Assessment of Fluid Shifts of Body Compartments using Both Bioimpedance Analysis and Blood Volume Monitoring

Fluid shifts are commonplace in chronic hemodialysis patients during the intra- and interdialytic periods. In this study, we evaluated fluid shifts of body compartments using both bioimpedance spectroscopy and blood volume monitoring from the start to the end of hemodialysis. 24 stable hemodialysis patients were included on the study. Relative change of blood volume was progressively reduced from the start to the end of hemodialysis (1 hr, -7.22±3.23%; 2 hr, -9.78±4.69%; 3 hr, -12.88±5.65%; 4 hr, -15.41±6.54%, respectively). Mean % reduction of intracellular fluid was not significantly different to that of extracellular fluid at the end of hemodialysis (Δ ICF, -6.58±5.34% vs. Δ ECF, -7.07±5.12%). Mean % fluid reduction of arms, legs and trunk was -11.98±6.76%, -6.43±4.37% and -7.47±4.56%, respectively at the end of hemodialysis. There were 3 characteristic patterns in blood-volume change. Similar amounts of fluid were removed from the extracellular and intracellular compartments during hemodialysis, with the arms showing the greatest loss in terms of body segments. The pattern of blood volume change measured by blood volume monitoring may be useful for more accurate determination of dry-weight and for correcting volume status in hemodialysis patients

Comparison of Blood Pressure Control and Left Ventricular Hypertrophy in Patients on Continuous Ambulatory Peritoneal Dialysis (CAPD) and Automated Peritoneal Dialysis (APD)

This study aimed to investigate the influence of different peritoneal dialysis regimens on blood pressure control, the diurnal pattern of blood pressure and left ventricular hypertrophy in patients on peritoneal dialysis. Forty-four patients undergoing peritoneal dialysis were enrolled into the study. Patients were treated with different regimens of peritoneal dialysis: 26 patients on continuous ambulatory peritoneal dialysis (CAPD) and 18 patients on automated peritoneal dialysis (APD). All patients performed 24-hour ambulatory blood pressure monitoring (ABPM) and echocardiography. Echocardiography was performed for measurement of cardiac parameters and calculation of left ventricular mass index (LVMI). There were no significant differences in average of systolic and diastolic blood pressure during 24-hour, daytime, and nighttime between CAPD and APD groups. There were no significant differences in diurnal variation of blood pressure, systolic and diastolic blood pressure load, and LVMI between CAPD and APD groups. LVMI was associated with 24 hour systolic blood pressure load (r = 0.311, P < 0.05) and daytime systolic blood pressure load (r = 0.360, P < 0.05). In conclusion, this study found that there is no difference in blood pressure control, diurnal variation of blood pressure and left ventricular hypertrophy between CAPD and APD patients. The different peritoneal dialysis regimens might not influence blood pressure control and diurnal variation of blood pressure in patients on peritoneal dialysis

Back to Basics: Pitting Edema and the Optimization of Hypertension Treatment in Incident Peritoneal Dialysis Patients (BRAZPD)

Systemic arterial hypertension is an important risk factor for cardiovascular disease that is frequently observed in populations with declining renal function. Initiation of renal replacement therapy at least partially decreases signs of fluid overload; however, high blood pressure levels persist in the majority of patients after dialysis initiation. Hypervolemia due to water retention predisposes peritoneal dialysis (PD) patients to hypertension and can clinically manifest in several forms, including peripheral edema. The approaches to detect edema, which include methods such as bioimpedance, inferior vena cava diameter and biomarkers, are not always available to physicians worldwide. For clinical examinations, the presence of pitting located in the lower extremities and/or over the sacrum to diagnose the presence of peripheral edema in their patients are frequently utulized. We evaluated the impact of edema on the control of blood pressure of incident PD patients during the first year of dialysis treatment. Patients were recruited from 114 Brazilian dialysis centers that were participating in the BRAZPD study for a total of 1089 incident patients. Peripheral edema was diagnosed by the presence of pitting after finger pressure was applied to the edematous area. Patients were divided into 2 groups: those with and without edema according to the monthly medical evaluation. Blood arterial pressure, body mass index, the number of antihypertensive drugs and comorbidities were analyzed. We observed an initial BP reduction in the first five months and a stabilization of blood pressure levels from five to twelve months. The edematous group exhibited higher blood pressure levels than the group without edema during the follow-up. The results strongly indicate that the presence of a simple and easily detectable clinical sign of peripheral edema is a very relevant tool that could be used to re-evaluate not only the patient's clinical hypertensive status but also the PD prescription and patient compliance

