Novel Insights into the Pathogenesis and Prevention of Intradialytic Hypotension

Factors associated with successful liberation from continuous renal replacement therapy in children and young adults: analysis of the worldwide exploration of renal replacement outcomes collaborative in Kidney Disease Registry

PURPOSE

Continuous renal replacement therapy (CRRT) is used for supportive management of acute kidney injury (AKI) and disorders of fluid balance (FB). Little is known about the predictors of successful liberation in children and young adults. We aimed to identify the factors associated with successful CRRT liberation.

METHODS

The Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Disease study is an international multicenter retrospective study (32 centers, 7 nations) conducted from 2015 to 2021 in children and young adults (aged 0-25 years) treated with CRRT for AKI or FB disorders. Patients with previous dialysis dependence, tandem extracorporeal membrane oxygenation use, died within the first 72 h of CRRT initiation, and those who never had liberation attempted were excluded. Patients were categorized based on first liberation attempt: reinstituted (resumption of any dialysis within 72 h) vs. success (no receipt of dialysis for ≥ 72 h). Multivariable logistic regression was used to identify factors associated with successful CRRT liberation.

RESULTS

A total of 622 patients were included: 287 (46%) had CRRT reinstituted and 335 (54%) were successfully liberated. After adjusting for sepsis at admission and illness severity parameters, several factors were associated with successful liberation, including higher VIS (vasoactive-inotropic score) at CRRT initiation (odds ratio [OR] 1.35 [1.12-1.63]), higher PELOD-2 (pediatric logistic organ dysfunction-2) score at CRRT initiation (OR 1.71 [1.24-2.35]), higher urine output prior to CRRT initiation (OR 1.15 [1.001-1.32]), and shorter CRRT duration (OR 0.19 [0.12-0.28]).

CONCLUSIONS

Inability to liberate from CRRT was common in this multinational retrospective study. Modifiable and non-modifiable factors were associated with successful liberation. These results may inform the design of future clinical trials to optimize likelihood of CRRT liberation success.

Hemodialysis Procedures for Stable Incident and Prevalent Patients Optimize Hemodynamic Stability, Dialysis Dose, Electrolytes, and Fluid Balance

The demographic profile of patients transitioning from chronic kidney disease to kidney replacement therapy is changing, with a higher prevalence of aging patients with multiple comorbidities such as diabetes mellitus and heart failure. Cardiovascular disease remains the leading cause of mortality in this population, exacerbated by the cardiovascular stress imposed by the HD procedure. The first year after transitioning to hemodialysis is associated with increased risks of hospitalization and mortality, particularly within the first 90-120 days, with greater vulnerability observed among the elderly. Based on data from clinics in Fresenius Medical Care Europe, Middle East, and Africa NephroCare, this review aims to optimize hemodialysis procedures to reduce mortality risk in stable incident and prevalent patients. It addresses critical aspects such as treatment duration, frequency, choice of dialysis membrane, dialysate composition, blood and dialysate flow rates, electrolyte composition, temperature control, target weight management, dialysis adequacy, and additional protocols, with a focus on mitigating prevalent intradialytic complications, particularly intradialytic hypotension prevention.

Development of a clinical automatic calculation of hypoglycemia during hemodialysis risk in patients with diabetic nephropathy

BACKGROUND

Hypoglycemia is one of the most common complications in patients with DN during hemodialysis. The purpose of the study is to construct a clinical automatic calculation to predict risk of hypoglycemia during hemodialysis for patients with diabetic nephropathy.

METHODS

In this cross-sectional study, patients provided information for the questionnaire and received blood glucose tests during hemodialysis. The data were analyzed with logistic regression and then an automated calculator for risk prediction was constructed based on the results. From May to November 2022, 207 hemodialysis patients with diabetes nephropathy were recruited. Patients were recruited at blood purifying facilities at two hospitals in Beijing and Inner Mongolia province, China. Hypoglycemia is defined according to the standards of medical care in diabetes issued by ADA (2021). The blood glucose meter was used uniformly for blood glucose tests 15 minutes before the end of hemodialysis or when the patient did not feel well during hemodialysis.

