CV Monitoring

Question 1

Mean Arterial Pressure (MAP)

Answer 1

[systolic + 2(diastolic)]/3

Question 2

Pulse Pressure

Answer 2

Systolic - Diastolic

Question 3

ratio of changing height away from heart to correlation of pressure

Answer 3

10 cm H20 = 7.5 mmHg

Question 4

Non-invasive BP techniques

Answer 4

1. Palpation = only assess systolic BP
2. Doppler = only systolic but with probe
3. Auscultation = USELESS
4. Oscillometry = preferred mode, with automated cuff
5. Tonometry = probe senses pressure required to occlude artery

Question 5

Oscillometry

Answer 5

Inflate past systolic –> pulsations are then transmitted at systolic as it deflates
- Maximum oscillations are the MAP and diastolic is calculated

Question 6

Incorrect cuff readings

Answer 6

Small cuff = abnormally high BP

Large cuff = abnormally low BP

Question 7

Arterial line sites

Answer 7

Radial = superficial, reliable, substantial collateral
Ulnar = deeper, more tortuous
Brachial = larger, more accurate pressure
Femoral = more arterial disease and possible pseudoaneurysm, infection risk
DP/PT = only in a pinch

Question 8

Arterial line indications

Answer 8

• anticipated hypotension requiring vasoactives
• wide fluctuations in BP during case
• multiple lab draws
• anticipated bleeding

Question 9

Complications of arterial lines

Answer 9

1. hematoma
2. bleeding
3. vasospasm
4. thrombi/emboli
5. air bubble
6. pseudoaneurysm
7. necrosis of skin
8. infection
9. nerve damage

Question 10

Factors that increase risk of complication of arterial line

Answer 10

1. prolonged cannulation
2. hyperlipidemia
3. multiple attempts
4. larger catheters

Question 11

Hyperresonance of arterial waveform

Answer 11

artifact that is caused by reverberation of the pressure waves within the system

Question 12

Piezoelectric effect

Answer 12

converts the mechanical strain of pulsation into electrical energy seen on the monitor

Question 13

ECG

Answer 13

mandatory monitor, continuous from beginning to end

Question 14

Leads of ECG

Answer 14

II = axis at 60 degress, parallel to atria (P waves)
- most sensitive for arrhythmias
V5 = most appropriate in the 5th intercostal space
- anterior and lateral wall ischemia

Question 15

Indications for CVC

Answer 15

1. monitor CVP
2. Anticipate lots of fluid administration
3. Anticipate or known pressor administration

Question 16

Contraindications for CVC

Answer 16

1. Tumor
2. Clots
3. Severe Tricuspid Regurgitation

Question 17

Techniques of confirming venous placement of CVC

Answer 17

• transduce vessel
• blood color
• U/S
• pulsatility
• PaO2

Question 18

Risks of CVC placement

Answer 18

1. Infection (sterile technique)
2. Hematoma
3. Hydrothorax
4. Pneumothorax
5. Arterial Puncture (don’t dilate)
6. Air embolus
7. Cardiac Perforation
8. Arrhythmia
9. Hemothorax
10. Tamponade

Question 19

Optimal placement of CVC

Answer 19

at the tip of the SVC - RA junction

Question 20

Pulmonary Artery Catheter

Answer 20

you can measure the CO and well as PA pressures with PA catheter
- can estimate LVEDP

Question 21

Low SV and low LVEDP on PA Catheter

Answer 21

Hypovolemia

Question 22

Low SV and High LVEDP on PA catheter

Answer 22

fluid overload

Question 23

High SV and hypotension

Answer 23

vasoplegia

Question 24

Contraindications to PA catheter

Answer 24

pre-existing LBBB

WPW

Question 25

Inserting PA catheter

Answer 25

1. Place into R atrium (15-20 cm) -> inflate balloon 2. Sudden increase in systolic = R ventricle 3. Sudden increase in diastolic = PA 4. Equilibration of pressure = PA occlusion pressure

Question 26

Complications of PA catheters

Answer 26

1. CVC bacteremia 2. Thrombogenesis 3. PA rupture 4. Valve Damage 5. Endocarditis 6. PA Infarct 7. Hemorrhage 8. Arrhythmia

Question 27

Measuring Cardiac Output

Answer 27

Thermodilution = inject volume of cold saline - change of temp at thermistor correlates to CO - lots of temp change = low flow and CO - no temp change = high flow and CO

Question 28

Fick Principle for O2 consumption

Answer 28

CO = Vo2/ CaO2 - CvO2