Anesthesiology Cardiopulmonary Disease

Front 1

What are the 2 functions of the cardiovascular system?

Back 1

1) Deliver O2, other metabolites to tissues
2) Remove CO2, other metabolic wastes from tissues

Front 2

Do arteries or veins have a large capacity?

Back 2

Veins
= 70%

Front 3

What is the distribution system of the body?

Back 3

Arteries

Front 4

What vessels control blood distribution?

Back 4

Arterioles

Front 5

what % of blood flow goes to the heart & lungs?

Back 5

15%

Front 6

What is the equation for arterial pressure?

Back 6

Flow (Q) x Resistance (R)

Front 7

_______ activity is required for the mechanical activity of the cardiovascular system to occur.

Back 7

Electrical
-Excitation- contraction coupling

Front 8

Te distribution of what 4 electrolytes are responsible for the electrical potential across cell membranes?

Back 8

1) Sodium
2) Potassium
3) Chloride
4) Calcium
-normal distribution of ions required for normal electrical activity to occur

Front 9

Where does the action potential in the heart begin?

Back 9

SA node

Front 10

What is the P wave in the ECG?

Back 10

As action potential spreads from SA node to atria get atrial contraction= P wave

Front 11

What happens to the electrical activity of the heart after causing atrial contraction?

Back 11

Action potential reaches AV node where conduction is relatively slowed and results in a normal P-R interval

Front 12

What happens to the electrical activity of the heart after going through the AV node?

Back 12

Goes through the purkinje fibers and ventricles contract all at once, resulting in a QRS complex , then as heart repolarizes see the T wave occur
-repolarization of atria is usually overridden by QRS complex

Front 13

What are you looking for when monitoring an ECG of a patient under anesthesia?

Back 13

Don't worry about size of waves bc leads could be in wrong place - looking to see if P wave, QRS complex, T wave; does every P wave have a QRS complex associated with it?

Front 14

What electrolyte is primary responsible for excitation-contraction coupling?

Back 14

Calcium!!!!

Front 15

Explain the process of cardiac contraction.

Back 15

Action potential--> inward Ca flux, triggers Ca++ release from sarcoplasmic reticulum, Ca binds troponin C (actin-myosin interaction) --> cell contracts

Front 16

The strength of cardiac contraction is dependent on the concentration of ______.

Back 16

calcium

Front 17

What is the equation for CO?

Back 17

HR x SV

Front 18

What are the 3 factors that affect cardiac output?

Back 18

1) Determinants
2) Cardiac factors
-HR, contractility
3) Coupling factors
-preload, afterload

Front 19

What % of total blood volume is distributed to the vessel rich group?

Back 19

75%

Front 20

What % of total blood volume goes to muscle groups?

Back 20

20%

Front 21

What % of total blood volume is distributed to fat?

Back 21

5%

Front 22

What % of total blood volume is distributed to the vessel poor group?

Back 22

<1%

Front 23

What part of the nervous system plays a part in controlling the cardiovascular system?

Back 23

Sympathetic, parasympathetic

Front 24

What are the 3 components of the humoral control of the cardiovascular system?

Back 24

1) Adrenal medulla
2) Renin-angiotensin
3) Arganine vasopressin (ADH)

Front 25

What are the 3 broad categories of cardiovascular system control?

Back 25

1) Nervous system
-autonomic
2) Humoral
3) Local control

Front 26

What autonomic input affects the atria? Ventricles?

Back 26

Atria: parasympathetic & sympathetic
Ventricles: just sympathetic, very little parasymp input

Front 27

How do most anesthetics affects the cardiovascular system?

Back 27

Most anesthetics depress the CV system
-hypotension
-bradycardia
-decrease contractility

Front 28

What are 2 ways to minimize the cardiovascular depressive effects of anesthesia?

Back 28

1) Careful dosing
-overcorrection may be worse than initial depression
2) Balanced anesthesia

Front 29

What is the hallmark of shock and heart failure?

Back 29

Tissue hypoxia

Front 30

What are 5 questions you should ask yourself when getting ready to anesthetize a patient w/ preexisting cardiovascular disease?

