Interdialytic Hypertension Research Articles

#2196 Impact of intradialytic exercise on blood pressure and quality of life in hemodialysis patients: a randomized controlled trial

Abstract Background and Aims Hemodialysis is essential for end-stage renal disease (ESRD) patients, but they often face complications affecting their quality of life and cardiovascular health. Exercise has emerged as a potential adjunct therapy for improving outcomes in hemodialysis patients. This study aimed to examine the effects of exercise during dialysis on laboratory parameters, intradialytic blood pressure events, and quality of life in hemodialysis patients. Method An Egyptian dialysis center conducted a 6-month randomized controlled trial involving 80 hemodialysis patients. Patients were randomized into two groups: an intervention group (40 patients), which engaged in 30-minute exercise)in the form of 15 minutes for cycler and 15 minutes for hand grip (three times per week during dialysis sessions, and a control group (40 patients), which did not exercise. Laboratory investigations were performed before and after the intervention, measuring hemoglobin, serum sodium, potassium, calcium, phosphorus, and intact parathyroid hormone (iPTH). Intradialytic blood pressure events were recorded, and quality of life (QOL) was assessed using the Arabic version of the kidney disease and Quality of Life-Short Form 36 (KDQOL-SF™) Questionnaire. Results The intervention group exhibited a statistically significant reduction in inter-dialytic hypertension episodes compared to the control group (partial η² = .142, Cohen's f = .407). Additionally, the intervention group showed a significant increase in the physical composite score (partial η² = .178, Cohen's f = .465) accompanied by a significant decrease in the mental composite score (partial η² = .232, Cohen's f = .550) Moreover, The intervention group demonstrated a significant reduction in serum calcium levels post-intervention compared to the control group (partial η² = .069, Cohen's f = .272), with a positive correlation between the change in calcium level and the change in the physical composite score. Conclusion These findings indicate that exercise during haemodialysis may contribute to better blood pressure control and improved physical functioning. Incorporating exercise into the dialysis routine may serve as an effective approach to optimize the health and well-being of haemodialysis patients. Further research should focus on long-term effects and optimal exercise protocols to maximize these benefits.

Audit of Hemodialysis in Children Weighing Less than 20 kg in an African Pediatric Nephrology Unit.

Peritoneal dialysis and kidney transplantation remain the preferred choices for renal replacement therapy in young children. These options, however, are not always feasible, and hemodialysis (HD) is therefore an accepted alternative. In small children presenting with end-stage renal disease, HD presents several challenges and is often unavailable in lower- and middle-income countries. To assess these challenges and outcomes of maintenance HD in young children, we performed an audit of children below 20 kg with end-stage renal disease, receiving HD for ≥4 weeks, from 1 January 2008 to 31 July 2016 at the Red Cross War Memorial Children's Hospital. We identified 15 children weighing 6.8-18.5 kg (mean 12.9 kg ±3.5 SD) and aged 11.5-105 months (mean 52.2 months±4.2 SD) at HD initiation. Mean duration of HD was 11.8 months (range 1-61.5 months ± 16.9 SD). Seven children underwent successful transplantation, two patients died, and four currently still receive HD. Two patients, while on HD, relocated to other centers. An average of 2.6 (range 1-5) different vascular accesses was required per patient. Technical difficulties were the most common cause of central-line removal (81%), while catheter-associated bacteremia was 1.1/1000 catheter days. Frequent problems were intradialytic hypotension, growth stunting, and interdialytic hypertension. HD in lower- and middle-income countries is feasible in small children but presents with certain challenges. Advocacy with lobbying for funding and development of "child-friendly" dialysis equipment and specialized centers with highly skilled personnel are the cornerstones of successful pediatric HD programs in less-resourced centers.

Sympathetic Activation and Baroreflex Function during Intradialytic Hypertensive Episodes

BackgroundThe mechanisms of intradialytic increases in blood pressure are not well defined. The present study was undertaken to assess the role of autonomic nervous system activation during intradialytic hypertensive episodes.Methodology/Principal FindingsContinuous interbeat intervals (IBI) and systolic blood pressure (SBP) were monitored during hemodialysis in 108 chronic patients. Intradialytic hypertensive episodes defined as a period of at least 10 mmHg increase in SBP between the beginning and the end of a dialysis session or hypertension resistant to ultrafiltration occurring during or immediately after the dialysis procedure, were detected in 62 out of 113 hemodialysis sessions. SBP variability, IBI variability and baroreceptor sensitivity (BRS) in the low (LF) and high (HF) frequency ranges were assessed using the complex demodulation technique (CDM). Intradialytic hypertensive episodes were associated with an increased (n = 45) or decreased (n = 17) heart rate. The maximal blood pressure was similar in both groups. In patients with increased heart rate the increase in blood pressure was associated with marked increases in SBP and IBI variability, with suppressed BRS indices and enhanced sympatho-vagal balance. In contrast, in those with decreased heart rate, there were no significant changes in the above parameters. End-of- dialysis blood pressure in all sessions associated with hypertensive episode was significantly higher than in those without such episodes. In logistic regression analysis, predialysis BRS in the low frequency range was found to be the main predictor of intradialytic hypertension.Conclusion/SignificanceOur data point to sympathetic overactivity with feed-forward blood pressure enhancement as an important mechanism of intradialytic hypertension in a significant proportion of patients. The triggers of increased sympathetic activity during hemodialysis remain to be determined. Intradialytic hypertensive episodes are associated with higher end-of- dialysis blood pressure, suggesting that intradialytic hypertension may play a role in generation of interdialytic hypertension.

