Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anesthesia > Pre anesthetic work up > Flashcards

Pre anesthetic work up Flashcards

1
Q

RVT checklist with pre anaesthetic work up

A

Communication of procedures and risk with client
Consent- written
Minimum patient database including diagnostics
Asses patient anaesthetic risk
Proper patient fasting
Anesthetic and monitoring equipment are ready
Pre-induction patient care
Sedation, preemptive analgesia, other medication, fluids, temp support, enemas, bandage removal and wound care

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Communications dos with anesthetic

A

Take the time to communicate with your client
Know their pet and the procedure they are coming in for
Know the pets history
Discuss possible complications
Get accurate contact info
Be honest about cost (include postop follow ups)
Keep client informed, esp if something goes wrong
Know what client wants in event of complications
Be thorough about post surgical care requirements (especially postop home care requirements)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Communication donts for anesthetic work ups

A

NEVER guarantee a cure
Don’t assume that the client understands what is happening
You must be able to explain procedures including sedation, anesthesia, surgical procedure, home care
Don’t lie to them
Side effects/complications that may occur
complications/mistakes that do occur
Cost and cost of complications

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Patient admiting

A

Confirm procedure, cost, contact info
Consent (written is always best option)
Confirm “what if” in the case of complication
Establish discharge (same day or hospital stay)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Patient history

A

In clinic medical (incl. Past labs) and anaesthetic history
Client history (chronic and acute)
Current medication
Fasting? Water withdrawal?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Minimum patient database

A

Patient signalment
Patient history (current and chronic conditions, medications, prior anaesthetics/surgeries)
Weight, TPR, mentation
Complete physical examination
Presurgical pain assessment
Preanesthetic diagnostic workup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why is species important with anesthesia

A

Horses and cats become excited on opioids
Dosing requirements different for every species
Horses require dedicated recovery areas to prevent injury
Large animals require ventilation support
Exotics are handled differently

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why is the breed important for anesthesia

A

Breed specific MDR1-deficiency
Sighthounds are sensitive to barbituates
Boxers are sensitive to acepromazine; terriers are resistant to acepromazine
Brachycephalic breeds are difficult to intubate; require monitoring during sedation and recovery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

WHy is the age important for anesthesia

A

Geriatrics often have decreased liver and renal functions and overall lowered anaesthetic tolerance
Neonates and pediatrics have higher fluid requirements, increased risk of hypothermia and different drug metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is sex and reproductive status important for anesthia

A

Pregnant patients are always at increased risk for drug affects both to patients and fetus
Increased cardiovascular demand
Risk of abortion or teratogenicity
Select drugs that do not cross the placenta if possible
Avoid acepromazine in stallions
Benzodiazepines cause floppy baby syndrome
Xylazine can cause abortion in cows and ewes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why is a PE important before doing GA

A

PE and drug order for premed must be done by the vet
Vet can perform the PE and give order up to 24 h before procedure; in this event, RVT must perform exam immediately (ensure there is no change in patient status) before administering medication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Minimal exam immediately before premedication

A

Weight, BCS
TPR, MM, hydration status, mentation status
Must record all values and findings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why is BCS important before GA

A

In clinic patients should be weighed a minimum of q24h
All anaesthetic patients to be weighed on the day of
Most important short term cause of weight change is hydration
Must know BCS in order to
Ideal BCS ⅗, 5/9
If low BCS, will need to consider hypoalbuminemia, low body fat, illness
If high BCS, will need to consider lean body weight for dosing, underlying cardiac disease, increased resp depression under GA, fatty liver syndrome in a cat on the postop period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is mentation important

A

Gives indication of underlying illness, CNS status. Patients with decreased mentation have increased risk under GA
Part of distance exam- always include distance exam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the normal resp rate of cats and dogs

A

<32

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is anormal TPR for a foal

A

T: 38.3-39.5
P: 80-120
R: 24-40

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a normal TPR for an equid

A

T: 37-38.5
P: 24-40
R: 8-16

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a normal TPR for a calf

A

T:38.4-39.5
P:60-100
R:20-50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a normal TPR in a bovid

A

T:37.8-39.2
P:60-80
R:10-30

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is in a qualitative exam

A

Heart sounds
Pulse quality
Lung sounds
Hydration status
Mentation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is in a Quantitative exam

