes mellitus was the most common cause of ESRD (47.9%, n=45). Patients on twice and thrice-weekly sessions were 51 (54.3%) and 43 (45.7%), respectively. The most common complication was hypotension (28.7%), followed by hypertension (17%), and nausea/vomiting (11.7%). The arteriovenous fistula was the most common access used (75.5%, n=71). Most patients were found to be on hemodialysis for more than five years (51.1%, n=48).

Conclusion

Blood pressure changes are critical while performing hemodialysis, just like we found hypotension as the most common intradialytic complication in our results, followed by hypertension. Others were fever, muscle cramps, and nausea/vomiting. a prospective follow-up study shall be done to have comparative and long-term results related to the acute and chronic complications of dialysis.

Intradialytic systolic blood pressure variation can predict long-term mortality in patients on maintenance hemodialysis

PURPOSE

It is unclear which time-points of intradialytic blood pressure (BP) best predict prognosis. Thus, it is important to assess the association between different time-points of intradialytic BP and prognosis in clinical practice.

METHODS

We recruited patients who underwent hemodialysis from January 2014 to June 2014. Data about dialysis were collected, including intradialytic BP. Cox regression analysis was performed to examine the association between different time-points of intradialytic BP and clinical events, with a follow-up through December 31, 2019. The primary endpoint was all-cause mortality.

RESULTS

A total of 216 patients were recruited and 62 (30.7%) patients died (6.1 per 100-person year) during the follow-up. Intradialytic SBP varied greatly in fatalities. Univariate and multivariate Cox regression models indicated that the adjusted hazard ratio for death was 1.80 and 5.06 when intradialytic systolic blood pressure (SBP) variation was analyzed in increments of 20 mmHg. Furthermore, we divided intradialytic SBP variation into three categories: < 15 mmHg, 15 ~ 30 mmHg,  ≥ 30 mmHg. Kaplan-Meier analysis indicated that both all-cause mortality and cardiovascular mortality increased significantly for patients with intradialytic SBP variation over 30 mmHg (P = 0.006 and 0.021). Univariate and multivariate Cox regression models indicated that the adjusted hazard ratio for death was 3.78 and 12.62 as intradialytic SBP variation ≥ 30 mmHg vs. intradialytic SBP variation < 15 mmHg.

CONCLUSION

Intradialytic SBP variation, rather than BP of specific intradialytic time-points, has the potential to predict long-term mortality in hemodialysis patients. BP stability is crucial for patients' prognosis.

Better peridialytic blood pressure control using carvedilol in end stage renal disease patients on twice weekly maintenance hemodialysis

BACKGROUND

While use of carvedilol in patients on hemodialysis is encouraged with its low dialyzability, evidence supporting its superiority over metoprolol in improving the blood pressure control during dialysis is lacking. This study was undertaken to study the blood pressure variations in the peridialytic period after conversion from metoprolol to carvedilol.

MATERIALS AND METHODS

In this this prospective, pre-post intervention study, patients on metoprolol were converted to carvedilol. Patients aged 18-65 years on biweekly dialysis with intradialytic rise in blood pressure {difference between pre- and post-dialysis systolic blood pressure > 10 mmHg with post-dialysis blood pressure of ≥ 130/80 mmHg} were recruited. The recorded blood pressure data post conversion to carvedilol was compared to the retrospective mean blood pressure recordings during metoprolol use.

RESULTS

Of the 48 subjects, the study mostly comprised young males (n-34, mean age- 37.06 ± 14.32 years). Both systolic and diastolic blood pressures at different time periods (pre-dialysis, intradialytic and post-dialysis) were significantly lower with carvedilol use than with metoprolol, p < 0.001. Mean pre-dialysis systolic blood pressures and diastolic blood pressures were 140.54 ± 7.68 and 84.42 ± 7.78 mmHg on carvedilol as compared to 148.12 ± 7.17 and 91.17 ± 6.97 mmHg on metoprolol (p < 0.001). Post-dialysis systolic blood pressures and diastolic blood pressures during Carvedilol regimen were better controlled at 147.42 ± 12.89 and 86.29 ± 7.31 mmHg, than 159.12 ± 8.18 and 97 ± 6.76 mmHg during metoprolol regimen (p < 0.001).