RESULTS

The incidence of hypoglycemia during hemodialysis was 50.2% (104/207). The risk prediction model included 6 predictors, and was constructed as follows: Logit (P) = 1.505×hemodialysis duration 8~15 years (OR = 4.506, 3 points) + 1.616×hemodialysis duration 16~21 years (OR = 5.032, 3 points) + 1.504×having hypotension during last hemodialysis (OR = 4.501, 3 points) + 0.788×having hyperglycemia during the latest hemodialysis night (OR = 2.199, 2 points) + 0.91×disturbance of potassium metabolism (OR = 2.484, 2 points) + 2.636×serum albumin<35 g/L (OR = 13.963, 5 points)-4.314. The AUC of the prediction model was 0.866, with Matthews correlation coefficient (MCC) of 0.633, and Hosmer-Lemeshow χ2 of 4.447(P = 0.815). The automatic calculation has a total of 18 points and four risk levels.

CONCLUSIONS

The incidence of hypoglycemia during hemodialysis is high in patients with DN. The risk prediction model in this study had a good prediction outcome. The hypoglycemia prediction automatic calculation that was developed using this model can be used to predict the risk of hypoglycemia in DN patients during hemodialysis and also help identify those with a high risk of hypoglycemia during hemodialysis.

Prediction of intradialytic hypotension using pre-dialysis features-a deep learning-based artificial intelligence model

BACKGROUND

Intradialytic hypotension (IDH) is a serious complication of hemodialysis (HD) that is associated with increased risks of cardiovascular morbidity and mortality. However, its accurate prediction remains a clinical challenge. The aim of this study was to develop a deep learning-based artificial intelligence (AI) model to predict IDH using pre-dialysis features.

METHODS

Data from 2007 patients with 943 220 HD sessions at seven university hospitals were used. The performance of the deep learning model was compared with three machine learning models (logistic regression, random forest and XGBoost).

RESULTS

IDH occurred in 5.39% of all studied HD sessions. A lower pre-dialysis blood pressure (BP), and a higher ultrafiltration (UF) target rate and interdialytic weight gain in IDH sessions compared with non-IDH sessions, and the occurrence of IDH in previous sessions was more frequent among IDH sessions compared with non-IDH sessions. Matthews correlation coefficient and macro-averaged F1 score were used to evaluate both positive and negative prediction performances. Both values were similar in logistic regression, random forest, XGBoost and deep learning models, developed with data from a single session. When combining data from the previous three sessions, the prediction performance of the deep learning model improved and became superior to that of other models. The common top-ranked features for IDH prediction were mean systolic BP (SBP) during the previous session, UF target rate, pre-dialysis SBP, and IDH experience during the previous session.

CONCLUSIONS

Our AI model predicts IDH accurately, suggesting it as a reliable tool for HD treatment.

Physical intradialytic patient-reported outcome measures in haemodialysis and haemodiafiltration: A cross-over study

AIM

Standard haemodialysis (sHD) is associated with a poor survival and marked adverse intradialytic patient-reported outcome measures (ID-PROMs). Whereas physical ID-PROMs (PID-PROMs) are alleviated by cool dialysate (cHD), survival is prolonged by haemodiafiltration (HDF). So far, PID-PROMs are not prospectively compared between HD and HDF.

METHODS

To assess whether PID-PROMs and thermal perception differ between sHD, cHD, low volume HDF (lvHDF) and high volume HDF (hvHDF), 40 patients were cross-over randomized to each modality for 2 weeks. Dialysate temperature (T_d ) was 36.5°C, except in cHD (T_d 35.5°C). Target convection volumes were 15 L in lvHDF and ≥ 23 L in hvHDF. PID-PROMs were evaluated with a modified Dialysis Symptom Index (mDSI) and thermal perception with the Visual Analogue Scale Thermal Perception (VAS-TP). T_b and room temperature were measured as well.

RESULTS

Except for the item 'feeling cold' during cHD (p = .01), PID-PROMs did not differ between modalities, but varied markedly between patients (11/13 items, p < .05). T_b increased in sHD, lvHDF, and hvHDF (+0.30, 0.35, 0.38°C, respectively, all p < .0005), but remained stable in cHD (+0.04°C, p = .43). Thermal perception remained unaltered in sHD and both HDF modalities, but shifted towards cold in cHD (p = .007).

