Cardiovascular Support

Question 1

What four things affect is cardiac output?

Answer 1

Preload
Afterload
Contractility
Heart rate

Question 2

Basic non invasive monitoring of cardiac function

Answer 2

Heart rate
Peripheral blood pressure
Pulse oximetry
Continuous ECG monitoring

Question 3

What two ways can you monitor cardiac output?

Answer 3

• Pulse control cardiac output: monitors CO via ventral venous catheter + thermodilution arterial line
• Oesophageal Doppler monitor: assesses blood flow through thoracic aorta

Question 4

Options for more intense cardiac monitoring

Answer 4

• echocardiogram
• invasive blood pressure monitoring via arterial line
• ABG
• central venous pressure
• central venous O2 sats

Question 5

What can you monitor to estimate preload?

Answer 5

Central venous pressure
Low CVP = reduced preload

Question 6

What are inotropes?

Answer 6

Medications that alter heart contractility

Question 7

What do positive inotropes do?
Examples

Answer 7

• increase contractility of heart > increase CO + MAP
• e.g. adrenaline, dobutamine, isoprenaline, milrinone

Question 8

How do catecholamines work as positive inotropes?
Examples

Answer 8

Stimulate sympathetic nervous system via a + B adrenergic receptors
e.g. adrenaline, dobutamine, isoprenaline

Question 9

What do negative inotropes do?
Examples

Answer 9

• reduce contractility of the heart > reduce CO+ MAP
• e.g. beta blockers, CCBs, flecainide

Question 10

What do vasopressors do?
Examples

Answer 10

• Cause vasoconstriction > increases systemic vascular resistance > increases MAP
• e.g. noradrenaline, vasopressin/ADH, adrenaline, metaraminol*

Question 11

What class of drugs if often used to treat bradycardia?
How do they work
Examples

Answer 11

• anti muscarinics
• e.g. atropine, glycopyronium
• block ACh receptors

Question 12

When is an intra-aortic balloon pump used?

Answer 12

• cardiogenic shock
• ACS
• after heart surgery

Question 13

What does a intra-aortic balloon bump do?

Answer 13

• increases coronary blood flow
• reduces afterload
• increases CO

Question 14

Outline the use of an intra-aortic balloon pump

Answer 14

• catheter inserted via femoral artery up to the descending thoracic aorta
• balloon in the tip of the catheter is inflated + deflated in time with heart contractions
• during diastole, the ballon is inflated > blood pushed into coronary arteries
• during systole, the balloon is deflated > creates aa vacuum effect > reduces afterload + increases CO

Question 15

What happens to an intra-aortic balloon pump during diastole?

Answer 15

during diastole, the ballon is inflated > blood pushed into coronary arteries > increases perfusion

Question 16

What happens to an intra-aortic balloon pump during systole?

Answer 16

During systole, the balloon is deflated > creates aa vacuum effect > reduces afterload + increases CO