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Dialysis Session (dialysis + session)
Selected AbstractsCool dialysate reduces asymptomatic intradialytic hypotension and increases baroreflex variabilityHEMODIALYSIS INTERNATIONAL, Issue 2 2009Lindsay J. CHESTERTON Abstract Intradialytic hypotension (IDH) remains an important cause of morbidity and mortality in chronic hemodialysis (HD) patients and can be ameliorated by cool temperature HD. The baroreflex arc is under autonomic control and is essential in the short-term regulation of blood pressure (BP). This study aimed to investigate if the baroreflex sensitivity (BRS) response to HD differed between standard and cool-temperature dialysate. Ten patients (mean age 67±2 years) prone to IDH were recruited into a randomized, crossover study to compare BRS variation at dialysate temperatures of 37 °C (HD37) and 35 °C (HD35). Each patient underwent continuous beat-to-beat BP monitoring during a dialysis session of HD37 and HD35. During HD37 2 patients developed symptomatic IDH, as opposed to 1 with HD35. However, asymptomatic IDH occurred with a frequency of 0.4 episodes per session with HD35 and 6.2 episodes per session during HD37 (odds ratio15.5; 95%CI 5.6,14.2). Although absolute BRS measurements did not differ between the 2 modalities, BRS variability increased during HD35. Our study has demonstrated that in IDH-prone patients, cool HD resulted in a reduction in heart rate and a greater reduction in cardiac output and stroke volume. Mean arterial pressure was maintained through a significantly greater increase in total peripheral resistance. Furthermore, although absolute BRS values during HD were not significantly altered by a reduction in dialysate temperature, there was a greater percentage increase in BRS values during cool HD. Understanding the varied causes of, and categorizing impaired hemodynamic responses to HD will enable further individualization of HD prescriptions according to patient need. [source] Uremic hyperhomocysteinemia: A randomized trial of folate treatment for the prevention of cardiovascular eventsHEMODIALYSIS INTERNATIONAL, Issue 2 2007Areuza C. A. VIANNA Abstract Homocysteine is a risk factor for atherosclerosis in the general population, and serum homocysteine levels are almost universally elevated in chronic renal failure patients. When such patients are treated with dialysis, cardiovascular disease accounts for more than 50% of their mortality, which, in some proportion, may be pathophysiologically related to the elevated serum homocysteine levels. From April 2003 to March 2005, we conducted a 2-year, double-blind, randomized, placebo-controlled trial of 186 patients with end-stage kidney disease due to any cause, who were older than 18 years and stable on hemodialysis. Patients were assigned to receive either oral folic acid 10 mg 3 times a week immediately after every dialysis session under nurse supervision or an identical-appearing placebo for the entire study. On admission, plasma total homocysteine (tHcy) levels were above 13.9 ,mol/L in 96.7% of patients (median 25.0 ,mol/L, range 9.3,104.0 ,mol/L). In the placebo group, tHcy levels remained elevated at 6, 12, and 24 months, while oral folate significantly decreased tHcy to a median value of 10.5 (2.8,20.3) ,mol/L, (p<0.01). During the study, 38 patients (folic acid group 17 vs. placebo group 21; p=0.47) died from cardiovascular disease. Kaplan,Meier life table analysis dealing with the incidence of cardiovascular events, both fatal and nonfatal (myocardial infarction, arrhythmias, angina, heart failure, cerebrovascular accident), showed that 2 years of folic acid treatment and the lowering of the homocysteine blood levels had no effect on cardiovascular events (p=0.41; hazard ratio 1.24, 95% CI 0.74,2.10). However, the carotid artery intima-media wall thickness measured in a blinded fashion decreased from 1.94 ± 0.59 mm to 1.67 ± 0.38 mm (p<0.01) after 2 years of folate therapy. In this short-term study of uremic patients, 2 years of folic acid supplementation normalized the tHcy blood levels in 92.3% of patients but did not change the incidence of cardiovascular events compared with the control group. However, ultrasonography of the common carotid arteries performed at entry and 24 months later showed a significant decrease in intima-media thickness with folate supplementation. This suggests that early folate supplementation may benefit patients with chronic renal failure by preventing cardiovascular deterioration. [source] Preliminary