Equine Fluids (MR) Flashcards Preview

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Flashcards in Equine Fluids (MR) Deck (52):
1

In horses which fluid type can not be used?

Hypotonic

2

Where is the water in a horse?

60% of Body Weight ICF is 40% of b.w. ECF is 20% of b.w - Plasma 25%, Interstitial 75%

3

What is different about a foals fluid status? Why?

Water % is higher = 75 - 80% of b.w. Diet is mainly milk

4

How does higher TBW affet higher specific gravity of foals?

much lower 1.003-1.008 is normal

5

What is Milk diet Na+ in mare milk?

low

6

Normal daily fluid requirements for Adult Horses?

50ml / kg / day

7

What are Sensible loses in a horse?

Fecal water loss Renal water loss

8

Insensible losses?

Evaporation from skin & respiratory tract

9

What is maintenance for horse?

Sensible + Insensible

10

Water consumption in horses is related to?

Eating = peri-prandial drinking

11

What is the Water % of grass?

90.00%

12

Failure to replace insensible losses leads to?

dehydration

13

What are examples that lead to loss of isotonic body?

Blood loss Diarrhea - Na+ loss Gastric reflux = Cl- loss

14

Evidence of fluid deficit: Hypovolemia?

loss of circulatory (blood) volume

15

Evidence of fluid deficit: Dehydration?

Excessive loss of total body water

16

What are ongoing losses?

Diarrhea Gastric reflux Excessive sweating

17

How do you determine if your Horse Need Fluids?Hypovolemia?Dehydration?

Thorough PE!!!!!! Heart rate Respiratory rate Pulse pressure Jugular fill Cold extremities Urine output (s.g.) Dehydration: Tacky Oral m.m. Skin tent (Sunken eyes) - more reliable in foals CRT

18

What is normal specific gravity in horse? Foal?

1.025 (- 1.065) 1.003-1.008

19

Why is PCV unreliable in horse?TP?

Splenic contraction in stress

20

Laboratory Evaluation of Dehydration?

PCV/TP (not sensitive or specific) - not reliable Lactate (product of anaerobic metabolism) – reliable Creatinine / BUN - sensitive

21

How can you measure volume status?

Central Venous Pressure Affected by head position (cfr jugular pulse)

22

Normal CVP in horse?

7-12 mm HG is normal in adults - only referral centers

23

How do you take Mean Arterial Pressure?

Tail cuff

24

What routes can you use to administer fluids in horses? When should each be used?

IV: essential for resuscitation PO/Enteral: only when GI tract is normal Intra Peritoneal: rare in horses Subcutaneous: veryyyyy rare in horses

25

Sites for IV catheter placement? Alternatives? Why?

Jugular vein - 1º site in horses Cephalic vein Horses - higher risk of kink. Smaller volume Lateral thoracic vein - difficult to place. Usually over the wire. Stays longer than cephalic. Smaller volume. Jugular Vein thrombus

26

What size catheter?

10 - 14 g Large bore catheter

27

Catheter options in Equine Medicine: big consideration?

Time needed bc inflammation

28

Catheter material:

Teflon easy, cheap, thrombogenetic (>24hr) Polyurethane - can stay a couple of weeks

29

Complications of IV fluid therapy?

Thrombophlebitis!!!! - very prone to inflammation. Overhydration in neonates / foals

30

Which fluids are available for horses?

Crystalloids: Isotonic / polyionic fluids (280 mEq/L) Hypertonic saline solution (HSS). Colloids: Plasma Synthetic colloids (hetastarch /pentastarch) Isotonic = Polyionic solutions

31

When is dextrose used?

Liver problems, Foals

32

What fluid would you use for a hypoproteinemic horse?

Plasma Colloids (synthetic) Keep fluid in vascular space. Crystalloid would cause ventral edema

33

How much fluid is needed?

Liters of water 'lost' = B.W. in kg x estimated % of dehydration (500 kg x 6% = 30 liters)

34

How do you formulate a Fluid Therapy Plan? 4 overlapping phases?

1: Resuscitation (< 2 hours) 2: Rehydration (12-24 hours) 3: Maintenance 4: Ongoing losses

35

Shock dose of fluids in Horse? 8% of body weight (one blood volume) For 500kg horse =

50-80ml/kg 40L !! Often clinically impractical. Begin rapid administration of crystalloids. Reassess Goal Directed Therapy (HR↓, lactate↓, PCV/TP↓, CRT↓) - after 15 min

36

What is normal osmolality?

280 smol/L

37

When isotonic fluid is not enough what should you give?

Hypertonic Saline Solution (HSS) 7% Sodium Chloride 1200mEq Na + 1200mEq Cl = 2400Osmol/L 2-4 ml/kg bolus (1-2L per 500kg) Immediate vascular expansion 2-3x the volume that is infused Alters the ECF (hypertonic) Leads to a shift in the ICF!!!!!

38

Big concern with fluids for e-lyte shifts? Why? Where?

Hyponatremia Chronic vs Acute Brain edema Demyelination Syndrome

39

What is rule in horses for giving hypertonic saline?

Every 1L HSS needs replacement with 10L isotonic fluid!!!!!! Then reassess

40

Natural Colloid & Synthetic Colloids? What are the types? What do they do? what are they especially useful for?

Equine Plasma Hetastarch(US) Pentastarch(EU). Contain large molecules that remain in the vascular space . Plug capillary endothelium. Improve plasma oncotic pressure . Hypoproteinemia

41

Rehydration Formula for horse? How long to achieve? When can enteral route be used? Fluid choice? Remember to do what with fluids?

Deficit= dehydration= % body water lost. Amount (L) = % dehydration X body weight (kg). 12-24 hours. Use enteral fluids if GI tract is healthy - cheaper & safer. Isotonic crystalloids Correct electrolyte imbalance

42

Maintenance in horse?

50 ml / kg / day. 1 liter/hr maintenance (500kg horse). Electrolyte supplementation if existing deficit /or if on fluids > 24 hours

43

Minimum dehydration required for clinical signs to appear?

5%Maintenance:

44

Base kind of fluids you use on?

Actual measurement of electrolytes and blood gases

45

Which electrolytes are important and added to fluids?

Ca2+, K+

46

Calcium: Added to each 5L bag?

25ml 23% calcium-gluconate / liter

47

Potassium: when added to fluids? How much?

hypokalemia or on iv fluids > 24h (and not eating) 10-40mEq / liter

48

In the absence of laboratory parameters of exact electrolyte status, what is the best choice for fluids?

Balanced isotonic/polyionic fluid

49

In equine medicine what is the only use for hypertonic saline?

Resuscitation

50

In horse with colic when is it safe to give enteral fluids?

When impaction is distal to cecum because a lot of water is absorbed in cecum, so you wont rupture stomach.

51

How many L can you give in the stomach of horse?

500kg = 6 - 8 L

52

To soften impaction how much fluid should be given?

2X Maintenance