CONCLUSION

Our study has brought into focus the younger population at risk of peridialytic hypertension. Switch from metoprolol to carvedilol is an effective anti-hypertensive strategy in dialysis patients with poorly controlled peridialytic blood pressures. Carvedilol was well tolerated.

Ischemic heart disease cause of intradialytic hypertension in a patient with diabetic nephropathy

A 73-year-old Japanese man was admitted with extreme intradialytic hypertension of four months' duration that was refractory to antihypertensive agents. He had started hemodialysis five years previously because of diabetic nephropathy. Coronary angiography revealed coronary artery disease with significant stenosis of the left main trunk and the right coronary artery, and he underwent a coronary artery bypass graft. Thereafter, the intradialytic hypertension disappeared. Ischemic heart disease appears to be one cause of intradialytic hypertension. <Learning objective: Intradialytic hypertension occurs in some patients with hemodialysis. Such patients are at increased risk for mortality and adverse cardiovascular events. Although the pathophysiological mechanisms remain unknown, ischemic heart disease appears to be one cause of intradialytic hypertension.>.

The effects of extracellular volume and intradialytic peripheral resistance changes on ambulatory blood pressure in hemodialysis patients with and without recurrent intradialytic hypertension

Background

Hypertension and extracellular volume (ECV) overload are interrelated mortality risk factors in hemodialysis (HD) patients, but confounding related to changes in ECV and vasoconstriction during and between treatments obfuscate their relationship. We sought to clarify independent contributions of post-HD ECV and intradialytic changes in vasoconstriction on ambulatory blood pressure (BP) in patients with and without recurrent intradialytic hypertension (IH).

Methods

In this prospective observational study, we obtained measurements of pre- and post-HD ECV with bioimpedance spectroscopy (BIS), pre- and post-HD total peripheral resistance index and 44-h ambulatory BP. Linear regression determined associations between post-HD ECV/weight and intradialytic change in total peripheral resistance index (TPRI) with interdialytic BP and slope.

Results

In fully-adjusted models for participants with complete data, post-HD ECV/weight associated with mean ambulatory BP (β = 133, P = 0.01; n = 52) and ambulatory BP slope (β = −4.28, P = 0.03; n = 42). ECV/weight was associated with mean ambulatory BP in those with recurrent IH (β = 314, P = 0.0005; n = 16) and with ambulatory BP slope in those without recurrent IH (β = −4.56, P = 0.04; n = 28). Interdialytic weight gain percentage and intradialytic TPRI change were not associated with ambulatory BP or slope in any analyses.

Conclusion

Ambulatory BP in HD patients is more strongly associated with post-HD ECV assessed with BIS than with intradialytic TPRI changes or interdialytic ECV increases. These findings highlight the essential role of recognizing and managing chronic ECV overload to improve ambulatory BP in HD patients, particularly so for those with IH.

Intradialytic complications among patients on twice-weekly maintenance hemodialysis: an experience from a hemodialysis center in Eritrea

Background

Twice-weekly maintenance hemodialysis sessions in patients with end stage renal disease are commonly practiced due to economic constraints in developing countries including Eritrea. To ameliorate the paucity of data on the subject, our study aims to shed light on the patterns of intradialytic complications exclusively in patients undergoing twice-weekly hemodialysis in the country.

Methods

A descriptive cross-sectional study was conducted from March 01 to July 31, 2018 at Dialysis Unit of Orotta National Referral Hospital, Asmara, Eritrea in patients with end stage renal disease undergoing twice-weekly hemodialysis. Hemodialysis sessions were assessed for intradialytic complications. Data were fed into and analyzed using Epi-Info and Microsoft Excel.

