Dialysis Technology

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Questions and Answers

What is the definition of ultrafiltration?

Movement of solutes across a membrane due to a concentration gradient without requiring dialysate

Movement of solutes across a membrane due to a pressure gradient without requiring dialysate

Movement of water across a membrane due to a pressure gradient without requiring dialysate (correct)

Movement of water across a membrane due to a concentration gradient without requiring dialysate

How do ultrafiltration and dialysis help manage blood volume and certain electrolyte concentrations?

By increasing fluid overload and electrolyte imbalances

By promoting fluid overload and electrolyte imbalances

By attenuating fluid overload and electrolyte imbalances (correct)

By having no impact on fluid overload and electrolyte imbalances

What promotes capillary permeability and shifting of fluid to the extravascular space during CPB?

Lack of use of hemoconcentrators before, during, and after CPB

Exposure to foreign surfaces of the extracorporeal circuit and surgical trauma (correct)

Use of hemoconcentrators before, during, and after CPB

Lack of exposure to foreign surfaces of the extracorporeal circuit and surgical trauma

What creates a solute concentration gradient across the membrane during ultrafiltration?

Diffusion of water Signup and view all the answers

What is the formula for transmembrane pressure (TMP) in ultrafiltration?

$TMP = (Pin + Pout)/2 + V$ Signup and view all the answers

What does an increase in transmembrane pressure (TMP) lead to in ultrafiltration?

Increased rate of effluent removal Signup and view all the answers

What is the effect of increased blood pressure on the glomerular filtration rate?

Increased glomerular filtration rate Signup and view all the answers

What does ultrafiltration remove in equal concentration to the plasma water?

Diffusible solutes Signup and view all the answers

What is typically not removed by ultrafiltration?

Solutes greater than 65,000 Da Signup and view all the answers

What does the sieving coefficient measure in ultrafiltration?

The ability of a solute to be filtered through the ultrafiltrator membrane Signup and view all the answers

What can ultrafiltration during cardiopulmonary bypass (CPB) remove?

Excess fluid Signup and view all the answers

What is the configuration of the ultrafiltrator in relation to the extracorporeal circuit?

Configured in parallel Signup and view all the answers

What does ultrafiltration during CPB lead to according to studies?

Increased protein and red blood cell concentrations Signup and view all the answers

What is used for precise measurements in ultrafiltration, especially in pediatric patients?

Flowmeter Signup and view all the answers

Who developed the first clinical dialysis procedure?

George Haas Signup and view all the answers

What did Thomas Graham's 1854 paper describe?

Separating substances using a semipermeable membrane Signup and view all the answers

Who built an artificial kidney using a regenerated cellulose membrane?

Willem Kolff Signup and view all the answers

When did the hollow fiber dialyzer become commercially available?

1970 Signup and view all the answers

What is the process of ultrafiltration based on?

Movement of water and solutes across a semipermeable membrane Signup and view all the answers

What did John Jacob Abel's 1913 dialysis procedure use to prevent clotting?

Anticoagulant derived from leech heads Signup and view all the answers

Who developed the flat plate dialyzer in 1947?

Leonard Skeggs and Jack Leonards Signup and view all the answers

What did Richard Stewart develop in 1956?

The hollow fiber dialyzer Signup and view all the answers

What is ultrafiltration achieved through?

Filtration of water across a semipermeable membrane using a hydrostatic pressure gradient Signup and view all the answers

What does a semipermeable membrane allow to pass?

Water and small molecular weight solutes Signup and view all the answers

What does ultrafiltration remove from the blood?

Plasma water or ultrafiltrate Signup and view all the answers

What is the process of ultrafiltration also known as?

Hemoconcentration Signup and view all the answers

What does Z-Buf, a form of ultrafiltration, primarily aim to correct during cardiopulmonary bypass (CPB)?

Hyperkalemia Signup and view all the answers

What is contraindicated during Modified Ultrafiltration (MUF) in pediatric patients post-cardiopulmonary bypass (CPB)?

Protamine administration Signup and view all the answers

What can ultrafiltration effectively remove, especially in patients with heparin-induced thrombocytopenia (HIT) during cardiopulmonary bypass (CPB)?

Direct thrombin inhibitors like bivalirudin Signup and view all the answers

What is the primary purpose of continuous ultrafiltration during rewarming on cardiopulmonary bypass (CPB)?

Attenuate the inflammatory response Signup and view all the answers

What does a balanced electrolyte solution replace during rewarming to enable continuous ultrafiltration on cardiopulmonary bypass (CPB)?

Ultrafiltrate Signup and view all the answers

What is a potential benefit of using Z-Buf in adults undergoing cardiac surgery?

Correct severe electrolyte and acid-base disturbances Signup and view all the answers

What can Z-Buf combined with Modified Ultrafiltration (MUF) lead to post-cardiopulmonary bypass (CPB)?

