CAM201: Fluids, and other drugs used in shock

Question 1

Describe Crystalloids

Answer 1

Saline (Na+CL- sodium chloride). Increases fluid volume. Useful in shock to support circulation.
No O2-carrying capacity. Usually very safe, low incidence of anaphylaxis, also very cheap.
Always use with care to avoid circulatory overload.
Remember that in shock there is increased vascular permeability, so giving fluids may only increase oedema.

Question 2

Describe Colloids

Answer 2

Fluid replacement that contains large carbohydrates and proteins.
Designed to replace blood volume to support circulation. No 02 carrying capacity.
Higher risk of anaphylaxis than crystalloid saline. Also pretty cheap.
Always use with care to avoid circulatory overload.
In shock there is increased vascular permeability, so can potentially worsen oedema.

Question 3

Describe the mechanism of Activated Protein C and when it is indicated for use

Answer 3

Activated Protein C is indicated in shock with disseminated Intravascular Coagulation (DIC).

APC is an anticoagulant which works by inhibiting factors 5a and 8a, and thus preventing thrombin formation. In this way, APC inhibits both the extrinsic and intrinsic pathways of the coagulation cascade.

Use with care: very high risk of bleeding