A novel multisensory device for the assessment and rehabilitation of perceptual and attentional competencies.

The present study aims to assess a novel technological device suitable for investigating perceptual and attentional competencies in people with or without sensory impairment. The TechPAD is a cabled system including embedded sensors and actuators to enable visual, auditory, and tactile interactions and a capacitive surface receiving inputs from the user. The system is conceived to create multisensory environments, using multiple units controlled separately and simultaneously. We assessed the device by adapting a spatial attention task comparing performances in different cognitive load conditions (high or low) and stimulation (unimodal, bimodal, or trimodal). 28 sighted adults were asked to monitor both the central and peripheral parts of the device and to tap a target stimulus (either visual, auditory, haptic, or multimodal) as fast as they could. Our results suggest that this new device can provide congruent and incongruent multimodal stimuli and quantitatively measure parameters such as reaction time and accuracy, allowing to investigate perceptual mechanisms in multisensory environments.Clinical Relevance-The TechPad is a reliable tool for the assessment of spatial attention during interactive tasks. its application in clinical trials will pave the way to its role in multisensory rehabilitation.

Peritoneal transport assessment by peritoneal equilibration test with 3.86% glucose: a long-term prospective evaluation.

The peritoneal equilibration test (PET) with 3.86% glucose concentration (3.86%-PET) has been suggested to be more useful than the standard 2.27%-PET in peritoneal dialysis (PD), but no longitudinal data for 3.86%-PET are currently available. A total of 242 3.86%-PETs were performed in 95 incident PD patients, who underwent the first test during the first year of treatment and then once a year. The classical parameters of peritoneal transport, such as peritoneal ultrafiltration (UF), D/D(0), and D/P(Creat), were analyzed. In addition, the absolute dip of dialysate sodium concentration (DeltaD(Na)), as an expression of sodium sieving, was studied. D/D(0) was stable, and a progressive decrease in UF was observed after the second PET, whereas D/P(Creat) firstly increased and then stabilized. DeltaD(Na) was the only parameter showing a progressive decrease over time. On univariate analysis, D/D(0) and DeltaD(Na) were found to be significantly associated with the risk of developing UF failure (risk ratio (RR) 0.987 (0.973-0.999), P=0.04, and RR 0.768 (0.624-0.933), P=0.007, respectively), but on multivariate analysis only DeltaD(Na) showed an independent association with the risk of developing UF failure (RR 0.797 (0.649-0.965), P=0.020). UF, D/D(0), and D/P(Creat) changed only in those patients developing UF failure, reflecting increased membrane permeability, whereas DeltaD(Na) significantly decreased in all patients. The 3.86%-PET allows a more complete study of peritoneal membrane transport than the standard 2.27%-PET. DeltaD(Na) shows a constant and significant reduction over time and is the only factor independently predicting the risk of developing UF failure in PD patients.

How to determine ionic dialysance for the online assessment of delivered dialysis dose.

BACKGROUND: Ionic dialysance may be equivalent to blood-water urea clearance corrected for recirculation (effective urea clearance); however, this is controversial. The aims of our study were (1) to verify in vivo whether the value of ionic dialysance is affected by the method of determination, given the effect of cardiopulmonary recirculation on inlet plasma water conductivity when the inlet dialysate conductivity is changed; and (2) to define the operative modalities for determining ionic dialysance to obtain an adequate estimate of effective urea clearance. METHODS: Thirty-three hemodialysis patients were studied during 186 dialysis sessions with low-flux polysulfone dialyzers using a modified Fresenius Medical Care 4008 B machine equipped with meters to measure inlet and outlet dialysate conductivities. This machine varied inlet dialysate conductivity (Cdi) according to the following pattern: starting from baseline (step 0), Cdi was increased by 8% (step 1). After Cdi had reached the target value, which took 8 to 10 minutes, it was lowered to 8% below the baseline value (step 2). After 8 to 10 minutes, when Cdi had reached the new target, it was returned to its starting value (step 3). Four values of conventional ionic dialysance (using the standard formula) and actual ionic dialysance (taking into account cardiopulmonary recirculation) were obtained for each cycle and were compared among them and with effective urea clearance (Kde). RESULTS: Mean conventional dialysance values at steps 0 to 2 and 2 to 3 (190 and 189 mL/min) were similar and higher than those at steps 0 to 1 and 1 to 2 (171 and 181 mL/min). Mean conventional ionic dialysance values underestimated Kde, particularly at steps 0 to 1 (-22.2 mL/min, P < 0.001) and 1 to 2 (-12.6 mL/min, P < 0.001). The actual dialysance values underestimated Kde by no more than 4.3 mL/min (P < 0.001). In steps 0 to 1 and 1 to 2, the underestimate of Kde by conventional dialysance increased at higher values of Kde, but this relationship did not exist when considering actual dialysance. CONCLUSIONS: The value of ionic dialysance is affected by the method of determination, given the effect of cardiopulmonary recirculation on inlet plasma water conductivity when inlet dialysate conductivity is changed. As a consequence, to provide a correct and direct estimate of effective urea clearance, ionic dialysance must be determined by changing inlet dialysate conductivity in such a way as to keep inlet plasma water conductivity constant by means of two symmetrical high and low dialysate conductivity steps.

Recombinant hepatitis B vaccine use in chronic hemodialysis patients. Long-term evaluation and cost-effectiveness analysis.

The prevalence of hepatitis B virus (HBV) infection in our unit was 45% (86/190); there were 77 (40.5%) and 9 (4.7%) patients with previous and persistent HBV infection, respectively. Recombinant hepatitis B vaccine was given to 118 chronic HD patients with a regimen of 3 double doses administered intramuscularly at 0, 1 and 2 months, obtaining a seroprotection rate of 67% (79/118), 57% (45/79) being high responders. At month 24, 78% (40/51) maintained protective levels of anti-HBs, 45% (18/40) of them being high responders. There was a statistically significant difference between responder and non-responder patients with regard to nutritional parameters such as serum total proteins and mean levels of transferrinemia. The number of diabetic patients was significantly increased in the nonresponder group. Patients with persistent antibodies ('persistent responders') were younger and had a shorter duration of HD treatment compared to those responders who rapidly lost anti-HBs ('transient responders'). Serological positivity for antibodies against hepatitis B core antigen significantly facilitates the decrease of anti-HBs antibodies over time. We detected seven episodes of HBV infection among HD patients at our unit before the beginning of the vaccination program. On the contrary, there were no episodes of HBV infection among responder vaccinees during the 24-month follow-up period. After the initial cost of vaccination, a savings of US$ 3,272 per year was realized by the elimination of frequent serologic screening of vaccine responders.