Results

A total of 29 patients were included in the five-month study period. Males were 19 (65.5%) and females were 10 (34.5%). More than half of the patients had diabetes. Out of the total 573 hemodialysis sessions, 176 (30.7%) of them involved one or more intradialytic complication. Hypotension was the most common complication occurring in 10% of the sessions followed by nausea and vomiting (5.24%), hypertension (5.06%), muscle cramps (4.71%), and headache (4.54%). Other complications such as back pain, chest pain, fever, chills and itching occurred in less than 3% of the sessions. There was no death immediately associated with the complications. Half of the intradialytic complications occurred in patients with diabetes. There was a positive correlation between intradialytic hypotension and diabetes, ultrafiltration volume as well as eating during hemodialysis. Use of central line catheter as a vascular access was associated with higher complication rate.

Conclusion

Twice-weekly hemodialysis for end stage renal disease patients probably has similar intradialytic complications as the “standard” thrice-weekly frequency. Although twice-weekly hemodialysis schedule is certainly unsuitable for some patients, its advantage of preserving residual kidney function can prevent excessive interdialytic weight gain and thus lowering the risk of intradialytic hypotension related with higher ultrafiltration rate. Being the first study in the country on dialysis complications, we recommend further large scale research in the future.

Intradialytic Hypertension Increases Non-access Related Hospitalization and Mortality in Maintenance Hemodialysis Patients

Background and Aims:

Intradialytic hypertension, in patients on maintenance hemodialysis, is associated with increased morbidity and mortality. As there is no data available from India, this study was aimed to determine the prevalence and outcome of intradialytic hypertension (IDH) in a tertiary care dialysis centre in India.

Methods:

This was a prospective analytical study of 120 patients on hemodialysis. At screening phase, all patients were subjected to fluid optimization and adjustment in the antihypertensive medicines for appropriate control of blood pressure (BP). BP measurements during hemodialysis were recorded. The prevalence of IDH was noted. IDH was defined as increase in systolic BP of >10 mmHg from pre to post hemodialysis or after 2^nd hour of dialysis when significant ultrafiltration had occurred, on 3 consecutive sessions. Factors associated with IDH were evaluated and compared with cohort without IDH. The outcome of these patients in terms of morbidity and mortality over a follow-up period of 12 months were recorded.

Results:

The prevalence of IDH was 21.9%. The baseline demographic parameters of patients in both the groups (with and without IDH) including age, sex, dialysis access, duration of dialysis, and comorbidities were similar. Laboratory parameters were similar except serum potassium and serum phosphorus, which were lower in patients with IDH. Out of all the variables studied, only low serum phosphorus was associated independently with IDH. During follow-up, at 6 months, 19/71 (26%) non-IDH and 12/20 (60%) IDH patients (P = 0.006) and at 12 month, 30/71 (42%) non-IDH patients and 12/20 (60%) IDH patients required admission (P = 0.05). Mortality at 6 months was similar, 5/71 (7%) in non-IDH and 4/20 (20%) in IDH (P = 0.10) patients, but was higher at 12 months, 11/71 (15.5%) in non-IDH and 8/20 (40%) in IDH (P = 0.028).

Conclusion:

Incidence of intradialytic hypertension is high (21.9%) with increased morbidity in terms of hospitalization and increased mortality over a period of one year.

Blood Pressure Changes among Patients Undergoing Hemodialysis in Yenagoa, Nigeria

INTRODUCTION

Hemodialysis (HD) is a common modality of renal replacement therapy in Nigeria. Despite its usefulness, it may have complications such as intra-dialytic hypotension (IDH) and intra-dialytic hypertension (IDHTN), both of which may impact negatively on the patient. The aim of the study was to examine blood pressure (BP) changes during HD, to determine the frequency of IDH and IDHTN in patients undergoing HD, and to possibly identify associated factors.

