Patient clearance time (tp) with different vascular access types.

BACKGROUND/AIMS: The dialysis delivered dose is limited by the rate at which urea can be transferred from the different body compartments. The time needed to clear the peripheral compartments of the body has been called the patient clearance time (tp). The aim of the study was to compare delivered dialysis dose using the tp index between patients dialyzed through a permanent central venous catheter (CVC) and patients with an arteriovenous fistula (AVF). METHODS: The study included 48 stable hemodialyzed patients. Patients were classified into two groups according to their vascular access type. The first group included 24 patients dialyzed through a permanent CVC and the second group consisted of 24 patients with a mature AVF. The following parameters were calculated twice for each patient: tp, Kt/V adjusted for the tp. RESULTS: tp was lower in the AVF dialysis modality than in CVC (26 ± 7 vs. 42 ± 14 min, p<0.001) while the (eqKt/V)tp was higher in AVF than in CVC dialysis (1.36 ± 0.11 vs. 1.19 ± 0.13, p<0.001). CONCLUSIONS: The patient clearance time is lower in AVF than in CVC dialysis, and this is accompanied by a higher delivered dialysis dose.

Correction of anemia with erythropoietin in chronic kidney disease (stage 3 or 4): effects on cardiac performance.

BACKGROUND: It is not clear whether the correction of anemia with erythropoietin (rhuEpo) in patients with chronic kidney disease (CKD) has any benefit on cardiac function and geometry. Most studies are based on indices of systolic function and left ventricular mass (LVM) and the results are conflicting. PATIENTS AND METHODS: We sought to investigate the effect of rhuEpo on LV systolic and diastolic performance using conventional and novel echocardiographic indices. Thirty one patients with CKD (stage 3 or 4) were included. Fifteen patients (group I) treated with rhuEpo targeting at Hb >or=13.0 g/dL, while the remaining (group II) were not treated. Clinical and laboratory parameters were recorded at baseline and 1 year later. Ejection fraction (EF) and LVM were carefully determined. Diastolic function was assessed by mitral inflow indices (E and A wave velocities, Edt deceleration time and E/A) and novel indices of mitral annulus motion using Tissue Doppler Imaging (Em, Am, and E/Em). An index of global cardiac function (Tei) was also calculated. RESULTS: At baseline, the 2 groups had comparable clinical and laboratory characteristics. After 1 year, a significant improvement in Hb levels (13.6 +/- 1.2 vs 10.3 +/- 1.2 g/dL, p < 0.05) as well as in systolic and diastolic function indexes was observed in group I compared to group II patients: EF (70.5 +/- 7.6 vs 63.4 +/- 9.3%, p < 0.05), LVM (116.5 +/- 34.9 vs 155.6 +/- 51.6 g/m(2), p < 0.05), Edt (233.9 +/- 98.6 vs 166.9 +/- 45.1 ms, p < 0.05), Tei index (0.35 +/- 0.12 vs 0.51 +/- 0.17, p < 0.01) and E/Em (9.7 +/- 2.4 vs 14.8 +/- 5.2, p < 0.05), respectively. Blood pressure and heart rate did not show significant changes. CONCLUSIONS: Correction of anemia with rhuEpo in patients with CKD seems to improve cardiac performance and geometry.

Sevelamer hydrochloride versus aluminum hydroxide: effect on serum phosphorus and lipids in CAPD patients.

BACKGROUND: Dietary phosphorus restriction, oral administration of phosphorus binders, and dialysis are the main strategies to control hyperphosphatemia in patients with stage 5 chronic kidney disease. Aluminum hydroxide (AH) and calcium carbonate, the most commonly used phosphorus binders, have serious disadvantages, such as aluminum toxicity and hypercalcemia. Sevelamer hydrochloride (SH) is a relatively new nonabsorbed calcium- and aluminum-free phosphorus binder. The present study was designed to evaluate the efficacy of SH in the control of hyperphosphatemia and its effect, compared to AH, on serum lipid parameters in patients on continuous ambulatory peritoneal dialysis (CAPD). METHODS: 30 stable patients on CAPD were included in an open-label, randomized crossover study. After a 2-week phosphorus binder washout period, 15 patients (group I) were administered SH for 8 weeks and in the remaining patients (group II), AH was introduced (phase A). After a new 2-week washout period, patients crossed over to the alternate agent for another 8 weeks (phase B). RESULTS: There were similar reductions in serum phosphorus levels over the course of the study with both agents: by 1.18 +/- 0.07 mg/dL (0.38 +/- 0.03 mmol/L) with SH and by 1.25 +/- 0.15 mg/dL (0.40 +/- 0.05 mmol/L) with AH in phase A (p = NS), and by 1.35 +/- 0.25 mg/dL (0.43 +/- 0.08 mmol/L) with AH and by 1.23 +/- 0.80 mg/dL (0.39 +/- 0.25 mmol/L) with SH in phase B (p = NS). Moreover, SH administration was associated with a 10.5% +/- 9.4% and a 20.1% +/- 6.8% fall in total cholesterol (p < 0.05) and low-density Lipoprotein cholesterol (p < 0.001) in phase A, and 11.9% +/- 7.2% (p < 0.05) and 21.5% +/- 2.4% (p < 0.001), respectively, in phase B. In both phases of the study, AH administration was not followed by a significant change in serum lipid parameters. CONCLUSION: Sevelamer hydrochloride is a well-tolerated alternative to calcium- or aluminum-containing phosphorus binder in the control of serum phosphorus in CAPD patients. Furthermore, SH improves the lipid profile in these patients.