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Biomedical subjects

A Brendolan

Publications and source records attributed to A Brendolan.

117 records · Page 7Linked to original sources
PubMedDate not supplied

Brain density changes during renal replacement in critically ill patients with acute renal failure. Continuous hemofiltration versus intermittent hemodialysis.

Computerized tomography (CT) studies of the brain were made on 12 patients with acute renal failure from different origin. Patients were treated for two subsequent days in random sequence with intermittent hemodialysis (HD) (one 4-h session and Kt/V > or = 1) and continuous veno-venous hemofiltration (CVVH) (one 24-h session and Kt/V > or = 1). CT scans were done before and after the HD and CVVH session in each patient. In baseline conditions, the only macroscopic morphological alteration was a slight brain edema in some patients. Significant changes in the density of white and gray matter were observed after the HD session in all patients (gray matter from 52.3 +/- 5.2 to 38.9 +/- 5.3 and white matter from 36.7 +/- 3.5 to 24.8 +/- 3.2 Hounsfield units, average delta -26.7%). No changes were observed after CVVH. We conclude that intermittent HD involves a remarkable degree of "unphysiology", leading to increased water content in the brain after each session. In acute patients this may lead to a post-dialytic brain edematogenic state. The physiological stability provided by continuous therapies such as CVVH avoids this unwanted effect, and suggests that continuous renal replacement therapies should be a first choice in these patients.

Acute Kidney Injury↗
PubMedDate not supplied

Cellulose triacetate: another membrane for continuous renal replacement therapy.

The evolution of technology and biomaterials has permitted a parallel development of renal replacement therapies in the acute, critically ill patient. From the original continuous artero-venous hemofiltration method new techniques such as continuous veno-venous hemofiltration, hemodiafiltration and high-flux dialysis have been developed and are clinically used. Similar progress has been made with artificial membranes. We investigated the possibility of using a modified cellulosic membrane for continuous therapies, assessing the hydraulic characteristics and clearance performances of high-flux cellulose triacetate hemodiafilter (0.7 m2) in vitro and in vivo. The flowdynamic characteristics of the filter suggest its optimal use in veno-venous pump-drive techniques. Efficiency was excellent, with urea daily clearances as high as 50 liters or more. The high permeability and porosity of the membrane also increased the clearances of larger solutes such as creatinine and inulin. No side effects occurred during treatment and we conclude that cellulose triacetate may be considered a good alternative to synthetic membranes in continuous renal replacement therapies.

Acute Kidney Injury↗
PubMedDate not supplied

[Rationale for the use of extracorporeal treatments for sepsis].

Sepsis is the leading cause of disability and mortality among critical patients; moreover, it causes high economic expenditures. Although very much is known about the pathophysiology of this condition and its mediators despite great investments directed to its control, mortality rates remain high. Recent treatment manuals emphasize the value of early goal-oriented therapy and also point to the high efficacy of activated protein C. Extracorporeal blood clearance may potentially become a new approach to treating this condition. There are reports on its positive clinical results that are likely associated with the effective removal of septic mediators. Human and animal studies, few and rather alike as they are, have yielded promising results. It is evident that the use of these procedures is justified; however, their efficiency in sepsis requires large-scale, correctly conducted studies.

Extracorporeal Circulation↗
PubMedDate not supplied

The importance of ultrafiltration on acid-base status in a dialysis population.

The amount of fluid withdrawn by ultrafiltration in a dialysis session plays an important role in regulating the acid-base status of patients. It has been previously demonstrated that an interdialytic weight gain of 3 kilograms requires the removal of 3 liters, mostly of extracellular fluid, which may contain 60-70 mMols of bicarbonate. Such losses require an increase in the buffer mass transfer to achieve a good buffer balance. The importance of interdialytic weight gain (IWG) on acid-base status was evaluated in two significantly different periods. In the period where the IWG was lower, predialytic pH and HCO3 were significantly higher than in the alternate period. Since dialysis schedule, dialysate buffer, daily protein intake and given medications did not differ during the two periods, we conclude that a reduced ultrafiltration due to less weight gain betters predialytic acid-base status.

Acid-Base Equilibrium↗
PubMedDate not supplied

Technical and clinical evaluation of a new system for ultrafiltration control during hemodialysis.

A new system for ultrafiltration control during hemodialysis is described. The apparatus consists of a computer operated system of load cells that register variations in weight of the outlet dialysate versus inlet dialysate. Once the weight loss of the patient has been established, the gravimetric control operates on the dialysate circuit to obtain the transmembrane pressure adequate to achieve the desired ultrafiltration rate and patient weight loss. The system can be used as a complete dialysis machine or as a separate module that can be adapted to any standard dialysis machine. This module was tested in more than 220 dialysis sessions, using different membranes and ultrafiltration rates. The difference between the scheduled and the real weight loss was always less than 100 g at the end of the dialysis session. The number of technical interventions required were few, as was the rate of complications related to the system. The system is safe and reliable and offers a low cost opportunity to improve dialysis tolerance by accurate and progressive ultrafiltration during the session.

Body Weight↗
PubMedDate not supplied

Total solute extraction versus clearance in the evaluation of standard and short hemodialysis.

The authors compared the efficiency of standard HD (t = 240 minutes, Qb = 300 ml/min, Qd = 500 ml/min) with short HD (t = 150 minutes, Qb = 500 ml/min, Qd = 700 ml/min). The study was carried out in 11 patients in two sequential dialysis sessions, utilizing the same high surface area hollow fiber dialyzers, after a 2 day interdialytic period. With short HD, as expected, the clearance (Cl) of BUN, creatinine (Cr), and phosphates (P) was significantly higher than in standard HD:Cl BUN = 331 vs. 225, Cl Cr = 286 vs. 193, and Cl P = 231 vs. 176 ml/min. No significant difference in the total BUN extraction (measured on the total amount of exhausted dialysate) was found between the two techniques. As to Cr and P, despite higher Cl in short HD, the total extractions were significantly lower. In conclusion, in the evaluation of short HD efficiency, instantaneous Cl can be adequate for small molecules, while for larger solutes, other parameters, such as total extraction, must be considered.

Blood Flow Velocity↗