CONCLUSION

(1) PID-PROMs did not differ between modalities, but varied markedly between patients. Hence, PID-PROMs are largely patient-dependent. (2) While T_b increased in sHD, lvHDF and hvHDF, thermal perception did not change. Yet, whereas T_b remained unaltered in cHD, cold perception emerged. Hence, as for bothersome cold sensations, cHD should be avoided in perceptive individuals.

Hidden risks associated with conventional short intermittent hemodialysis: A call for action to mitigate cardiovascular risk and morbidity

The development of maintenance hemodialysis (HD) for end stage kidney disease patients is a success story that continues to save many lives. Nevertheless, intermittent renal replacement therapy is also a source of recurrent stress for patients. Conventional thrice weekly short HD is an imperfect treatment that only partially corrects uremic abnormalities, increases cardiovascular risk, and exacerbates disease burden. Altering cycles of fluid loading associated with cardiac stretching (interdialytic phase) and then fluid unloading (intradialytic phase) likely contribute to cardiac and vascular damage. This unphysiologic treatment profile combined with cyclic disturbances including osmotic and electrolytic shifts may contribute to morbidity in dialysis patients and augment the health burden of treatment. As such, HD patients are exposed to multiple stressors including cardiocirculatory, inflammatory, biologic, hypoxemic, and nutritional. This cascade of events can be termed the dialysis stress storm and sickness syndrome. Mitigating cardiovascular risk and morbidity associated with conventional intermittent HD appears to be a priority for improving patient experience and reducing disease burden. In this in-depth review, we summarize the hidden effects of intermittent HD therapy, and call for action to improve delivered HD and develop treatment schedules that are better tolerated and associated with fewer adverse effects.

Predicting factors of intradialytic hypotension in the last half of hemodialysis therapy

Background

Intradialytic hypotension (IDH) is one of the most frequent complications of hemodialysis. IDH alters a patient’s quality of life and has a strong association with mortality. IDH mainly occurs when ultrafiltration during hemodialysis exceeds the pace of the plasma refill. Ultrasonography has been used to evaluate the intravascular volume status. We evaluated the association between IDH and baseline laboratory data or ultrasound findings during IDH during the latter half of a hemodialysis session.

Methods

Sixty-two patients who underwent hemodialysis were enrolled in this study. The peak early mitral inflow wave velocity (peak E-velocity), the inferior vena cava (IVC) dimensions, and number of B-lines were estimated at two time points (just after the start and at the midpoint of the hemodialysis session). We compared the parameters between the patients without IDH throughout the hemodialysis session (non-IDH group) and patients with IDH only during the latter half of the hemodialysis session (IDH in the latter half group).

Results

Of the 62 study participants, 28 patients were in non-IDH group, and 16 patients were in IDH in the latter half group. The serum sodium level was significantly lower in the IDH in the latter half group (135 ± 4 mEq/L) than in the non-IDH group (138 ± 4 mEq/L) (P = 0.015). The rate of decrease of the peak E-velocity was significantly higher in the IDH in the latter half group (0.33 ± 0.13) than in the non-IDH group (0.24 ± 0.14) (P = 0.037). The best cutoff point of the serum level of sodium was 137 mEq/L, with a sensitivity of 68.8% and specificity of 64.3%. The area under the receiver operating characteristic (ROC) curve was 0.71. The best cutoff point of the rate of decrease of the peak E-velocity was 0.295, with a sensitivity of 73.3% and a specificity of 71.4%. The area under the ROC curve was 0.71.

Conclusions

A low serum level of sodium at baseline and an early decrease in the peak E-velocity during hemodialysis may be related to intradialytic hypotension in the latter half of a hemodialysis session. Careful observation may be needed in the hemodialysis patients in whom the serum level of sodium is below 137 mEq/L or the rate of decrease of the peak E-velocity is over 0.295.

Intradialytic hypotension: Is intradialytic acupuncture a complementary option? A case report

BACKGROUND

Intradialytic hypotension (IDH) is a common complication during hemodialysis (HD) and is positively associated with either poor quality of life or mortality. The present case report described the effect of intradialytic acupuncture (IA) in decreasing the occurrence of IDH.

