Fluid Administration/Nursing Care
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Transcript Fluid Administration/Nursing Care
CTVT pgs. 883-894
A&A pgs. 27-39
(Anesthetist)
*Step-by-step fluid calculation on my website
Indications for Fluid Administration
Dehydration
Hypovolemia
Disease that depletes the normal fluid
and electrolyte balance
(polyuria, decreased intake of fluids, diarrhea)
Surgery
Potential of fluid loss or excessive blood loss
Maintenance of blood pressure and organ perfusion
Normal Fluid Balance
The body is made up of approximately 60% water
This is divided into intracellular (2/3 of body fluid) and
extracellular fluids (1/3 of body fluid)
Extracellular fluid is further divided into
Interstitial- fluid in your body’s tissues
Intravascular- fluid in the vessels
The body maintains fluid balance (homeostasis) on a constant
basis
Works via osmotic pressure
Normal Fluid Balance
Osmotic pressure
Number of positive and negative charges in an area must
be equal:
Water- moves freely, follows Na+
Electrolytes- rely on positive and negative charges to
maintain balance
ICF- Potassium(+) and Magnesium (+) Phosphate (-)
ECF- Sodium (+) and Chloride (-)
Normal plasma osmolarity is 300 mOsm/L
Fluid Treatment Questions
How much fluid will be needed to rehydrate the
patient, right now?
How much fluid will be needed to compensate for ongoing
losses?
How much fluid will be needed to maintain the
animal’s daily necessary requirements?
What is the animal’s surgical fluid rate?
Total circulating blood volume:
Dog = 85 ml/kg
Cat = 55 ml/kg
Daily Maintenance Requirements
Sensible losses (measurable losses)
Urine output
1-2 ml/kg/hr = normal
Insensible losses
Feces
Respiration
Unexpected Fluid Loss
Ongoing Losses
Vomiting
Diarrhea
Polyuria
Pleural effusion
Blood loss
Add to rehydration calculation
Every 1 ml lost = 2 mls of replacement fluid needed
Assessing Dehydration
1. Skin turgor test
What about obese animals?
Emaciated animals?
2. Mucous membranes (MM)
Moist/tacky/dry?
3. Eye position
4. Serial body weights
*Loss of 1 kg during a 24 hour period is about equal to loss of 1 L of water.
Assessing Perfusion
1. Capillary refill time (CRT)
Normal value?
2. Heart rate & pulse
3. Blood pressure
4. Cool extremities
Routes of Fluid Administration
Oral: minimal loss, normal intake
Subcutaneous: mild-moderate dehydration
Given on dorsal midline/flank
Intravenous: moderate-severe dehydration;
perioperative precaution
Intraperitoneal: mild to moderately dehydrated; large
volumes
This method is not commonly used in cats and dogs
Intraosseous: head of the femur/humerus of small
animals
Neonates or animals with poor venous access; birds and reptiles
Intravenous Catheterization
Why is this important?
Provide fluid therapy
Administer emergency drugs quickly
Name two (NAVEL)
Leave in until patient is fully recovered!
CRI of analgesics or anesthetics
Calculations to follow…
Induce anesthesia
Can easily titrate IV medications on a sedated animal
Safely administer vesicants
Anesthetic fluid therapy
Requires IV catheter placement
What vein?
What size?
Prep site- what technique?
Considerations/Risks
Transfer of patient- disconnecting from P or air introduced
Injection port- drugs must be injected slowly!
Limb ties
Non-aseptic technique
Hypervolemia
Purpose of Anesthetic Fluid Therapy
To maintain blood volume AND pressure
Be prepared for expected OR unexpected blood loss
What’s an example of a bloody surgery?
Combat bradycardia & vasodilation due to anesthetic drugs
Your anesthetized patient WILL have hypotension
Especially long surgeries
Correct known dehydration or electrolyte abnormalities
How do we know this??
Primary IV set for intravenous fluid therapy.
Fluid bag
IV line attachment
Injection port
You can see the drops
while manually calculating
fluid rates here
Drip chamber
IV pumps come in many
brands and sizes.
BAXTER 6300 DOUBLE PUMP
IV Pump/
Fluid Stand
HESKA VET IV infusion pump
Crystalloids –vs- Colloids
Crystalloids are solutions of salts and water with variable
electrolyte composition and contain no protein or colloids
Are in intravascular compartment for less than an hour
Rapidly excreted in urine (if renal function is normal)
Classified by their osmolarity:
Isotonic, hypertonic, or hypotonic
Colloids contain larger insoluble molecules, which act to
retain existing fluid and promote movement of fluid into
intravascular spaces
Remain within the circulation (cannot freely cross vascular
endothelium)
Crystalloid Effect on Body’s Cells
Normal plasma osmolarity = 290-310 mOsm/L
Hypotonic Crystalloids
Lower osmotic pressure (osmolarity) than blood –
thereby encouraging movement of fluids into
interstitial fluid and then into cells
Contain low amounts of Na+ and Cl Indicated for maintenance of cardiac patients or
hypernatremic patients
Examples:
5% Dextrose in water (D5W)
0.45% Saline (NaCl)
Normasol-M; Plasmalyte 56
*Provide more water than electrolytes*
Isotonic Crystalloids
Most common type of fluids used to replace
body fluids; osmolarity = to blood
Rehydration, maintenance, and anesthesia
0.9% saline, BES, or Dextrose solutions
Note: dextrose solutions are used for specific purposes, not
for maintenance or shock
For each 1 ml increase in vasculature fluid, you
need to give 3-4 mls of isotonic fluid
Isotonic Crystalloids
Normal Saline (0.9% NaCl)
-slightly acidifying effect due to high Cl Used for irrigation, lavage, flush
Balanced electrolyte solutions
Contain other electrolytes in addition to Na+ and Cl Such as?