A

TPR
RR
mm
CRT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

You must report these PE findings to the DVM before giving premeds

A

Change in weight
Hypothermia or hyperthermia
Abnormal HR, rhythm, or murmur; weak, overly strong (bounding) or irregular pulse
Increased resp rate or effort; altered lung sounds
Delayed CRT; pale, cyanotic or icteric mm
Dehydration
Cachexia
Change in mentation or neurological changes
Vomit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are common additional diagnositics before surgery

A

Minimum testing is usually: PCV, TP, BUN, BG
Can be done immediately prior to anesthesia; or within reasonable time frame
When testing is declined in whole or part there should be a signed consent form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Your anesthetic record must include your pre anesthetic exam findings such as

A

Drugs patient is taking
Current weight, BCS
TPR, MM, CRT, mentation
Anything is abnormal
Anything that was examined and found normal
Also verbally communicate any abnormalities to the VIC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

5 classes of patients based on anaesthetic risk

A

PS1 minimal risk
PS2 Low risk
PS3 moderate risk
PS4 high risk
PS5 extreme risk; patient will die without procedure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Physical status classification is

A

Based on minimal patient database
5 classes of patients based on anaesthetic risk
There is NEVER no risk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the goal of preop stabilization

A

Goal: stabilise patient as much as possible prior to any anaesthetic/surgical procedure; this ensures least patient risk
Depends on whether procedure is elective, required or emergency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does preop stabilization look like

A

Fluids to restore dehydration
Postpone until ideal BCS
Stop bleeding, treat infections, blood transfusions
In the event of an emergency, you may not be able to wait and “E” is placed after PS score. Example: PS3E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are some inherent risk of GA

A

CNS depression
Suppression of hypothalamic control of temp and other homeostatic functions
Also decreases ability to vasoconstrict in response to any drops in blood pressure
Decreased HR, cardiac output
Decreased RR, tidal volume
Vasodilation due to gas anaesthetics will contribute to hypotension
Risk of esophageal reflux and aspiration pneumonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How to limit risk of GA

A

Fasting
Temp support
O2 support
Fluid support
Patient monitoring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is fasting and why

A

Fast = no food, can have water
NPO= nil per os= nothing per mouth= no food or water
Fasting is important before anesthetic induction
Decreases risk associated with vomit and regurgitation during induction, surgery and recovery
Job of RVT to instruct client on fasting protocol BEFORE surgery date
Must confirm at time of admitting that patient was fated
If the client is uncertain, assume the patient has not been fasted. May require postponing surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How long do you fast a dog or cat

A

Food: 8-12h
Water: 2-4h

33
Q

How long to fast a horse

A

Food: 8-12h
Water: 0-2h
Horses have risk of gastric ulceration if empty stomach; OK if horse gets small mount of hay if anaesthetic is short

34
Q

How long to fast cattle

A

Food: 24-48h
water; 8-12h

35
Q

How long to fast small ruminants

A

Food: 12-18h
Water: 8-12h

36
Q

Do not use standard fasting protocols on the following; consult with VIC for special instructions

A

Patients less then 2 kg
Neonates <8 weeks
Exotics
Diabetics- also need to instruct on insulin
Patients with cachexia or less than ideal BCS
There is an increased risk of hypoglycemia in all of the above groups

37
Q

Emergency anesthesia and fasting

A

Emergent cases may not have time to fast
Need to weigh risk of postponing surgery against possible complications
Options
Increase monitoring
Use positioning of body to decrease risk of aspiration
Can induce vomit
Can place stomach tube

38
Q

Complications of not fasting

A

Esophageal reflux
Esophageal trauma
Aspiration pneumonia

39
Q

What is esophageal reflux

A

Different from vomiting
Gastroesophageal sphincter relaxes under GA→ when patient is in lateral, there is passive flow of stomach contents into the esophagus
Risk of reflux increases if not fasted
Occurs intraop and recovery (risk until patient can swallow and hold head)

40
Q

Esophageal trauma and GA

A

Complication of esophageal reflux
Stomach acid enters esophagus and causes damage to the esophageal lining
Clinical signs: vomit, nausea, dysphagia, post op anorexia
If severe enough, this could eventually lead to esophageal stricture- scar tissue develops where trauma occurred