METHODS

A 70-year-old female with diabetic nephropathy had been receiving regular dialysis twice weekly since end-stage renal disease was diagnosed. She had several episodes of intradialytic systolic blood pressure (iSBP) drop accompanied with severe complications within one month. In the 10 dialysis sessions prior to IA intervention, the case patient experienced two episodes of nadir iSBP < 90 mmHg, seven episodes of iSBP drop ≥ 20 mmHg, among which two episodes occurred with symptoms; and three episodes of iSBP drop required nursing intervention.

INTERVENTIONS

Dialysis sessions proceeded as usual with the patient receiving five sessions of 30-min IA as an add-on therapy starting from the second hour of dialysis.

RESULTS

In the 10 sessions with IA administered alternately, she experienced one episode of nadir iSBP < 90 mmHg and three episodes of iSBP drop ≥ 20 mmHg, among which two episodes occurred with symptoms. Occurrence of IDH reduced and no IDH necessitating nursing intervention occurred during IA-HD sessions.

CONCLUSIONS

The administration of IA showed potential effect in decreasing the occurrence of IDH.

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.

Management of acute intradialytic cardiovascular complications: Updated overview (Review)

An increasing number of patients require renal replacement therapy through dialysis and renal transplantation. Chronic kidney disease (CKD) affects a large percentage of the world's population and has evolved into a major public health concern. Diabetes mellitus, high blood pressure and a family history of kidney failure are all major risk factors for CKD. Patients in advanced stages of CKD have varying degrees of cardiovascular damage. Comorbidities of these patients, include, on the one hand, hypertension, hyperlipidemia, hyperglycemia, hyperuricemia and, on the other hand, the presence of mineral-bone disorders associated with CKD and chronic inflammation, which contribute to cardiovascular involvement. Acute complications occur quite frequently during dialysis. Among these, the most important are cardiovascular complications, which influence the morbidity and mortality rates of this group of patients. Chronic hemodialysis patients manifest acute cardiovascular complications such as intradialytic hypotension, intradialytic hypertension, arrhythmias, acute coronary syndromes and sudden death. Thus, proper management is extremely important.

A randomized trial of albumin infusion to prevent intradialytic hypotension in hospitalized hypoalbuminemic patients

BACKGROUND

Intradialytic hypotension (IDH) is a frequent complication of intermittent hemodialysis (IHD), occurring from 15 to 50% of ambulatory sessions, and is more frequent among hospitalized patients with hypoalbuminemia. IDH limits adequate fluid removal and increases the risk for vascular access thrombosis, early hemodialysis (HD) termination, and mortality. Albumin infusion before and during therapy has been used for treating IDH with the varying results. We evaluated the efficacy of albumin infusion in preventing IDH during IHD in hypoalbuminemic inpatients.

METHODS

A randomized, crossover trial was performed in 65 AKI or ESKD patients with hypoalbuminemia (albumin < 3 g/dl) who required HD during hospitalization. Patients were randomized to receive 100 ml of either 0.9%sodium chloride or 25% albumin intravenously at the initiation of each dialysis. These two solutions were alternated for up to six sessions. Patients' vital signs and ultrafiltration removal rate were recorded every 15 to 30 min during dialysis. IDH was assessed by different definitions reported in the literature. All symptoms associated with a noted hypotensive event as well as interventions during the dialysis were recorded.

RESULTS

Sixty-five patients were submitted to 249 sessions; the mean age was 58 ([Formula: see text] 12), and 46 (70%) were male with a mean weight of 76 ([Formula: see text] 18) kg. The presence of IDH was lower during albumin sessions based on all definitions. The hypotension risk was significantly decreased based on the Kidney Disease Outcomes Quality Initiative definition; (15% with NS vs. 7% with albumin, p = 0.002). The lowest intradialytic SBP was significantly worse in patients who received 0.9% sodium chloride than albumin (NS 83 vs. albumin 90 mmHg, p = 0.035). Overall ultrafiltration rate was significantly higher in the albumin therapies [NS - 8.25 ml/kg/h (- 11.18 5.80) vs. 8.27 ml/kg/h (- 12.22 to 5.53) with albumin, p = 0.011].

