Cardiovascular Monitoring

Question 1

Disadvantages: Cardiac Output Monitoring

Answer 1

Invasive (need peripheral or pulmonary arterial line)
Time consuming
Technically demanding
Higher cost

Question 2

What (8) things should be looked for on pre-anesthetic CV evaulation?

Answer 2

Demeanor + activity level
Temperature
Respiration
Pulse, rhythm, quality
Mucous membrane color
CRT
Hydration status
Cardiac auscultation

Question 3

Demeanor, activity level, and temperature often _____________ with cardiovascular disease

Answer 3

Decrease
This is an indicator of heart failure and/or poor organ perfusion (DO2)

Question 4

Respiratory effort may _____________ due to poor organ perfusion (DO2) and/or pulmonary edema from heart failure

Answer 4

Increase (dyspnea)

Question 5

What are characteristics of a healthy pulse?

Answer 5

Pulse rate should be adequate for the patient and in synchronicity with each heart beat
Pulse rhythm should be regular
Pulse quality should be strong

Question 6

What is pulse pressure?

Answer 6

PP = systolic - diastolic
Is not blood pressure
May be absent when MAP < 40 mmHg

Question 7

What is the relationship between hydration status and blood volume?

Answer 7

Blood volume (volemia) is directly dependent from the hydration status
Dehydrated patients are usually hypovolemic
Hypovolemic patients may or may not be dehydrated

Question 8

What are the (9) ways hydration status is assessed?

Answer 8

Prolonged skin turgor
Decreased mm moisture
Hemoconcentration (high PCV, high TP)
Increased Cr and BUN (severe)
Concentrated urine
Low urine output*
Tachycardia*
Decreased body weight
Depress or lethargy
* = change due to consequent hypovolemia

Question 9

What is the importance of cardiac auscultation?

Answer 9

Heart sounds
Heart rate, rhythm, and quality
Localize and identify murmurs, identify abnormal sounds

Question 10

Murmurs and abnormal rhythms are often correlated with what?

Answer 10

Decreased forward flow (decreased CO)

Question 11

What is the most important CV parameter monitored during anesthesia?

Answer 11

BP monitoring
One of the earliest indicators of trouble

Question 12

How is arterial blood pressure monitored directly vs indirectly?

Answer 12

Direct: arterial catheter
Indirect: doppler, oscilometric

Question 13

Advantages: Direct Arterial Blood Pressure (5)

Answer 13

Continuous monitoring
Accurate
Monitor SAP, MAP, DAP
Gives a waveform
Allows arterial samples

Question 14

Disadvantages: Direct Arterial Blood Pressure (5)

Answer 14

Invasive
Technically difficult
Time consuming
Needs a monitor
More expensive

Question 15

What should NIBP cuff width be?

Answer 15

40% limb circumference
Small = BP too high
Large = BP too low

Question 16

Advantages: Doppler (6)

Answer 16

Gives SAP
Continuous arterial blood flow assessment
Cheap
Easy
Allows HR count
Can be used in all species

Question 17

Disadvantages: Doppler (6)

Answer 17

Movement interference
Electrical noise interference
Gives only SAP (not MAP or DAP)
Does not detect very low BP (SAP < 40mmHg)
Noisty
May underestimate SAP in very small animals (e.g. cats, rabbits)

Question 18

Advantages: Oscillometric (6)

Answer 18

Gives SAP, MAP, DAP
Most will give HR
Some are cheap
Very easy to use
May come with other parameters to monitor
Can cycle automatically

Question 19

Disadvantages: Oscillometric (7)

Answer 19

Delayed response
Not continuous
May not work in very large or very small animals
Reading may not be accurate
Some are expensive
Movement interference
May not detect low BP (SAP < 50-60 mmHg)

Question 20

Consequences of mild but prolonged hypotension

Answer 20

CNS damage
Renal damage and failure
GI tissue necrosis
Muscle hypoperfusion and necrosis
Hepatic hypoperfusion
May lead to death

Question 21

Consequences of severe hypotension

Answer 21

Severe CNS damage
Severe myocardial damage
Acute death

Question 22

Consequences of hypertension

Answer 22

Increase bleeding
CNS damage (bleeding and/or ICP)
Glomerular hypertension (renal)
Retinal detachment
Retinal bleeding
Increased myocardial work

Question 23

Treatment for hypotension

Answer 23

Always try to increase CO and tissue perfusion first to maintain DO2
Can increase SVR (vasoconstriction) but be careful with decreasing tissue perfusion and DO2

Question 24

What are (6) causes for hypotension?

Answer 24

Bradycardia (decreased CO)
Decreased contractility (decreased CO)
Cardiac valve malfunction (decreased CO)
Outflow obstruction (decreased CO)
Vasodilation (decreased SVR and afterload)
Hypovolemia (decreased CO)

Question 25

Consequences of hypovolemia (9)

Answer 25

Low BP
Decreased central venous pressure
Prolonged CRT
Poor mm color
Low urine output
Tachycardia
Weak pulse
Cool extremities
Depress or lethargy

Question 26

Treatment for hypovolemia

Answer 26

Blood volume restoration
Crystalloids, colloids, blood products

Question 27

ECG: Abnormalities

Answer 27

Catecholamine release
Hypoxia, hypercapnia
Hypovolemia, hypotension
Electrolyte imbalance
Drugs
Myocardial inflammation, disease, or stimulation
Thoracic/non-thoracic trauma
Visceral organ disease (GDV, spleen)
Intracranial disorders

Question 28

Ruminants, Small Animals, Neonates, Horses: Species Differences

Answer 28

Ruminants: hypertensive
Small animals difficult to monitor
Neonates mildly hypotensive and HR dependent
Horses have lower HR