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Biomedical subjects

Claudio Ronco

Publications and source records attributed to Claudio Ronco.

At least 37 records · Page 2Linked to original sources
PubMed2006

Oxidant and carbonyl stress-related apoptosis in end-stage kidney disease: impact of membrane flux.

Apoptosis is a highly regulated process which mostly affects cell-mediated immunity. In this open-label, randomized, prospective clinical study, we determined the impact in 10 hemodialysis patients treated with high-, medium-, and low-flux membranes on spontaneous or plasma-induced apoptosis, on monocytes, as well as on oxidant and carbonyl stress. High- and medium-flux membranes significantly reduced patients' plasma-dependent proapoptotic activity on U937 monocytic cell lines. Patients who had the highest levels of plasma-induced proapoptotic activity exhibited the highest plasma levels of advanced oxidation protein products (AOPPs) and carbonyls. Plasma carbonyl residues but not AOPPs were significantly lowered. Finally, a significant correlation could be drawn between the extent of plasma-induced proapoptotic activity and both plasma carbonyl and AOPP levels.

Adult↗
PubMed2006

Factors affecting hemodialysis and peritoneal dialysis efficiency.

The peritoneal dialysis system has three major components: the peritoneal microcirculation, the peritoneal membrane, and the dialysate compartment. All these three that includes the composition of the solution and the modalities of delivery. All these three components may have an important impact on the final performance of the technique. As in the hemodialysis system, factors affecting diffusion of solutes as well as factors affecting convective transport may contribute to the final clearance of a given solute. Ultrafiltration responds to the same pressures applied to the extracorporeal dialysis system, but osmotic gradients represent by far the most important active component.

Biological Transport↗
PubMed2006

Integration of peritoneal dialysis in the treatment of uremia.

The real integration of a specific therapy into the renal replacement program is represented by the possibility of easy and free patient transfer from one treatment to another without restrictions. In the case of peritoneal dialysis we feel that its integration in the therapeutic approach of uremia represents an ethical obligation for the physician, a clinical opportunity for the patient and a good cost/benefit solution for care givers. A full conviction that peritoneal dialysis represents a real therapeutic option for ESRD patients is necessary to achieve a real integration of this therapy in the uremia treatment program. A positive cost benefit ratio, both from the clinical and the economical points of view must also be seeked. The patient indirectly, must receive the same positive conviction, based on solid data and clinical results, comparable to those achievable in hemodialysis. Furthermore the patient must know that such treatment will provide an equal opportunity for kidney transplant compared to other therapies. Such a kind of feeling and knowledge must include information on patient's survival, rate of complications, treatment adequacy, availability of different techniques within the treatment and complete summary of advantages and disadvantages.

Humans↗
PubMed2006

Evolution of technology for automated peritoneal dialysis.

Automated peritoneal dialysis (APD) is important for the further penetration of PD in the dialysis marketplace. Long dwell, equilibration PD (CAPD) has limited applicability in many patients due to inadequate solute clearance or fast membrane transport characteristics. Providing large volumes of dialysate over circumscribed hours is highly labor intensive without an automated system. Early attempts at APD were crude but effective in reducing labor, which was generally provided by nursing staff. Later evolution of PD technology has been greatly accelerated by the microchip, and by miniaturization of components. Current generation machines allow individualized fill volumes, variable tidal volumes and additional daytime automated exchanges, teledialysis, memorized delivery control, and full portability. The ideal machine should not only be able to perform all treatment schedules, but it should also optimize the performance of a selected treatment strategy. Biocompatible solutions, improved osmotic agents, and sorbent technology are all adaptable to APD. The eventual evolution toward continuous flow PD will resolve many of the current problems with both CAPD and APD.

Humans↗
PubMed2006

Continuous flow peritoneal dialysis: current state-of-the-art and obstacles to further development.

Peritoneal dialysis (PD) is still underutilized as home based renal replacement therapy and in-patient treatment of acute renal failure. Hindering the expansion of PD is poor solute clearance, which is a result of the intermittent dwell technique. Continuous flow PD is an old concept that has demonstrated urea clearances from 2-5 times higher than standard PD. It relies on a 2-3 l dwell volume and continuous dialysate flow at 100-300 ml/min. This high flow rate dictates the need for an efficient dual lumen catheter, or two separate catheters with ports separated maximally, as well as a means to generate or regenerate large volumes of fluid. A modified hemodialysis system can easily be adapted to regenerate sterile peritoneal dialysate, and a dual lumen catheter with excellent flow characteristics has been designed. Ultrafiltration control and a means to accurately balance transperitoneal with external ultrafiltration persist as technical challenges. Continuous flow PD remains an attractive modality for daily home dialysis and treatment of acute renal failure.

Equipment Design↗
PubMed2006

A new home based bioimpedance system for PD.