CONCLUSION

In hypoalbuminemic patients who need HD, albumin administration before the dialysis results in fewer episodes of hypotension and improves fluid removal. Albumin infusion may be of benefit to improve the safety of HD and achievement of fluid balance in these high-risk patients. ClinicalTrials.gov Identifier: NCT04522635.

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.

Intradialytic hypotension and relationship with cognitive function and brain morphometry

Background

The haemodynamic stress brought about by dialysis could justify the loss of structural and functional integrity of the central nervous system (CNS). The main objective of this study was to analyse the relationship between intradialytic hypotension (IDH) and cognitive function and brain morphometry.

Methods

The cross-sectional KIDBRAIN study (Cohort Study of Morphological Changes of the Brain by MRI in Chronic Kidney Disease Patients) included 68 prevalent patients with no history of neurological disorders (cerebrovascular disease and cognitive impairment) undergoing haemodialysis (HD). We analysed 18 non-consecutive dialysis sessions (first three of each month over a 6-month period) and various definitions of IDH were recorded. Global cognitive function (GCF) was assessed using the Mini-Mental State Examination (MMSE) and parameters of structural integrity of the CNS were obtained using volume morphometry magnetic resonance imaging analysis [grey matter (GM), white matter (WM) and hippocampus).

Results

A greater number of sessions with IDH were associated with less volume of WM (r = −0.359,P = 0.003) and hippocampus (r = −0.395, P = 0.001) independent of cardiovascular risk factors according to multivariable linear regression models (β = −0.198, P = 0.046 for WM; β = −0.253, P = 0.017 for hippocampus). The GCF by the MMSE was 27.3 ± 7.3.1 and was associated with WM volume (β = 0.403, P = 0.001) independent of GM and hippocampus volume. Symptomatic IDH was associated with GCF (r = −0.420, P < 0.001) in adjusted analysis (β = −0.339, P = 0.008).

Conclusions

Even when asymptomatic, IDH is associated with a lower WM and hippocampus volume and reduced GCF in patients undergoing HD, thus suggesting greater vulnerability of the brain to the haemodynamic stress that may be generated by a dialysis session.

Integrated strategies to prevent intradialytic hypotension: research protocol of the DialHypot study, a prospective randomised clinical trial in hypotension-prone haemodialysis patients

INTRODUCTION

In patients on maintenance haemodialysis (HD), intradialytic hypotension (IDH) is a clinical problem that nephrologists and dialysis nurses face daily in their clinical routine. Despite the technological advances in the field of HD, the incidence of hypotensive events occurring during a standard dialytic treatment is still very high. Frequently recurring hypotensive episodes during HD sessions expose patients not only to severe immediate complications but also to a higher mortality risk in the medium term. Various strategies aimed at preventing IDH are currently available, but there is lack of conclusive data on more integrated approaches combining different interventions.

METHODS AND ANALYSIS

This is a prospective, randomised, open-label, crossover trial (each subject will be used as his/her own control) that will be performed in two distinct phases, each of which is divided into several subphases. In the first phase, 27 HD sessions for each patient will be used, and will be aimed at the validation of a new ultrafiltration (UF) profile, designed with an ascending/descending shape, and a standard dialysate sodium concentration. In the second phase, 33 HD sessions for each patient will be used and will be aimed at evaluating the combination of different UF and sodium profiling strategies through individualised dialysate sodium concentration.

ETHICS AND DISSEMINATION

The trial protocol has been reviewed and approved by the local Institutional Ethics Committee (Comitato Etico AVEN, prot. 43391 22.10.19). The results of the trial will be presented at local and international conferences and submitted for publication to a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03949088).

Intradialytic hypotension prevalence, influencing factors, and nursing interventions: prospective results of 744 hemodialysis sessions

INTRODUCTION

The aim of this study was to evaluate intradialytic hypotension (IDH) prevalence, influencing factors, and nursing interventions in hemodialysis (HD) patients.

METHODS

This descriptive and cross-sectional study was conducted at a private dialysis center. The patients were followed-up in terms of IDH development based on the European Best Practice Guidelines criteria during six consecutive HD sessions. The study followed the STROBE checklist.

