Mod1: Monitoring for Cardiac Surgery - CENTRAL VENOUS PRESSURE

Question 1

_{CENTRAL VENOUS PRESSURE - INDICATIONS}

Secures vascular access for:

Answer 1

Evaluating cardiac function

^{CVP/RAP (preload)}

^{To evaluate R atrial and ventricular function and tricuspid function}

Administer fluids, vasoactive drug therapy, TPN fluid

Aspiration of air

Conduit for insertion pulmonary artery catheter or transcutaneous pacing leads

Difficult vascular access or repeated blood sampling required

Question 2

_{CENTRAL VENOUS PRESSURE - INDICATIONS}

T/F: CVP/RAP is a good indicator of left sided function

Answer 2

False

CVP/RAP is not a good indicator of left sided function

Question 3

_{CENTRAL VENOUS PRESSURE - INDICATIONS}

What are normal CVP/RAP values?

Answer 3

2-6 mmHg

Question 4

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

What must be carefully considered when choosing a site for CVP cannulation?

Answer 4

Patient’s underlying medical condition

Clinical setting and skill level of anesthesia provider

Question 5

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

What should be considered when selecting a site for CVP cannulation in a pt with underlying bleeding process

Answer 5

choose a site where bleeding from the vein or surrounding vessels can easily be detected and corrected

Question 6

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

Between Internal jugular and subclavian approach which is preffered for CVP cannulation in a pt with Bleeding diatheses?

Answer 6

Internal jugular > subclavian approach

Question 7

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

What is Bleeding diatheses?

Answer 7

an unusual susceptibility to bleed (hemorrhage) mostly due to hypocoagulability (a condition of irregular and slow blood clotting), in turn caused by a coagulopathy (a defect in the system of coagulation).

Question 8

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

Between Internal jugular and subclavian approach which is preffered for CVP cannulation in a pt with Emphysema?

Answer 8

Internal jugular > subclavian approach

IJ is associated with a reduced chance of a pneumothorax

Question 9

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

Why is the RIJ preferred for Transvenous pacing?

Answer 9

Direct route to right ventricle

Question 10

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

Provider must be aware of the length of the catheter chosen in relation to the site of insertion. How many cm greater will proper positioning of the cather tip in th SVC be on the left vs the right?

Answer 10

3-5 cm greater on the left than right

This is why left sided catheter should be longer

Question 11

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

What’s the most common site for CVP cannulation

Answer 11

Right internal jugular vein

Question 12

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

What are advantages of the right IJ site for CVP cannulation?

Answer 12

Easily accessible (short/direct access to the RA)

Predictable anatomy

Good landmarks

High success rate (>90%)

Thrombus formation less likely (d/t high blood flow rate and pts can still move heads arround)

Question 13

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

Which complications are associated with the right IJ when used as a CVP cannulation site?

Answer 13

Carotid artery puncture

Brachial plexus injury

Pneumothorax (esp. pts w/ short necks)

Hard to maintain sterility (esp. in pts w/ lots of oral seceretions)

Question 14

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

Advantages of Left internal jugular vein site?

Answer 14

Same as right

Question 15

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

What are “catheter length” considerations when the Left IJ is cannulated for CVP monitoring?

Answer 15

A longer catheter may be needed for the catheter to be seated in the right position

Remember that proper position of the catheter tip in the SVC will be 3-5cm greater on the left than on the right

Question 16

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

Disadvantages of Left internal jugular vein site?

Answer 16

Thoracic duct damage

Cupola of the pleura higher on left side

^{(which potentially increase the risk for a pneumothorax)}

Left IJ is smaller than the right IJ

Difficulty maneuvering catheter through jugular-SC junction

Carotid artery puncture

^{(LIJ seats more on top of the left carotid than the right IJ seats on top of the right carotid)}

Embolization of dominant L cerebral hemisphere

Most providers have less experience with inserting lines on the left side

^{(Which creates and increased risk for adverse events)}

Question 17

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

Why is the risk of Thoracic duct damage greater with LIJ cannulation than with RIJ cannulation?

