Autonomic imaging:The cardiorenal axis

In this chapter, we discuss the pathophysiology of the various chronic cardiorenal interactions and their consequences on the sympathetic nervous system (SNS). Increased activity of SNS is observed in all stages of chronic renal disease. The chronic elevation of SNS activity is a major contributor of the complex pathophysiology of hypertension, heart failure, insulin resistance, sleep disorders, diuretic resistance, and progressive kidney disease. Overactivity of SNS contributes to the high incidence of cardiovascular events and cardiac mortality, especially in patients with end-stage renal failure. The dysfunction of sympathetic innervation can be visualized directly by use of [123 I]-metaiodobenzylguanidine ([123 I]-MIBG) scintigraphy.</p

Clinical applications of biofeedback systems in hemodialysis

Despite the tremendous progress in hemodialysis technology over the past decades, hemodynamic instability during hemodialysis is still a frequent complication. This is caused by the fact that in most patients large amounts of fluid are being removed over a short period of time, in combination with an increasingly higher proportion of (elderly) patients with significant cardiovascular co-morbidity. In recent years various closed-loop techniques have been developed to prevent hemodynamic instability during hemodialysis. These techniques differ with respect to the input and output parameters but have in common that they are based on current concepts of the pathophysiology of dialysis hypotension. In this chapter we will outline the pathophysiology of dialysis hypotension and discuss the various closed-loop techniques for hemodialysis that are currently available.</p

Relative blood volume measurements during hemodialysis:Comparisons between three noninvasive devices

The monitoring of relative blood volume changes (ΔRBV) has been advocated for the prevention of hemodialysis (HD) hypotension. Stand-alone devices (Crit-Line) or devices incorporated into the HD apparatus (blood volume monitor [BVM], Hemoscan) are widely used for this purpose. Comparisons between devices are scarce. The aim of this study was, first, to compare ΔRBV results from these 3 devices with ΔRBV calculated from changes in laboratory-derived hemoglobin (ΔRBV-lab-Hb) and, second, to compare ΔRBV results between the different devices. Fourteen patients received 2 HD treatments in a randomized order: one with the Hemoscan and Crit-Line combination and one with the BVM and Crit-Line combination. ΔRBV-lab-Hb was measured at 2 and 4 hr into the HD session. Bland-Altman analyses showed that ΔRBV results from the 3 devices differed systematically from ΔRBV-lab-Hb, i.e., the difference between the 3 devices and ΔRBV-lab-Hb varied significantly (p &lt; 0.05) with the magnitude of the measurement. The interdevice comparison showed considerable differences in ΔRBV results. At the end of the treatment, a significant difference (p &lt; 0.05) between ΔRBV measured by the Hemoscan and Crit-Line device (-9.8 ± 2.7% and -11.5 ± 4%, respectively) was found. In most patients, a systematic difference between Crit-Line and Hemoscan and between Crit-Line and BVM was observed. Relative blood volume change measurements by Crit-Line, Hemoscan, and BVM yield results that differ systematically from the results obtained from laboratory-derived Hb changes. Furthermore, there are substantial differences in ΔRBV results between the 3 ΔRBV devices.</p

Automatic feedback control of relative blood volume changes during hemodialysis improves blood pressure stability during and after dialysis

Automatic feedback systems have been designed to control relative blood volume changes during hemodialysis (HD) as hypovolemia plays a major role in the development of dialysis hypotension. Of these systems, one is based on the concept of blood volume tracking (BVT). BVT has been shown to improve intra-HD hemodynamic stability. We first questioned whether BVT also improves post-HD blood pressure stability in hypotension-prone patients and second, whether BVT is effective in reducing the post-HD weight as many hypotension-prone patients are overhydrated because of an inability to reach dry weight. After a 3-week period on standard HD, 12 hypotension-prone patients were treated with two consecutive BVT treatment protocols. During the first BVT period of 3 weeks, the post-HD target weight was kept identical compared with the standard HD period (BVT-constant weight; BVT-cw). During the second BVT period of 6 weeks, we gradually tried to lower the post-HD target weight (BVT-reduced weight; BVT-rw). In the last week of each period, we studied intra-HD and 24 hr post-HD blood pressure behavior by ambulatory blood pressure measurement (ABPM). Pre- and post-HD weight did not differ between standard HD and either BVT-cw or BVT-rw. Heart size on a standing pre-dialysis chest X-ray did not change significantly throughout the study. There were less episodes of dialysis hypotension during BVT compared with standard HD (both BVT periods: p &lt; 0.01). ABPM data were complete in 10 patients. During the first 16 hr post-HD, systolic blood pressure was significantly higher with BVT in comparison with standard HD (both BVT periods: p &lt; 0.05). The use of BVT in hypotension-prone patients is associated with higher systolic blood pressures for as long as 16 hr post-HD. BVT was not effective in reducing the post-HD target weight in this patient group.</p