RESULTS

A total of 744 hemodialysis sessions of 124 patients were monitored. IDH developed in 51.6% of the patients and the prevalence was 17.60%. The most common nursing interventions were stopping ultrafiltration and isotonic saline solution administration. White blood cell (WBC) (p = 0.017) and creatinine (p = 0.005) values were statistically significantly higher in patients developing IDH. WBC was found to increase IDH development risk 0.796 times (95% CI [0.657-0.996], p = 0.021).

CONCLUSION

Nursing staff awareness regarding the frequency of IDH in hemodialysis patients and the related symptoms needs to be increased.

Long-Term Peridialytic Blood Pressure Patterns in Patients Treated by Hemodialysis and Hemodiafiltration

Introduction

Online postdilution hemodiafiltration (HDF) is associated with a lower all-cause and cardiovascular mortality than hemodialysis (HD). This may depend on a superior peridialytic (pre- and postdialysis, and the difference between these 2 parameters) hemodynamic profile.

Methods

In this retrospective cohort analysis of individual participant data (IPD) from 3 randomized controlled trials (RCTs) (n = 2011), the effect of HDF and HD on 2-year peridialytic blood pressure (BP) patterns was assessed. Long-term peridialytic systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP), as well as the deltas (post- minus predialytic) were assessed in the total group of patients. Thereafter, these variables were compared between patients on HD and HDF, and in the latter group between quartiles of convection volume.

Results

Mean pre- and postdialysis SBP, DBP, and MAP declined significantly during follow-up (predialytic: SBP −2.16 mm Hg, DBP −2.88 mm Hg, MAP −2.64 mm Hg), PP increased (predialytic 0.96 mm Hg). Peridialytic deltas remained unaltered. Differences between the 2 modalities, or between quartiles of convection volume were not observed. BP changes were independent of various baseline characteristics, including the decline in body weight over time.

Conclusion

We speculate that the combination of a decreasing SBP and an increasing PP may be the clinical sequelae of a worsening cardiovascular system. Because especially HDF with a high convection volume has been associated with a beneficial effect on survival, our study does not support the view that superior peridialytic BP control contributes to this effect.

Intradialytic Hypotension: Mechanisms and Outcome

Intradialytic hypotension (IDH) occurs in approximately 10-12% of treatments. Whereas several definitions for IDH are available, a nadir systolic blood pressure carries the strongest relation with outcome. Whereas the relation between IDH may partly be based on patient characteristics, it is likely that also impaired organ perfusion leading to permanent damage, plays a role in this relationship. The pathogenesis of IDH is multifactorial and is based on a combination of a decline in blood volume (BV) and impaired vascular resistance at a background of a reduced cardiovascular reserve. Measurements of absolute BV based on an on-line dilution method appear more promising than relative BV measurements in the prediction of IDH. Also, feedback treatments in which ultrafiltration rate is automatically adjusted based on changes in relative BV have not yet resulted in improvement. Frequent assessment of dry weight, attempting to reduce interdialytic weight gain and prescribing more frequent or longer dialysis treatments may aid in preventing IDH. The impaired vascular response can be improved using isothermic or cool dialysis treatment which has also been associated with a reduction in end organ damage, although their effect on mortality has not yet been assessed. For the future, identification of vulnerable patients based on artificial intelligence and on-line assessment of markers of organ perfusion may aid in individualizing treatment prescription, which will always remain dependent on the clinical context of the patient.

Ultrasound-based clinical profiles for predicting the risk of intradialytic hypotension in critically ill patients on intermittent dialysis: a prospective observational study

BACKGROUND

Intradialytic hypotension, a complication of intermittent hemodialysis, decreases the efficacy of dialysis and increases long-term mortality. This study was aimed to determine whether different predialysis ultrasound cardiopulmonary profiles could predict intradialytic hypotension.

METHODS

This prospective observational single-center study was performed in 248 critically ill patients with acute kidney injury undergoing intermittent hemodialysis. Immediately before hemodialysis, vena cava collapsibility was measured by vena cava ultrasound and pulmonary congestion by lung ultrasound. Factors predicting intradialytic hypotension were identified by multiple logistic regression analysis.