MATERIALS AND METHODS

The study design was a retrospective review of records of patients who had HD in the Rainbow Dialysis Center, a foremost private dialysis center in Bayelsa State. The records of all adults who had HD in the center from June 2014 to June 2018 were reviewed. Data retrieved include sociodemographics, type and cause of renal disease, and clinical and laboratory parameters such as BPs, packed cell volume, urea, and creatinine.

STATISTICAL ANALYSIS USED

Data were analyzed with SPSS version 20.0. Data were presented in tabular forms. Variables were expressed as mean with standard deviation, frequencies, and percentages. The means were compared using Student's t-test or analysis of variance where appropriate. Chi-square test was used to compare proportions. Statistical significance was set at P < 0.05.

RESULTS

One hundred and thirty-six cases were recruited for the study. IDH and IDHTN were found in 16.9% and 16.2% of the patients, respectively. There was no significant difference between the mean predialysis and postdialysis systolic, diastolic, mean arterial BP, or pulse pressure (P > 0.05). Older age was positively and significantly associated with IDHTN (P = 0.047).

CONCLUSIONS

IDH and IDHTN were prevalent among the patients studied, with the latter being slightly more likely to occur with advancing age. There is a need for adequate BP monitoring and management during HD.

Intradialytic hypotension: beyond hemodynamics

Intradialytic hypotension is a major complication during hemodialysis session, associated with increased risk of cardiovascular events and mortality. Its pathophysiology is believed to be multifactorial and remains not well elucidated. The aim of this study is to put forward new mechanisms behind the development of intradialytic hypotension. The study included sixty-five subjects on chronic hemodialysis, divided into two groups: intradialytic hypotensive (n=12) and normotensive (n=53), according to the variation of systolic blood pressure between post-dialysis and pre-dialysis measurements. Renin and angiotensin converting enzyme I plasma concentrations increased in both groups but more likely in normotensive group. Aldosterone plasma concentration is increased in the normotensive group while it decreased in the intradialytic hypotension group. Plasma endothelin concentrations showed higher values in intradialytic hypotension group. Post-dialysis asymmetric dimethylarginine and angiotensin converting enzyme 2 plasma concentrations were significantly higher in intradialytic hypotension group as compared to normotensive one. Collectrin plasma concentrations were significantly lower in intradialytic hypotension group. Finally, post-dialysis vascular endothelial growth factor C plasma concentration significantly increased in intradialytic hypotension group. In conclusion, endothelial dysfunction characterized by a lower level of vasoactive molecule seems to play a critical role in intradialytic hypotension development.

Intradialytic hypertension is associated with low intradialytic arterial oxygen saturation

Background

The pathophysiology of a paradoxical systolic blood pressure (SBP) rise during hemodialysis (HD) is not yet fully understood. Recent research indicated that 10% of chronic HD patients suffer from prolonged intradialytic hypoxemia. Since hypoxemia induces a sympathetic response we entertained the hypothesis that peridialytic SBP change is associated with arterial oxygen saturation (SaO2).

Methods

We retrospectively analyzed intradialytic SaO2 and peridialytic SBP change in chronic HD patients with arteriovenous vascular access. Patients were followed for 6 months. We defined persistent intradialytic hypertension (piHTN) as average peridialytic SBP increase ≥10 mmHg over 6 months. Linear mixed effects (LME) models were used to explore associations between peridialytic SBP change and intradialytic SaO2 in univariate and adjusted analyses.

Results

We assessed 982 patients (29 872 HD treatments; 59% males; 53% whites). Pre-dialysis SBP was 146.7 ± 26.5 mmHg and decreased on average by 10.1 ± 24.5 mmHg. Fifty-three (5.7%) patients had piHTN. piHTN patients had lower intradialytic SaO2, body weight and interdialytic weight gain. LME models revealed that with every percentage point lower mean SaO2, the peridialytic SBP change increased by 0.46 mmHg (P < 0.001). This finding was corroborated in multivariate analyses.