Results from the Use of New Vascular Access (Hemaport) for HemodialysisHEMODIALYSIS INTERNATIONAL, Issue 1 2003J Ahlmén One of the most important factors for an optimal chronic hemodialysis is a well- functioning vascular access. Still the A-V-fistula is the best alternative. When repeated failures arise new access alternatives are needed. The Hemaport combines a PTFE-graft with a percutaneous housing of titan. Starting and stopping the dialysis session is simple and needle-free. The first clinical experiences are presented. Thirteen patients (m-age 60 years) in 6 centres had used the Hemaport system. Out of 11 functioning devices 7 were placed on the upper arm and 4 were located on the thigh. The total days in observation were 2.156 days with 769 dialysis sessions performed. Six patients had used the Hemaport system for more than 6 months. Mean blood flow was 364, range 100,450 ml/min with a mean venous and arterial pressure of 100 mm Hg, range 30,250, and 16 mm Hg respectively, range , 140 to + 259. Thrombosis interventions have been required in 14 percent to obtain a functioning vascular access. Two patients contributed with more than half of these events. Mechanical or pharmacological thrombolysis can be performed through the Hemaport dialysis lid without open surgery. Six implants have been removed and in 5 of these cases a new Hemaport was implanted. The reasons for removing the device were related to insufficient vascular flow, thrombosis, and/or infection. In patients with repeated access problems, a new vascular access (Hemaport) has been clinically used for about 1 year. By its design, Hemaport offers a novel approach. [source] Homocysteine, malondialdehyde and endothelial markers in dialysis patients during low-dose folinic acid therapyJOURNAL OF INTERNAL MEDICINE, Issue 5 2002T. Apeland Abstract. Apeland T, Mansoor MA, Seljeflot I, Brønstad I, Gøransson L, Strandjord RE (Rogaland Central Hospital, Stavanger; and Ullevål University Hospital, Oslo; Norway). Homocysteine, malondialdehyde and endothelial markers in dialysis patients during low-dose folinic acid therapy. J Intern Med 2002; 252: 456,464. Objectives. Haemodialysis patients have elevated levels of the atherogenic amino acid homocysteine. We wanted to assess the effects of small doses of intravenous folinic acid (the active form of folic acid) on some biochemical risk factors of cardiovascular disease. Design. Longitudinal and open intervention study. Setting. Two dialysis units in the County of Rogaland. Subjects. All patients on maintenance haemodialysis were invited, and 32 of 35 patients gave their informed consent. Interventions. After each dialysis session, the patients were given 1.0 mg of folinic acid intravenously thrice a week for a period of 3 months. Prior to and during the study, all patients were on maintenance supplementation with small doses of vitamins B1, B2, B3, B5, B6 and B12. Main outcome measures. Changes in the levels of (i) plasma total homocysteine (p-tHcy) and folate, (ii) circulating endothelium related proteins , markers of endothelial activation and (iii) serum malondialdehyde (S-MDA) , a marker of oxidative stress and lipid peroxidation. Results. The p-tHcy levels were reduced by 37% (P < 0.0001), whilst the serum and erythrocyte folate levels increased by 95 and 104%, respectively (P < 0.0001 for both). The circulating levels of endothelium related cellular adhesion molecules and haemostatic factors remained high and unchanged, except the thrombomodulin (TM) levels increased (P = 0.0004). The high levels of S-MDA were reduced by 26% (P = 0.003). Conclusions. Low doses of folinic acid given intravenously to dialysis patients reduced their levels of p-tHcy and S-MDA and thus improved their cardiovascular risk profile. The concurrent increment in TM levels was unexpected and of unknown clinical significance. [source] Effects of a Vitamin E-Modified Dialysis Membrane and Vitamin C Infusion on Oxidative Stress in Hemodialysis PatientsARTIFICIAL ORGANS, Issue 6 2001Jaromír Eiselt Abstract: Hemodialysis deteriorates oxidative stress. Vitamin E is an antioxidant whose regeneration is provided for by vitamin C. The authors tested the effects of a vitamin E-modified membrane (E), nonmodified cellulose membrane (O), and vitamin C infusion (500 mg, C) into the arterial blood line during dialysis on parameters of oxidative stress. In a short-term study, 24 patients were subjected to a single dialysis session with E, O, E with C, and O with C protocols. In a long-term study (12 weeks), 20 patients