Lecture 29: Peri-anesthesia Monitoring and Complications-II Flashcards
1
Q
To evaluate HR under anesthesia it is very important to first know the ___
A
Resting heart rate of each patient
2
Q
What is resting HR for large dogs under anesthesia
A
35-100bpm
3
Q
What is resting HR for medium dogs under anesthesia
A
50-120bpm
4
Q
What is resting HR for small dogs under anesthesia
A
80-150
5
Q
What is resting heart rate for cats under anesthesia
A
90-160
6
Q
What is resting HR for horses under anesthesia
A
25-45
7
Q
If severely bradycardia or arrhythmia how long do you count to get accurate HR
A
20-30 seconds
8
Q
What does ECG tell you
A
Only electrical signal not the function
9
Q
What is the first monitoring equipment you place
A
Capnograph and/or pulse ox
10
Q
What is the standard lead for small animals and where is it placed
A
Lead 2- placed between right arm and left leg
11
Q
What is the standard lead for horses and cows
A
Base-apex lead
12
Q
What is the deflection direction if traveling from - to +
A
Positive
13
Q
What is deflection direction if traveling from + to -
A
Negative
14
Q
Which animals is a negative deflection QRS normal for
A
cows, horses, and birds
15
Q
T or F: you treat all arrhythmias
A
False
16
Q
What is the most common arrhythmia under anesthesia
A
Sinus bradycardia
17
Q
What is sinus bradycardia for cats under anesthesia
A
<90bpm
18
Q
What is sinus bradycardia for small dogs (except dachshunds) under anesthesia
A
<80-100bpm
19
Q
What is sinus bradycardia for medium dogs and mini dachshunds
A
<50-80bpm
20
Q
What is sinus bradycardia for large dogs
A
<35-50bpm
21
Q
Identify the arrhythmia
A
sinus bradycardia
22
Q
What are the causes of sinus bradycardia
A
- Vagal
- Non-vagal
23
Q
What are the vagal causes of sinus bradycardia
A
Anesthetic, opioids, sedatives, hypothermia, abdomen, neck, eye manipulation
24
Q
What are the non-vagal causes of sinus bradycardia
A
- Cardiac dz
- Endocrine dz
- Neurological dz
- Electrolyte abnormality
- Beta-blocker, Ca2+ channel blocker
25
When do you treat sinus bradycardia
If hypotension or very young
26
Why do you need to treat sinus bradycardia in very young animals
They have a fixed SV (CO=SV xHR) so if decrease HR, decrease CO which will then decrease BP (BP=CO xSVR)
27
What is the treatment for sinus bradycardia that applies to both causes
1. Decrease inhalant
28
What is tx for vagal bradycardia
1. Atropine
2. Glycopyrolate
Anticholinergics
29
Atropine or glycopyrolate: most likely causes tachycardia
Atropine
30
Atropine or glycopyrolate: increase HR to high normal
Glyco
31
Which is not used for emergencies: atropine or glycopyrolate
Glyco
32
Why do you not want to use alpha 2 agonists with anticholinergics within 1hr of each other
Alpha 2 agonists will vasoconstrict and anticholinergics will increase HR—> increase resistance and workload on heart and can lead to cardiac arrest
33
You give dexmedetomidine, how long do you have to wait to give atropine?