Back 30

1) What is the pathophysiology & hemodynamic consequences of the disease process?
2) What anesthetic drugs are available?
3) What is the impact of the planned procedure?
4) What monitoring techniques are available?
5) What support drugs are available?

Front 31

What is the pathophysiology of an aortic stenosis?

Back 31

-Left ventricular outflow obstruction, decreases CO
-Increase left ventricular pressure
-Left ventricular hypertrophy
-Decrease left ventricular compliance
-Contractility may be increased or unchanged
-potential alterations of coronary blood flow, coronary perfusion due to hypertrophy & heart has to relax for blood to flow in

Front 32

What ar ethe effects of anesthetics on the cardiovascular system?

Back 32

Depression
-decrease contractility
-decrease vascular tone (relative hypovolemia, alter preload/ afterload)

Front 33

Why are animals with cardiovascular disease less able to compensate for anesthetic-induced changes?

Back 33

Have a decreased reserve capacity

Front 34

What are 3 things to look for when trying to evaluate the respiratory pattern of a patient during a physical exam?

Back 34

1) Dyspnea?
2) Cough?
-pulmonary edema, pleural effusion
3) Mucous membranes
-cyanosis, pallor, poor CRT

Front 35

What are 5 components during a physical exam that can reveal cardiovascular disease?

Back 35

1) Respiratory pattern
2) Jugular distention, pulses
3) Femoral pulses
-rate, intensity, regularity, association w/ ventricle contraction
4) Cardiac auscultation
-murmur, arrhythmias
5) Abdominal palpation
-ascites, hepatomegaly

Front 36

What is a really important piece of history when trying to diagnose cardiovascular disease?

Back 36

Are they exercise intolerant

Front 37

What can a nocturnal cough imply?

Back 37

Early symptom of heart failure

Front 38

What does jugular distension indicate?

Back 38

Right sided heart failure

Front 39

What are 4 possible abnormalities in lab data related to cardiovascular failure seen on CBC, chemistry panel and UA?

Back 39

1) Increased BUN/ creatinine
2) Increased liver enzymes
3) Polycythemia/ anemia
-due to chronic hypoxia
4) Electrolyte abnormalities
-diuretic therapy
*see hepatic and renal changes later in disease

Front 40

What are 4 preanesthetic evaluation techniques used aside from lab data?

Back 40

1) Electrocardiogram
-arrhythmias, indication of cardiac enlargement
2) Blood pressure
-may be misleading due to compensatory changes
3) Thoracic radiographs
-Cardiac enlargement
-pulmonary changes
4) Echocardiograph**
-diagnostic & quantitative assessment
-provides best info in most cases!

Front 41

What are 3 examples of congenital heart disease?

Back 41

1) Patent ductus arteriosus
2) Aortic stenosis
3) Pulmonic stenosis
*if see one look for more!

Front 42

What is an example of an acquired heart disease?

Back 42

Mitral valve insufficiency

Front 43

What are 2 examples of common significant preexisting arrhythmias?

Back 43

1) Atrial fibrillation
2) Third degree heart block

Front 44

What are 2 examples of common pericardial disease?

Back 44

Effusion, hemorrhage
Cardiac tamponade

Front 45

What are 2 cardiomyopathies?

Back 45

Hypertrophic VS dilated

Front 46

What are 2 circulatory issues that can result in cardiovascular disease?

Back 46

Anemia, polycythemia
Hypotension/ hypovolemia

Front 47

What are 2 things you should do prior to anesthetizing an animal with cardiovascular disease?

Back 47

1) Stabilize heart rate & rhythm
2) Optimize cardiac function

Front 48

What are 3 characteristics you want in an anesthetic used in patients with cardiovascular disease?

Back 48

1) Minimal cardiovascular effect
2) Short duration of action
3) Reversible

Front 49

What are 5 ways to support CV & respiratory function?

Back 49

1) + inotropes
2) + chronotropes
3) Antiarrhythics
4) IPPV
-positive pressure ventilation
5) Fluids

Front 50

What are 3 health conditions that can predispose an animal to fluid volume overload?