Association between quality of life and various aspects of intradialytic hypotension including patient-reported intradialytic symptom score

BackgroundThere is increasing awareness that, besides patient survival, Quality of Life (QOL) is a relevant outcome factor for patients who have a chronic disease. In haemodialysis (HD) patients, intradialytic hypotension (IDH) is considered one of the most frequent complications, and this is often accompanied by symptoms. Several studies have investigated QOL in dialysis patients, however, research on the association between intradialytic symptoms and QOL is minimal. The goal of this study was to determine whether the occurrence of IDH has an influence on the perception of QOL.MethodsDuring 3 months, haemodynamic data, clinical events, and interventions of 2623 HD-sessions from 82 patients were prospectively collected. The patients filled out a patient-reported intradialytic symptom score (PRISS) after each HD session. IDH was defined according to the EBPG as a decrease in SBP 20mmHg or in MAP 10mmHg associated with a clinical event and need for nursing interventions. Patient's self-assessment of QOL was evaluated by the 36-Item Short-Form Health Survey.ResultsThere were no significant associations between the mental summary score or the physical summary score and the proportion of dialysis sessions that fulfilled the full EBPG definition. A lower PRISS was significantly associated with the proportion of dialysis sessions that fulfilled the full EBPG definition (R=-0.35, P=0.0011), the proportion of dialysis sessions with a clinical event (R=-0.64, P=0.001), and the proportion of dialysis sessions with nursing interventions (R=-0.41, P=0.0001). The physical component summary and mental component summary were significantly negatively associated with the variable diabetes and positively with PRISS (P=0.003 and P=0.005, respectively). UF volume was significantly negatively associated with mental health (P=0.02) and general health (P=0.01).ConclusionsOur findings suggest that the EBPG definition of IDH does not capture aspects of intradialytic symptomatology that are relevant for the patient's QOL. In contrast, we found a significant association between QOL and a simple patient-reported intra-dialytic symptom score, implying that how patients experience HD treatment influences their QOL

Association between quality of life and various aspects of intradialytic hypotension including patient-reported intradialytic symptom score

There is increasing awareness that, besides patient survival, Quality of Life (QOL) is a relevant outcome factor for patients who have a chronic disease. In haemodialysis (HD) patients, intradialytic hypotension (IDH) is considered one of the most frequent complications, and this is often accompanied by symptoms. Several studies have investigated QOL in dialysis patients, however, research on the association between intradialytic symptoms and QOL is minimal. The goal of this study was to determine whether the occurrence of IDH has an influence on the perception of QOL. Methods During 3 months, haemodynamic data, clinical events, and interventions of 2623 HD-sessions from 82 patients were prospectively collected. The patients filled out a patient-reported intradialytic symptom score (PRISS) after each HD session. IDH was defined according to the EBPG as a decrease in SBP ≥20 mmHg or in MAP ≥10 mmHg associated with a clinical event and need for nursing interventions. Patient’s self-assessment of QOL was evaluated by the 36-Item Short-Form Health Survey. Results There were no significant associations between the mental summary score or the physical summary score and the proportion of dialysis sessions that fulfilled the full EBPG definition. A lower PRISS was significantly associated with the proportion of dialysis sessions that fulfilled the full EBPG definition (R = − 0.35, P = 0.0011), the proportion of dialysis sessions with a clinical event (R = − 0.64, P = 0.001), and the proportion of dialysis sessions with nursing interventions (R = − 0.41, P = 0.0001). The physical component summary and mental component summary were significantly negatively associated with the variable diabetes and positively with PRISS (P = 0.003 and P = 0.005, respectively). UF volume was significantly negatively associated with mental health (P = 0.02) and general health (P = 0.01). Conclusions Our findings suggest that the EBPG definition of IDH does not capture aspects of intradialytic symptomatology that are relevant for the patient’s QOL. In contrast, we found a significant association between QOL and a simple patient-reported intra-dialytic symptom score, implying that how patients experience HD treatment influences their QOL

Association between quality of life and various aspects of intradialytic hypotension including patient-reported intradialytic symptom score