were randomized into groups with C and without C on each dialysis, and both groups had dialysis using O, E, and again O membrane for 4 weeks each. In the short-term study, thiobarbituric acid reacting substances (TBARS) in plasma rose after dialysis (p < 0.02) with O, and no changes were observed in the other 3 protocols. In the long-term study, predialysis TBARS declined when using E both in the groups with C (p < 0.02) and without C (p < 0.05). A switch over to O resulted in TBARS returning to baseline levels. The E membrane prevented an increase in lipid peroxidation during single dialysis, and long-term use of the E membrane also resulted in a decrease in the predialysis lipid peroxidation level. The antioxidant capacity of the E membrane was not enhanced by vitamin C infusion. High doses of vitamin C administered during dialysis using a nonmodified cellulose membrane prevented an increase in lipid peroxidation, most probably due to the enhanced rate of endogenous vitamin E regeneration. [source] Alternatives to standard hemodialysisHEMODIALYSIS INTERNATIONAL, Issue 2007Mark S. MACGREGOR Abstract Survival of patients on hemodialysis remains poor, but the benefits of increasing urea clearance have probably been maximized within our current treatment schedules. Long dialysis sessions (8 hr) produce impressive outcomes, with mortality 53% to 55% lower than conventional schedules. Even increasing from 4 to 5 hr may improve survival. Increased frequency of dialysis (6 times weekly) produces impressive reductions in left ventricular mass and could conceivably be implemented in-center. Preliminary data suggest a 61% reduction in mortality with increased frequency. Nightly dialysis combines longer sessions with increased frequency and has produced remarkable clinical gains in blood pressure, left ventricular mass, serum phosphate, and sleep apnea. However, the data are mainly from case series and impact on mortality remains unknown. Expansion of home hemodialysis would be necessary for this modality to grow. Convective therapies remove middle molecules more effectively, and observational data suggest hemodiafiltration has the potential to improve mortality by 35% to 36%. Hemodiafiltration has the advantage of being relatively easy to implement. The uremic milieu is complex and further investigation of the underlying pathophysiology is needed to inform future dialysis interventions. The survival data above are from observational studies, and hence benefits are likely to be exaggerated. Randomized trials of dialysis interventions are desperately needed. They remain difficult to perform, because of the complexity of both the patient population and the interventions, and because of limited available funding. [source] Fallacies of High-Speed HemodialysisHEMODIALYSIS INTERNATIONAL, Issue 2 2003Zbylut J. Twardowski Chronic hemodialysis sessions, as developed in Seattle in the 1960s, were long procedures with minimal intra- and interdialytic symptoms. Financial and logistical pressures related to the overwhelming number of patients requiring hemodialysis created an incentive to shorten dialysis time to four, three, and even two hours per session in a thrice weekly schedule. This method spread rapidly, particularly in the United States, after the National Cooperative Dialysis Study suggested that time of dialysis is of minor importance as long as urea clearance multiplied by dialysis time and scaled to total body water (Kt/Vurea) equals 0.95,1.0. This number was later increased to 1.3, but the assumption remained unchanged that hemodialysis time is of minimal importance as long as it is compensated by increased urea clearance. Patients accepted short dialysis as a godsend, believing that it would not be detrimental to their well-being and longevity. However, Kt/Vurea measures only removal of low molecular weight substances and does not consider removal of larger molecules. Besides, it does not correlate with the other important function of hemodialysis, namely ultrafiltration. Whereas patients with substantial residual renal function may tolerate short dialysis sessions, the patients with little or no urine output tolerate short dialyses poorly because the ultrafiltration rate at the same interdialytic weight gain is inversely proportional to dialysis time. Rapid ultrafiltration is associated with cramps, nausea, vomiting, headache, fatigue, hypotensive episodes during dialysis, and hangover after dialysis; patients remain fluid overloaded with subsequent poor blood pressure control, left