Fluid Therapy - Colloids

What is the most permeable part of the vascular system?

capillaries

fluids that contain large, insolulbe molecules that do not freely cross a semipermeabble membrane and act to "hold" water within the vascular space for a longer duration that crystalloids

colloids

Which value in the starling equation helps to explain why a severely hypoproteinemic patient develops pitting limb edema, but not pulmonary edema?

reflection coefficient

in disease states, changes in the ? and ? coefficients make it difficult to predict the pharmacokinetics of colloids in vivo using the starling force equation

filtration and reflection coefficients

pressure exerted by large molecules that helps to hold water within the vascular space

colloid osmotic pressure (COP)

how is colloid osmotic pressure (COP) measured?

Colloid osmometer

What is the major contributor to COP in the intravascular space?

Albumin

What are some proposed benefits of colloids?

-Longer intravascular effects

-Smaller volume needed for intravascular expansion

-Less dilutional coagulopathies

-Decreased tissue edema formation

idea that electroneutrality must be maintained

Gibbs-Donnan Effect

natural colloid examples?

-Albumin (human and canine)

-Fresh/Frozen plasma

-Whole blood

synthetic colloids examples

-Hydroxyethyl starch (e.g. Hetastarc, pentastartch, tetrastarch)

-Gelatin

-Dextran

TF albumin has a uniform size

T

highly preserved among species

Albumin functions?

-Carrier molecule

-Maintains COP

-Coagulation/inflammation

-Role in healing

Purified canine albumin with less frequent/severe adverse affects than human albumin in dogs

Lyophilizied Canine Albumin

albumin that many be used in critically ill patients but can cause adverse reactions such as anaphylaxis and delayed hypersensitivity rxns

Human albumin

Never administer human albumin to a patient that has received ? in the past

human albumin

3 multiple choice options

weak colloids used primarily for replacement of clotting factors in patients with coagulopathies

blood products (fresh frozen plasma or whole blood)

Adverse effects of synthetic colloids?

Acute renal failure

Anaphylaxis

Volume overload

Coagulopathy

Immunosuppression

primary synthetic colloid used in vet med described by molecular weight and degree of substitution

Hydroxyethyl starch

Which has a greater correlation with negative effects on coagulation for hydroxyethyl starches?

Degree of substitution

1 multiple choice option

a ? degree of substitution correlates to a greater negative effect on coagulation for hydroxyethyl starches

higher

1 multiple choice option

hydroxyethyl starch commonly administered as a CRI with a higher degree of substitution so greater adverse effect on coagulation,

Hetastarch

hydroxyethyl starch with a lesser degree of substitution so minimal adverse effect on coagulation,

Voluven or Vetstarch

How should colloid therapy be monitored?

COP

USG

Osmolality