Flashcards in Equine Fluids (MR) Deck (52):
In horses which fluid type can not be used?
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%
What is different about a foals fluid status? Why?
Water % is higher = 75 - 80% of b.w. Diet is mainly milk
How does higher TBW affet higher specific gravity of foals?
much lower 1.003-1.008 is normal
What is Milk diet Na+ in mare milk?
Normal daily fluid requirements for Adult Horses?
50ml / kg / day
What are Sensible loses in a horse?
Fecal water loss Renal water loss
Evaporation from skin & respiratory tract
What is maintenance for horse?
Sensible + Insensible
Water consumption in horses is related to?
Eating = peri-prandial drinking
What is the Water % of grass?
Failure to replace insensible losses leads to?
What are examples that lead to loss of isotonic body?
Blood loss Diarrhea - Na+ loss Gastric reflux = Cl- loss
Evidence of fluid deficit: Hypovolemia?
loss of circulatory (blood) volume
Evidence of fluid deficit: Dehydration?
Excessive loss of total body water
What are ongoing losses?
Diarrhea Gastric reflux Excessive sweating
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
What is normal specific gravity in horse? Foal?
1.025 (- 1.065) 1.003-1.008
Why is PCV unreliable in horse?TP?
Splenic contraction in stress
Laboratory Evaluation of Dehydration?
PCV/TP (not sensitive or specific) - not reliable Lactate (product of anaerobic metabolism) – reliable Creatinine / BUN - sensitive
How can you measure volume status?
Central Venous Pressure Affected by head position (cfr jugular pulse)
Normal CVP in horse?
7-12 mm HG is normal in adults - only referral centers
How do you take Mean Arterial Pressure?
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
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
What size catheter?
10 - 14 g Large bore catheter
Catheter options in Equine Medicine: big consideration?
Time needed bc inflammation
Teflon easy, cheap, thrombogenetic (>24hr) Polyurethane - can stay a couple of weeks
Complications of IV fluid therapy?
Thrombophlebitis!!!! - very prone to inflammation. Overhydration in neonates / foals
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
When is dextrose used?
Liver problems, Foals
What fluid would you use for a hypoproteinemic horse?
Plasma Colloids (synthetic) Keep fluid in vascular space. Crystalloid would cause ventral edema
How much fluid is needed?
Liters of water 'lost' = B.W. in kg x estimated % of dehydration (500 kg x 6% = 30 liters)
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
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
What is normal osmolality?
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!!!!!
Big concern with fluids for e-lyte shifts? Why? Where?
Hyponatremia Chronic vs Acute Brain edema Demyelination Syndrome
What is rule in horses for giving hypertonic saline?
Every 1L HSS needs replacement with 10L isotonic fluid!!!!!! Then reassess
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
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
Maintenance in horse?
50 ml / kg / day. 1 liter/hr maintenance (500kg horse). Electrolyte supplementation if existing deficit /or if on fluids > 24 hours
Minimum dehydration required for clinical signs to appear?
Base kind of fluids you use on?
Actual measurement of electrolytes and blood gases
Which electrolytes are important and added to fluids?
Calcium: Added to each 5L bag?
25ml 23% calcium-gluconate / liter
Potassium: when added to fluids? How much?
hypokalemia or on iv fluids > 24h (and not eating) 10-40mEq / liter
In the absence of laboratory parameters of exact electrolyte status, what is the best choice for fluids?
Balanced isotonic/polyionic fluid
In equine medicine what is the only use for hypertonic saline?
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.
How many L can you give in the stomach of horse?
500kg = 6 - 8 L