Back 50

1) Pulmonary edema
2) Pleural effusion
3) Ascites

Front 51

What are 2 ways to conserve fluid rates used for patients with cardiovascular disease?

Back 51

1) Maintenance rates reduces
2) Conservative bolus rates

Front 52

What are 4 ways to monitor fluid therapy?

Back 52

1) Auscultation
2) Pulse oximetry
3) Blood gases
4) Central venous pressure

Front 53

What 2 preanesthetic drugs should you avoid use of in patients with cardiovascular disease?

Back 53

Acepromazine, alpha2 adrenergic agonists

Front 54

What preanesthetics are typically used in patients with cardiovascular disease?

Back 54

Opioids +/- benzodiazepines
-anticholinergics used judiciously

Front 55

What is the first choice for an induction agent in a patient that has cardiovascular disease?

Back 55

Etomidate

Front 56

What should you use for an induction agent in a small animal with cardiovascular disease if etomidate is not available?

Back 56

Neuroleptanalgesics

Front 57

When is ketamine a good choice for a small animal with cardiac disease?

Back 57

Dilated cardiomyopathy
-not a good choice for hypertrophic cardiomyopathies

Front 58

Should you use propofol to induce a small animal with cardiovascular disease?

Back 58

USE CAUTION

Front 59

What drugs do we like to use for maintenance in a patient with cardiovascular disease?

Back 59

Isoflurane or sevoflurane
+ opioid
+ local anesthetics if appropriate

Front 60

What do we use to induce large animals with cardiovascular disease?

Back 60

Ketamine + benzodiazepine &/or guaifenesin

Front 61

what anesthetic do we use to maintain large animals with cardiovascular compromise/

Back 61

Isoflurane or sevoflurane
+ local anesthetics if appropriate

Front 62

What is the definition of respiration? Ventilation?

Back 62

Respiration: Metabolic event at the cellular level, utilization of O2, generation of CO2
Ventilation: gas exchange at the alveolar level

Front 63

What is the definition of tidal volume?

Back 63

Amount of air we move in with each breath

Front 64

How can you decrease end tidal CO2?

Back 64

Increase minute ventilation- increase respiratory rate or tidal volume- can increase either one or both

Front 65

What is the expiratory reserve volume?

Back 65

The volume left in the lung after max expiration

Front 66

What allows for gas exchange during the expiratory pause?

Back 66

Functional residual capacity***
-anything that affects this will push a patient towards hypoxia

Front 67

What are 3 parameters that often affect the functional residual capacity?

Back 67

1) Disease
2) Body condition
3) Positioning
-e.g. butt in air and head down so all the abdominal contents push forward on lungs & reduce functional residual capacity

Front 68

What is the equation for minute ventilation?

Back 68

RR x TV

Front 69

**what is the main neural control mechanism of ventilation?

Back 69

CO2
but there's a back up safety where if oxygen gets low enough respiration will increase

Front 70

What are the 2 components of bellows mechanism?

Back 70

1) Chest wall
2) Diaphragm

Front 71

What are the components of the upper airways that affect ventilation?

Back 71

nasal passages, larynx, trachea, bronchi, bronchioles
anatomic dead space

Front 72

What is the "lung parenchyma"?

Back 72

Alveoli

Front 73

What are the 4 components of ventilation?

Back 73

1) Neural control mechanisms
2) Bellows mechanism
3) Upper airway
4) Lung parenchyma

Front 74

What is the intrathoracic pressure during inspiration?

Back 74

Slight negative intrathoracic pressure

Front 75

Is inspiration an active or passive process? expiration?

Back 75

Inspiration: active
Expiration: passive

Front 76

Does inspiration or expiration augment venous return?

Back 76

Inspiration

Front 77

What is the intrathoracic pressure during expiration?

Back 77

Slight positive pressure

Front 78

Why is it important to try to minimize positive pressure use?

Back 78

Decreases venous return during those parts of ventilator cycle

Front 79

Why do you have to ventilate an animal any time you open up the thorax?

