Transcript Chapter 19 - Delmar Cengage Learning

Chapter 19
Fluid Therapy and Emergency Drugs
Copyright © 2011 Delmar, Cengage Learning
Basics of Body Fluid
• Water is the primary body fluid
• Body water is distributed among three types of
compartments: intracellular, intravascular, and
interstitial
– Intracellular fluid (ICF) = fluid within the cell
(two-thirds of body water)
– Extracellular fluid (ECF) = fluid within the blood
vessels and in the tissue spaces between the blood
vessels and cells (one-third of body fluid)
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Basics of Body Fluid
• Body water contains solutes (substances that dissolve in
solvent; particles)
– Electrolytes are substances that split into ions when
placed in water
– Primary ions in the body are sodium, potassium,
chloride, phosphate, and bicarbonate
• Cations are positively charged ions
• Anions are negatively charged ions
• Body water is the solvent in biological systems
• To establish equilibrium, body water moves along its
concentration gradient
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Basics of Body Fluid
• Extracellular fluid shifts between the
intravascular space (blood vessels) and the
interstitial space (tissues) to maintain a fluid
balance with the ECF compartment
• Fluid exchange occurs only across the capillary
walls
• Fluid therapy in animals may involve the use of
crystalloids and/or colloids
• Crystalloids are diffusible substances that
dissolve in solution
• Colloids are nondiffusible substances
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Fluid Therapy
• The basis for fluid therapy depends on the
animal’s hydration status (refer to Table 19-1 in
your textbook)
• Fluid therapy can replace water, sodium,
potassium, and chloride electrolytes, and restore
hydrogen ion balance (pH balance)
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Fluid Administration
• Intraperitoneal fluids
– Given when IV access is not available
– Injection site must be aseptic
– Disadvantages include:
• The possibility of sepsis
• Can’t use IP routes in animals awaiting abdominal
surgery
• Inability to use hypertonic solutions
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Routes of Fluid Administration
Route of
administration
Advantages
Disadvantages
Oral
• Safest route
• Easy
• Less rapid
absorption
• Possible
aspiration
• Cannot use for
vomiting animals
Subcutaneous
• Relatively easy
to administer
• Absorption
distributed over
time
• Possible
infection
• Must use isotonic
fluids
• Slower
absorption
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Routes of Fluid Administration
Route of administration Advantages
Disadvantages
Intravenous
• Precise amount
given is available
rapidly
• Various tonicities
of fluid can be used
• Possible fluid
overload and vessel
damage
• Requires close
monitoring
• Must be sterile
Intraperitoneal
• Relatively rapid
absorption
• Can be used
when IV access is
not available
• Possible infection
• Cannot use
hypertonic solutions
• Abdominal surgery
hindered after
administration
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Routes of Fluid Administration
Route of
administration
Advantages
Disadvantages
Intraosseous
• Useful for small
animals, birds, and
pocket pets
• Can be used when
vein inaccessible
• Rapid absorption
• Lack of confidence in
administering fluid via
this route
• Possible infection
Rectally
• Good absorption
• Rapid absorption
• Not frequently used
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Tonicity of Fluids
• Tonicity refers to the osmotic pressure of a
solution based on the number of particles per
kilogram of solution (osmolality)
• An isotonic solution has the same osmotic
pressure as blood and extracellular water
• A hypotonic solution has osmolality lower than
that of blood; RBCs can swell
• A hypertonic solution has osmolality higher than
that of blood; RBCs can shrink
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Types of Crystalloids
• Isotonic
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–
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0.9% sodium chloride (normal saline)
Lactated Ringer’s solution
Normosol
Plasmalyte
• Hypotonic
– 5% dextrose in water (D5W)
– ¼ NS (0.25% normal saline)
– ½ NS (0.45% normal saline)
• Hypertonic
– 0.9% normal saline with 5% dextrose
– 10% dextrose in water
– 3% normal saline
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Problems With Fluid Administration
• Fluid overload is a condition in which the
administration of fluid occurs at a greater rate
than the rate at which the body can use or
eliminate the fluid
– This is a condition associated with fluids administered
via the parenteral route
– Signs of fluid overload includes respiratory changes,
fluid deposition in the subcutaneous space, or weight
gain
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Types of Colloids
• Colloid solutions are fluids with large molecules that
enhance the oncotic force of blood, causing fluid to move
from the interstitial and intracellular spaces into the
vascular space
• Natural
– Plasma
– Albumin
– Whole blood
• Synthetic
– Dextrans
– Hydroxyethyl starch
– Oxypolygelatin
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Fluid Additives
• Special additives can be supplemented to
