Mod 1: Hemoperfusion Overview and Mechanisms
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Questions and Answers

What cytokines are reported to have reductions associated with the use of VetResQ?

  • IL-4, IL-5, and TNF-alpha
  • IL-1, IL-3, and IL-7
  • IL-6, IL-8, and IL-1 (correct)
  • IL-2, IL-10, and IL-12

    • Which of the following statements accurately describes the survival benefits associated with albumin dialysis systems like MARS and Promethus?

  • They are the primary treatment for liver failure with proven survival rates.
  • They negate the effects of albumin-bound toxins completely.
  • They have established significant survival benefits in all cases.
  • Survival benefits have not been established, but they improve hepatic encephalopathy. (correct)

    • What is one of the primary functions of the MARS and Promethus systems in liver failure treatment?

  • To enhance nutrient absorption in the intestines
  • To provide total organ replacement
  • To directly repair liver tissue
  • To remove albumin-bound molecules like bilirubin (correct)

    • Which aspect of the MARS and Promethus systems requires additional consideration?

    <p>Their optimal use and safety concerns</p> Signup and view all the answers

    In non-controlled trials, what was noted as an outcome associated with the treatment using VetResQ?

    <p>Improved survival rates</p> Signup and view all the answers

    What is one advantage of hemoperfusion over IHD and CRRT?

    <p>It allows for the removal of larger molecules that bind to proteins.</p> Signup and view all the answers

    Which solutes are most effectively cleared using high-flux dialyzers?

    <p>Solutes between 12,000 and 15,000 Daltons.</p> Signup and view all the answers

    What primarily influences solute clearance in intermittent hemodialysis?

    <p>Pore size of the dialyzer and concentration gradients.</p> Signup and view all the answers

    Which scenario may indicate the need for hemoperfusion as a treatment option?

    <p>Impairment of drug excretion due to renal failure.</p> Signup and view all the answers

    Which property of a solute is a deterrent to its extracorporeal removal?

    <p>A volume of distribution greater than 1-2 L/kg.</p> Signup and view all the answers

    What does convection in solute clearance rely on?

    <p>Pressure to push solutes through the filter.</p> Signup and view all the answers

    What is a common limitation of IHD and CRRT in terms of solute clearance?

    <p>They can be limited in clearing larger molecules or those that bind to proteins.</p> Signup and view all the answers

    Which of the following drug groups is hemoperfusion more efficient at removing compared to hemodialysis?

    <p>Lipid-soluble drugs</p> Signup and view all the answers

    What type of kinetics occur in hemoperfusion if there is no saturation of the filter?

    <p>First-order kinetics</p> Signup and view all the answers

    When should cartridges in hemoperfusion be replaced?

    <p>When they become saturated</p> Signup and view all the answers

    Which of the following statements about one-compartment kinetics is correct?

    <p>Drug distribution is uniform throughout the body.</p> Signup and view all the answers

    What is the priming volume of the Adsorba (Baxter) 150 cartridge?

    <p>110 mL</p> Signup and view all the answers

    Why might hemoperfusion be considered over other forms of therapy?

    <p>It can target specific toxins due to strong adsorption.</p> Signup and view all the answers

    What is a characteristic of two-compartment kinetics?

    <p>Solutes concentrate more readily in fat compartments.</p> Signup and view all the answers

    What is the primary use of the MARS system in clinical settings?

    <p>To facilitate liver dialysis by binding toxins to albumin.</p> Signup and view all the answers

    Which of the following solutes should be efficiently removed by hemoperfusion?

    <p>Barbiturates</p> Signup and view all the answers

    Which type of cartridge provides the highest surface area for adsorption?

    <p>Atlas cartridge</p> Signup and view all the answers

    What is a limitation of hemoperfusion when applied to certain solutes?

    <p>Some solutes may redistribute to the intravascular space.</p> Signup and view all the answers

    In cases of ibuprofen and naproxen clearance, what was used to demonstrate effectiveness?

    <p>Carbon cartridges</p> Signup and view all the answers

    What is primarily used as the adsorbent in hemoperfusion?

    <p>Biomass-derived activated charcoal</p> Signup and view all the answers

    What type of pores are characterized by diameters less than 2 nm?

    <p>Microporous</p> Signup and view all the answers

    Hemoperfusion is a newer therapy that has always been consistently adopted since its introduction.

    <p>False</p> Signup and view all the answers

    Sorbent materials in hemoperfusion can only be microporous regardless of application.

    <p>False</p> Signup and view all the answers

    What is the primary therapeutic purpose of hemoperfusion?

    <p>Blood purification</p> Signup and view all the answers

    Hemoperfusion is delivered in a method similar to _________ .

    <p>hemodialysis</p> Signup and view all the answers

    What is the principal determinant of how much and how fast a solute will be adsorbed in hemoperfusion?

    <p>Surface area</p> Signup and view all the answers

    The process of creating a massive internal surface area in sorbents is achieved through a thermal–chemical reaction called _____ activation.

    <p>sorbent</p> Signup and view all the answers

    Match the following terms with their respective descriptions:

    <p>Activated Carbon = Material used for adsorbent in hemoperfusion Extracorporeal = Therapy performed outside the body Cytokines = Proteins involved in cell signaling Hemoadsorption = Process of removing substances from blood through adsorption</p> Signup and view all the answers

    Which of the following statements correctly describes modern hemoadsorbents?

    <p>They effectively remove drugs and toxins from the blood.</p> Signup and view all the answers

    Match the following pore size classifications with their corresponding definitions:

    <p>Microporous = Less than 2 nm Mesoporous = Between 2 nm and 50 nm Macroporous = Greater than 50 nm Nanoporous = Less than 1 nm</p> Signup and view all the answers

    Which type of adsorbent is primarily used for molecules exceeding 50 kDa?

    <p>Macroporous</p> Signup and view all the answers

    Improvements in adsorbent technology are expected to diminish the efficacy of hemoperfusion.

    <p>False</p> Signup and view all the answers

    What is a significant limitation of hemoperfusion in clinical settings?

    <p>Lack of commercially available dedicated equipment</p> Signup and view all the answers

    Activated charcoal is primarily mesoporous in structure.

    <p>False</p> Signup and view all the answers

    What is the pore size range typically targeted for drug overdose and poisoning clearance?

    <p>150 Da to 1,500 Da</p> Signup and view all the answers

    Which of the following forces is the primary factor in adsorption?

    <p>Van der Waals force</p> Signup and view all the answers

    Covalent bonds in adsorption are weaker than hydrogen bonds.

    <p>False</p> Signup and view all the answers

    What is the role of pore size in the process of adsorption?

    <p>Pore size determines which molecules can be adsorbed based on their physical dimensions.</p> Signup and view all the answers

    Adsorption can be affected by the presence of __________, which influence the electrostatic attraction between molecules.

    <p>charge</p> Signup and view all the answers

    Match the following sorbent properties with their descriptions:

    <p>Van der Waals force = Weak bond responsible for initial molecular attraction Ionic bonds = Stronger electrical forces between charged particles Hydrogen bonds = Bonds that are stronger than van der Waals but weaker than ionic bonds Covalent bonds = The strongest form of bond, involving sharing of electrons</p> Signup and view all the answers

    What provides the primary advantage of using modern sorbents in hemoperfusion?

    <p>They have adjustable and precise pore sizes.</p> Signup and view all the answers

    Name one application of hemoperfusion in managing medical conditions.

    <p>Management of toxicosis</p> Signup and view all the answers

    Hemoperfusion devices have been specifically designed for veterinary use from the start.

    <p>False</p> Signup and view all the answers

    What are the four forces responsible for adsorption in hemoperfusion?

    <p>The four forces responsible for adsorption in hemoperfusion are: van der Waals force, hydrogen bonds, ionic bonds, and covalent bonds.</p> Signup and view all the answers

    Different adsorbent types have varying pore sizes. What type of activated carbon is typically used for removing small molecules like drugs and their metabolites?

    <p>Microporous</p> Signup and view all the answers

    Activated carbon is initially formed through a process called pyrolysis, where the material is heated in the absence of oxygen. The pores in the original polymer are interconnected.

    <p>False</p> Signup and view all the answers

    Activated carbon hemoperfusion has been used to treat various toxicities. However, there are limitations of hemoperfusion. Which of the following is NOT a limitation?

    <p>The use of activated carbon hemoperfusion is more effective for removing water-soluble molecules than lipid-soluble molecules.</p> Signup and view all the answers

    What are the potential therapeutic applications of activated carbon hemoperfusion?