41
Q

Aspiration pneumonia and GA

A

Complications of esophageal reflux
Stomach contents flow into oral cavity and from the oral cavity, enter the airways while patient is recumbent
high risk during recovery

42
Q

What causes aspiration pneumonia

A

Filling of alveoli with fluid (acute airway obstruction)
Infection and inflammation of the lungs (24-72 h post op)
Can be very severe, fatal

43
Q

How to diagnose aspiration pneumonia

A

Crackles on auscultation
Decreased oxygenation; cyanosis
Fluid oral cavity
Fluid from nares
Post op ADR, fever, increased resp sounds, tachypnea

44
Q

Preventing aspiration pneumonia

A

Fasting
Keep ETT cuff inflated until patient swallows
Stomach tube
Patient positioning
If patient has not aspirated yet but is at risk
Lateral?
If patient has aspirated and is unconscious
Sternal?

45
Q

What are some common complications with not fasting animals for GA

A

Nausea
V/D
Side effect of hydro and/or GA
Filled intestines and bladder
Decreases accessibility to abdominal organs
Increased risk of contamination
Longer surgery times
Bloating in ruminants
Require a stomach tube to release rumen gasses even if they have been fasted

46
Q

Core body temp support is

A

Thermoregulation is a homeostatic process controlled by the hypothalamus
Core heating is by
- Shivering, muscle contraction, increased metabolic rate, vasoconstriction of peripheral blood vessels
Core cooling is by
- Decreased metabolic rate, vasodilation of peripheral blood vessels, panting, salivation, sweating

47
Q

Major causes of temp drop during GA are

A

Depression of the hypothalamus (thermoregulatory centre)
Decreased metabolic rate
Muscles don’t contract/loss of shiver
Vasodilation (especially acepromazine and inhalants)
Cold 100% O2
Open body cavity (especially if open abdomen)
Evaporation of alcohol during surgical prep
Conduction loss to stainless steel

48
Q

What are some factors that affect heat loss

A

Intrinsic (patient) factors that cant be altered
- BCS
- Size of animal – smaller animals have higher surface area to body mass so lose heat faster
- Neonates and geriatrics have less thermoregulation
Extrinsic (external) factors that can be altered
- Drug selection – some cause more vasodilation than others
- Ambient temp
- Duration of GA – longer procedure = colder
- Degree of shaving and type/volume of surgical scrub

49
Q

How to monitor core body temp

A

Know temp BEFORE premedicating
From the time of induction, monitor every 15 minutes until patient is recovered
After recovery, monitor every 30 min until patient can sustain temperature >37.4 °C
Methods:
Esophageal thermometer - most accurate
Rectal thermometer – most convenient
Axillary/ear is not accurate enough

50
Q

What are the important temps under GA

A

36-38 °C – allowable range under GA
>37.4 °C – patient can maintain own temp; do not heat
36-37 °C – must provide active heating support
<36 °C – must inform DVM
<33 °C – dying

51
Q

Complications from low body temp

A

Prolongs anaesthetic recovery and general recovery (especially in cats)
Predisposes patient to anaesthetic overdose
Due to decreased metabolism of drugs
Can maintain cool patients on lower anaesthetic dose
Shivering during recovery will increase oxygen demands
Below 33*C, brainstem is depressed and theres is cardiac malfunction

52
Q

How to minimize heat loss under GA

A

Stabilize room temperature prior to premedication (turn up heat, especially in winter)
Prudent use of alcohol and scrub water (don’t drown your patient; remove excess scrub/alcohol)
Place barrier between patient and table top
Warm IV fluids to ~37.5°C; same for saline used for abdominal flushes
Blankets, circulating warm water blanket; forced warm air blanket (Bair huggers); warm water bottles
Minimize surgical and general anesthetic times

53
Q

Things to avoid for heating under GA and why

A

Electric Heating pads and Lamps
- Often poor control and get too hot
- Sedated/anesthetized patient can’t move away
- Cause contact area burns (even if mild heat for a prolonged time)
- Especially cats (genetic predisposition)
- ~ 1 week to appear; can cause sepsis
Aggressive heating of exterior body surface
- Causes peripheral vasodilation (body thinks it is too hot vasodilation of surface capillaries cooled blood from surface goes to core and drops temp furthe

