A new procedure allowing the complete removal and prevention of hemodialysis biofilms.

Most currently used disinfectants for dialysis machines have a good bactericidal efficacy on biofilms but leave dead cells on the surface. This contributes to the regrowth of biofilm and the release of pyrogens. A new anti-biofilm procedure consisting of sequential treatment combining enzymes and detergents is able to detach adherent cells. The efficacy of this procedure was assessed both in vitro and in reality. For in vitro studies, a biofilm model was set up. Studies were also performed in reality in a clinically used dialysis machine. Biofilm removal was first monitored by image analysis. Then, the biomass was detached by scraping and quantified by plate counts and endotoxin level measurement. Treated samples were compared to untreated control samples. The procedure led to the complete detachment of the biomass, both in vitro and in the reality situation. The aim of this procedure is to replace or complete the usual disinfection methods for medical devices.

Six years' experience with short daily hemodialysis: do the early improvements persist in the mid and long term?

Observational studies from several groups have shown consistent beneficial effects in patients treated with short daily hemodialysis (SDHD). The cardiovascular and nutritional changes appear during the first few months after the initiation of SDHD. An extensive review of 17 patients from a group of 36 ESRD patients treated for up to 6 years with SDHD was undertaken to compare the clinicobiologic results during the initial period of standard hemodialysis (3 x 4 hr/week) and the short daily hemodialysis period at 1 year (SDHD(1)) and subsequent years (SDHD(2)). The statistical analysis of the clinicobiologic data clearly shows that the initial favorable results obtained during the first year of SDHD do persist in the mid and long term, which shows the more physiologic nature of this dialytic approach. The amelioration of left ventricular hypertrophy is of particular interest, showing a regression of ventricular dilation during the first year followed by a reduction of interventricular septum and posterior wall thickness during the subsequent years.

Daily Hemodialysis versus Standard Hemodialysis: TAC, TAD, Weekly eKt/V, std(Kt/V), and PCRn.

Seven patients, mean age 42.57 ± 15.69 years (range 21 - 67 years), on standard hemodialysis (SHD), 4 - 5 hours, three times per week for 11.0 ± 6.63 years (range 1 - 18 years), were switched to daily hemodialysis (DHD), 2 - 2.5 hours, six times per week. For each type of treatment similar parameters were applied, and the total weekly time was the same. Mean duration of DHD was 15.4 ± 4.98 months (range 7 - 20 months). We report here our results of quantification in each method, including time-averaged concentration (TAC), normalized protein catabolic rate (PCRn), equilibrated Kt/V (eKt/V), equivalent normalized continuous standard clearance [std(Kt/V)], equivalent renal urea clearance (eKRn), and time-averaged deviation (TAD). With DHD, urea TAC was reduced from 19.09 ± 3.47 to 15.16 ± 3.21 mmol/L (p = 0.026), urea TAD diminished from 4.76 ± 1.04 to 2.52 ± 0.57 mmol/L (p = 0.000 53), PCRn increased from 1.11 ± 0.23 to 1.42 ± 0.24 g/kg/day (p = 0.001), weekly eKt/V increased from 4.11 ± 0.31 to 4.74 ± 0.43 (p = 0.000 25), std(Kt/V) rose from 2.17 ± 0.06 to 4.02 ± 0.25 (p = 0.0001), and eKRn increased from 12.96 ± 0.60 to 21.7 ± 3.09 mL/min (p = 0.000 45). On DHD the most important quantitative variation is the decrease of urea TAD (closer to that of a healthy kidney), due to the increased frequency of dialysis; std(Kt/V) practically doubled and represents 30% of that of normal renal function. These changes are probably the main explanation for the clinical improvements, but it is difficult to dissociate the effects of increased dialysis dose from the effects of decreased TAD.

Time Needed to Improve Clinical Parameters By Daily Hemodialysis.

Daily hemodialysis therapy (DHD), 2 hours, 6 times per week, is able to cure complications that persist on standard hemodialysis (SHD), 4 hours, 3 times per week. Cardiovascular manifestations (high blood pressure, left ventricular hypertrophy), nutritional deficient states, and postdialysis asthenia are improved during the first month of DHD therapy and are usually cured at 3 months. Daily hemodialysis may be considered as a rescue therapy. The next step will be to select which patients can return to the classical SHD therapy without recurrence of their complications.