Hemodialysis in children: general practical guidelines

Over the past 20 years children have benefited from major improvements in both technology and clinical management of dialysis. Morbidity during dialysis sessions has decreased with seizures being exceptional and hypotensive episodes rare. Pain and discomfort have been reduced with the use of chronic internal jugular venous catheters and anesthetic creams for fistula puncture. Non-invasive technologies to assess patient target dry weight and access flow can significantly reduce patient morbidity and health care costs. The development of urea kinetic modeling enables calculation of the dialysis dose delivery, Kt/V, and an indirect assessment of the intake. Nutritional assessment and support are of major importance for the growing child. Even if the validity of these “urea only” data is questioned, their analysis provides information useful for follow-up. Newer machines provide more precise control of ultrafiltration by volumetric assessment and continuous blood volume monitoring during dialysis sessions. Buffered bicarbonate solutions are now standard and more biocompatible synthetic membranes and specific small size material dialyzers and tubing have been developed for young infants. More recently, the concept of “ultrapure” dialysate, i.e. free from microbiological contamination and endotoxins, has developed. This will enable the use of hemodiafiltration, especially with the on-line option, which has many theoretical advantages and should be considered in the case of maximum/optimum dialysis need. Although the optimum dialysis dose requirement for children remains uncertain, reports of longer duration and/or daily dialysis show they are more effective for phosphate control than conventional hemodialysis and should be considered at least for some high-risk patients with cardiovascular impairment. In children hemodialysis has to be individualized and viewed as an “integrated therapy” considering their long-term exposure to chronic renal failure treatment. Dialysis is seen only as a temporary measure for children compared with renal transplantation because this enables the best chance of rehabilitation in terms of educational and psychosocial functioning. In long term chronic dialysis, however, the highest standards should be applied to these children to preserve their future “cardiovascular life” which might include more dialysis time and on-line hemodiafiltration with synthetic high flux membranes if we are able to improve on the rather restricted concept of small-solute urea dialysis clearance

Sympathetic Activation and Baroreflex Function during Intradialytic Hypertensive Episodes

BACKGROUND: The 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 FINDINGS: Continuous 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/SIGNIFICANCE: Our 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