Back 79

Because pressure depends on intact thoracic wall

Front 80

What are 2 types of ventilation/ perfusion mismatching? What is an example of a cause of each?

Back 80

1) well ventilated/ no perfusion
-physiologic dead space ventilation
2) No ventilation/ well perfused
-Shunt

Front 81

What does V/Q = when its well ventilated/no perfusion?

Back 81

V/Q= infinity

Front 82

What does V/Q = when there no ventilation but well perfused?

Back 82

V/Q=0

Front 83

What V/Q affects oxygenation the most?

Back 83

Low V/Q or shunt

Front 84

What is hypoxic pulmonary vasoconstriction?

Back 84

A defense mechanism to deflect perfusion away from poorly ventilated regions of the lung
-obtunded by inhalant anesthetics

Front 85

What is the end product of cellular metabolism?

Back 85

CO2

Front 86

How is CO2 eliminated?

Back 86

moves along partial pressure gradient from mitochondria --> alveoli---> ambient air

Front 87

What are the 3 forms that CO2 is transported as?

Back 87

1) Dissolved CO2 (5%)
2) Carbonic acid which dissociates into H2CO3 + H+
3) In RBCs
-bound to Hb, dissociates into H2CO3 + H+ (carbonic anhydrase)

Front 88

What are the 3 things that determine oxygen transport?

Back 88

CO
Affinity of Hb for O2
CaCO2 (arterial blood oxygen content)

Front 89

There is little change in hemoglobin saturation > _____ mmHg PO2.

Back 89

70**

Front 90

There is a marked change in saturation of hemoglobin between ___-____ mmHg PO2.

Back 90

10-40 mmHg*

Front 91

What does a left shift in the oxyhemoglobin dissociation curve mean?

Back 91

Increased affinity for oxygen

Front 92

What are 3 factors that will cause a let shift in the oxyhemoglobin dissociation curve?

Back 92

1) Decreased temp
2) Decreased 2-3 DPG
3) Decreased H+

Front 93

What are the 2 components of oxygen in circulation?

Back 93

Oxygen bound to Hb
Oxygen dissolved in plasma

Front 94

What is the normal hemoglobin saturation/

Back 94

> 98%
-<2% dissolved in plasma

Front 95

How does high inspired O2 affect oxygen & CO2 concentrations?

Back 95

Increases dissolved O2
Causes modest (10%) increase in CaCO2

Front 96

How are ventilation and oxygen saturation & content related? CO2?

Back 96

Modest effect on oxygen saturation & content
Linear relationship b/w CO2

Front 97

CaO2 is markedly affected by____.

Back 97

Hb

Front 98

What should you do if you have a low oxygen saturation and pulse ox reading is low?

Back 98

Increase ventilation some & might increase CV
-common reaction is to turn up the flow rate, but if delivering appropriate amount of oxygen this doesn't help

Front 99

Is there a big difference b/w oxygen content in an animal that is breathing room air vs 100% O2?

Back 99

No doesn't change much, but in an anemic animal it could make the difference b/w life & death

Front 100

***What is the equation to approximate the PaO2?

Back 100

Estimated PaO2= 5 x % inspired O2

Front 101

What are 4 ways that anesthesia alters ventilation?

Back 101

1) Decreases responsiveness of central & peripheral chemoreceptors
2) Decreased external signs of impaired ventilation
3) Decreased responsiveness O2
4) Decreased hypoxic ventilatory drive

Front 102

What are 3 ways sequelae to anesthetics *depressing ventilatory function?

Back 102

1) Hypoventilation
2) Hypercarbia
3) Hypoxemia

Front 103

When is supplemental oxygen a good idea with patients with cardiopulmonary issues?

Back 103

Almost always, even with just 'sedation'

Front 104

When should you intubate & protect airways in patients with cardiopulmonary disease? Use controlled ventilation?

Back 104

Almost ways a good idea to do both
-even with just sedation provide controlled ventilation

Front 105

What is one big challenge when performing a physical exam on an animal with a preexisting respiratory disease?

Back 105

May be difficult to detect anything without significant stress

Front 106

What are 3 things to note about dyspnea upon patient evaluation?

