Transcript PATIENT PREPARATION

PATIENT PREPARATION
CHAPTER 2 Part 1
PATIENT PREPARATION
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The RVT has numerous responsibilities in the
pre-anesthetic period. The pre-anesthetic
period is the period immediately preceding
the induction of anesthesia.
This period can be from minutes to weeks
PRE-ANESTHETIC
RESPONSIBILITIES OF AN RVT:
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obtaining patient history
reviewing consent form with an owner
making sure the patient is fasted
performing a physical exam
drawing blood and running diagnostic tests
placing an IV catheter
calculating drug doses
administering pre-medications
preparing anesthetic equipment
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SEE BOX 2-1 pg. 6 for more info…
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FEELING OVERWHELMED?
MINIMUM DATABASE
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ANESTHESIA IS NOT A COOKIE CUTTER
PROCEDURE: Age, breed, size, & health status
play a role in the selection of anesthetic agents
and techniques
Every patient should have a minimum
database, which would ideally include:
HISTORY
 PHYSICAL EXAM FINDINGS
 DIAGNOSTIC TEST RESULTS
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TAKING THE PATIENT HISTORY
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DO’s:
Be thorough
 Be effective at framing questions to gain the most
information
 Schedule an appointment several days before the
planned procedure
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DON’Ts:
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Don’t ask “yes” or “no” questions
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For example, how can you reframe this question: “Does
your dog drink a lot of water?”
Don’t ask leading questions
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For example, how can you reframe this question: “ Your
dog doesn’t drink very much water does he?”
TAKING THE PATIENT HISTORY
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What questions should I ask?
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What procedure(s) is/are being performed today?
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How old is your animal?
Is there a history of previous illnesses/problems/treatment and if so,
do you have past medical records?
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Confirm the affected limb, confirm tumors to be removed & determine if
client want histopathology
Be sure to ask duration, volume/severity, frequency, character/appearance
Is your pet currently ill?
What medications has your pet been on?
Does your pet have any allergies or a history of drug reactions?
Has your pet had any previous anesthetic problems?
Is your pet current on vaccines?
Is your pet in heat or pregnant?
TAKING THE PATIENT HISTORY
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SIGNALMENT: includes species, breed, age, sex,
and reproductive status
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This information influences the anesthetic plan
SPECIES & BREED
Each species has unique responses to anesthetic agents.
Drug doses will vary between species.
 Examples:
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Horses and cats are more sensitive to opioids than dogs and
ruminants
 Cats can tolerate some drugs given alone, while the same
drug may cause seizure-like activity in dogs
 Large animals are prone to respiratory depression
 Boxers & giant breeds are more sensitive to acepromazine
 Sighthounds are sensitive to barbiturates
 Brachycephalic breeds are difficult to intubate
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TAKING THE PATIENT HISTORY
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AGE
 Very
young animals-less than 8 wks of age-are
much less capable of metabolizing injectable
drugs because necessary liver pathways are not
fully developed.
 Young animals are also more prone to
hypothermia and hypoxia
 Geriatric patients-who have reached 75% of the
normal lifespan- may have difficulty metabolizing
drugs due to liver or renal failure
TAKING A PATIENT HISTORY
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SEX & REPRODUCTIVE STATUS
 Confirming
the sex of the animal is especially
important in cats
TAKING THE PATIENT HISTORY
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SEX & REPRODUCTIVE STATUS
 For
males, confirm the presence of both testicles in
the scrotum
 For
females, ask about the possibility of pregnancy,
the last estrous cycle, check for a spay scar or a
tattoo
TAKING THE PATIENT HISTORY
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SEX & REPRODUCTIVE STATUS
 For
females, ask about the possibility of
pregnancy.
 Determine the client’s wishes if the animal is
found to be pregnant
CONSENT FORM
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Have the client sign a consent form/estimate.
This should be done in person. By phone is an
option, although this is not ideal. Make sure a
witness also hears the authorization.
A consent form reviews anesthetic risks,
resuscitation options, blood work options, and
phone numbers for the owner.
Some forms also state that a drug will be used on
their animal in an extra-label manner.
* If possible, have the owner read the estimate and consent
form before the day of surgery.
PATIENT DISPOSITION & LEVEL OF
CONSCIOUSNESS
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Anxious or aggressive animals may require a
combination of drugs for sedation
Fearful or aggressive animals may require a
different route of medication administration
(oral, induction chamber)
PATIENT DISPOSITION & LEVELS
OF CONSCIOUSNESS
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Level of consciousness refers to the
patient’s responsiveness to stimuli or how
easily it can be aroused.