Improved post-CPB outcomes and reduced levels of inflammatory mediators Signup and view all the answers

What is a key difference between ultrafiltration and dialysis in managing patient volume and electrolyte imbalances?

Efficiency in removing middle-molecule uremic solutes Signup and view all the answers

What can ultrafiltration effectively manage originating from potassium-based cardioplegia and red blood cells during cardiopulmonary bypass (CPB)?

Potassium loads Signup and view all the answers

What is a potential benefit of using Modified Ultrafiltration (MUF) for pediatric patients post-cardiopulmonary bypass (CPB)?

Concentrating residual circuit blood for transfusion without the risk of hypervolemia Signup and view all the answers

What does ultrafiltration primarily aim to remove during cardiopulmonary bypass (CPB) to maintain the patient's plasma concentration of diffusible solutes?

Excess water Signup and view all the answers

Study Notes

History and Development of Dialysis Technology

Dialysis is a process where blood is separated from a crystalloid solution by a semipermeable membrane, allowing solute transport by diffusion from a higher to a lower concentration.
Thomas Graham's 1854 paper "Osmotic Force" described separating substances using a semipermeable membrane and the direct relation between solute molecular weight and diffusion rate.
John Jacob Abel's 1913 dialysis procedure used a collodion membrane and an anticoagulant derived from leech heads to prevent clotting.
The first clinical dialysis procedure was performed by George Haas in 1924, and he made significant progress with the addition of a blood pump and the use of heparin as an anticoagulant.
Willem Kolff, after World War II, built an artificial kidney using regenerated cellulose membrane and developed the rotating drum kidney; he dialyzed 15 patients between 1943 and 1944, with one surviving.
Leonard Skeggs and Jack Leonards developed the flat plate dialyzer in 1947, which reduced blood volume and increased membrane surface area.
Richard Stewart began the development of the hollow fiber dialyzer in 1956, which provided high-efficacy solute transport, low priming volume, and low resistance to blood flow.
The hollow fiber dialyzer became commercially available in 1970 and is the most widely used type of dialyzer and ultrafiltrator currently.
Ultrafiltration is achieved through the filtration of water across a semipermeable membrane using a hydrostatic pressure gradient, creating a solute concentration gradient between the blood and the ultrafiltrate side of the membrane.
A semipermeable membrane has microscopic holes that only allow water and small molecular weight solutes to pass, resulting in a concentration of blood cells and large molecules on one side and water and small molecules on the other.
Ultrafiltration removes plasma water or ultrafiltrate from the blood using a microporous membrane material commonly manufactured in a hollow fiber configuration.
The process of ultrafiltration, also known as hemoconcentration, is based on the movement of water and solutes across a semipermeable membrane, equalizing concentrations in a process called convection.

Ultrafiltration and Hemoconcentration in Cardiopulmonary Bypass (CPB)

Ultrafiltration during CPB is primarily used to remove excess water, concentrate cellular elements and proteins in the blood, and maintain the patient's plasma concentration of diffusible solutes.
Continuous ultrafiltration during rewarming on CPB has been hypothesized to attenuate the inflammatory response, particularly during the peak of cytokine and complement levels.
A balanced electrolyte solution can replace ultrafiltrate during rewarming to enable continuous ultrafiltration, potentially reducing the inflammatory response.
Z-Buf, a form of ultrafiltration, has been used to correct hyperkalemia, particularly during cardiopulmonary bypass.
Potassium loads during CPB, originating from potassium-based cardioplegia and red blood cells, can be effectively managed through ultrafiltration and replacement with a low-potassium solution.
Z-Buf has also been used to correct severe electrolyte and acid-base disturbances in adults undergoing cardiac surgery, offering rapid corrections and the ability to select the concentration of diffusible solutes in the replacement fluid.
Modified Ultrafiltration (MUF) has been described for pediatric patients, concentrating residual circuit blood for transfusion without the risk of hypervolemia, but requiring the patient to remain cannulated post-CPB.
MUF can transfer nearly all circuit contents to the patient while the circuit remains primed with crystalloid solution, but protamine administration is contraindicated during MUF.
Ultrafiltration can effectively remove direct thrombin inhibitors like bivalirudin, especially in patients with heparin-induced thrombocytopenia (HIT), a complication of heparin administration.
Ultrafiltration can address challenges in managing hemodilution, electrolyte levels, and fluid shifts associated with the systemic inflammatory response during CPB.
Z-Buf, when combined with MUF, has shown improved post-CPB outcomes and reduced levels of inflammatory mediators, demonstrating its potential clinical benefits.
Ultrafiltration and dialysis, while serving similar functions in managing patient volume and electrolyte imbalances, have differences in efficiency in removing middle-molecule uremic solutes.

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Description

Test your knowledge of the history and development of dialysis technology and its applications in ultrafiltration and hemoconcentration during cardiopulmonary bypass (CPB) with this informative quiz. From the early advancements in dialysis to the use of ultrafiltration to manage electrolyte imbalances during CPB, this quiz covers key concepts and historical milestones in the field.