Colloids

Question 1

How do Colloids work?

Answer 1

1. high molecular weight molecules - less able to cross semi permeable membrane
2. exert oncotic pressure - draw fluid intravascularly
3. results in plasma expansion
4. useful in resus when trying to raise the BP

Question 2

Gelatine

Answer 2

1. most commonly used in Gelofusine
2. hydrolysis of bovine collagen
3. cheaper than albumin

Question 3

What does Gelofusine consist of?

Answer 3

1. sodium 154 mml/l

2. chloride 120 mmol/l

Question 4

What are the complications of Gelofusine?

Answer 4

1. risk of anaphalaxis

2. increases risk of bleeding + may be prothrombotic

Question 5

Hydroxyethyle starches -

Answer 5

1. semsythetic polysaccharide
2. structually similar to glycogens
3. more expensive than gelatins

Question 6

Hydroxyethyl starches - adverse effects

Answer 6

1. accumulates in interstitial spaces and gets deposited in peripheral tissue - causes pruritus
2. coagulation problems
3. prophylaxis
4. can cause renal impairment

Question 7

Other fluids which act as Colloids

Answer 7

1. Blood - of bleeding
2. Human albumin solution
3. Fresh frozen plasma, cryoprepicipate - usually used when bleeding/dic

Question 8

Which fluid compartment do colloids impact?

Answer 8

Plasma/Intravascular compartment of the the extracelular fluid