Fluid Therapy (L 19-20) Flashcards
What is the body fluid distribution?
ICF 2/3
ECF 1/3
- Interstitial 3/4
- Plasma 1/4
What percent of body weight is on average intravascular blood volume?
Dogs 10%
Cats 8%
Horse 7%
Where is Na+ primarily distributed in the body?
ECF
Where is K+ primarly distributed in the body?
ICF
Where is Cl- primarly distributed in the body?
ECF
Where is HCO3_ primarily distributed in the body?
ECF
Define Osmosis
Movement of water through semipermeable membranes
Define Osmotic pressure
Pressure on one side of the membrane that prevents movement of water
Define Osmolarity
particles/L solution
Define Osmolality
Particles/kg H2O
Define Oncotic pressure
created by large molecules–>pulls water towards it
What is serum osmolality?
300mOsm/kg
(270-350)
Define hydration
State of extracellular volume (interstitial & intravascular space)
Define Volemia
Only intravascular volume
How do you assess hydration status?
Skin elasticity (turgor)
Body weight
MM moisture
Urinary production/USG (oliguria, high USG)
What types of fluids are crystalloids?
Isotonic, hypotonic or hypertonic
Cheap
But only 1/4-1/3 of volume infused is still present in vasculature after 1hr. Can cause edema with large infusions.
What Cx with variying levels of dehydration?
- <5% - not detectable
- 5% - dry MM, normal skin turgor
- 6-7% - dry MM, mildly decreased skin turgor
- 10% - eyes sunken, highly decreased skin turgor, increased CRT
- 12-15% - signs of shock, death imminent
What fluids should not be used in shock fluid thereapy?
Fluids with Low or no sodium.
Ex: Dextrose in water and hypotonic saline solutions
What are the clinical uses of hypotonic crystalloids?
Replace water deficits/losses
Drug admixtures
What can misuse of hypotonic crystalloids do?
Large doses rapitdly can cause water intoxication (sellular edema)
What are the advantages of isotonic crystalloids?
- Commonly available/economical
- Replace interstitial deficits
- Restores effective circulating volume
- Good replacement solutions for D+/V+ & diuresis loss
- Polyionic crystalloids do not alter normal electrolyte values
What are the disadvantages of crystalloids?
- Rapidly redistributed to interstitial fluid compartment
- only 20% remains intravascular (need large volumes)
- Interstitial Edema
- Cerebral
- Pulmonary
- Systemic
- Hemodilution
- RBC’s, Albumin & Coagulation factors (bleeding)
- Rebleeding
If you use LRS for long term fluid therapy what do you need to add to the bag?
K+ (only get from diet)
What is the Na+, Cl-, K+ & HCO3 levels in LRS?
- Na+ = 130
- Cl- = 109
- K+ = 4
- “HCO3” = 28 lactate (turned to HCO3 by liver)