Conclusion

We observed an inverse relationship between intradialytic SaO2 and the blood pressure response to HD. These findings support the notion that hypoxemia activates mechanisms that partially blunt the intradialytic blood pressure decline, possibly by sympathetic activation and endothelin-1 secretion. To further explore that hypothesis, specifically designed prospective studies are required.

Intradialysis blood pressure changes among chronic kidney disease patients on maintenance haemodialysis in a tertiary hospital south - south Nigeria: a 2 year retrospective study

Introduction

Haemodialysis (HD) which is a form of renal replacement therapy commonly prescribed for patients with chronic kidney disease (CKD). However, it is not without deleterious haemodynamic responses which may occur either during or immediately after the termination of the procedure. These may include hypotension or hypertension.

Methods

This was a retrospective study that reviewed chronic kidney disease (CKD) patients on maintenance haemodialysis at the renal unit of University of Calabar Teaching Hospital, Calabar, Nigeria. In all, 71 patients were reviewed but only 64 patients had complete data for analysis. Socio-demographic, clinical and biochemical data were obtained from the records in the dialysis unit.

Results

There were more males 38 (59.4%) than females 26 (40.6%) in the study. The mean age was 51.71±15.43 years and 43.04±14.03years for males and females respectively. The prevalence of intradialysis hypertension 29 (45.3%) was higher than that of intradialysis hypotension 20 (31.3%) and the commonest cause of CKD requiring haemodialysis was diabetic nephropathy. The factors associated with intradialysis hypotension were lower post-dialysis systolic blood pressure (PDSBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and less number of antihypertensive medications; while the factors associated with intradialysis hypertension were higher post-dialysis systolic blood pressure (SBP), MAP, greater number of antihypertensive medications and longer duration of haemodialysis.

Conclusion

Our study shows that there are several modifiable factors associated with blood pressure fluctuations among CKD patients on maintenance haemodialysis in the renal unit of the University of Calabar Teaching Hospital, Calabar.

Hypertension control among euvolemic hypertensive hemodialysis patients in Malaysia: a prospective follow-up study

Objectives

Existing literature does not provide enough information on evaluation of factors associated with pre-dialysis controlled hypertension among euvolemic hemodialysis (HD) patients. We conducted a study to evaluate the rate and factors influencing pre-dialysis controlled hypertension among euvolemic HD patients.

Design

A multicenter prospective follow-up study.

Setting

Tertiary care teaching hospital and its associated private dialysis centers.

Participants

This study included 145 euvolemic eligible hypertensive patients. Various sociodemographic, clinical factors and drugs were investigated and analyzed by using appropriate statistical methods to determine the factors influencing hypertension control among the study participants.

Results

On baseline visit, the mean pre-dialysis systolic and diastolic BP (mmHg) of study participants was 161.2 ± 24. and 79.21 ± 11.8 retrospectively, and 30 (20.6%) patients were on pre-dialysis goal BP. At the end of the 6-months follow-up, the mean pre-dialysis systolic BP and diastolic BP (mmHg) of the patients was 154.6 ± 18.3 and 79.2 ± 11.8 respectively, and 42 (28.9%) were on pre-dialysis goal BP. In multivariate analysis, the use of calcium channel blockers (CCBs) was the only variable which had statistically significant association with pre-dialysis controlled hypertension at baseline (OR = 7.530, p-value = 0.001) and final (OR = 8.988, p-value < 0.001) visits.

Conclusions

In present study, the positive association observed between CCBs and controlled hypertension suggests that CCBs are effective antihypertensive drugs in the management of hypertension among euvolemic HD patients.

Strengths and limitations of this study

This study involved a group of patients from tertiary-level teaching hospital and its associated private dialysis centers of Malaysia.To the best of the authors' knowledge, this is the first study to assess the factors influencing pre-dialysis controlled hypertension in a cohort of 145 euvolemic HD patients in a Malaysian setting.For determining the factors influencing hypertenion control multivariate analysis was conducted.Being a prospective follow-up study, the findings of the present study need to be interpreted with caution since it is limited to only 6 months follow up.Nevertheless, a multicenter study with a large sample size and longer follow up time is needed to confirm the findings of the current study.