Background: There is increasing awareness that, besides patient survival, Quality of Life (QOL) is a relevant outcome factor for patients who have a chronic disease. In haemodialysis (HD) patients, intradialytic hypotension (IDH) is considered one of the most frequent complications, and this is often accompanied by symptoms. Several studies have investigated QOL in dialysis patients, however, research on the association between intradialytic symptoms and QOL is minimal. The goal of this study was to determine whether the occurrence of IDH has an influence on the perception of QOL. Methods: During 3 months, haemodynamic data, clinical events, and interventions of 2623 HD-sessions from 82 patients were prospectively collected. The patients filled out a patient-reported intradialytic symptom score (PRISS) after each HD session. IDH was defined according to the EBPG as a decrease in SBP ≥20 mmHg or in MAP ≥10 mmHg associated with a clinical event and need for nursing interventions. Patient's self-assessment of QOL was evaluated by the 36-Item Short-Form Health Survey. Results: There were no significant associations between the mental summary score or the physical summary score and the proportion of dialysis sessions that fulfilled the full EBPG definition. A lower PRISS was significantly associated with the proportion of dialysis sessions that fulfilled the full EBPG definition (R = - 0.35, P = 0.0011), the proportion of dialysis sessions with a clinical event (R = - 0.64, P = 0.001), and the proportion of dialysis sessions with nursing interventions (R = - 0.41, P = 0.0001). The physical component summary and mental component summary were significantly negatively associated with the variable diabetes and positively with PRISS (P = 0.003 and P = 0.005, respectively). UF volume was significantly negatively associated with mental health (P = 0.02) and general health (P = 0.01). Conclusions: Our findings suggest that the EBPG definition of IDH does not capture aspects of intradialytic symptomatology that are relevant for the patient's QOL. In contrast, we found a significant association between QOL and a simple patient-reported intra-dialytic symptom score, implying that how patients experience HD treatment influences their QOL

The Prevalence of Intradialytic Hypotension in Patients on Conventional Hemodialysis : A Systematic Review with Meta-Analysis

Background: Intradialytic hypotension (IDH) is considered to be a frequent complication of hemodialysis (HD) and is associated with symptom burden, increased incidence of access failure, cardiovascular events, and higher mortality. This systematic literature review aims to analyse studies that investigated the prevalence of IDH. A complicating factor herein is that many different definitions of IDH are used in literature. Methods: A systematic literature search from databases, Medline, Cinahl, EMBASE, and the Cochrane library to identify studies reporting on the actual prevalence of IDH was conducted. Studies were categorized by the type of definition used for the prevalence of IDH. A meta-analysis of the prevalence of IDH was performed. Results: In a meta-analysis comprising 4 studies including 1,694 patients and 4 studies including 13,189 patients, the prevalence of HD sessions complicated by IDH was 10.1 and 11.6% for the European Best Practice Guideline (EBPG) definition and the Nadir <90 definition, respectively. The proportion of patients with frequent IDH could not reliably be established because of the wide range in cutoff values that were used to identify patients with frequent IDH. There was a large variety in the prevalence of symptoms and interventions. Major risk factors associated with IDH across studies were diabetes, a higher interdialytic weight gain, female gender, and lower body weight. Conclusion: Our meta-analysis suggests that the prevalence of IDH is lower than 12% for both the EBPG and the Nadir <90 definition which is much lower than stated in most reviews

Supplementary Material for: Criteria for Continuous Kidney Replacement Therapy Cessation in ICU Patients

Introduction: In intensive care unit (ICU) patients with acute kidney injury, specific recommendations to guide the decision to cease continuous kidney replacement therapy (CKRT) are lacking. Methods: We performed a survey to identify criteria currently used to cease CKRT in real-life clinical practice in the Netherlands. We used an online questionnaire with multiple choice questions designed with web-based software from SurveyMonkey. Results: We received 169 completed questionnaires from intensivists (n = 126) and nephrologists (n = 43). Essential determinants for the cessation of CKRT were a spontaneously increasing diuresis (indicated by 92% of the respondents), absence of fluid overload (indicated by 88% of the respondents), and improvement in creatinine clearance (indicated by 61% of the respondents; intensivists 56%; nephrologists 77%, p = 0.03). Most often mentioned cut-off values used for increase in diuresis were 0.25 and 0.5 mL/kg/h (35% and 33%, respectively). Actual CKRT cessation was often postponed until the filter clots or until circuit disconnection is needed because of patient transport for diagnostic or intervention procedures (indicated by 58% of the respondents). Expected discharge from the ICU was the most frequently reported determinant to switch from CKRT to hemodialysis (indicated by 67% of the respondents). Conclusions: CKRT cessation in clinical practice is mostly based on spontaneously increasing diuresis, absence of fluid overload, and improvement in creatinine clearance and is often delayed until filter clotting or disconnection of the circuit because of logistic reasons