Flash Notes Miscellaneous - Fluid Therapy

Question 1

what is osmolarity? what is osmolality?

Answer 1

osmolarity: number of particles/liter of solution ~ total concentration of a solution or fluid environment measured in milliosmoles/liter, osmolality: same but measured in milliosmoles/kg

Question 2

what is tonicity?

Answer 2

effect of a solution/fluid environment has on cell colume, so fluid moves in response to the concentration gradient created by the surrounding environment limited by the permeability of the cell membrane - effective osmolarity of the surrounding fluid/environment on cell volume

Question 3

what is isotonic? hypotonic? hypertonic?

Answer 3

isotonic: no change, hypotonic: increase in volume, so cells swell, & hypertonic: volume decreases, so cell shrinks

Question 4

what is hypovolemia?

Answer 4

ineffective circulating blood volume, absolute hypovolemia: actual loss of fluid out of the vascular space, relative hypovolemia: usually caused by vasodilation such that circulating volume is inadequate (seen with severe inflammatory conditions like anaphylaxis/sepsis)

Question 5

what are replacement fluids?

Answer 5

fluids used to replace deficits (similar to plasma) given as bolus or continuous infusion

Question 6

what are maintenance fluids?

Answer 6

fluids used for daily requirements, so lower levels of sodium/chloride than plasma but higher levels of calcium, potassium, and magnesium provided alongside water/calories - patients are switched to theses once intial deficit is corrected, so continuous infusion only NO BOLUS due to risk of edema

Question 7

what are resuscitation fluids?

Answer 7

correction of life-threatening hypovolemia - fluid therapy for patients with extreme loss

Question 8

what are crystalloid fluids?

Answer 8

solutions with electrolytes/other substances that are able to cross into all fluid compartments of the body, mainstay of resuscitation & all types of fluid therapy (normal or 0.9% saline, dextrose solutions, LRS, normosol, plasmalyte) hypertonic crystalloids: concentrations of saline greater than 0.9%, 7% hypertonic saline most commonly used in vet med

Question 9

what are balanced solutions?

Answer 9

constituents & concentrations resemble content & osmolality of normal extracellular fluid (LRS, 0.9% saline, & 5% dextrose)

Question 10

what are colloids?

Answer 10

molecules of high molecular weight usually proteins or carbs that are not readily able to cross cell membranes & therefore remain in the vascular space for longer durations (hetastarch, dextrans, plasma, albumin)

Question 11

what is COP?

Answer 11

colloid osmotic pressure, pressure created by the presence of colloids in a solution that prevents movement of fluid across a semi-permeable membrane

Question 12

what are the 2 most common colloids used in vet medicine?

Answer 12

6% hetastarch % 6% dextran

Question 13

what changes will affect fluid flow across a capillary membrane in a patient resulting in an increased net flow into the interstitium causing edema?

Answer 13

increase in blood pressure, decrease in tissue COP, or increase in permeability

Question 14

what is the fluid portion of the body? how is it split up?

Answer 14

60% of total body weight, 2/3 is intracellular fluid & 1/3 is extracellular fluid (4% plasma & 15% interstitial)

Question 15

T/F: total body fluid is 60% of the total body weight

Answer 15

TRUE

Question 16

total body water & ECF compartments are larger in what animals?

Answer 16

neonates - 70% TBW & 30% ECF

Question 17

intravascular fluid loss is reflected by changes in what?

Answer 17

changes in cardiovascular system - heart rate, pulse strength, CRT, mucus membrane color, & body temperature

Question 18

loss of fluids from the interstitium & intracellular areas are apparent from what clinical signs?

Answer 18

clinical signs of dehydration - loss of skin turgor, dryness of mucus membranes, & sunken eyes

Question 19

what are the 2 questions you must start with for identification & need for treatment using fluids?

Answer 19

is there a fluid deficit & what fluids should be used for replacement

Question 20

what lab values increase with fluid loss? what about with hypovolemia? what factors may obscure the clinical picture?

Answer 20

increase: PCV, total solids, total protein, USG, & albumin, hypovolemia: lactate & hypotension when severe - hemorrhage or protein loss may obscure the lab picture

Question 21

T/F: in young calves with diarrhea, clinical signs correlate with dehydration & metabolic acidosis

Answer 21

TRUE

Question 22

T/F: calves have loss of fluid & loss of HCO3 that may be severe

Answer 22

TRUE

Question 23

hypovolemia results in a switch to what metabolism? what is seen with that?

Answer 23

switch to anaerobic metabolism - increased lactate & lactic acidosis

Question 24

what clinical signs are seen in small animals with 5-6% dehydration in regards to skin tenting, mucus membranes, CRT, & signs of shock (increased heart rate, weak pulses, & cool extremities)?

Answer 24

may see skin tenting, mucus membranes likely ok, potentially increased, not likely to see signs of shock

Question 25

what clinical signs are seen in small animals with 6-8% dehydration in regards to skin tenting, mucus membranes, CRT, & signs of shock (increased heart rate, weak pulses, & cool extremities)?

