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Flashcards in Fluid therapy Deck (26):
1

need for fluid therapy

Replacement of fluids “lost”
Maintenance of fluid “needs”

2

ways to loose fluid

Blood loss
Dehydration
excessive urination
Vomiting, diarrhoea
Sequestered fluid (“third space”– in bowel, in cavities)

3

"flushing things out"

azotaemia (pre-renal, renal, post-renal) may require fluid therapy as a means of increasing Glomerular Filtration Rate (GFR)
Animals intoxicated with water soluble substances may also benefit from fluid therapy

4

whats in a fluid bag

Water
Electrolytes - Sodium, Chloride, Potassium, Magnessium, Calcium
± Buffers - Lactate, Citrate
± Dextrose

5

Fluid Therapy to Deliver Nutrients

When animals cannot receive nutrition through the gastrointestinal tract (enteral nutrition) animals may be fed parenterally

6

fluid types

Crystalloids
Colloids - Natural, Synthetic

7

fluid tonicities

Isotonic
Hypertonic
Hypotonic

8

Crystalloids - Components

Water + small molecules
Electrolytes - Sodium, Chloride, Potassium, Magnessium, Calcium
± Buffers - Lactate, Citrate
± Dextrose

9

crystalloids

Most common used fluid in practice
Cheapest
Can be administered PO, IV, SQ, IO, IP
After administered, distributes equally amongst all fluid compartments - Only a third of volume remains intravascularly after equilibration
Complications only related to amounts of fluid used (too little/too much)

10

Synthetic Colloids - Components

water + large molecules
electrolytes - sodium, chloride
+/- buffers - lactate, citrate

11

Synthetic Colloids

Some form of colloid available in most practices
Can be rather expensive
Generates colloid osmotic pressure - This delays equilibration of fluid with other compartments, Useful for resuscitation of intravascular volume
Complications include fluid overload and coagulopathy
unavailable in UK
possible harm to patients – kidney injury mainly

12

natural colloids

Blood products - Fresh whole blood, Packed red blood cells, Fresh frozen plasma
Concentrated albumin solutions

13

parenteral nutrition

Mixture of amino acids solutions, dextrose, lipids (all crystalloids)
Provides energy and building blocks for protein synthesis

14

Effects of Tonicity

Isotonic = same tonicity as blood
Hypertonic = much higher than blood
Hypotonic = less than blood
Tonicity determines distribution of fluid between compartments, i.e., tonicity is what can move fluids from one compartment to another

15

Isotonic fluid administered IV - effect

fluid distributed equally amongst all compartments

16

Hypertonic fluid administered IV - effect

Draws fluid from intracellular and interstitial compartments into intravascular compartmen

17

Hypotonic fluid administered IV - effect

Fluid shifts to the intracellular compartment – cellular oedema

18

isotonic crystalloid use

Rehydration
Resuscitation – treatment of hypovolaemia
Correction of acid/base electrolytes
Deliver drugs
Induce diuresis

19

Considerations for colloid use

Require rapid resuscitation
Want to increase COP
Need resuscitative effect to last more than 1 hr
Most colloids are isotonic
Typically used when animal is oedematous

20

hypertonic saline use

Not used very much
extremely rapid resuscitation
Very effective!
Patient has to be well hydrated for hypertonic saline to work
Can be used to treat brain oedema
Very small doses required

21

mannitol

Most commonly used for brain oedema
Treatment for acute glaucoma
Sometimes used for oliguric renal failure
Osmotic diuretic – main effect is to shift fluid into the intravascular space to be excreted by the kidneys

22

hypotonic fluid use

Not used very much at all
Supposed to be a true “maintenance fluid”
For short term use – only a few hours
Only really useful if you are treating extremely hypernatraemic patients
Nicknamed “Devil’s Fluid” - Causes too many complication with electrolytes and cellular oedema

23

Parenteral Nutrition - Indications

Dysfunctional GI tract - vomiting, diarrhoea
Existing malnutrition or risk of becoming malnourished
contraindicated enteral feeding
Pancreatitis (?)
Unable to protect airway

24

Total Parenteral Nutrition

Meets 100% of energy requirements
Very hypertonic (hyperosmolar)
Needs to be delivered via jugular catheters

25

Partial or Peripheral Parenteral Nutrition

Only meets 40-70% of energy
Lower osmolarity
can be given peripherally

26

parenteral nutrition in use

used in referral practices - Requires special expertise, equipment
Needs to be handled completely aseptically
Amino acids and dextrose ready to use
Meets 40-70% energy depending on case