    <p>Activated carbon hemoperfusion has shown promise in managing toxicosis, including drug overdose, poisoning, and toxin removal. It also has potential in inflammatory conditions, like sepsis and heat stroke, where cytokine removal might be beneficial. There is ongoing research to explore its application in other conditions, like leptospirosis and immune-mediated hemolytic anemia.</p> Signup and view all the answers

    In the early days, activated carbon posed challenges in hemoadsorption due its bioincompatibility issues. How were these challenges addressed?

    <p>Adding a thin coating of cellulose nitrate and albumin to the carbon particles</p> Signup and view all the answers

    What are the characteristics of modern activated carbon hemoperfusion devices?

    <p>Modern activated carbon hemoperfusion devices have a more uniform spherical shape, a larger surface area (1,200 m²/g - 1,600 m²/g), and a smooth external surface, making them hemocompatible without additional polymeric coatings.</p> Signup and view all the answers

    Study Notes

    Hemoperfusion Overview

    • Hemoperfusion is an alternative to IHD and CRRT for solute removal.
    • It adsorbs substances onto cartridges, offering advantages for specific solutes (larger molecules or protein-bound substances) that are poorly removed via diffusion or convection.
    • Pharmacokinetic properties (solubility, binding, distribution volume) influence treatment choice.

    Solute Clearance Mechanisms

    • Diffusion: Clearance relies on concentration gradients; effectiveness depends on dialyzer pore size (low-flux <300 Da, high-flux ~12,000-15,000 Da).
    • Convection: Using pressure to push solutes through the filter. Diffusion and convection clearance are similar for smaller MW molecules.

    Clinical Indications for Hemoperfusion

    • Used in cases with progressive deterioration, midbrain dysfunction, drug excretion impairment, or poisoning with slow-acting substances.
    • Important for toxins removable at a faster rate than endogenous elimination. Decision depends on drug interactions.

    Comparison of Dialysis Methods

    • Table summarizing which treatments are more effective for various drug groups.

    Solute Kinetics in Hemoperfusion (HP)

    • Solute clearance follows first-order kinetics (until saturation) when the filter isn't saturated. Clearance equation provided to illustrate components.

    Compartmental Kinetics in Hemoperfusion (HP)

    • One-compartment: Treats the body as a single compartment, where drug distribution volume equals the treatment volume. The drug is primarily in the blood.
    • Two-compartment: The body is divided into multiple (blood, tissues etc) compartments where solute movement creates concentration differences. Solute may be more concentrated in one compartment, limiting removal.

    Cartridge Saturation

    • Adsorbents typically saturate after 1-6 hours.
    • Different adsorbents saturate at different rates, necessitating cartridge replacement to maintain efficacy.

    Adsorbents

    • Specific products (e.g., Adsorba, AimaLojic cartridges) are discussed including priming volumes and surface area.

    Polymer Sorbents & Specific Systems

    • Specialized polymers are used for targeted adsorption of specific substances.
      • MARS (Molecular Adsorbent Recirculating System) and Promethus systems are relevant technologies.

    Clinical Indications and Decision-Making

    • HP is primarily used for cases requiring potent toxin removal.
    • Treatment selection (CRRT, IHD, HP) based on factors like patient stability, solute properties & clearance goals.
      • HP is effective in reducing ibuprofen and naproxen concentrations in patients.

    Case Studies and Data

    • Cytokine clearance (e.g., IL-6, IL-8) is observed but evidence for survival benefit is limited.
    • Some studies have shown a reduction in IL-6, IL-8, and IL-1 with hemoperfusion.
    • Alternative therapies (plasmapheresis) relevant.
    • MARS and Promethus systems are discussed as examples, improving hepatic encephalopathy and removing albumin-bound molecules in liver failure, but survival benefits need verification.

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    Related Documents

    Activated Carbon Hemoperfusion and Plasma Adsorption PDF
    Principles of Hemoperfusion Lecture Slides PDF

    Description

    This quiz explores hemoperfusion as a method for solute removal, comparing it with IHD and CRRT. Key mechanisms such as diffusion and convection for solute clearance are examined, along with clinical indications for using hemoperfusion in toxicology. Learn how pharmacokinetic properties influence treatment decisions.

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