Apex- Monitors and Equiptment > Hemodynamics

Question 1

A blood pressure cuff that is too large:

A- falsely increases BP measurement
B- requires less pressure to occlude the artery
C- increases risk of radial neuropathy
D- has a bladder width of less than 40% of the circumference of the extremitiy

Answer 1

B. requires less pressure to occlude the artery

Question 2

The ideal bladder length and width of a BP cuff should be what % of the extremity circumference

Answer 2

80% length
40% width

Question 3

Where is SBP/DBP the lowest vs highest

& Where is the PP most narrow vs widest

Answer 3

At the aortic root → SBP lowest, DBP highest, PP narrowest

At the dorsalis pedis artery → SBP is highest, DBP is lowest, and PP is the widest

Question 4

Arm positioning:

For every 10cm change, the BP changes by ________ mmHg.

For every 1” change, the BP changes by ________ mmHg

Answer 4

10cm = 7.4mmHg change
1” = 2mmHg change

Question 5

If the BP cuff location is above the heart, the BP reading wil lbe falsey (increased/decreased) - why

what if it’s below the heart?

Answer 5

above the heart- falsely decreased → less hydrostatic pressure

below the heart - falsey increased → more hydrostatic pressure

Question 6

If the BP cuff is 10” below the level of the heart. What is the true BP at the level of the heart?

Answer 6

10” x 2mmHg = 20mmHg
20mmHg less than what’s displayed on the monitor

Question 7

Why should BP cuff measurement probably be avoided in someone with a previous axillary lymph node dissection?

Answer 7

It is thought it could impair lymphatic drainage and cause limb edema but is controversial

Question 8

3 most common causes of an over-dampened arterial-line waveform:

2 other things to check for

Answer 8

1. air bubbles in the tubing
2. clot at the catheter tip
3. low flush bag pressure

kinks or a loose connection

Question 9

Arterial line associations:

Initial upstroke →
Peak of the waveform →
Dicrotic notch →
Trough of the waveform →
Area under the curve →
Peak minus trough value →

Answer 9

Initial upstroke → contractility
Peak of the waveform → systolic BP
Dicrotic notch → Aortic valve closure
Trough of the waveform → Diastolic BP
Area under the curve → Stroke volume
Peak minus trough value → Dicrotic notch

Question 10

Where should your a-line transducer be leveled at?

What if your concernred about cerebral perfusion?

Answer 10

Right atrium

External auditory meatus (corresponds with the circle of Willis)

Question 11

Characteristics of your BP components with an underdampened a-line system

2 things that could cause it

2 signs in your waveform that may indicate it’s underdampened

Answer 11

SBP will be overestimated
DBP will be underestimated
MAP = accurate

stiff/noncompliant tubing & catheter whip (artifact)

multiple artifacts present in the waveform + after flushing the system, theres severeal oscillations that occur prior to re-establishing baseline

Question 12

Why should you probably always be looking at MAP when evaluating arterial lines

Answer 12

bc if your system is overdampened or underdampned, your MAP will always be accurate

Question 13

What are the specific BP characterstics of an over-dampened arterial line system?

2 things you’ll notice in your waveform

5 things that can cause it

Answer 13

SBP is underestimated
DBP is overestimated
MAP is accurate

loss of dicrotic notch & no oscillations following a flush

air bubble in tubing, clot in catheter, low flush bag pressure, kinked tubing, loose connection

Question 14

Where should the tip of the CVP catheter rest?

Answer 14

just above the junction of the vena cava and the right atrium (not inside the right atrium)

Question 15

When inserting a central line in the right IJ, how far should the catheter be advanced to achieve the correct placement?

Answer 15

15cm

Question 16

Where should the tip of the PA catheter reside?

how far from the VC junction?

Answer 16

in the pulmonary artery, distal to the pulmonic valve

25-35cm from the VC junction (so ~45cm from skin)

Question 17

While floating a swan, what is the classic presentation of a pulmonary artery rupture?

Answer 17

hemoptysis

Question 18

Other than close proximity, why do we access the right IJ over the left IJ?

Answer 18

Left IJ carriers the highest risk of injuring the thoracic duct (risk of chylothorax)

Question 19

What is the most common complication while obtaining central access?