Back 106

-inspiratory? expiratory?
-Upper vs lower airway?
-Parenchymal vs non-parenchymal disease

Front 107

What are 2 signs of hypoxemia &/or hypoventilation upon patient evaluation?

Back 107

Mucous membranes
-cyanosis, pallor, poor capillary refill time
Dyspnea

Front 108

What are 3 signs discovered upon patient evaluation that indicates respiratory and cardiovascular disease?

Back 108

1) Jugular vein distension, jugular pulses
2) Femoral pulses
3) Cardiac auscultation

Front 109

What is the best way to evaluate ventilatory function using lab data?

Back 109

Arterial blood gas

Front 110

What PaO2 is considered hypoxemia?

Back 110

PaO2 < 60 mmHg

Front 111

What PaCO2 is defined as hypoventilation?

Back 111

PaCO2> 60 mmHg

Front 112

What are you looking for when using pulse oximetry for preanesthetic evaluation?

Back 112

SpO2< 90%

Front 113

What are you looking for when using capnogrpahy for preanesthetic evaluation of an animal that you suspect cardiovascular disease in/

Back 113

ETCO2> 60 mmHg

Front 114

What are you looking for when examining thoracic radiographs during preanesthetic evaluation of an animal you suspect cardiovascular disease in?

Back 114

Pulmonary changes
Cardiovascular changes

Front 115

What are 3 common airway & tracheal diseases?

Back 115

1) Trauma
2) Brachycephalic syndrome
- stenotic nares, elongated soft palate, everted laryngeal ventricles, hypoplastic trachea
3) Collapsing trachea

Front 116

What are 4 common primary lung diseases?

Back 116

1) Pneumonia
2) Pulmonary contusions
3) Neoplasia
4) "Asthma"- reactive airway disease

Front 117

What are 3 pleural space diseases?

Back 117

1) Effusion (blood, chyle, inflammatory)
2) Pneumothorax
3) Diaphragmatic hernia

Front 118

What are 3 common thoracic wall diseases?

Back 118

1) Rib fractures
2) Laceration/ puncture
3) Coonhound paralysis

Front 119

What are 3 anesthetic goals with patients with cardiopulmonary disease?

Back 119

1) Minimize stress & excitement
2) O2 supplementation
3) Potentially catastrphic of all inductions
-BE PREPARED: assortment of ETT, stylets, tracheotomy kit, suction, laryngoscrope, plenty of light
-monitors: pulse ox, capnography

Front 120

What are 4 ways to monitor that is routine, but pays special attention to respiration?

Back 120

1) Pulse oximetry
2) Capnography
3) Arterial blood gases
4) Auscultation

Front 121

What are 2 ways to support respiration & CV function?

Back 121

-IPPV
caution in some patients
be prepared to tap chest if needed
-fluid support
Susceptible to overload

Front 122

What preanesthetic should be used in small animal patients with cardiovascular disease?

Back 122

Acepromazine/ benzodiazepines/ low dose opioids
- use anticholinergics judiciously

Front 123

What are 3 induction agents that can be used in small animals with cardiovascular disease?

Back 123

Rapid induction technique preferred
1) Propofol - thiopental- etomidate
-fastest, etomidate least respiratory depressant
2) Ketamine / diazepam: slower
-poorer intubation quality, little respiratory depression
3) Mask, neuroleptanalgesic techniques: slowest
-usually a poor choice

Front 124

What is used for maintenance in small animals with cardiovascular disease?

Back 124

Inhalant of choice
-supplement w/ local anesthetic techniques if applicable

Front 125

What should be considered in a large animal with significant upper airway disease?

Back 125

Standing tracheostomy

Front 126

What are 3 things to consider when performing anesthesia in large animals with cardiovascular disease?

Back 126

1) Can procedure be done standing?
2) Preoxygenate? Nasal O2?
3) Patient positioning?
-local anesthesia when possible

Front 127

Does the drug protocol for CV disease in a large animal need to be altered?

Back 127

Not really, just be prepared for difficult intubation