Fluid Therapy Pt 1

Interstitial fluid

Fluid found in the tissues, surrounds the cells

Vascular space

Plasma, fluid found in the blood vessels

Transcellular fluid

Fluid that is contained within epithelial lined spaces e.g. joints

What percentage of total body water is made up by intracellular fluid?

40%

Where is intracellular fluid contained?

Within the body cells

What is the main component of cytoplasm?

Intracellular fluid

What percentage of total body water is made up by extracellular fluid?

20%

What percentage of extracellular fluid is found in interstitial spaces?

15%

What percentage of extracellular fluid is found in intravascular spaces?

4%

What percentage of extracellular fluid is found in transcellular spaces?

1%

Osmosis

Movement of water through a semi-permeable membrane from a weak solution towards a concentrated solution

What is osmotic pressure?

The minimum pressure that needs to be applied to a solution to prevent the inward flow of pure solvent across a semi-permeable membrane.

What does osmotic pressure prevent?

The inward flow of pure solvent across a semi-permeable membrane.

Osmotic pressure is also defined as...

The measure of the tendency of a solution to pull in pure solvent by osmosis

What is osmotic pressure controlled by?

Proteins within the fluid

What are the two types of fluid compartments in the body?

Intracellular and extracellular fluid compartments

What do intracellular and extracellular fluid compartments contain?

Different concentrations of important solutes known as ions

What are ions?

Electrically charged particles found in body water

What are electrolytes?

Combination of ions that form a substance which breaks down in body water

What is the role of plasma proteins in the blood?

Plasma proteins help maintain osmotic pressure.

What is oncotic pressure?

Oncotic pressure is the specific osmotic force applied by plasma proteins.

Why do plasma proteins remain in the blood?

Capillaries are relatively impermeable to proteins.

How do plasma proteins affect fluid in the vasculature?

Plasma proteins encourage fluid to stay within the vasculature.

How to animals gain fluid?

By eating and drinking

How do animals lose fluid?

By faeces, urine, skin and the respiratory tract

What are abnormal ways of fluid loss?

- Polyuria

- Diarrhoea

- Vomiting

- Blood loss

- Evaporation (during long surgery)

Conditions which may increase fluid intake:

- Diabetes mellitus

- Diabetes insipidus

- Hyperadrenocorticism (Cushing's)

- Hyperthyroidism

How does Diabetes Mellitus cause an increase in fluid intake?

The animal becomes very thirsty and tend to urinate a lot more (polyuria) due to an excessive amount of drinking

Conditions which may decrease fluid intake include

- Fractured jaw

- Anaesthesia

- Systemic illness

How does a fractured jaw result in a decrease in fluid intake?

Animal cannot physically drink water

How does anaesthesia result in a decrease in fluid intake?

They are under for a long time

How does a systemic illness result in a decrease in fluid intake?

The animal becomes so ill that they don't want to drink and have inappetence

What is an indication for fluid therapy related to dehydration?

Replacement of fluid deficit (Animal has lost more fluid than is able to replace and becomes dehydrated)

What is an indication for fluid therapy related to blood volume?

Correct perfusion deficits (Hypovolaemia)

What is an indication for fluid therapy involving blood?

Administration of blood and blood products

What is the normal percentage for dehydration?

<5% (only assumed dehydrated from what owner has said)

What are the clinical signs of mild dehydration?

5-6%, subtle skin tent

What are the clinical signs of moderate dehydration?

6-10%, definite skin tent, mucous membrane dry/tacky, slow CRT <2 secs, sunken eyes

What are the clinical signs of severe dehydration?

10-15%, skin tent stays in place, prolonged CRT, very dry mucous membranes, sunken and dull eyes, progressive signs of hypovolaemia, leading to shock and death

Standard giving sets =

20 drops/ml of fluid

Paediatric giving set =

60 drops/ml of fluid

Blood administration set =

15 drops/ml of blood