Fluid overload and uncontrolled hypertension may be considered important mortality risk factors in peritoneal dialysis (PD) population. Even malnutrition is highly prevalent in PD patients. It is now well established that lower levels of serum markers of nutrition such as albumin, creatinine, and prealbumin are associated with increased mortality in PD patients [Fein, P.A. et al: Adv Perit Dial 2002;18:195-199]. Moreover cardiovascular disease is a leading cause of death in patients with end-stage renal disease, and hypertension and volume expansion are highly prevalent in long-term PD patients. Many studies in hemodialysis and in PD have demonstrated that phase sensitive bioelectrical impedance analysis is a widely used and proven method for evaluating patient's body composition. The vectorial bioimpedance analysis is a validated system to evaluate the hydration and nutritional state of hemodialysis and PD patients with acceptable sensitivity and specificity. The aim of this study is to evaluate the reliability and accuracy of the new multifrequency BodyComp bioimpedance analyzer as a home based tool versus traditional Bia Vector.

Adult↗
PubMed2006

The potential application of sorbents in peritoneal dialysis.

Sorbents have been designed to remove small and middle molecular weight toxins, including low molecular weight proteins, peptides, cytokines and chemokines in patients undergoing renal replacement therapy. Sorbents assist the process of peritoneal dialysate regeneration and have the potential to improve the efficiency of continuous flow peritoneal dialysis.

Humans↗
PubMed2006

Recent evolution of renal replacement therapy in the critically ill patient.

The epidemiology of severe acute renal failure has dramatically changed in the past decade. Its leading cause is sepsis and the syndrome develops mostly in the intensive care unit as part of multiple organ dysfunction syndrome. After the significant improvements obtained from the mid 1970s to the mid 1990s, the past decade has seen a dramatic evolution in technology leading to new machines and new techniques for renal and multiple organ support. Extracorporeal therapies are now performed using adequate treatment doses, which have resulted in improved survival in the general population. At the same time, patients with sepsis seem to benefit from the use of increased doses, as in the case of high-volume hemofiltration or of increased membrane permeability and sorbents as in the case of continuous plasmafiltration adsorption. The humoral theory of sepsis and the peak concentration hypothesis have spurred a significant interest in the use of such extracorporeal therapies for renal support and possibly for the therapy of sepsis. Ongoing research and prospective studies will further elucidate the role of such therapies in this setting.

Critical Care↗
PubMed2006

Solute removal during continuous renal replacement therapy in critically ill patients: convection versus diffusion.

INTRODUCTION: The best modality, for continuous renal replacement therapy (CRRT) is currently uncertain and it is poorly understood how transport of different solutes, whether convective or diffusive, changes over time. METHODS: We conducted a prospective cross over study in a cohort of critically ill patients, comparing small (urea and creatinine) and middle (beta2 microglobulin) molecular weight solute clearance, filter lifespan and membrane performance over a period of 72 hours, during 15 continuous veno-venous dialysis (CVVHD) and 15 continuous veno-venous hemofiltration (CVVH)sessions. Both modalities were administered based on a prescription of 35 ml/kg/h and using polyacrylonitrile filters. RESULTS: Median filter lifespan was significantly longer during CVVHD (37 hours, interquartile range (IQR) 19.5 to 72.5) than CVVH (19 hours, IQR 12.5 to 28) (p = 0.03). Median urea time weighted average (TWA) clearances were not significantly different during CVVH (31.6 ml/minute, IQR 23.2 to 38.9) and CVVHD (35.7 ml/minute, IQR 30.1 to 41.5) (p = 0.213). Similar results were found for creatinine: 38.1 ml/minute, IQR 28.5 to 39, and 35.6 ml/minute, IQR 26 to 43 (p = 0.917), respectively. Median beta2m TWA clearance was higher during convective (16.3 ml/minute, IQR 10.9 to 23) than diffusive (6.27 ml/minute, IQR 1.6 to 14.9) therapy; nonetheless this difference did not reach statistical significance (p = 0.055). Median TWA adsorptive clearance of beta2m appeared to have scarce impact on overall solute removal (0.012 ml/minute, IQR -0.09 to 0.1, during hemofiltration versus -0.016 ml/minute, IQR -0.08 to 0.1 during dialysis; p = 0.79). Analysis of clearance modification over time did not show significant modifications of urea, creatinine and beta2m clearance in the first 48 hours during both treatments. In the CVVHD group, the only significant difference was found for beta2m between 72 hours and baseline clearance. CONCLUSION: Polyacrylonitrile filters during continuous hemofiltration and continuous hemodialysis delivered at 35 ml/kg/h are comparable in little and middle size solute removal. CVVHD appears to warrant longer CRRT sessions. The capacity of both modalities for removing such molecules is maintained up to 48 hours.

Adult↗
PubMed2006

Year in review 2005: critical care--nephrology.

We summarize original research in the field of critical care nephrology accepted or published in 2005 in Critical Care and, when considered relevant or directly linked to this research, in other journals. The articles have been grouped into four categories to facilitate a rapid overview. First, physiopathology, epidemiology and prognosis of acute renal failure (ARF): an extensive review and some observational studies have been performed with the aim of describing aspects of ARF physiopathology, precise epidemiology and long-term outcomes. Second, several authors have performed clinical trials utilizing a potential nephro-protective drug, fenoldopam, with different results. Third, the issue of continuous renal replacement therapies dose has been addressed in a small prospective study and a large observational trial. And fourth, alternative indications to extracorporeal treatment of ARF and systemic inflammatory response syndrome have been explored by three original clinical studies.

Critical Care↗