RESULTS

Intradialytic hypotension was observed in 31.9% (n = 79) of the patients, interruption of dialysis because of intradialytic hypotension occurred in 6.8% (n = 31) of the sessions, and overall 28-day mortality was 20.1% (n = 50). Patients were classified in four ultrasound profiles: (A) 108 with B lines > 14 and vena cava collapsibility > 11.5 mm m^-2, (B) 38 with B lines < 14 and vena cava collapsibility ≤ 11.5 mm m^-2, (C) 36 with B lines > 14 and vena cava collapsibility Di ≤ 11.5 mm m^-2, and (D) 66 with B lines < 14 and vena cava collapsibility > 11.5 mm m^-2. There was an increased risk of intradialytic hypotension in patients receiving norepinephrine (odds ratios = 15, p = 0.001) and with profiles B (odds ratios = 12, p = 0.001) and C (odds ratios = 17, p = 0.001).

CONCLUSION

In critically ill patients on intermittent hemodialysis, the absence of hypervolemia as assessed by lung and vena cava ultrasound predisposes to intradialytic hypotension and suggests alternative techniques of hemodialysis to provide better hemodynamic stability.

Clinical research on individualized hemodialysis preventing unconventional hypotension in diabetic nephropathy patient

OBJECTIVE

This study aims to evaluate the effectiveness of individualized hemodialysis for unconventional hypotension in diabetic nephropathy patients.

METHODS

A total of 60 patients were selected and randomly divided into study group and control group. The control group used the standard dialysis model, while the study group used the individualized hemodialysis scheme, in which the dialysis was performed using an individualized dialysis machine temperature control, pattern of natrium, and pattern of step ultrafiltration in combination with dialysate-containing glucose.

RESULTS

The total occurrence rate of hypotension, dry weight standard-reaching rate, and blood quality during and after dialysis in the study group were superior to those in the control group (P < 0.05). Furthermore, the symptom scores in the study group (dizziness score, chest distress score, sweating score, muscle spasm score, gastrointestinal symptom score, and temporary mind change score) were lower than those in the control group (P < 0.05). The serum sodium, potassium, and chloride concentration in these two groups after dialysis was not statistically different (P > 0.05).

CONCLUSION

The combined application of low temperature, pattern of natrium, pattern of step ultrafiltration, and dialysate-containing glucose individualization is safe and effective for preventing and controlling the occurrence of intradialytic hypotension (IDH), improve symptoms, and improve the dry weight standard-reaching rate.

Techniques to improve intradialytic haemodynamic stability

PURPOSE OF REVIEW

Intra-dialytic hypotension (IDH) remains a significant problem for patients undergoing chronic haemodialysis. IDH causes symptoms that degrade patients' experience, compromises dialysis delivery and is strongly associated with adverse patient outcomes. Greater understanding of the link between IDH and dialysis-induced ischaemia in heart and brain has characterized mechanistic pathways, with repeated episodes of ischaemia resulting in organ dysfunction. This review provides updates from published evidence over the last 2 years across the range of potential interventions for IDH.

RECENT FINDINGS

A literature search was undertaken to identify articles published in peer review journals between January 2016 and April 2018 using terms 'intradialytic hypotension,' 'haemodynamic instability,' 'ESRF,' 'renal replacement therapy,' 'dialysis' in Medline and EMBASE and identified 58 references from which 15 articles were included in this review. Interventions included: cooling the dialysate; sodium profiling; convective therapies; strategies to minimize inter-dialytic weight gain (IDWG) and improve accuracy of target weight assessment; prescribing of antihypertensive medications; and carnitine supplementation.

SUMMARY

IDH remains a significant clinical problem. Recent evidence from the last 2 years does not support any major changes to current practice, with cooling of the dialysate and reduction of IDWG remaining cornerstones of management.