Timing of blood pressure medications and intradialytic hypotension

Intradialytic hypotension (IDH) is a prevalent yet serious complication of hemodialysis, associated with decreased quality of life, inadequate dialysis, vascular access thrombosis, global hypoperfusion, and increased cardiovascular and all-cause mortality. Current guidelines recommend antihypertensive medications be given at night and held the morning of dialysis for affected patients. Despite little evidence to support this recommendation, more than half of patients on dialysis may employ some form of this method. In this article, we will review the available evidence and clinical considerations regarding timing of blood pressure medications and occurrence of IDH, and conclude that witholding BP medications before hemodialysis should not be a routine practice.

Role of Lung Ultrasound in Adjusting Ultrafiltration Volume in Hemodialysis Patients

Chronic fluid over-hydration is common in dialysis patients. It is associated with mortality and cardiovascular events. Optimal methods for adjusting fluid volume status and ideal dry weight remain uncertain. The purpose of this study was to evaluate the usefulness of ultrasound in quantifying body water. In 35 hemodialysis patients, we performed ultrasound of the chest, pre-tibial skin tissue thickness (TT), heart and inferior vena cava (IVC) before and after dialysis. We compared B-line scores of lungs, IVC diameters and cardiac functions in pre-dialysis and post-dialysis groups. We then estimated the correlations between ultrasound parameters and ultrafiltration volumes. Ultrafiltration parameters were adjusted prospectively for subsequent dialysis. As a result, both extravascular and intravascular water decreased during ultrafiltration. The median numbers of B-line scores (10 [0-42] vs. 4 [0-30]; p < 0.001); mitral valve blood flow velocities E (0.83 ± 0.23 m/s vs. 0.70 ± 0.20 m/s; p < 0.001), A (0.93 ± 0.28 vs. 0.89 ± 0.23 m/s; p < 0.001) and E/e' (12.47 ± 4.92 vs. 10.37 ± 4.0; p < 0.001); IVC diameters at end-expiration (17.51 ± 3.33 mm vs. 14.26 ± 3.45 mm; p < 0.001); and right pre-tibial TT (2.86 ± 1.36 mm vs. 2.43 ± 1.24 mm; p < 0.001) decreased during dialysis. Ultrafiltration volume was most associated with B-line score (adjusting for age and sex) (β = -3.340; p = 0.003). In addition, the B-line score after dialysis was significantly associated with left ventricular ejection fraction (r = -0.393; p = 0.019) and TT (r = -0.447; p = 0.007). Ultrafiltration volume was prospectively increased then if the B-line score was >6 in the previous dialysis. All patients tolerated the protocol well without any symptoms. Ultrafiltration volume was most associated with lung water, reflected by variation in B-line score. It was not associated with cardiac function, IVC diameter, IVC collapse rate or TT. Lung ultrasound is a useful imaging tool for dialysis patients.

Dry-weight reduction improves intradialytic hypertension only in patients with high predialytic blood pressure

BACKGROUND

The aim of this study was to investigate whether additional volume reduction by ultrafiltration can improve blood pressure in patients with intradialytic hypertension (IDH) defined as at least 10 mmHg systolic blood pressure (SBP) rise during hemodialysis.

PATIENTS AND METHODS

This prospective, open-label, single-center study included 11 IDH patients with normal predialytic blood pressure (BP) (group A), 11 IDH patients with high predialytic BP (group B), and 18 patients without IDH as control. Serum angiotensin-II, aldosterone (ALD), angiotensin-converting enzyme, endothelin-1, nitric oxide, and asymmetric dimethylarginine were measured before and after the treatments.