Answer 25

slow return of skin tent, mucus membranes may be dry, mild increase in CRT, less likley to see signs of shock

Question 26

what clinical signs are seen in small animals with 10-12% dehydration in regards to skin tenting, mucus membranes, CRT, & signs of shock (increased heart rate, weak pulses, & cool extremities)?

Answer 26

very slow return of skin tent, dry mucus membranes, increased CRT, & may see signs of shock

Question 27

what clinical signs are seen in small animals with 12-15% dehydration in regards to skin tenting, mucus membranes, CRT, & signs of shock (increased heart rate, weak pulses, & cool extremities)?

Answer 27

skin may not retract, very dry mucus membranes, very increased CRT, & signs of shock present

Question 28

how does body condition affect skin tenting in small animals?

Answer 28

increased tenting of skin if thin, decreased skin tenting if fat

Question 29

how is base deficit determined in a calf under 8 days old that has a base deficit of 0?

Answer 29

alert, good suckling reflex, standing/still standing but depressed

Question 30

how is base deficit determined in a calf over 8 days old that has a base deficit of -5?

Answer 30

still standing but depressed

Question 31

how is base deficit determined in a calf over 8 days old that has a base deficit of -10?

Answer 31

sternal & more depressed

Question 32

how is base deficit determined in a calf over 8 days old that has a base deficit of -15?

Answer 32

no suckle & moderate dehydration

Question 33

how is base deficit determined in a calf over 8 days old that has a base deficit of -20?

Answer 33

no suckle & severe dehydration

Question 34

how is base deficit determined in a calf under 8 days old that has a base deficit of -5?

Answer 34

weak suckle & slight dehydration

Question 35

how is base deficit determined in a calf under 8 days old that has a base deficit of -10?

Answer 35

no suckle & moderate dehydration

Question 36

how is base deficit determined in a calf under 8 days old that has a base deficit of -15?

Answer 36

lateral & extreme depression

Question 37

what calculation is used to determine fluid need in large animals?

Answer 37

horses/cows 50ml/kg/day, 100ml/kg/day in neonates

Question 38

what calculation is used to determine fluid need in small animals?

Answer 38

40-60ml/kg/day; [(BW(kg)X30) + 70] or, if under 2 kg or greater than 50 kg, use BW^0.75 X 70

Question 39

what are some examples of how animals can lose fluids?

Answer 39

gastric reflux in horses, effusions in FIP, & cows with choke with excessive salivation

Question 40

what are some pathways for fluid deficits to occur? why is this important to consider?

Answer 40

lake of intake, hemorrhage, urine loss with polyuria, respiratory (excessive panting), salivation, skin (burns, severe wounds), inflammation, & intestines - NEED TO KNOW TO DECIDE WHAT REPLACEMENT FLUIDS TO USE

Question 41

what fluids can calcium not be mixed with?

Answer 41

bicarbonate & LRS

Question 42

what animals may need dextrose added to their fluids?

Answer 42

hypoglycemia patients, neonates, toy breed dogs, & liver disease patients

Question 43

what animals may need bicarbonate added to their fluids?

Answer 43

calves with diarrhea - NOT FOR LACTIC ACIDOSIS

Question 44

what is kmax for potassium additives in fluids?

Answer 44

0.5mEq/kg/hr - enteral intake is best to correct potassium deficits

Question 45

what is the most important extracellular ion? what about most important intracellular ion?

Answer 45

extracellular: Na, intracellular: K+

Question 46

what does chloride do in acidosis? with vomiting? with abomasal obstruction?

Answer 46

in acidosis: will increase, vomiting: lost woth vomiting, & abomasal obstruction: very low

Question 47

what must also be corrected with a low calcium or low potassium?

Answer 47

must correct low magnesium!!!

Question 48

how are enteral fluids used?

Answer 48

very useful - always use if available, voluntary intake/force feeding - or feeding tubes

Question 49

when should subcutaneous administration of fluids be used for fluid therapy?

Answer 49

small animals or any species with loose skin, patients with mild deficits without signs of shock, & supplementation if not drinking well yet/with chronic disease (chronic renal failure cat)

Question 50

when should intravenous administration of fluids be used for fluid therapy?

Answer 50

any species with accessible veins (jug, cephalic, & saph most common), vital for resuscitation of severe deficits

Question 51

when should intraosseous administration of fluids be used for fluid therapy?

Answer 51

small animals/birds/reptiles/foals/neonates in very dehydrated patients or difficult to catheterize - volume & speed similar to IV

Question 52

when should intraperitoneal administration of fluids be used for fluid therapy?

Answer 52

primarily done in small lab animals - enterocentesis is a concern

Question 53

why do you want a large bore catheter for a hypovolemic animal?

Answer 53

faster flow of fluids - catheter must be smaller than vein to decrease phlebitis

Question 54

what are the shock doses used for fluid therapy?

Answer 54

80ml/kg for dogs, 50ml/kg for cats, & 8% body weight for horses/cows

Question 55

what determines how fluid moves passively between the different areas of fluids?

Answer 55

concentration gradients of large molecules (COP), sodium, & in response to hydrostatic pressure (capillary blood pressure or tissue pressure)

Question 56

what is a shock fluid dose?

Answer 56

shock dose ~ blood volume