Fluid therapy

Question 1

indications

Answer 1

replacing what was lost, keeping up with what the pet is losing, maintaining balance when the animal can’t do it themselves

Question 2

keys to fluid therapy planning

Answer 2

right type of fluid, right amount of fluid, right speed of administration

Question 3

how much of the total body weight does fluid make up?

Answer 3

~60% of TBW
young animals: 70-80%
older animals: 50-55%
obese animals: <60%
emaciated animals: >60%

Question 4

where are fluids kept in the body?

Answer 4

intracellular and extracellular spaces
ICF: 40% TBW
ECF: 20% TBW

Question 5

what are the two compartments that fluid in the extracellular space is divided between?

Answer 5

interstitial fluid (ISF) and intravascular fluid (IVF)

Question 6

interstitial fluid (ISF)

Answer 6

tissue space
surrounds the cell and is outside of the blood vessels
separated by cell membrane and vascular endothelium

Question 7

intravascular fluid (IVF)

Answer 7

in blood vessels
separated by the vascular endothelium
plasma

Question 8

barrier permeability to different substances

Answer 8

water: moves across all barriers, moves through osmosis
electrolytes: moves across vascular endothelium but not cell membranes without active transport (only 1/4 of administered electrolytes stay in IVF, 3/4 move to ISF)
large molecules: (plasma proteins) hard to move from IVF, can draw fluid into IVF from the ISF by oncotic pressure

Question 9

where does sodium and potassium hang out in the sodium potassium pump?

Answer 9

sodium in extracellular and potassium in intracellular
SodiumEX ICK+

Question 10

electrolyte roles

Answer 10

maintain acid-base status, osmotic pressure, and regulates movement of body water between compartments

Question 11

concentration of electrolytes in intracellular body compartment

Answer 11

most abundant cation: potassium
most abundant anion: phosphate

Question 12

concentration of electrolytes in extracellular body compartment

Answer 12

most abundant cation: sodium
most abundant anion: chloride

Question 13

hyponatremia

Answer 13

low sodium levels

Question 14

hypernatremia

Answer 14

high sodium

Question 15

types of fluids

Answer 15

colloids and crystalloids
choice based on composition of fluid and the physiochemical properties
also based on osmolarity and electrolyte composition

Question 16

osmolarity

Answer 16

how similar the fluid is to cat/dog blood
cat/dog blood osmolarity= 300 mOsm/kg

Question 17

crystalloids

Answer 17

fluids with electrolytes and water
characterized by their osmolarity compared to blood (hypertonic, isotonic, hypotonic)

Question 18

hypotonic fluids

Answer 18

provide more water than electrolytes
uses: hypernatremia, patients with cardiac or renal issues
contraindications: resuscitation fluids
ex: Dextrose 5% in water, 0.45% NaCl, Normolsol M, Plasmalyte 56

Question 19

why should you never give D5W SQ?

Answer 19

the sugar in dextrose provides a medium for bacterial growth which causes cellulitis +/- abscess

Question 20

isotonic fluids

Answer 20

equal portions water and electrolytes
most commonly used: resuscitation, rehydration, replacement of ongoing losses, hyponatremia
contraindications: caution with long term use and large volume: can lead to tissue edema and acid-base disturbances
ex: 0.9% NaCl, Plasmalyte 148, Plasma-Lyte A, Normosol R, LRS

Question 21

hypertonic fluids

Answer 21

more electrolytes than water
uses: resuscitation, head trauma/traumatic injury (causes decreased intracranial pressure)
contraindications: don’t admin fast (no faster than 0.5-1 mL/kg/min= bradycardia)
ex: 3-7% hypertonic NaCl, dilute and never admin >7.5%

Question 22

colloids

Answer 22

solutions containing protein or starch molecules that contain a high-molecular weight and are suspended in an isotonic crystalloid
remain in vasculature and offer prolonged volume expansion
uses: hypoproteinemia, resuscitation, when crystalloids can’t handle the job
contraindications: renal patients (oncotic force decreases renal filtration pressure), have been associated with causing coagulopathies

Question 23

normal fluid ins

Answer 23

drinking and eating
normal metabolic processes (oxidation of food materials)

Question 24

normal fluid outs

Answer 24

normal urine loss, water loss, respiration/panting, sweating (more for horses)

Question 25

sensible losses

Answer 25

measurable losses

Question 26

insensible losses

Answer 26

unmeasurable losses

Question 27

normal losses per day

Answer 27

40-60 mL/kg/day
fecal losses: ~5 mL/kg/day
respiratory and transcutaneous: ~15 mL/kg/day
urinary losses: ~20 mL/kg/day