54
Q

Causes of Hyperthermia under GA

A

> 39 °C
Most often seen just before/during recovery
Causes from most to least common:
Excessive external heat source (too much warming)
Cat that reacts to mu-agonists (hydromorphone, fentanyl)
Malignant hyperthermia (rare, more common in pigs)

55
Q

Management of hyperthermia under GA

A

Remove heat source; fans
Reverse drug if possible
Cold IV fluids
Turn up 100% oxygen flow

56
Q

Factors that cause hypoxia

A

Decreased RR and tidal volume with
Mu-agonsits
Alpha-2 agonists (all species; most severe in ruminants)
ALL general anesthetics
Propofol, alfaxalone cause induction apnea
Isoflurane suppresses CO2 drive
Decreased ventilation results in less O2 uptake and decreased CO2 exhaustion
Also decreases ability to move O2 and CO2 around body

57
Q

Oxygen for patients under GA

A

Patients under GA require a minimum of 33% O2 to maintain oxygen saturation of blood
Room air is 21% O2; not sufficient to meet tissue demands when combined with depresses resp function
Must have 100% O2 support to achieve maximum oxygen saturation of blood

58
Q

Weight and resp function with GA

A

Tidal volume already decreased under GA
Increased weight requires more effort to expand and expel lungs: especially if animal is recumbent
Dependant lung areas (“down” side of patient in lateral) may develop atelectasis
Alveoli partially collapse in this area due to poor inflation
Applies to
Morbidity obese animals
Large animals (Eq, Bovine)
May require manual/automatic ventilation

59
Q

Brachycephalic’s and oxygen support under GA

A

Risk of soft palate collapse. If animal also has stenotic nares, their entire airway could be cut-off
Watch for resp distress, increasing lethargy, cyanosis
Continuous monitoring from time of sedation until completely recovered
Worst risk is sedation and recovery (i.e., not intubated)
When intubated, will breathe better then they ever have before. May keep ETT in even after recovered (do not pull with swallow); release cuff so animal can pull out on own when they want
Be aware patient may also have collapsing trachea and size ETT appropriately

60
Q

What is a normal BP

A

Normal BP (no medications): 120/80 (94)
Varies with age, species, health status, and situation

61
Q

Blood pressure is maintained by a combination of:

A

HR
Cardiac output
Degree of vascular contraction
Oncotic pressure (presence of albumin and colloids in plasma keep water in the blood vessels)
Fluid volume
Adequate BP required for delivery of O2 and nutrients to cells; removal of CO2 and waste products

62
Q

Blood pressure UNDER GA looks like and depends on

A

There is always a drop in BP under GA
Degree of hypotension depends on
Drugs used (inhalants, acepromazine, alpha-2)
Patient stability (underlying cardiovascular/renal disease; hydration status; geriatrics and neonates)
Duration of GA
Any blood loss will contribute to hypotension

63
Q

Factors causing hypotension in anesthetized patients

A

Decreased cardiac function
- Decreased HR, decreased cardiac output
- Less volume of blood moved per unit time
- Most severe depression by alpha-2 agonists, inhalants, injectable anesthetics
- If severe enough, can cause cardiogenic shock
Vasodilation
- Inhalant anesthetics, acepromazine
- Causes a relative decrease in fluid volume; with time, fluid moves from interstitial space to vascular space
- If severe enough, could result in vasogenic shock
Evaporative losses
- Open body cavities, dry gasses
- Real loss of fluid volume
Perioperative hemorrhage
- Can be minimal to severe
- Real loss of fluid volume

64
Q

IV catheterization benefits

A

It is best to IV catheterize patients under heavy sedation and/or GA
Benefits
Can deliver IV fluids to maintain blood volume & support blood pressure
Can be hard to get IV access later due to low BP
Rapid administration for emergency drugs
Used to administer CRI’s
Reduces the risk of perivascular injection
Can administer a number of IV drugs one after another with flushing between each one (trauma)

65
Q

Acceptable BP under GA

A

Dog, cat: 110-160/50-70 (60-90)
Eq: >80/>50 (60-90)