60 minutes
34
T or F: anticholinergics can cause paradoxical bradycardia and/or AV block
True
35
T or F: paradoxical bradycardia likely resolves on own in few minutes
True
36
What is tx for non-vagal sinus bradycardia
1. Isoproteronol
2. Pacemaker
37
What is sinus tachycardia in a cat
<180bpm
38
What is sinus tachycardia in small dogs (except dachshunds)
<160
39
What is sinus tachycardia in medium dogs and miniature dachshunds
>140
40
What is sinus tachycardia in large dogs
>120-140
41
Which wave is difficult to see in sinus tachycardia
P wave
42
What arrhythmia is occurring
Sinus tachycardia
43
Why is sinus tachycardia a problem
Shorter diastolic period leading to shorter ventricular filling time and less coronary perfusion. Decrease CO due to smaller SV
44
What are the causes of sinus tachycardia
1. High sympathetic tone
2. Compensatory response (baroreceptor reflex)
45
What are some causes of high sympathetic tone leading to sinus tachycardia
1. Less than adequate depth of anesthesia
2. Pain
46
In high sympathetic tone sinus tachycardia what is relationship between BP and HR
Increase together
47
What are some causes of compensatory response sinus tachycardia
Hypovolemia, hypotension
48
What is the relationship of HR and BP in compensatory response sinus tachycardia
HR increases due to decrease BP
49
What is tx for high sympathetic tone sinus tachycardia
1. More analgesics
2. Increase vaporizer
50
What is tx for compensatory response sinus tachycardia
1. Decrease inhalant
2. Fluid bolus 5mL/kg
3. Colloid
4. Tx hypotension
51
What drugs can be given to tx sinus tachycardia in high sympathetic and compensatory response
1. Esmolol- beta-adrenergic antagonist
2. Diltiazem- Ca2+ channel blocker
52
What is happening during respiratory sinus arrhythmia
1. During inspiration decrease in pleural pressure
2. Increased venous return
3. Increased atrial pressure
4. Stretch receptor stimulation
5. Increase HR
6. Decrease HR on expiration
53
What is this showing? Blue line- respiration
respiratory sinus arrhythmia
54
T or F: treatment is necessary for respiratory sinus arrhythmia
True
55
What is an AV block
Disturbance that affects the transmission of an atrial pulse to the ventricles
56
What occurs in 1st degree AV block?
1. Delayed transmission
2. P-R interval is prolonged
57
What are some causes of 1st degree AV block
1. Vagal
2. Non-vagal- beta blocker, Ca2+ channel blocker, electrolyte abnormality, underlying Heart dz
58
T or F: no treatment is needed for first degree AV block
True
59
What is 2nd degree AV block
Not all P waves are followed by QRS complex, occasional drops
60
What is mobitz type I 2nd degree AV block
Vagal
Progressive prolongation of P-R intervals before the dropped beat
61
What is Mobitz type II 2nd degree AV block
Pathological
No prolongation of P-R intervals before the dropped beat
62
63
What is tx for vagal/type I 2nd degree AV block
Anticholinergics (Glyco, atropine)
64
What is tx for type II 2nd degree AV block
Pacemaker
65
What is 3rd degree AV block
Complete AV dissociation, no relationship between P waves and QRS complex
66
How does the QRS complex appear with 3rd degree AV block
Wide, bizarre, escape beats
67
What is the cause of 3rd degree AV block
Pathological- heart disease, hyperkalemia, severe digoxin toxicity
68
What is the ventricular rate if 3rd degree block is taking place near junction
40-60bpm
69
What is the ventricular rate if 3rd degree AV block is taking place closer to ventricle
20-40bpm
70
What species is often asymptomatic with 3rd degree AV block because of adequate ectopic pacemaker rate of 100-130
Cats
71
What is tx for 3rd degree AV block
1. Pacemaker
2. Abort procedure if possible
72
What type of AV block is this and what are the blue arrows
3rd degree AV block
Blue arrows: escape beats
73
What type of AV block is this
1st degree
74
What type of AV block is this
2nd degree- type I
75
What are VPC’s
Depolarization of an ectopic focus that is more premature than the signal oriented at the SA node
Missing P wave, shorter R-R interval and wide and bizarre QRS
76
What are the causes of VPC’s
1. Re-entry (inflammatory, structural, toxic, infiltration, traumatic, ischemic heart dz)
2. High sympathetic tone- GDV, pain, high stress
77
What piece of monitoring equipment do you want to pay attention to for VPC’s besides ECG
Pulse ox wave form
AUC of each triangle= SV and will get smaller with VPC
78
What kind of arrhythmia is this
VPC
79
What is VTach
4 or more VPC’s occurring in succession at HR >160
80
What do you do if you notice VTAC
Immediately check if patient has pulse, if no pulse start CPR
81
If patient with VTach has a pulse, you treat if it is
Causing hypotension or getting worse
82
What are some drugs used to tx VPC or VTach
1. Lidocaine- Na+ channel blocker
2. Procainamide- Class IA antiarrythmic
83
What is accelerated idoventricular rhythm
Slow ventricular tachycardia <160
84
What is cause of accelerated idioventricular rhythm
GDV, splenic disease
85
What is wrong here
escape beats- normal safety system for SA and/or AV node failure
86
What this
accelerated idioventricular rhythm- <160
87
T or F: you treat an escape beat like a VPC
False, do not treat it as VPC it is a defect system and treating it as VPC can cause cardiac arrest
88
If escape beat rhythm is not fast enough what can you give
Anticholinergics