Answer 19

dysrhythmias

Question 20

The incidence of catheter- related infection increases after how many days?

Answer 20

3 days

Question 21

Why don’t we place the CVP tip in the right atrium?

Answer 21

can cause dysthryhmias, thrombus formation, and cardiac perforation

Question 22

fill out chart

Answer 22

Question 23

label distances

Answer 23

Question 24

If you advance a PA catheter 10cm beyond the calculated distance and still dont see the expected waveform, what should you assume and do?

Answer 24

assume the catheter coiled
→ deflate the balloon, withdraw the catheter to the junction of the VC and RA and try again.

if you encounter resistance while pulling back, the catheter is possibly knotted or entangled with the chordae tendineae → get CXR to rule out

Question 25

What kind of complications can occur while obtaining central venous access (5)

Answer 25

Arterial puncture PTX Air embolism Neuropathy Catheter knot

Question 26

What kind of complications can occur while floating a PA catheter? (4)

Answer 26

1. PA rupture (hemoptysis) 2. RBBB 3. CHB if pre-existing LBBB 4. Dysrhythmias

Question 27

Answer 27

A- Wave | atrial systole , occurs just after the P wave (atrial depol) ## Footnote RA contraction

Question 28

What is the CVP waveform a reflection of?

Answer 28

The pressure in the RA | 3 peaks (a,c,v), 2 troughs (x,y) ## Footnote Each represents pressure changes in the RA as blood moves in and out

Question 29

Describe what is happening with the atria vs ventricles in each segment

Answer 29

Question 30

CVP is A. Falsely increased by placing the transducer abover the zero point B. increased by PEEP C. decreased by pericardial tamponade D. Unchanged by a ventricle septal defect

Answer 30

B. Increased by PEEP ## Footnote PEEP increases PVR creating an additional resistance agaisnt RV ejection which an increase RVEDP and CVP

Question 31

Normal CVP in the adult

Answer 31

1-10mmHg

Question 32

Where should CVP be zeroed at

Answer 32

4th ICS, mid anteroposterior level (phlebostatic axis)

Question 33

Factors that increase CVP (4)

Answer 33

1. Hypervolemia 2. Tricuspid stenosis or regurg 3. Pulmonary HTN 4. Cardiac tamponade

Question 34

T/F- a low CVP is almost always caused by hypovolemia

Answer 34

True ## Footnote unelss the transducer is moved above the zero point

Question 35

What is this CVP wave form showing ## Footnote When would this occur and what are 2 causes?

Answer 35

Loss of **a** wave ## Footnote Afib and V-pacing if underlying asystole

Question 36

What's depicted? ## Footnote Conditions that cause it?

Answer 36

Large A- wave ## Footnote Tricuspid stensosis, diastolic dysfunction, myocardia ischemia, chronic lung disease (RV hypertrophy), AV disassociation, Junctional rhythm, asynchronous V-pacing, PVCs

Question 37

What's going on here ## Footnote What causes it (3)

Answer 37

Large V-Wave ## Footnote TR allows a portion of the RV volume to pass through the closed by incompetent valve during RV contraction → this increases the volume and pressure in the RA and manifests as large V waves

Question 38

What PA waveform is this ## Footnote what is it the same as and what is the normal value

Answer 38

Right Atrial pressure | = CVP ## Footnote Normal = 1-10mmHg

Question 39

What PA waveform is this? ## Footnote 2 key things as to how the wavefrom changes from the previous site

Answer 39

Right Ventricular Pressure | 15-30/0-10mmHg ## Footnote Systolic pressure increases and diastolic pressure = CVP

Question 40

What PA waveform is this? ## Footnote How do the pressure change from previous location & what is the dicrotic notch formed by?

Answer 40

PAP | 15-30/5-15 ## Footnote systolic pressure remains the same, distolic pressure rises dicrotic notch is formed by the pulmonic valve closure during diastole

Question 41

PA waveform ## Footnote what is this waveform equivelent to?