Epidemiology of Interdialytic Ambulatory Hypertension and the Role of Volume Excess

Background: The epidemiology of hypertension among hemodialysis (HD) patients is difficult to describe accurately because of difficulties in the assessment of blood pressure (BP). Methods: Using 44-hour interdialytic ambulatory BP measurements, we describe the epidemiology of hypertension in a cohort of 369 patients. To seek correlates of hypertension control, antihypertensive agents were withdrawn among patients with controlled hypertension and ambulatory BP monitoring was repeated. Results: Hypertension (defined as an average ambulatory systolic BP ≧135 mm Hg or diastolic BP ≧85 mm Hg, or the use of antihypertensive medications) was prevalent in 82% of the patients and independently associated with epoetin use, lower body mass index and fewer years on dialysis. Although 89% of the patients were being treated, hypertension was controlled adequately in only 38%. Poor control was independently associated with greater antihypertensive drug use. Inferior vena cava (IVC) diameter in expiration was associated with increased risk of poorly controlled hypertension both in cross-sectional analysis and after withdrawal of antihypertensive drugs. Conclusions: Interdialytic hypertension is highly prevalent and difficult to control among HD patients. End-expiration IVC diameter is associated with poor control of hypertension in cross-sectional analyses as well as after washout of antihypertensive drugs. Among HD patients, an attractive target for improving hypertension control appears to be the reduction of extracellular fluid volume.

Intradialytic Hypotension Strikes Again

Intradialytic hypotension (IDH) has plagued hemodialysis (HD) patients and their caregivers since the early days of renal replacement therapy. Its persistence in the current era is evident from the results of the 1426-patient Hemodialysis (HEMO) study in this issue of JASN in which a median of 12.5

Approach for guideline development

The first wave of European Best Practice Guidelines (EBPG) in haemodialysis was completed in spring 2002 and was published in November 2002 in Supplement 7 of Volume 17 of Nephrology, Dialysis and Transplantation [1]. This issue contained the guidelines on: (i) measurement of renal function, when to refer and when to start dialysis; (ii) haemodialysis adequacy; (iii) biocompatibility; (iv) dialysis fluid purity; (v) chronic intermittent haemodialysis and prevention of clotting in the extracorporeal system; (vi) haemodialysis-associated infection and (vii) vascular disease and risk factors. From the start of the development procedure of the first wave, it had been decided that a second wave would follow, dealing with a remaining number of topics of interest. The first meeting of the work group responsible for the writing process was held on 8 April 2003. The following topics were to be dealt with: (i) intradialytic haemodynamic instability; (ii) vascular access; (iii) malnutrition and acidosis and (iv) dialysis strategies. Two other topics had originally been planned as well, but were abandoned at this early stage: (i) interdialytic hypertension, because it appeared that the Kidney Diseases Outcomes Quality Initiatives (K/DOQI), the body responsible for the generation of nephrological guidelines for the National Kidney Foundation (NKF) in the United States, was planning at that moment to produce extensive guidelines on this topic, as a section of the ‘Clinical practice guidelines for cardiovascular disease in dialysis patients’; in spring 2003 the K/DOQI were already far advanced in the preparation of these guidelines which were due for the beginning of 2005; (ii) Bone disease and mineral metabolism, because K/DOQI was on the verge of finalizing guidelines on this topic, whereas also the Kidney Disease: Improving Global Outcomes (KDIGO) initiative, a new emerging organization aiming at harmonization of guidelines worldwide and at producing new global guidelines, was preparing a consensus on the topic as well [2]. In June 2003, during the World Congress of Nephrology (WCN) in Berlin, representatives of the K/DOQI, KDIGO and EBPG met to discuss these issues. It was decided to offer the EBPG work group ample opportunity to have an input on the sections on interdialytic hypertension in the upcoming clinical practice guidelines for cardiovascular disease in dialysis patients of K/DOQI. As the latter were planned to contain recommendations on intradialytic haemodynamic instability as well, it was likewise decided that the EBPG work group would have an input in the generation of these recommendations as well. Since EBPG was planning specific and extended guidelines on this topic, however, rather than recommendations, and had the intension to cover a broader spectrum of questions based on a more extended literature review, it was decided to continue the foreseen development of guidelines on intradialytic haemodynamic instability by the EBPG. While starting the guideline development, it was decided to abandon the concept followed during the previous wave, where each topic was covered by one work group member, under peer review by the entire work group. For the upcoming wave, it was decided to compose subgroups with 3 to 4 experts, each with a chairman, having a coordinating role. The concept of peer review by the entire work group during the whole development process was, however, maintained. It was also decided that the work group on malnutrition would contain a dietician, and that the subgroup on vascular access would contain a vascular surgeon and an interventional radiologist. Furthermore, it was taken into account that the Vascular Access Society had published recommendations on vascular access, and care was taken to include members in the subgroup on vascular access, who had taken part in the development of these recommendations as well. The work group was composed after approval of its members by the European Renal Association – European Dialysis and Transplantation Association (ERA–EDTA) (Table 1). Each guideline was divided into a number of major subheadings (Table 2). Correspondence and offprint requests to: Raymond Vanholder, Department of Internal Medicine, Nephrology Science, OK12, University Hospital, Ghent, Belgium. Email: raymond.vanholder@ugent.be Nephrol Dial Transplant (2007) 22 [Suppl 2]: ii1–ii4