crystalloid solutions
• When administering additives, it is important to
remember to withdraw and discard an amount of
fluid equal to the amount of additive being
supplemented
• Types of additives:
–
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50% dextrose
Potassium
Sodium bicarbonate
Calcium
Vitamins
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Calculating Fluid Volumes
• Must consider that animals require fluids for the
following:
– Rehydration
– Maintenance
– Ongoing fluid loss
• Make sure the units of measure are the same
when performing these calculations
• Make sure the volumes make sense; we don’t
give 1,000 liters to a 4-pound cat
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Calculating Fluid Volume
• Example: an adult 14-lb cat
with 3% dehydration comes
into the clinic; it is estimated
that the cat vomited 100 ml of
fluid overnight
• Maintenance fluid is the
volume of fluid needed daily to
maintain body function
• Maintenance fluids can be
dosed at 50 ml/kg/day in adults
and 110 ml/kg/day in young
animals
• Step 1: convert 14 lb to kg
using the conversion factor 2.2
lb = 1 kg
14 lb x 2.2 lb/kg = 6.4 kg
• Step 2: calculate maintenance
volume
6.4 kg x 50 ml/kg/day = 318
ml per day
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Calculating Fluid Volume
• Example: an adult 14-lb cat
with 3% dehydration comes
into the clinic; it is estimated
that the cat vomited 100 ml of
fluid overnight
• Rehydration fluid is based on
the estimated percent of
dehydration
% dehydration x weight in kg =
deficit in liters
• Step 1: convert 14 lb to kg
using the conversion factor 2.2
lb = 1 kg
14 lb x 2.2 lb/kg = 6.4 kg
• Step 2: calculate replacement
for dehydration
3% = 0.03
0.03 x 6.4 kg = 0.192 l
0.192 l x 1,000 ml/l = 192 ml
192 ml x 0.8 (80% of dehydration
value replaced in 24 hours) =
154 ml to replace on first day
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Calculating Fluid Volume
• Example: an adult 14-lb
cat with 3% dehydration
comes into the clinic; it is
estimated that the cat
vomited 100 ml of fluid
overnight
• Ongoing fluid loss is an
estimation based on the
additional loss of fluid
due to vomiting or
diarrhea
• Take estimated volume
• Step 1: take estimated
volume lost in fluid and
add to the other volumes
• Final step: take all values
and add together
318 ml + 154 ml + 100 ml =
572 ml
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How and How Quickly
Is It Given?
• Rate of fluid replacement parallels the severity of
dehydration
• Ideally, fluids are given over a 24-hour period
• Fluids are stored and given by fluid bags or bottles
attached to administration sets
• Fluids are administered with either:
– An adult administration set that delivers 15 gtt/ml (usually)
– A pediatric administration set that delivers 60 gtt/ml (usually)
– See text and “Fluid & Electrolytes for Veterinary Technicians” CD
for sample calculations
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Fluid Administration Using a
Special Administration Chamber
• Steps for using a Special Administration
Chamber
– Wash hands
– Follow the manufacturer’s directions for priming the
setup
– Allow 10–15 mL of the fluid being administered to
flow into the chamber
– Close the clamp between the bag and chamber
– Clean the injection site on the administration
chamber with alcohol
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Fluid Administration Using a
Special Administration Chamber
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Inject the medication into the chamber
Open the clamp and add the appropriate amount of fluid
Clamp the tube above the administration chamber
Gently agitate the chamber to mix the fluids
Open the clamp below the chamber
Establish the appropriate flow rate
Open the clamp above the administration chamber to
administer fluid as ordered
Chart the procedure including date, time, medication, dosage,
amount of fluid inflused, and patient’s reaction
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Emergency Drugs
• In an emergency situation, it is important to
remember basic life support
– A = airway = establish a patent airway (endotracheal
tube, suctioning, tracheostomy)
– B = breathing = provide oxygen to the patient by
providing airway or mechanical ventilation
– C = circulation = get blood moving, either by manual
manipulation of the heart or by the use of drugs
• Refer to Table 19-3 of your textbook
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Emergency Drugs
• The goal of emergency treatment is to maintain
adequate oxygenation of vital organs
• Oxygenation of vital organs is the goal of both
the respiratory and cardiovascular systems
• The primary goal of the respiratory system is to
promote gas exchange
• The primary goal of the cardiovascular system is
perfusion of organs and tissues
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Emergency Drugs
• When making first contact with the owner of an
animal that needs emergency care, obtain the
following information:
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Nature of the illness/injury
Condition of the animal
Time injury/event occurred
Any preexisting illness and medications
Age, breed, sex, and weight of animal, if available
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