Buffered alkalinizing affects due to bicarbonate
precursors (lactate)
Examples: Normasol-R, LRS, Plasmalyte 148
Hypertonic Crystalloids
Saline greater than 0.9% (ex. 3% NaCl, 7% NaCl)
Administered for resuscitation or shock
Greater osmotic pressure than blood
-encouraging movement of fluid from the interstitial space into
circulation (vasculature)
Why is this a “quick fix”?
Quickly increases blood volume and pressure
For each 1 ml given, increases vasculature volume by 5-10 mls
NOTE: If given too quickly, can cause interstitial or ICF dehydration
*Provides more electrolytes than it provides water*
Colloids
Contains large molecules suspended in an isotonic crystalloid
Used for resuscitation –hypoproteinemia, acute blood loss,
clotting disorders
Natural or synthetic
Whole blood and plasma transfusions
Increase IVF and perfusion when RBCs are abnormal
Anaphylaxis
Hetastarch and Vetstarch
Increase IVF and perfusion when RBCs are normal
Crystalloids – vs. - Colloids
Crystalloids
Colloids
LRS
Whole blood
Normosol-R/M
FFP
Plasma-Lyte
Dextran 70*used
Sodium Chloride 0.9%-
less and less
Hetastarch
Vetstarch
Oxyglobin *no
longer made
Normal saline
3%- Hypertonic saline
Dextrose 5% in Water
(D5W)
General Rule of thumb
Know drug compatibilities!
It can be undesirable to mix multiple drugs in a
syringe or intravenous fluids- sometimes drug
interactions are visible, other times they are
not
Physical incompatibilities include: precipitation
and chemical inactivation
Fluids should be warmed before being given
Fluid incubator, line warmer, “warmies”
What colors should NOT be added to warmies?
Hypervolemia- Causes
Excessive total volume
Excessive rate of fluid administration
Decreased cardiac or kidney function
Double check calculations!
Know your patient!
“Does this amount make sense?”
Hypervolemia- Clinical Signs
Serous nasal discharge
Chemosis- edema of the ocular conjunctiva
Pitting edema –skin remaining indented for a prolonged
amount of time after removal of firm finger pressure
(Over saturation of the cells)
Restlessness and coughing- during recovery
Hyperpnea- abnormal increase in depth and rate of
respiration but not to the point of labored
Fluid Protocols and Rates
Maintenance
Rehydration
Anesthesia
Resuscitation/Shock
Calculation examples on page 38 of A&A
Maintenance Rate
Maintenance volume is the amount of fluid and
electrolytes needed on a daily basis to keep the
volume of water and electrolyte content normal in a
well-hydrated patient
Animals that refuse or cannot eat, recently dehydrated
Remember insensible and sensible losses?
40-60 ml/kg/24h
Usually isotonic crystalloids
Maintenance Problem
A 10 lb 4 year old s/F DSH named Arlene has recovered from
anesthesia for major dental surgery and will probably not be
eating or drinking. Your vet would like her to be on IV fluids
overnight from 6pm-7am.
1. What type of fluids would you prepare?
2. How many milliliters per hour will you set your pump to?
3. What’s the minimum amount of fluid you should ensure is
in the fluid bag before clocking out?
4. How many gtt/sec will Arlene receive if your pump breaks?
(Your infusion set is 60 gtt/ml)
Rehydration Formula
% dehydrated x body weight (kg) x 1000 ml/kg
= ml of fluid needed for replacement
This formula is used for patients who are dehydrated
and may or may not have ongoing losses (i.e. vomiting
/ diarrhea)
To be given over a specified period of time
We also have to account for ongoing losses
Ex: 20 ml excessive urine = 40 ml fluid
Rehydration Problem
A 5 yr old, 11 lb Pomeranian is 6% dehydrated and has
vomited about 25 mls since he was admitted to your
clinic for surgery today. Your vet asks to correct his fluid
status over the next 3 hours with IV LRS.
1. What vein would you most likely place an IV catheter in?
2. What gauge would you choose?
3. How many mls/hr will you set your fluid pump to?
4. gtt/sec?
Anesthetic Protocol
To compensate for losses during surgery
To sustain oxygen saturation and tissue perfusion
Common rate is 10 ml/kg/hr (old school)
CATS: 3 ml/kg/hr
DOGS: 5 ml/kg/hr
Hypotension?
*Can increase to 20 ml/kg/hr (cats) and 40 ml/kg/hr (dogs)
Anesthetic Protocol Calculation
Your next surgical patient is a 28 lb spaniel mix OHE. Her
blood work was WNL and she has no known disease.
1. What fluid type will your vet most likely choose?
2. What will the rate of fluid administration be per hour?
3. How many gtt/sec using a 15 gtt/ml set?
Resuscitation/Shock Protocol
Patient:
Is experiencing hypovolemia or shock state
Has lost significant amount of total blood volume
If a 20 lb dog lost 10% of its blood volume, how many
mls of blood would this be?
Goal is to replace fluid in the vasculature AND increase
perfusion
Dogs
Isotonic fluids:
80-90 ml/kg
Hypertonic crystalloids: 3-4 ml/kg
Colloids:
10-20 ml/kg
Cats
55 ml/kg
2-3 ml/kg
5-10 ml/kg
Resuscitation/Shock
Give ¼ of total dose as a bolus
Check parameters and reassess
By using crystalloids and colloids together, you can
increase benefits and decrease side effects.
Calculate half the shock dose of each, still only give ¼ of that
Resuscitation Problem
A 3 year old 50 lb Labrador retriever is in hypovolemic
shock and needs IV Hetastach per Dr. Dev.
1. What is the total dose of Hetastarch in mls?
2. How much Hetastarch will you give initially?