Optimization of sodium removal in paired filtration dialysis by single pool sodium and conductivity kinetic models.

Sodium removal is one of the main factors affecting intradialytic cardiovascular stability and interdialytic hypertension, and its removal should therefore be individualized. The aims of this study were: (1) to test the ability of a single-pool variable volume (SPVV) sodium kinetic model (NaKM) to optimize sodium removal in paired filtration dialysis (PFD), and (2) to test a SPVV conductivity kinetic model (CKM) in order to verify whether CKM can be used as an alternative for NaKM in estimating sodium balance. The mean difference between the NaKM-predicted and measured end-PFD plasma water ionized sodium concentrations was 0.00 +/- 0.55 mEq/l, which means that the model has an imprecision of < or = 1.1 mEq/ l. The mean difference between predicted and measured sodium removal was 0.21 +/- 16.86 mEq/session, which means a model overestimate of 0.21 mEq/session. The mean difference between the CKM-predicted and measured end-PFD ultrafiltrate conductivity was 0.01 +/- 0.05 mS/cm, which means an inaccuracy of the model of 0.01 mS/cm and an imprecision of < or = 0.1 mS/cm. The regression in the ionized sodium concentration measured in plasma or blood on the conductive values of the ultrafiltrate shows an error of < or = 2 mEq/l in the prediction of the ionized sodium concentration in blood by means of ultrafiltrate conductivity measurements. These results demonstrate that both models make it possible to obtain a level of dialytic sodium removal that is almost equivalent to interdialytic sodium loading. Moreover, given that it does not require blood sampling and the possibility of making repeated and inexpensive ultrafiltrate conductivity measurements, the CKM allows online monitoring of programmed sodium removal.

Determining the adequacy of sodium balance in hemodialysis using a kinetic model.

The importance of sodium balance avoiding intradialytic cardiovascular instability and interdialytic hypertension and pulmonary edema is well known. An early analytical single-pool kinetic model created to evaluate sodium balance in hemodialysis, using flame photometry to determine plasma and dialysate sodium concentrations, has been shown to have a level of imprecision of +/- 2.8 mEq/l in predicting end-dialysis sodium plasma water concentrations (NaPWt). The ionometric determination of sodium concentrations seems to be more accurate and refers to the activity of the sodium capable of crossing dialysis membranes. On the basis of the theoretical premises of the model mentioned above, we developed a computerized single-pool kinetic model which makes it possible to calculate the ionized dialysate sodium activity (NaDI) required to reach a pre-established target of end-dialysis blood sodium activity (NaBI). Thirty-seven non-diabetic and anuric patients undergoing regular thrice-weekly hemodialysis were given their usual dialysis treatment, with NaDI at the usual value for each patient (range 137-147 mEq/l) and kept constant throughout dialysis. At the beginning and end of the session, NaDI and NaBI were measured in quadruplicate by means of a Nova-1 device (Direct Potentiometry, Pabisch Instruments). The validity of this kinetic model was tested by considering the difference between predicted and observed (P-O) NaBI at the end of dialysis [(t)]. P-O NaBI(t) was -0.37 +/- 0.42 mEq/l, which was statistically different from 0 (p < 0.001). When P-O NaBI(t) was plotted against ONaBI(t), it was more negative at the higher values of ONaBI(t). P-O intradialytic sodium removal (Nag) was -12.5 +/- 17.8 mEq/session, which was also statistically different from 0 (p < 0.001). The imprecision of this kinetic model was less than 0.84 mEq/l, as estimated by doubling the SD of P-O NaBI(t) (0.42 = 0.84 mEq/l). Although the reasons for its inaccuracy especially at higher ONaBI(t) values remain to be clarified, these data are the expression of a satisfactory clinical model.