66
Q

When to report BP under GA

A

Dog, cat Systolic <90; MAP <70; Diastolic <40
Eq Systolic <90; MAP <80; Diastolic <40

67
Q

Surgical fluids are determined by

A

Amount of fluids required to maintain BP in the presence of drugs that cause cardiac depression and vasodilation
ALWAYS recommended
Isotonic cystalloids (LRS, Normosol, Plasmalyte) appropriate for most patients
Administer via IV catheter

68
Q

When do you administer surgical fluids

A

From time of induction until patient is recovered
Any dehydration is corrected BEFORE general anesthesia (not part of surgical rate)
Return to appropriate maintenance rate after recovery to prevent fluid overload
Must record fluid type, rate, total volume(or start and stop times), any changes in fluid rate as they occur

69
Q

What are the common surgical fluid rates by species

A

Surgical fluid rate in otherwise healthy patient:
CATS: 2-3 ml/kg/h
DOGS: 3-5 ml/kg/h
Large animal: 5-10ml/kg/h
This rate is used on its own!
Adjust with changes in BP, lungs sounds, HR, bleeding….
Know THIS rate for exam purposes!

70
Q

FLuid bolus for surgical fluids is used for

A

Given when patients are hypotensive (despite surgical fluid rate) or bleeding profusely
I.e., when the surgical fluid rate is not enough
Start with a SINGLE crystalloid bolus
10 ml/kg over 15 min
Can repeat up to 3-4 times if necessary
Check with the vet before administering

71
Q

Reasons fro surgical fluids

A

Offsets causes of hypotension (vasodilation and decreased cardiac output)
Treats fluid loss
Supports tissues that receive the most blood flow
Kidneys > brain > heart
Even mild hypotension can result in post-anesthetic renal damage
Also corrects electrolyte and acid-base imbalances (commonly occur under GA and with pathology)
Supports renal drug elimination

72
Q

Volume overload can occur from

A

Too much fluid (excessive total volume infused)
Too fast fluids - Giving fluids too fast prevents them from entering into the extracellular fluid volume properly
Given the appropriate rate and volume to the wrong patient
Hct <20
Low albumin
Patients < 5 kg
Heart failure
Renal disease

73
Q

Physiological effects of volume overload

A

Hypertension
Very bad if pre-existing heart disease; causes heart to work harder and can cause cardiac overload
Increases blood loss
Fluids move to 3rd spaces in the body (abdomen, pleural space, pulmonary spaces)
Pulmonary edema
Cerebral edema
Can dilute oxygen carrying capacity of blood

74
Q

SIgns of volume overload

A

Increased Lung sounds/Crackles
↑respiratory rate and dyspnea
Coughing and restlessness if patient is awake
Tachycardia
Increased BP
Hemodilution (decrease the relative PCV)
Ocular and nasal discharge, chemosis
Subcutaneous edema
Neurological signs

75
Q

How to prevent volume overload

A

Know your calculations
Use an appropriate-sized fluid bag (ex. 100 ml for cat spay)
Clamp off the line when transporting patients
Check IV line and rate hourly. Caution: most drip sets will alter their rate slowly over time.
Ideally, use an infusion pump
Monitor equipment
Monitor patient

76
Q

How to treat volume overload

A

No definitive therapy
Main treatments:
Discontinue fluids
Start on diuretics
Provide oxygen support
Best to prevent fluid overload rather than treat it!

77
Q

What are some tips to use when calculating fluid volumes

A

Convert weight to kilograms
Calculate the hourly rate
ml/h (SA); L/h (LA)
Always enter this value into the medical notes
Then, calculate the drip rate from the above
Whole drops per whole seconds
Drip sets :
>10-15 kg: 10 drop/ml set
<10 kg: 60 drop/ml set (aka “pediatric” set)
Double check your numbers and make sure that they MAKE SENSE. For example, you would never give 50 ml/h to a cat
Mark your fluid bag with “Start” and “End” so you know how much fluid your patient has received = total volume infused.
Be aware that certain patients will have altered rates. Heart failure and renal disease may require decreased fluid rates; fever and younger animals require high rates, etc. If in doubt, ask.

78
Q
A

Anesthesia (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions