Fluid Notes Flashcards
Maintenance fluids
40-60mL/kg/day in adults/// 80-120 mL/kg/day in foals
needs are affected by species, age, fasting vs fed, ambient temp
DECREASE by HALF if fasted
Deficit of fluids is measured as….
estimated percent dehydrated x body weight (kg)= deficit in liters
ex: horse is 450kg x 0.05= 22.5L deficit
Blood volume of horses is approx. ___% of BW
8%
What are three unquantifiable losses in horses?
Unquantifiable- moisture lost in respiration, evaporation from losses/exudates (ex: burn wounds), feces
Quantifiable- urine, NG tube, body cavity effusions, blood loss
Monitor your fluid therapy-
repeat PE, repeat PCV/TP, lactate, and/or USG, urinary frequency
Blood volume expansion-
Isotonic crystalloids (maintenance fluids), colloids, hypertonic saline, whole blood
What are used for main. fluids??
Isotonic crystalloids- LRS and plasmalyte are most commonly used
Distribute quickly into entire extracellular space
(Approx. 1/3 stays in vasculature), 10L bolus- about 3 L blood volume expansion
What is the disadvantage of using maintenance fluids?
Takes a long time to get in, large volumes may increase bleeding in trauma p or cause intestinal edema in colic cases
What is advantages of using main. fluids?
distributes to all spaces
_____ are fluids that contain a molecule that can exert oncotic pressure and can be natural or synthetic
colloids
Natural colloids vs. synthetic colloids-
Natural- plasma, albumin
Synthetic- Hetastarch, dextran
Advantage vs. disadvantages of colloids-
disadvantages- coag. at high doses
advantages- lasting oncotic support, low volume= quick to infuse
What fluids are short lived (0.5-3 hrs) and MUST be followed up with isotonic volume replacement?
Hypertonic saline
What is the dose of hypertonic saline?
4mL/kg (2 L for most adult horses)
KNOW LISTING OF ADVANTAGES OF ORAL FLUID TX
Hydrates intestinal contents, can complement or replace IV fluid tx, stimulates GI motility, decreased need for precise control of e’lytes as compared to IV administration, greatly cheaper
Volume of adult horse stomach is __-___ L
8-10L
Standard size of IV jugular catheter:
14 gauge
Fetlock drop and/or hip hike will be seen on the unsound or sound limb?
Sound limb
Why do we start with FL with regional anesthesia?
FL lameness often changes the flight pattern of the HL
Carbocaine-
onset is 60-90 sec and duration is up to 2 hours, 3mL usually used per nerve to effectively eliminate sensation in 5-10 mins
What is the largest nerve and requires 30 mins for full effect???
Tibial nerve
How to calculate fluid deficit?
Estimate % dehydration x bw in kg= deficit in Liters
example of how to calculate deficit:
450 kg horse that is 5% dehydrated
450kgx 0.05= 22.5 L deficit
blood volume of a horse is about ___% of bw
can only draw like 1% of their blood in body weight
8%
Subjective tools to estimate deficit are…
Hollow above the eyes, skin tent, mm/CRT, fecal consistency, urine color and frequency
Objective tools to estimate deficits are….
PCV/TP, BUN and creatinine, Urine specific gravity and lactate, HR
What is blood volume expansion used for? What are the fluids that do this?
Maintaining perfusion to vital organs and stabilize the p so they will survive anesthesia;
Isotonic crystalloids, colloids, hypertonic saline
what is the volume expansion of giving 20 L of LRS?
Approx 1/3 stays in vasculature
so 10L bolus means 3 L for volume expansion
6-7 L
For isotonic crystalloids (LRS, 0.9% saline, 5% dextrose, plasmalyte) stay in the vasculature aka are available for volume expansion?
1/3
3 L of LRS means how much volume expansion?
2 L of hypertonic saline means how much L volume expansion (know that hypertonic saline is 8x tonicity of plasma and pulls fluids from interstitum to vasculature)
3L= 1L volume expansion
2 L= 8 L of volume expansion
1 L of colloids= ___ liters of volume expansion
2 Liters
1 Liter of hypertonic saline= ____ L volume expansion
4 L volume expansion
What are the 3 common e’lyte supplementations in horses???
Potassium, calcium, magnesium
Do not exceed ? of Potassium– very important in small patients, regardless of species
0.5 meq/kg/hr
Getting IV fluids in faster
Larger jugular catheter
Multiple catheters
Usually two jugular catheters; cephalic and lateral thoracic also an option
Larger bore, shorter tubing
Extension set and administration set-The smallest diameter tubing in the system decides the rate!
Raise the fluids up higher to take advantage of gravity
Oral fluid therapy advantages-
Hydrate intestinal contents - treat impactions
Can complement or replace IV fluid therapy
Stimulate GI motility – gastrocolic reflex
Decreased need for precise control of electrolytes compared to IV administration
Greatly decreased cost
Hypertonic Saline
Approx 8 times the tonicity of plasma– pulls fluid by osmosis from interstitium into the vasculature- short lived- 0.5-3 hours
Must follow up with isotonic volume replacement
Dose 4 ml/kg (2 liters for most adult horses)
1 liter = 4 liters of blood volume expansion
Dose of hypertonic saline
Dose 4 ml/kg (2 liters for most adult horses)
1 liter = 4 liters of blood volume expansion
Advantages and disadvantages of hypertonic saline
Adv – cheap, low volume, improved microvascular perfusion
Disadv – cannot use if hypernatremic or hyperchloremic, short-lived effect 0.5-3 hrs
