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Zaccaria Ricci

Publications and source records attributed to Zaccaria Ricci.

23 records · Page 2Linked to original sources
PubMed2003

Coupled plasma filtration adsorption: rationale, technical development and early clinical experience.

The adjuvant treatment of sepsis remains a major therapeutic challenge. Blood purification is theoretically appealing if the humoral theory of sepsis is accepted as the basis for intervention. In this setting, blood purification would provide a broad-based restoration of humoral homeostasis thereby avoiding both excessive inflammation and counterinflammation. Several techniques of blood purification have been tried or are under active investigation. One of these is the so-called coupled plasma filtration adsorption (CPFA). CPFA is a novel extracorporeal blood purification therapy aimed at nonselectively reducing the circulating levels and activities of both pro- and anti-inflammatory mediators during sepsis and multiorgan failure. In vitro studies have shown CPFA to be effective in binding a broad range of such mediators proving its technical efficacy. Subsequent animal models have shown a beneficial effect on survival in endotoxemia. These studies have provided the necessary technical developments and biologic rationale for initial human studies. Two phase I/IIa clinical studies have now been performed. Both studies have shown that CPFA improves blood pressure and restores immune function in patients with severe sepsis and multiorgan dysfunction. In this article, we will discuss some of the basic principles involved in sorbent technology, and how these may contribute to treatment efficacy, review animal experiments with CPFA and finally discuss the results of recent human studies and their implications.

Adsorption↗
PubMed2002

A pilot study of coupled plasma filtration with adsorption in septic shock.

OBJECTIVE: To test the hypothesis that nonselective plasma adsorption by a hydrophobic resin (coupled plasmafiltration and adsorption) could improve hemodynamics and restore leukocyte responsiveness in patients with septic shock. DESIGN: Prospective, pilot, crossover clinical trial. SETTING: General intensive care unit in a teaching hospital. SUBJECTS: Ten patients with hyperdynamic septic shock. INTERVENTIONS: Patients were randomly allocated to 10 hrs of either coupled plasma filtration adsorption plus hemodialysis (treatment A) or continuous venovenous hemodiafiltration (treatment B) in random order. We measured the change in mean arterial pressure, norepinephrine requirements, and leukocyte tumor necrosis factor-alpha (TNF-alpha) production (both spontaneous and lipopolysaccharide-stimulated) after 10 hrs of each treatment. We also tested TNF-alpha production from normal human adherent monocytes incubated with patients' plasma obtained before and after the resin, both with or without incubation with an anti-interleukin-10 monoclonal antibody. RESULTS: Mean arterial pressure increased after 10 hr by 11.8 mm Hg with treatment A and by 5.5 mm Hg with treatment B (p =.001). There was an average decrease of norepinephrine requirement of 0.08 microg/kg/min with treatment A and 0.0049 microg/kg/min with treatment B (p =.003). All patients but one survived. Spontaneous and lipopolysaccharide-induced TNF-alpha production from patients' whole blood increased over time with treatment A. This increase was more marked in blood drawn after the device (plasmafiltrate-sorbent plus hemodialyzer) (p =.009). Preresin plasma suppressed lipopolysaccharide-stimulated production of TNF-alpha by 1 x 10(6)cultured adherent monocytes from healthy donors. This suppressive effect was significantly reduced after passage of plasma through the resin (p =.019) and after incubation with anti-interleukin-10 monoclonal antibodies (p =.028). CONCLUSIONS: In patients with septic shock, coupled plasmafiltration-adsorption combined with hemodialysis was associated with improved hemodynamics compared with continuous venovenous hemodiafiltration. This result might be related to its ability to restore leukocyte responsiveness to lipopolysaccharide. These findings suggest a potential role for blood purification in the treatment of septic shock.

APACHE↗
PubMedDate not supplied

Pulse high-volume hemofiltration in critically ill patients: a new approach for patients with septic shock.

Mortality rates in septic shock remain unacceptably high despite advances in our understanding of the syndrome and its treatment. Humoral factors are increasingly recognized to participate in the pathogenesis of septic shock, giving a biological rationale to therapies that might remove varied and potentially dangerous humoral mediators. While plasma water exchange in the form of hemofiltration can remove circulating cytokines in septic patients, the procedure, as routinely performed, does not have a substantial impact on their plasma levels. More intensive plasma water exchange, as high-volume hemofiltration (HVHF)can reduce levels of these mediators and potentially improve clinical outcomes. However, there are concerns about the feasibility and costs of HVHF as a continuous modality--very high volumes are difficult to maintain over 24 hours and solute kinetics are not optimized by this regimen. We propose pulse HVHF (PHVHF)-HVHF of 85 ml/kg/hr for 6-8 hours followed by continuous venovenous hemofiltration (CVVH) of 35 ml/kg/hr for 16-18 hours-as a new method to combine the advantages of HVHFimprove solute kinetics, and minimize logistic problems. We treated 15 critically ill patients with severe sepsis and septic shock using daily PHVHF in order to evaluate the feasibility of the technique, its effects on hemodynamics, and the impact of the treatment on pathologic apoptosis in sepsis. Hemodynamic improvements were obtained after 6 hours of PHVHF and were maintained subsequently by standard CVVHas demonstrated by the reduction in norepinephrine dose. PHVHFbut not CVVHsignificantly reduces apoptotic plasma activity within 1 hour and the pattern was maintained in the following hours. PHVHF appears to be a feasible modality that may provide the same or greater benefits as HVHFwhile reducing the workload and cost.

Animals↗