ventricular hypertrophy, diastolic dysfunction, and high cardiovascular mortality. Short, high-efficiency dialysis requires high blood flow, which increases demands on blood access. The classic wrist arteriovenous fistula, the access with the best longevity and lowest complication rates, provides "insufficient" blood flow and is replaced with an arteriovenous graft fistula or an intravenous catheter. Moreover, to achieve high blood flows, large diameter intravenous catheters are used; these fit veins "too tightly," so predispose the patient to central-vein thrombosis. Longer hemodialysis sessions (5,8 hrs, thrice weekly), as practiced in some centers, are associated with lower complication rates and better outcomes. Frequent dialyses (four or more sessions per week) provide better clinical results, but are associated with increased cost. It is my strong belief that a wide acceptance of longer, gentler dialysis sessions, even in a thrice weekly schedule, would improve overall hemodialysis results and decrease access complications, hospitalizations, and mortality, particularly in anuric patients. [source] Preliminary Results from the Use of New Vascular Access (Hemaport) for HemodialysisHEMODIALYSIS INTERNATIONAL, Issue 1 2003J Ahlmén One of the most important factors for an optimal chronic hemodialysis is a well- functioning vascular access. Still the A-V-fistula is the best alternative. When repeated failures arise new access alternatives are needed. The Hemaport combines a PTFE-graft with a percutaneous housing of titan. Starting and stopping the dialysis session is simple and needle-free. The first clinical experiences are presented. Thirteen patients (m-age 60 years) in 6 centres had used the Hemaport system. Out of 11 functioning devices 7 were placed on the upper arm and 4 were located on the thigh. The total days in observation were 2.156 days with 769 dialysis sessions performed. Six patients had used the Hemaport system for more than 6 months. Mean blood flow was 364, range 100,450 ml/min with a mean venous and arterial pressure of 100 mm Hg, range 30,250, and 16 mm Hg respectively, range , 140 to + 259. Thrombosis interventions have been required in 14 percent to obtain a functioning vascular access. Two patients contributed with more than half of these events. Mechanical or pharmacological thrombolysis can be performed through the Hemaport dialysis lid without open surgery. Six implants have been removed and in 5 of these cases a new Hemaport was implanted. The reasons for removing the device were related to insufficient vascular flow, thrombosis, and/or infection. In patients with repeated access problems, a new vascular access (Hemaport) has been clinically used for about 1 year. By its design, Hemaport offers a novel approach. [source] QTc interval and QTc dispersion during haemodiafiltrationNEPHROLOGY, Issue 6 2004FULVIO FLOCCARI SUMMARY: Background and Aim: Our aim was to evaluate QTc interval and QTc dispersion in 27 end-stage renal disease (ESRD) patients undergoing Acetate Free Biofiltration (AFB) in order to ascertain any correlations between the electrrocardiographic (ECG) parameters, serum Na+, K+, Ca++, Mg++ and intraerythrocytic Mg++ (Mg++e) concentrations. All measures were made at t0 (session beginning), t1 (first hour), t2 (second hour), t3 (third hour), and t4 (session end). Results: Blood pressure, heart rate, bodyweight and total ultrafiltration in the three dialysis sessions were constant. A significant progressive increase occurred in serum Ca++ during the sessions, while there was a significant diminution in serum K+. The pattern for Mg++ concentrations in serum and erythrocytes differed: in serum it decreased, whereas Mg++e increased. At t4, the QTc interval was reduced to a significant extent with respect to the baseline value. QTc dispersion significantly increased at t1 without there being significant variations at other times with respect to t0. At t2, t3 and t4, values promptly returned to baseline levels. QTc had a negative correlation with serum Ca++ levels at t4. In contrast, an inverse correlation was found between QTc dispersion and serum K+ at t1. No other correlations could be found between any other electrolytes, QTc interval or QTc dispersion. Conclusion: In conclusion, the decrease observed in the QTc interval at the end of an AFB session was inversely related to serum Ca++ concentrations. Moreover, an increase in QTc dispersion occurred during the first hour of the session, and was negatively correlated with serum K+. [source] | ||||||||||