Answer 17

The Thoracic duct enters the venous system at the junction of the LIJ vein and the subclavian vein, so it can potentially be damaged

This is not the case on the right side because the thoracic duct typycally drains into the venous system at the level of the subclavian vein; so the risk of injury is lower

Question 18

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

Where do thoracic ducts terminate? What’s the difference between Left vs right terminations?

Answer 18

On the left side, the Thoracic duct enters the venous system at the junction of the LIJ vein and the left subclavian vein, so it can potentially be damaged during cannulation

This is not the case on the right side because the thoracic duct typycally drains into the venous system at the level of the subclavian vein; so the risk of injury is lower

Question 19

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

What are advantages of Subclavian Vein cannulation for CVP?

Answer 19

Easy accessibility

Good landmarks

Stability of catheter for long-term use

Easy to maintain sterility because it is farther away from pt’s nasal and oral secretions

Question 20

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

What are disadvantages of Subclavian Vein cannulation for CVP?

Answer 20

High rate pneumothorax

Hemothorax

Pleural effusion

Question 21

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

If attempt of cannulation of subclavian vein is unsuccessful on one side, attempt on contralateral side is contraindicated w/o first obtaining CXR. Why is that?

Answer 21

Because you do not want to cause bilateral pneumothorax

Question 22

_{CENTRAL VENOUS PRESSURE - SITES OF CANNULATION}

What should you be aware of regarding holding pressure if the cannula accidentaly enters the arterial circulation during subclavian vein cannulation?

Answer 22

Holding pressure will be more demanding

It’s much more difficult to hold pressure on the chest than it would be on the neck

Question 23

_{CVP - SITES OF CANNULATION - External jugular vein}

What are advantages of the EJ site for CVP cannulation?

Answer 23

Superficial and safe access (pt on heparin)

Both right and left are good options

Question 24

_{CVP - SITES OF CANNULATION - External jugular vein}

Why is the EJ vein not an ideal site for CVP cannulation?

Answer 24

Tortious nature

Lower success rate

Kinks at SC vein

Enters the SC vein at a steep angle

Question 25

_{CVP - SITES OF CANNULATION - Antecubital vein} What are Advantages of the Antecubital vein when used as a CVP cannulation site?

Answer 25

Few complications Typical location for PIC line placement

Question 26

_{CVP - SITES OF CANNULATION - Antecubital vein} Which controversy surround CVP values when measured at the AC site?

Answer 26

Some studies suggest that CVP is higher when measured from an AC line, but this is not clinically significant

Question 27

_{CVP - SITES OF CANNULATION - Antecubital vein} What are Disadvantages of the Antecubital vein when used as a CVP cannulation site?

Answer 27

Lowest success rate Thrombosis Thrombophlebitis

Question 28

_{CVP - SITES OF CANNULATION - Femoral vein} What are Advantages of the Femoral vein when used as a CVP cannulation site?

Answer 28

High success rate Easy landmarks Large diameter

Question 29

_{CVP - SITES OF CANNULATION - Femoral vein} What are disadvantages of the Femoral vein when used as a CVP cannulation site?

Answer 29

Catheter sepsis Thrombophlebitis Patients are unable to ambulate

Question 30

_{CVP - SITES OF CANNULATION - Femoral vein} Why is the Femoral vein typically not an ideal site for more than 24 hrs?

Answer 30

Increased risk for infections This also applies to the femoral areterial line

Question 31

_{CVP - SITES OF CANNULATION - Femoral vein} Why should the Femoral line be inserted below the level of the inguinal line?

Answer 31

To decrease the risk of injury to the inguinal liguament

Question 32

_{CVP - SITES OF CANNULATION - Femoral vein} What's a difficulty with obtaining CVP measurements from a femoral line?

Answer 32

Will require a longer catheter line that resides in the IVC

Question 33

_{CENTRAL VENOUS PRESSURE} WHERE SHOULD DISTAL ORIFICE OF any CVP CATHETER BE POSITIONED?

Answer 33

Insertion catheter (7.5 or 9 Fr.) into venous circulation and advancing until distal orifice positioned **adjacent** or **within RA**

Question 34

_{CENTRAL VENOUS PRESSURE} WHERE SHOULD DISTAL ORIFICE OF CATHETER BE POSITIONED to **Guide fluid management**?

