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Hemodialysis Sessions (hemodialysis + session)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Relation Between Echinocytosis and Erythrocyte Calcium Content in Hemodialyzed Uremic Patients

ARTIFICIAL ORGANS, Issue 6 2001
B. Agroyannis
Abstract: A rise in intracellular calcium concentration in erythrocytes has multiple effects on these cells. The purpose of this study was to determine the changes of calcium content in red blood cells (RBCs) and of echinocyte percentages in uremic patients during hemodialysis sessions. In 30 uremic patients under hemodialysis, the calcium content of RBCs and echinocyte percentages were determined in 3 blood samples collected at 0 min hemodialysis (prehemodialysis), 45 min hemodialysis, and 240 min hemodialysis (end hemodialysis) for a 4 h hemodialysis session. Calcium content of RBCs and echinocytes were also determined in 22 normal subjects (controls). The findings of the present study were that the mean values (±SD) of calcium content of RBCs in patients at 0 min hemodialysis, 45 min hemodialysis, and 240 min hemodialysis were 2.00 ± 1.0, 2.66 ± 0.87, and 1.62 ± 0.66 ,g/ml respectively and 0.65 ± 0.07 ,g/ml in controls. These values show that the calcium content of RBCs in uremic patients at 0 min hemodialysis, 45 min hemodialysis, and 240 hemodialysis was significantly higher than in controls (p < 0.0001), and that RBC calcium content at 45 min hemodialysis was significantly higher in comparison to that at 0 min hemodialysis (p < 0.001) and to that at 240 min hemodialysis (p < 0.0001), while that at 240 min hemodialysis was significantly lower than at 0 min hemodialysis (p < 0.05). The mean values (±SD) of echinocyte percentages in patients at 0 min hemodialysis, 45 min hemodialysis, and 240 hemodialysis were 11.93 ± 6.18, 17.23 ± 4.1, and 7.96 ± 5.67% respectively, and in controls ranged from 0 to 1%. The values in uremic patients show a transient increase of echinocyte percentages at 45 min hemodialysis, which is significant in comparison to that at 0 min hemodialysis (p < 0.001) and to that at 240 min hemodialysis (p < 0.0001). Echinocyte percentages at 240 min hemodialysis were significantly lower to those at 0 min hemodialysis (p < 0.001). Correlation between calcium content of erythrocytes and echinocyte percentages shows a significantly positive relationship at 45 min hemodialysis (r = 0.368, p < 0.05) but no significant relationship at 0 min hemodialysis and 240 min hemodialysis. In conclusion, uremic patients under hemodialysis present with high calcium content in erythrocytes and abnormal erythrocytes like echinocytes. A rapid and transient increase of erythrocyte calcium is also accompanied by transient elevation of echinocytes in the first hour of hemodialysis (45 min hemodialysis), which returns after hemodialysis to lower than prehemodialysis levels. [source]

Fallacies of High-Speed Hemodialysis

HEMODIALYSIS INTERNATIONAL, Issue 2 2003
Zbylut 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]

Exercise Training During Hemodialysis Reduces Blood Pressure and Increases Physical Functioning and Quality of Life

ARTIFICIAL ORGANS, Issue 7 2010
Maycon De Moura Reboredo
Abstract Hypertension and cardiovascular diseases are highly prevalent in hemodialysis patients and are associated with the reduction of physical functioning and quality of life. We evaluated the effects of supervised aerobic exercise training on physical functioning, blood pressure, quality of life, and laboratory data in hemodialysis patients. Fourteen patients were evaluated at the beginning and after 12 weeks of stretching exercises (control phase) and at the end of 12 weeks of aerobic exercise training performed during hemodialysis sessions (intervention phase). Patients underwent a 6-min walking test (6MWT), 24-h ambulatory blood pressure monitoring, a Medical Outcomes Study 36,Item Short-Form Health Survey (SF-36) quality of life questionnaire, and blood sample collections. After the intervention phase, the 6MWT distance increased from 508.7 ± 91.9 m to 554.9 ± 105.8 m (P = 0.001), systolic and diastolic blood pressure decreased respectively from 150.6 ± 18.4 mm Hg to 143.5 ± 14.7 mm Hg and from 94.6 ± 10.5 mm Hg to 91.4 ± 9.7 mm Hg (P < 0.05), while hemoglobin levels increased from 10.8 ± 1.2 g/dL to 11.6 ± 0.8 g/dL (P < 0.05). Moreover, there was a significant increase in the physical functioning, social functioning, and mental health dimensions of the SF-36. Aerobic exercise training during hemodialysis increased physical functioning, reduced blood pressure levels, and improved the control of anemia and quality of life in patients with end-stage renal disease. [source]