Fluid state and blood pressure control in patients on maintenance hemodialysis

Cardiovascular disease is the main cause of high mortality in dialysis patients. Hypertension is a risk factor for cardiovascular disease and despite the use of highly efficient antihypertensive drugs (AHD), blood pressure (BP) is poorly controlled in the vast majority of hemodialysis (HD) patients. The pathogenesis of dialysis-associated hypertension is multifactorial, but the fluid state is a dominant factor for control of BP. The assessment of an optimal fluid state, so-called dry weight (DW), is usually based on clinical observations and other methods for evaluation of fluid state such as ultrasound of the inferior vena cava diameter (IVCD) and plasma levels of atrial natriuretic peptide (ANP). The aims of the present study were to: 1. evaluate the utility of IVCD measurements and ANP in assessing DW in maintenance HD (I, II). 2. determine whether endogenous plasma Asymmetrical Dimethyl Arginine (ADMA, an inhibitor of NO release) plays a role in the pathogenesis of dialysis-associated hypertension (III). 3. determine whether control of extracellular volume (ECV) is associated with normotension in HD patients (IV-V). IVCD values and their changes during and 2 hours after HD were compared to those in BV, measured with radioisotopes and monitored continuously (I). Pre- and postdialysis ANP levels were compared to BV, IVCD and vasoactive hormones (II). ADMA was determined in HD and CAPD patients and related to BP (III). The fluid state was evaluated with bioimpedance, ultrasound of IVCD and continuous monitoring of BV and compared in normotensive HD patients treated with long and short HD and in hypertensive patients treated with short HD (IV). The effect of intensified fluid removal during 3 months on BP (48h BP monitoring) and AHD was assessed in 16 hypertensive HD patients (IV). The main findings are: 1. IVCD measured at the end of or shortly after HD may be misleading in assessing DW due to fluid shift from the interstitial to the intravascular compartment which, in some cases, is not completed until 2 or more hours after HD. This time-lag limits the practical applicability of the method (I). 2. ANP release during HD is influenced by factors other than those related to changes in intravascular volume, such as age, presence of heart disease and possible interaction with other hormones, such as vasopressin and noradrenaline and its plasma levels are not useful for assessing the fluid state (II). 3. Plasma ADMA levels in dialysis patients are lower than those that might cause vasoconstriction due to inhibition of NO release. It is doubtful whether ADMA plays a significant role in the pathogenesis of dialysis-associated hypertension (III). 4. The normotensive patients treated with long and short HD had a similar fluid state and BP which were significantly lower than those in the hypertensive patients (IV). 5. We were able to reduce significantly ECV in 10 patients (group 1), but not in 6 patients (group 2). There was significant reduction in BP, especially during the night as well as in the dose of AHD in group 1. In group 2, BP and AHD dose remained unchanged (V). We concluded that fluid overload plays a major role in the pathogenesis of dialysis-associated hypertension. Its removal leads to improve the control of BP and its diurnal rhythm with little, if any, AHD. Normotension in HD patients may be achieved independently of the duration and dose of HID, if the control of postdialysis ECV is adequate. However, this is more difficult to achieve with short than with long HD, during which the UF rate is slower, the BV change smaller and intradialytic symptoms less common. There is no "gold standard" for the assessment of DW in patients on maintenance HD. All methods proposed have limitations and careful and continued clinical evaluation of the patient remains the method of choice for assessing DW

Conforming to the EU Food Quality and safety Standards in Bulgaria,

This book is an attempt to present shortly, but systematically, basic results, conclusions and recommendations from the joint research project „Conforming to EU standards and market requirements in the SME of Bulgaria: economic and social effects in the food industry”, headed by Prof. h. Jean-Pierre Gern of the University of Neuchatel, Switzerland. The project was financed by the Swiss National Foundation of Scientific Research in the frame of SCOPES 2005-2008 program. The basic research goal was to reveal social and economic effects of the obligatory implementation of the EU standards on quality, safety and environment protection on SME in the Bulgarian food industry and THE retail sector. The standards relate both to the quality and safety of products and workplaces, as well as to the environment protection. The results and conclusions could be of interest not only for specialized scientific community, but also for official bodies, responsible for conforming to the European food quality and safety standards, non-government organizations like different food sectors and retailers’ organizations, etc.Sofia University St. Kliment Ohridski, Faculty of Economics and Business Administration, Sofia, 112 p., ISBN 978-954-9399-08-0 (In English

Внедряване на европейските стандарти за качество и безопасност на храните в България (икономически и социални ефекти).

СУ „Св. К. Охридски”, Стопански факултет, София, 128 с., А4, ISBN 978-954-9399-07-

Икономически и социални ефекти от внедряването на европейските стандарти за качество и безопасност на храните в България

Настоящата книга представя основните резултати, изводи и препоръки от изследването по съвместен международен проект “Conforming to EU standards and market requirements in the SME of Bulgaria: economic and social effects in the food industry” с ръководител проф. Жан-Пиер Герн от Университета в Нюшател (Швейцария). Проектът е подпомогнат финансово от Националната фондация за научни изследвания на Швейцария. Основната цел на изследването е да се разкрият социално-икономическите ефекти от въвеждането на стандартите за качество и безопасност на храните в малките и средните предприятия от хранително-вкусовата промишленост, търговията с храни и общественото хранене в България. Разгледани са стандартите за качество и безопасност на продукта, условията на труд и опазването на околната среда. Получените резултати и изводи биха представлявали интерес както за специализираната научна общност, така и за редица държавни органи, отговорни за спазването на европейските стандарти за качество и безопасност на храните, а така също и за неправителствени организации, като браншови асоциации от секторите на хранителната индустрия, търговията с храни и др.Софийски университет „Св. Климент Охридски”, Стопански факултет, 367 с., А 4, София, ISBN 978-954-9399-09-