 BAR,
QAR
 Lethargy – mild decrease in LOC & can be aroused
with minimal difficulty
 Obtunded – more depressed patients that cannot
be fully aroused
 Stuporous – sleeplike state; can only be aroused
with painful stimuli
 Comatose – cannot be aroused and is
unresponsive to all stimuli including pain.
PHYSICAL EXAM
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HYDRATION STATUS
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Dehydration increases the risk for hypotension, poor tissue
perfusion, & kidney damage
PERCENT
DEHYDRATION
PHYSICAL SIGNS
<5%
Not detectable
5-6%
Mild loss of skin elasticity
6-8%
the above + dry m.m., depressed globes
within orbits
8-10%
The above + more persistent skin tent,
increased PCV/TP
10-12%
The above + dry, pale m.m, CRT >2sec
12-15%
Signs of shock, death
PHYSICAL EXAM
HYDRATION STATUS
 Ideally, dehydration should be corrected prior to surgery:
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(Wt in kg)(1000 mL/kg)(% dehydration)
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EXAMPLE:
A 33 lb dog that is 9% dehydrated, needs _______mL
33 lb /2.2 = 15 kg
(15 kg)(1000 mL/kg) = 15,000 mL
(15,000 mL)(0.09) = 1350 mL
PHYSICAL EXAM
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EXAMINE STRUCTURES OF THE HEAD
 ORAL
CAVITY:
 Check
mucous membrane color, CRT: If gums are
pigmented check the conjunctiva, inner vulva,
prepuce
PHYSICAL EXAM
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EYES & EARS
 Look
for signs of dehydration, check pupillary
light reflexes
 Check the ears for signs of infection, or growths
PHYSICAL EXAM
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AUSCULTATION: listen to the rate, rhythm, and
sounds of the heart and lungs
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Normal resting heart rate:
Dogs: 60-180
 Cats: 110-220
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Normal respiratory rate:
Dogs: 10-30
 Cats: 25-40
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Rhythm: listen for normal sinus rhythm vs.
arrhythmias
 Abnormal sounds: crackles, wheezes, evidence of
respiratory distress (flared nostrils, open-mouth
breathing, respiratory stridor)
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Listen to all 4 quadrants of the chest
PHYSICAL EXAM
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PULSE: assess the strength and the rate
The femoral artery is the easiest location to
palpate a pulse
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locations: metatarsal, metacarpal arteries
A strong or weak pulse loosely correlates with
blood pressure
Pulse deficits may indicate heart disease
PHYSICAL EXAM
WEIGHT: assign a body condition score
(either use 5 scale or 9 scale)
 Drug doses and IV fluid rates are based on
weight in addition to species. DON’T
ESTIMATE. Weigh accurately.
 Use a pediatric scale (if available) if <5 kg;
use gram scale if <1 kg
 Compare current weight to previous
weights.
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PHYSICAL EXAM
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WEIGHT
OBESE ANIMALS can experience dyspnea, they can be
difficult to draw blood from, harder to assess hydration
status, and difficult to auscultate.
 Obese animals do NOT need a higher dose of
anesthetics. Although the body mass is larger, the
central nervous system is not.
 THIN ANIMALS can be at risk for hypothermia and may
have an underlying condition causing the weight loss.
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PHYSICAL EXAM
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OTHER SYSTEMS:
 Body
Temperature: 100.0°-102.5° for dogs & cats
 MS: signs of lameness, pain
 Lymph: evaluate size of lymph nodes
 Abdomen: evaluate for tense or painful abdomen,
evaluate organ size, presence of fluid or gas
 Repro: evaluate testicles, mammary glands, vulva,
prepuce
 Integument: check for bruising, petechiae,
pyoderma
FASTING
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Fasting usually begins the night before surgery
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Adult dog or cat: Withhold food for 8-12 hours before surgery.
Water is withheld anywhere from 2-4 hours before surgery,
depending on the veterinarian’s preference.
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Neonate and pediatric patients (<8 wks): Much shorter fasting
period (depending on species, could be 4-6 hrs, or no fasting) to
avoid dehydration or hypoglycemia.
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GI surgery: Withhold food for 24 hours, water for 8-12 hours.
Why fast?
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Fasting is done to avoid vomiting/regurgitation during surgery or
recovery which can cause esophagitis, respiratory obstruction, or
aspiration pneumonia.
FASTING
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In addition to not fasting long enough, it is not safe to have
animals fasted for too long.
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This usually refers to animals refusing to eat for various reasons usually when the surgery is not elective: serious GI
obstructions/perforations, or in the situation where 2 surgeries are
performed several days apart and the animal does not want to eat
between the surgeries.