RESULTS

Basic angiotensin-converting enzyme, ALD, endothelin-1, and asymmetric dimethylarginine serum levels were significantly increased in group B compared with control (P < 0.05). On comparing the results from the first and 13th dialysis sessions in group A, the dry weight was reduced by - 0.15 ± 0.16 kg after 12 sessions and the predialytic SBP increased by 3.18 ± 6.25 mmHg before and by 7.37 ± 14.90 mmHg at 4 h during the 13th session. In group B, the dry weight was reduced by 0.67 ± 0.53 kg (P = 0.006 vs. group A) at the 13th session and they had - 12.09 ± 16.20 mmHg less SBP before (P = 0.009 vs. group A) and - 11.82 ± 14.66 mmHg at 4 h of the 13th session. The decrease in dry weight was associated with significantly higher decreases in angiotensin-II and ALD serum levels in group B compared with group A.

CONCLUSION

Reducing fluid overload in IDH patients with high predialytic BP can effectively improve their BP, but had no effect on BP in normal predialytic BP IDH cases.

Bilateral renal artery stenosis as a cause of refractory intradialytic hypertension in a patient with end stage renal disease

Background

We report a 61-year-old female with end-stage renal disease (ESRD) secondary to polycystic kidney disease (PKD) complicated by intradialytic hypertension (IDH). Increased sympathetic drive leading to increased stroke volume and/or vasoconstriction with an inappropriate increase in peripheral vascular resistance (PVR) has been postulated to be the cause of IDH.

Case presentation

Attempts to control her blood pressure by reducing her goal weight; increasing dialysis times/ frequency and decreasing her sodium concentrate in the dialysis fluid were unsuccessful. Acting upon literature evidence suggesting renovascular disease as a cause of IDH, we referred her to an interventional radiologist for evaluation of the renal arteries. Selective angiogram of both renal arteries revealed right sided atherosclerotic renal artery stenosis (RAS) treated with insertion of a balloon mounted 6 mm stent and left sided fibromuscular dysplasia (FMD) treated with 5 mm balloon angioplasty.

Conclusions

This case highlights the need for interrogating the renal arteries radiologically for a potential cause in difficult to control IDH and comments on the association between PKD and FMD that has not yet been reported.

Effect of Isothermic Dialysis on Intradialytic Hypertension

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

Augmented Cardiopulmonary Baroreflex Sensitivity in Intradialytic Hypertension

Introduction

End-stage renal disease (ESRD) patients with a paradoxical increase in blood pressure (BP) during hemodialysis (HD), termed intradialytic hypertension (ID-HTN), are at significantly increased risk for mortality and adverse cardiovascular events. ID-HTN affects up to 15% of all HD patients, and the pathophysiologic mechanisms remain unknown. We hypothesized that ESRD patients prone to ID-HTN have heightened volume-sensitive cardiopulmonary baroreflex sensitivity (BRS) that leads to exaggerated increases in sympathetic nervous system (SNS) activation during HD.

Methods

We studied ESRD patients on maintenance HD with ID-HTN (n = 10) and without ID-HTN (controls, n = 12) on an interdialytic day, 24 to 30 hours after their last HD session. We measured continuous muscle sympathetic nerve activity (MSNA), beat-to-beat arterial BP, and electrocardiography (ECG) at baseline, and during graded lower body negative pressure (LBNP). Low-dose LBNP isolates cardiopulmonary BRS, whereas higher doses allow assessment of physiologic responses to orthostatic stress.

Results

The ID-HTN patients had significantly higher pre- and post-HD BP, and greater interdialytic fluid weight gain compared to controls. There was a significantly greater increase in MSNA burst incidence (P = 0.044) during graded LBNP in the ID-HTN group, suggesting heightened cardiopulmonary BRS. The ID-HTN group also had a trend toward increased diastolic BP response during LBNP, and had significantly greater increases in BP during the cold pressor test.

Conclusion

Patients with ID-HTN have augmented cardiopulmonary BRS that may contribute to increased SNS activation and BP response during HD.