plasmapheresis

Question 1

Apheresis-

Answer 1

the blood of a patient or donor is passed through a medical device that first separates the components of blood then returns the remainder with or without extracorporeal treatment or replaces the separated components.

Question 2

What forms the buffy coat in a blood sample

Answer 2

Leukocytes and platelets

Question 3

What is plasma

Answer 3

The acellular liquid portion of blood after centrifugation

Question 4

Anticoagulation for plasmapheresis

Potential complications

Answer 4

citrate, 1:13 ratio to blood.

48 hr duration of effect

Calcium sequestration and effective hypocalcemia
Chvosteks and Trousseaus signs
Bleeding

Question 5

Minimum patient conditions for plasmapheresis

Answer 5

HTC: 20% by volume (37-47 female 40-54 male)
Hb: 70 g/L (normal: 135-170g/l male 120-165 g/l female)
WBC 1million/uL, (4-10 thousand/uL)
Platelets: 20million/uL (150-400 thousand/uL)

Ions are in normal range

Hemodynamically stable
Blood pressure is at minimum 90/60, max 160/110
Pulse 60-120/min

Peripheral or central venous catheter with 40/60mL/min

Question 6

Types of plasmaphaeresis

Answer 6

Autologous plasmapheresis - returning the removed plasma with or without treatment

Plasma exchange therapy, replacing lost plasma with

• Saline
• Albumin solution
• 70%albumin 30% saline
• Fresh frozen plasma

Donation

Question 7

Cytapheresis

Answer 7

Removing cells from the patients blood, WBCs or thrombocytes.
In some cases of IBD or myeloproliferative disorders with symptoms resulting from excessively viscous/cellular blood.

Question 8

When is Cytapheresis used

Answer 8

Removing cells from the patients blood, WBCs or thrombocytes.

For donation/harvesting of patients Peripheral blood stem cells.

Indications:

• severe/compressive hepatosplenomegaly from hematology disorders
• leukocytosis above 300K/uL in CML or 500K/uL in CLL, to remove excessive cell load prior to chemotherapy - reducing risk for tumor lysis syndrome
• for thrombocyte depletion in manifested hypercoagulability states with excess thrombocytes, essential thrombocytosis. above 1000billion/L platelets

Question 9

Photopheresis

Answer 9

Treating buffy coat cells extracorporeally with irradiation therapy, for some lymphocytic leukemia

Question 10

Flow rates for plasmapheresis

why is flow rate important

extracorporeal blood vol

Answer 10

40-60ml/min for adults

10-20ml/min for children

Flow rate needs to be maintained to prevent the osmotic changes from the plasma being too great, causing hemolysis of the cells in the solution.

300 ml is extracorporeal with one venous line

~100ml with two venous lines in Semmelweis

Question 11

Complications/difficulties of venous puncture for setting up the lines

Answer 11

Patient anxiety

Venous spasm

Sclerotic/damaged veins from repeated puncture

bleeding, compartment syndrome

Question 12

Puncture sites for setting up the catheter and their pros/cons

Answer 12

Sublavian vein:
very stable blood flow
high risk of PTX and not easily punctured

Internal jugular vein:
Easy to puncture, can be guided by ultrasound
Prone to collapsing

Common femoral vein:
Easy to puncture
High infection risk
uncomfortable, immobile patient

Question 13

Side effects of plasmapheresis

Answer 13

Hypocalcemia
Paresthesias

hypovolemia

allergy, hives, anaphylaxis

Question 14

What are some molecules removed by plasmapheresis

Answer 14

Autoantibodies, alloantibodies
Circulating immune complexes

Paraproteins, ie light chains

Lipoproteins

Exogenous toxins

Inflammatory mediators and cytokines

Question 15

How much plasma is exchanged?

Answer 15

(0.065 x body weight kg) x (1-HCT)
or
40ml/body weight
or 
60ml/body weight
or
between 1 and 1.5 times the plasma volume
total plasma voluem - 3.5L

Question 16

Volumes for Total body water

ECF

Plasma and interstitial fluid

Answer 16

TBW 0.6 times body weight - 42 L

ECF
1/3 of TBW
14 L

plasma 3.5

Interstitial 11.5

Question 17

Substitution fluids

Answer 17

5% Albumin solution. With Na or Na poor solutions

Question 18

Pros and cons of Albumin as substitution fluid

Answer 18

pros:
not a blood product, minimal HBV/HCV risk
rare to have allergic reactions
blood type independent
no cytokines

disadvantages:
expensive
lacks coagulation factors
lacks immunoglobulins

Question 19

Fresh frozen plasma pros and cons

Answer 19

pros:
Contains coagulation factors
Contains immunoglobulins
Contains complement factors

Disadvantages:
Blood product
HIV and hepatitis potential
Allergic/anaphylactic reactions
requires ABO compatibility
contains citrate and in an impaired liver may cause citrate toxicity - metabolic alkalosis, hypomagnesia and hypocalcemia

Question 20

Frequency of plasma exchange therapy

Answer 20

Whole plasma replacement eleminates 60% of the macromolecules, 1.5 volume replacement 75%

5 times in 10 days 90% of macromolecules

IGs are regenerated in 2-3 days
Complement is regenerated in 2 days
Coagulation factors in 1-2 days

therapeutic PEX should be done daily or every 2nd day/.

Question 21

1st line indications for plasmapheresis

Answer 21

Guillain-Barre syndrome
Myasthenia gravis crisis
Neuromyelitis optica
Chronic inlammatory demyelinating polyneuropathy

Goodpasture syndrome

TTP
HELLP syndrome

Symptomatic antiphospholipid syndrome of SLE

Symptomatic cryoglobulinemia with necrotizing vasculitis

Liver transplant and ABO incompatibility
Wilsons disease

Question 22

2nd line indications for plasmapheresis

Answer 22

ANCA associated RPGN-Wegeners if not sufficiently responsive to steroids and cyclophosphamide

Multiple myeloma nephropathy

graft vs host disease - photophoresis
FSGS after kidney transplantation

disseminated encephalomyelitis
Stiff person syndrome, anti GAD antibodies

Waldenstroms macroglobulinemia, IgM gammopathy and hyperviscosity

Question 23

Speeds for plasma and cytopheresis

Answer 23

plasmapheresis centrifuge speed 2K/min

cytopheresis speed 1K/min