Butyrate production in patients with end-stage renal disease

Background: Chronic kidney disease (CKD) is associated with a decreased intestinal barrier function, causing bacterial translocation over the intestinal wall and triggering a systemic inflammatory response. Butyrate, a short-chain fatty acid produced by certain bacterial strains, is considered instrumental to keep the intestinal barrier intact. There are indications that a decreased amount of these specific bacterial species is part of the cause of the decreased intestinal barrier function in CKD. The aim of this study is (i) to determine if Dutch patients with end-stage renal disease (ESRD) have a decreased amount of butyrate-producing species and butyrate-producing capacity and (ii) whether this correlates with systemic inflammation. Methods: We used qPCR to evaluate the most abundant butyrate-producing species F. prauznitzii, E. rectale and Roseburia spp. and the BCoAT gene, which reflects the butyrogenic capacity of the intestinal microbiota. Fecal samples were collected from healthy kidney donors (n=15), preemptive renal transplant recipients (n=4) and dialysis patients (n=31). Markers of inflammation (CRP and IL-6) and intestinal permeability (D-lactate) were measured in plasma. Results: Patients with ESRD did not have a significantly decreased amount F. prauznitzii, E. rectale and Roseburia spp. or the BCoAT gene. Neither was there a significant correlation with CRP, IL-6 or D-lactate. On the individual level, there were some patients with decreased BCoAT levels and increased levels of CRP, IL-6 and D-lactate. Conclusions: Patients with ESRD do not have a decreased amount of the most abundant butyrate-producing species nor a decreased butyrate-producing capacity.

Body Fluids in End-Stage Renal Disease: Statics and Dynamics

BACKGROUND

Abnormalities in fluid status in hemodialysis (HD) patients are highly prevalent and are related to adverse outcomes.

SUMMARY

The inherent discontinuity of the HD procedure in combination with an often compromised cardiovascular response is a major contributor to this phenomenon. In addition, systemic inflammation and endothelial dysfunction are related to extracellular fluid overload (FO). Underlying this relation may be factors such as hypoalbuminemia and an increased capillary permeability, leading to an altered fluid distribution between the blood volume (BV) and the interstitial fluid compartments, compromising fluid removal during dialysis. Indeed, whereas estimates of extracellular volume by bioimpedance spectroscopy are highly predictive of mortality, absolute BV assessed by the saline dilution technique was predictive of intra-dialytic morbidity. Changes in relative BV during HD are positively related to ultrafiltration rate (UFR) and, at least in some studies, negatively to FO. High UFR is also related to changes in central venous oxygen saturation (ScvO2), a marker for tissue perfusion. On the one hand, high UFR and more pronounced declines in ScvO2, but on the other hand, flat relative BV curves are also predictive of mortality; the relation between outcome which statics and dynamics of fluid status appears to be complex. Key Message: While technological developments enable the clinician to monitor statics and dynamics of fluid status and hemodynamics during HD in an accessible way, the role of technology-based interventions needs further study.

Cycles, Arrows and Turbulence: Time Patterns in Renal Disease, a Path from Epidemiology to Personalized Medicine?

Patients with end-stage renal disease (ESRD) experience unique patterns in their lifetime, such as the start of dialysis and renal transplantation. In addition, there is also an intricate link between ESRD and biological time patterns. In terms of cyclic patterns, the circadian blood pressure (BP) rhythm can be flattened, contributing to allostatic load, whereas the circadian temperature rhythm is related to the decline in BP during hemodialysis (HD). Seasonal variations in BP and interdialytic-weight gain have been observed in ESRD patients in addition to a profound relative increase in mortality during the winter period. Moreover, nonphysiological treatment patters are imposed in HD patients, leading to an excess mortality at the end of the long interdialytic interval. Recently, new evidence has emerged on the prognostic impact of trajectories of common clinical and laboratory parameters such as BP, body temperature, and serum albumin, in addition to single point in time measurements. Backward analysis of changes in cardiovascular, nutritional, and inflammatory parameters before the occurrence as hospitalization or death has shown that changes may already occur within months to even 1-2 years before the event, possibly providing a window of opportunity for earlier interventions. Disturbances in physiological variability, such as in heart rate, characterized by a loss of fractal patterns, are associated with increased mortality. In addition, an increase in random variability in different parameters such as BP and sodium is also associated with adverse outcomes. Novel techniques, based on time-dependent analysis of variability and trends and interactions of multiple physiological and laboratory parameters, for which machine-learning -approaches may be necessary, are likely of help to the clinician in the future. However, upcoming research should also evaluate whether dynamic patterns observed in large epidemiological studies have relevance for the individual risk profile of the patient.