SACCM 179: Apheresis

Question 1

How are indications for apharesis classified in human medicine

Answer 1

Category 1: apheresis is accepted as first-line therapy (e.g., Myasthenia Gravis)
Category 2: second-line therapy (e.g., IMHA)
Category 3: controlled trials are limited or results are inconclusive (e.g., ITP, MODS from sepsis)
Category 4: considered ineffective or harmful

Question 2

List blood components in order of increasing density

Answer 2

plasma &laquo_space;platelets &laquo_space;lymphocytes &laquo_space;monocytes &laquo_space;granulocytes &laquo_space;red blood cells

Question 3

What can centrifugal TPE remove, that filtration TPE cannot?

Answer 3

cell components

Question 4

How do anticoagulant applications differ between centrifugal and filtration TPE?

Answer 4

centrifugal TPE –> most commonly uses regional citrate - systemic heparinization only in patients with high risk of clotting
filtration TPE –> either regional citrate or heparinized protocols used

Question 5

What is the ideal volume of distribution for TPE?

Answer 5

< 1 L/kg

Question 6

How much plasma volumes are removed with each TPE treatment and what approximate percentage of the substance will this remove?

Answer 6

1.0-1.5 x plasma volumes
results in the removal of 60-70% of substances in the intravascular space

removing more than 1.0-1.5 x plasma volume within one treatment does reach significant increases in substance removal because efficacy is reduced - needs time to distribute into the IV space again

Question 7

List 8 complications of TPE

Answer 7

• transfusion reactions to plasma
• hypocalcemia (citrate use)
• alkalosis (citrate use)
• blood loss via clotting of the extracorporeal circuit
• hypotension
• acute kidney injury (from synthetic colloids)
• hypoproteinemia
• hemorrhage (systemic anticoagulants)

Question 8

If the extracorporeal circuit volume is > _____% of the patient’s total blood volume, the extracorporeal circuit should be primed

Answer 8

> 20 %

Question 9

How do you calculate a dog’s and cat’s plasma volume

Answer 9

Dog plasma volume (ml) = (1-hematocrit) X (body weight in kg x 85 ml/kg)
Cat plasma volume (ml) = (1-hematocrit) X (body weight in kg x 55 ml/kg)

Question 10

What are the three properties of toxins that may indicate successful decontamination with TPE?

Answer 10

volume of distribution < 1 L/kg AND
high molelcular weight OR > 80% protein binding