Answer 34

Tip positioned within either **RA** or **vena cava** near **caval-atrial junction**

Question 35

_{CENTRAL VENOUS PRESSURE} For monitoring CVP waveform, why should the tip of the catheter BE POSITIONED within the atrium?

Answer 35

To accurately reflect pressure changes in RA The waveform will not be dampened

Question 36

_{CENTRAL VENOUS PRESSURE} WHERE SHOULD DISTAL ORIFICE OF CATHETER BE POSITIONED for **Aspiration of air emboli**?

Answer 36

Tip (prefer multiport) in **RA** near **SVC-atrial junction** This is because air emboli will flow pass this point and accumulate in the superior aspect of the junction And this will allow for optimal aspiration

Question 37

_{INTERPRETING CVP WAVEFORM} CVP Waveform consists of five phasic events, which are?

Answer 37

Three ascents (a, c, v) Two descents (x, y)

Question 38

_{INTERPRETING CVP WAVEFORM - 3 Ascent Waves} What does the ***a wave*** represent?

Answer 38

**Right atrial contraction** This is the highest pressure wave on the curve Occurs at end-diatole Follows P wave on EKG

Question 39

_{INTERPRETING CVP WAVEFORM - 3 Ascent Waves} A large a wave could be indicative of which conditions?

Answer 39

Tricuspid stenosis Pulmonary HTN ↓ RV compliance

Question 40

_{INTERPRETING CVP WAVEFORM - 3 Ascent Waves} What does the ***c wave*** represent?

Answer 40

**Isovolumetric ventricular contraction** This is the second ascent wave or the next highest wave on curve Occurs as a result of the *Bulging of closed tricuspid valve* into RA during early phase of RV contraction as a consequence of Isovolumetric ventricular contraction Occurs in conjunction with QRS wave Always follows the EKG R-wave

Question 41

_{INTERPRETING CVP WAVEFORM - 3 Ascent Waves} What does the ***v wave*** represent?

Answer 41

**Right atrial filling** Occurs during late in ventricular systole while the Tricupsid valve is still closed and the atrium is filling Occurs as a result of increase in RAP while atrium fills against a closed tricuspid valve Peaks just after the EKG T-wave

Question 42

_{INTERPRETING CVP WAVEFORM - 3 Ascent Waves} Large v waves could be indicative of which conditions?

Answer 42

Tricuspid regurgitation RV papillary muscle ischemia RV failure Constrictive pericarditis Cardiac tamponade

Question 43

_{INTERPRETING CVP WAVEFORM - 2 Descent Waves} What does the ***x wave*** represent?

Answer 43

**Systolic collapse of RA pressure** Occurs while the Tricupsid is pulling away in the RV during ventricular ejection Tricuspid valve pulled downward at end of ventricular systole

Question 44

_{INTERPRETING CVP WAVEFORM - 2 Descent Waves} What does the ***y wave*** represent?

Answer 44

**Diastolic collapse of RA pressures** Occurs when Tricuspid valve opens & RA empties passively into ventricle

Question 45

INTERPRETING CVP WAVEFORM

Answer 45

(Listen to slide 52) No audio

Question 46

INTERPRETING CVP WAVEFORM

Answer 46

(listen to slide 52) No Audio

Question 47

_{INTERPRETING CVP WAVEFORM} In some pathologic conditions, the a, c & v waves can change dramatically. In A-fib and A-flutter there will be no a-waves any longer, why?

Answer 47

The RA is quivering and not contracting

Question 48

_{INTERPRETING CVP WAVEFORM} Nodal rhythms, heart blocks and certain arrythmias will develop large a-waves or "canon-waves", why?

Answer 48

The RA is contracting against a closed Tricupsid valve

Question 49

_{INTERPRETING CVP WAVEFORM} Tricupsid stenosis or RV failure will also have the "canon-wave", why?

Answer 49

The RA is contracting against a stenotic valve

Question 50

_{INTERPRETING CVP WAVEFORM} In Tricupsid regurg, the ***c-wave*** and ***v-wave*** are fused, and the normal *x-descent* will disappear, why?

Answer 50

Effect of the regurgitant flow