Fluid Therapy Flashcards
Where is water found in the body?
40% intracellular fluid (ICF)
20% extracellular fluid (ECF)
15% interstitial fluid
5% plasma
<1% transcellular - cerebrospinal and synovial joint fluid
Ways of fluid intake?
Drinking
Food
Metabolism (fat breakdown 10% max)
What of fluid output?
Respiration - insensible
Urine - sensible
Faeces - sensible
Skin - insensible
What are sensible loses?
When the body can adjust the fluid loss to conserve or get rid of fluid.
30-40ml/kg/day
What are insensible loses?
When the body cannot adjust the losses.
10-20ml/kg/day
Can sometimes increase amount of loss (i.e., infection) but not decrease
What is the maintenance amount of fluid required daily?
40-60ml/kg/day
Average of 50ml/kg/day
What is dehydration?
Where an animal has a problem balancing the input and output of fluid from the body.
Initially fluid is lost primarily from the blood.
What is fluid concentration?
Concentration or tonicity of fluid is determined by the amount of substances contained in the fluid (solution).
What do the terms ‘solution’, ‘solute’, and ‘solvent’ mean?
Solution - a solute dissolved within a solvent.
Solute - the solid portion of a solution.
Solvent - the liquid portion of a solution.
What do the terms ‘isotonic’, ‘hypertonic’, and ‘hypotonic’ mean?
Isotonic - concentration (osmotic pressure) equal to plasma.
Hypertonic - concentration (osmotic pressure) higher than plasma.
Hypotonic - concentration (osmotic pressure) lower than plasma.
What are electrolytes and what are the benefits?
The combination of ions to form a substance that will break down in water.
- help maintain an acid base status
- provide osmotic pressure and regulate the movement of water
How would you assess a patients hydration status?
Clinical examination - skin tenting? well/unwell? overall?
Urine testing - passing normal amounts of urine? specific gravity in normal range?
Blood testing - packed cell volume within normal range?
What is normal urine output?
1-2ml/kg/hr
or
24-48ml/kg/day
What is normal specific gravity for a cat and dog?
Cat - 1.035 - 1.060
Dog - 1.015 - 1.045
Higher = dehydration
What are normal PCV levels in blood testing?
Cat - 24-45%
Dog - 37-55%
Increase in PCV may indicate dehydration.
Decrease in PCV may indicate anaemia or haemorrhage.
What is the normal body pH?
7.4
What is pH?
The degree to which blood is alkaline or acidic.
What is metabolic acidosis?
Where an acid state in the body occurs due to altered metabolism - unable to excreted acid or is losing excess alkali.
- vomiting
- diarrhoea
- renal failure
- shock
What is metabolic alkalosis?
Where an alkaline state in the body occurs due to altered metabolism - loosing excess acid.
- vomiting stomach contents only
- over administration of bicarbonate
What is respiratory acidosis?
Where an acid state in the body occurs when respiratory system cannot excrete acid.
- respiratory obstruction
- acute respiratory failure
- hypoventilation for any reason
- anaesthetic problems
What is respiratory alkalosis?
Where an alkaline state in the body occurs when respiratory system looses excess acid.
- hyperventilation
- pain, stress
- hyperthermia
- excessive IPPV
What are the 3 categories of fluid solutions?
Crystalloids - solution containing water and electrolytes.
Colloids - solution containing large molecules: plasma expanders.
Blood/blood products.
What are crystalloids?
Used to rectify fluid and electrolyte loss.
Balance abnormal body pH.
What are colloids?
Contain large molecules - create fluid shift from ICF to plasma.
Expand plasma volume.
Do not provide any O2 carrying capacity – consider concurrent O2 administration
Divided into the categories of synthetic and natural
What are blood and blood products and what are they used for?
Whole blood – haemorrhage, anaemia, haemolysis
Plasma (FP/FFP) – burns, hypovolaemia
Packed red cells – anaemia
Cryo-precipitate – clotting/bleeding disorders
What are the routes of administration of fluid?
Oral
Intravenous, cephalic, saphenous, jugular;
rabbits – marginal ear vein
Sub-cutaneous, flank, scruff
Intraperitoneal, into abdominal cavity
Intraosseous, into medullary cavity, usually femur
What is the management of a drip line?
- Use unopened, sterile materials
- Prepare aseptically
- Insert catheter up to the hilt
- Ensure catheter is taped in dry
- Change catheters ~ every 48-72hrs and dressings as needed
- Use heparinised saline to provide patent catheter
- Check bag is right fluid, in date and clear
- Check administration site for swelling, bruising, pain and perivascular fluid
- Check line regularly for kinks, blockages and interference
How would you monitor patient fluids?
- Check clinical signs for hydration level
- Monitor TPR and mucous membranes
- Record urine output and SG
- Monitor PCV
- Monitor ongoing losses
(Central venous pressure) - Record all findings on fluid monitoring chart/ hospitalisation sheet
- Review fluid therapy plan regularly
What are the signs of over-hydration?
Soft, moist cough – pulmonary oedema
Dyspnoea, tachypnoea
Tachycardia
Lethargy
Runny nose
Decreased PCV
Increased urine output
What is a low pH in the blood called?
Acidic
When occurs in the blood is known as Acidosis.
What is a high pH in the blood called?
Alkaline
When occurs in the blood is known as Alkalosis.
What is osmosis?
The movement of WATER from an area of LOW concentration to an area of HIGH concentration across a semi-permeable membrane, until the concentrations are equal.
What is osmotic pressure?
The pressure with which water molecules are drawn across the semi-permeable membrane.
What is hydrostatic pressure?
The force exerted by a fluid against a wall, which causes movement of fluid between compartments.
How is water moved in capillaries?
Determined by the balance between the hydrostatic pressure generated by the heart and the oncotic pressure generated by the proteins present in plasma.
High hydrostatic blood pressure in capillaries
Pressure forces plasma and nutrients move out of capillaries into interstitial tissue
Increased concentration of blood & low plasma volume = HYPOVOLAEMIA
Fluid and cellular waste in interstitial space enter the capillary by osmosis
How is water moved in cells?
ECF and cytoplasm concentration need balanced osmotic pressure within cells prevents excess fluid absorption.
Fluid and nutrients move into cells from ECF.
Fluid and waste is pushed out of the cell to ECF.
Fluid that is not absorbed into capillary taken to lymphatic system.
What causes oedema?
Decreased plasma proteins or ineffective lymphatic drainage.
What is the difference between dehydration and hypovolaemia?
Dehydration is a lack of fluid in the interstitial compartment.
Hypovolaemia is a lack of fluid in the intravascular compartment.
What are factors affected by dehydration?
Mucous membrane moisture
Skin turgor
Eye position within orbit
What are factors affected by hypovolaemia?
Capillary refill time (1-2 seconds)
Heart Rate
Pulse Quality
Blood Pressure