Prolonged fasting leads to a longer recovery period, delays
healing, and puts the animal at risk for other medical
problems ( ex: hepatic lipidosis).
Options include hand/syringe feeding, inserting feeding
tubes, or total parenteral nutrition.
PATIENT PREPARATION
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Be sure the animal is properly identified
 Use
a cage card or ID collar or BOTH
DIAGNOSTIC TESTS
DIAGNOSTIC TESTS
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The extent of the diagnostic testing will
depend on the clinic, the owner, and what is
ideal for the patient
It is important to provide the most complete
and affordable testing available
DIAGNOSTIC TESTS
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COMPLETE BLOOD COUNT:
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PCV and RBC
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used to determine the blood’s ability to deliver oxygen to tissues. Increases
usually indicates dehydration (which leads to increased viscosity of the blood,
poor perfusion and decreased cardiac output). Decreased levels usually
indicates anemia.
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TOTAL PLASMA PROTEIN
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usually indicates dehydration if increased. Decreased values may indicate
decreased production by the liver or a loss through the renal, hepatic or GI
systems. Decreased levels can lead to increased drug potency.
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PCV less than 25% in a dog or less than 20% in a cat should be reported immediately
Values of less than 4.0 should be reported immediately
BLOOD SMEAR
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used to evaluate red blood cell & white blood cell morphology and platelet
estimation.
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Report all decreases in platelet count or abnormal coagulation test results
DIAGNOSTIC TESTS
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URINALYSIS:
SPECIFIC GRAVITY
 used to detect evidence of dehydration or renal insufficiency
GLUCOSE and KETONES
 used to detect diabetes
WBCs and RBCs
 can be seen with urinary tract infections and crystalluria
(can also be normal in small amounts)
USE THESE RESULTS IN CONJUNCTION WITH OTHER TESTS
DIAGNOSTIC TESTS
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CHEMISTRY PANEL:
MOST COMMONLY EVALUATED PARAMETERS
PRE-OPERATIVELY ARE:
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ALT: liver
ALP (or ALKP): liver, possibly bone, possibly GI tract
BUN: kidneys
Creatinine: kidneys
Glucose: diabetes screen
Electrolytes: Na, K, Ca
The more parameters that are evaluated, the
better picture we have of the patient.
DIAGNOSTIC TESTS
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CLOTTING TIMES:
Not commonly performed for routine procedures
unless coagulopathies are suspected such as in breeds
that are commonly affected by hereditary coagulation
disorders.
 PT, (A)PTT
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In-clinic testing is performed by either
performing a Buccal Mucosal Bleeding Time
(BMBT), a short nail trim to the quick, or
placing whole blood in a plain red top. Blood
should clot within 4 minutes.
DIAGNOSTIC TESTS
ECG
Evaluates electrical activity of the heart, pattern,
rhythm
Perform if heart disease is suspected, there is a
history of trauma, electrolyte abnormalities, or
if the animal is geriatric
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DIAGNOSTIC TESTS
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RADIOGRAPHS
not routinely done in private practice, but are
indicated with dyspnea, abnormal heart/lung
sounds, or history of recent trauma.
HEARTWORM TEST – it is important to know
heartworm status before undergoing anesthesia
DETERMINATION OF (ASA)
PHYSICAL STATUS CLASSIFICATION
Classification based on history, physical
exam, and diagnostics performed
 Classification is objective and can change
with animal’s status
 Correct problems before surgery if
possible
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Category
Physical condition
Examples
PI
Minimal risk
Normal, healthy animal
w/o underlying disease
Spay, neuter, declaw, hip
rads
P II
Slight risk, minor
disease
Slight to mild systemic
disturbances; animal
compensate
Neonates, geriatric,
obese, skin tumors,
uncomplicated hernia,
local infection
P III
Moderate risk, obvious
disease
Moderate systemic
disease, mild clinical
signs
Anemia, moderate
dehydration, fever, lowgrade murmur or heart
disease
P IV
High risk, significant
disease
Preexisting systemic
disease
Severe dehydration,
shock, uremia, high fever,
severe heart or lung
disease, diabetes,
emaciation
Life threatening disease
PV
Extreme risk, moribund that may not be corrected
by surgery, animal may
not survive 24 hrs
Advanced heart, liver,
kidney, lung, or terminal
disease, severe shock,
head injury, severe
trauma
2yr old, mixed breed intact male weighing 12lbs; BCS: 2/5,
T-103.5, HR-160, RR-40; 8% dehydrated
Bloodwork: PCV: 35%, TP: 7.6 g/dl
What anesthetic status would you give this dog?
Preanesthetic Pic of the Day
Based on the picture, what anesthetic category
would you place
Oscar in?