Answer 41

PAOP | 5-15mmHg ## Footnote equivilent to the CVP of the left heart a wave = left atrial contraction (systole) c wave = mitral valve elevation into the LA during systole (isovolumetric contraction) v wave = passive LA filling

Question 42

Which findings are observed when the tip of the pulmonary artery catheter enters the region shown in the image (select 2):

Answer 42

Dicrotic notch and increased DBP

Question 43

What are 3 things that could signify the tip of the PAC is NOT in zone 3

Answer 43

1. PAOP > PA end diastolic pressure 2. nonphaseic PAOP tracing 3. Inability to aspirate blood from the distal port when in the wedged position

Question 44

When does PAOP overestimate LVEDV? (select 2): -PA catheter tip in West zone 3 - PEEP - Diastolic dysfunction - AI

Answer 44

PEEP & Diastolic dysfunction Anything that impairs the normal pressure gradient between the PAC tip and the LV can impact your interpretation of PAOP (LAP) - makes sense ## Footnote PAOP overestimates LVEDV with PEEP and diastolic dysfunction PAOP underestimates LVEDV with AI ehhhh

Question 45

2 conditions where PAOP overestimates LVEDV ## Footnote what condition underestimates it?

Answer 45

PEEP and diastolic dysfunction ## Footnote underestimates → Aortic insuffiency

Question 46

Which situation underestimates cardiac output obtained by the thermodiluation method? A. Over-warmed injectate B. Right-to-left intracardiac shunt C. High injectate volume D. Partially wedged PAC

Answer 46

C. High injectate volume

Question 47

Which port of the PAC is used for the thermodilution method of assessing cardiac output? ## Footnote 2 key things with each injection

Answer 47

proximal port ## Footnote 1. each injection should occur during the same phase of the respiratory cycle 2. injection should be completed in < 4 seconds

Question 48

Using the thermodilution method of assessing CO, the area under the curve is (directly/inversely) proportional to cardiac output

Answer 48

AUC is INVERSELY related to CO →if CO is high, the injectate rapidly travels towards the distal tip of the PAC and the AUC is smaller → if CO is low, it takes longer for the injectate to travel past the distal tip of the PAC and the AUC is larger

Question 49

What 4 conditions can overestimate CO when using the thermodilution method of assessing CO? | What 2 conditions can underestimate CO ## Footnote What 2 conditions have an unpredictable effect on CO

Answer 49

overstimate → injectate volume too low/hot partially wedged PAC thrombus on tip of PAC | underestimate → injectate volume too high/too cold ## Footnote unable to predict → intracardiac shunt, tricuspid regug

Question 50

Factors that increase mixed venous o2 saturation (select 2): -thyroid storm -sodium nitroprusside toxicity -anemia -sepsis

Answer 50

SNP toxicity & sepsis Cyanide toxicity → impaired o2 utilization Sepsis → high cardiac output state + arterial admixture ## Footnote anemia reduces o2 delivery and decreases SvO2 Thyroid storm increases o2 demand and decreases SvO2

Question 51

Mixed venous o2 sat is dependent on what 4 variables

Answer 51

1. CO 2. O2 consumption 3. Hemoglobin 4. Hemoglobin saturation%

Question 52

What is SvO2 and what is the normal value

Answer 52

Mixed venous o2 saturation 65-75%

Question 53

What factors REDUCE SvO2 | mixed venous o2 saturation

Answer 53

increased o2 consumpution → pain, stress, thyroid storm, shivering, fever decreased o2 delivery → decreased PaO2, hgb, CO

Question 54

What factors increase SvO2 | mixed venous o2 sat

Answer 54

decreased o2 consumpution → hypothermia, cyanide toxicity increased o2 delivery → increased PaO2, Hgb, CO

Question 55

How does sepsis affect SvO2 and why?

Answer 55

it increases it → sepsis creates a high CO state with an arterial admixture (sepsis causes end-organ hypoxia, but oxygen essentially bypasses the tissues [arterial admixture] and SvO2 remains elevated).

Question 56

Why is a PAC required to measure SvO2? | mixed venous o2 saturation

Answer 56

bc different organs exract different amounts of o2 - so a venous sample must contain blood returning from the SVC, IVC, and coronary sinus > a mixing of these 3 souorces occurs in the PA

Question 57

Preload responsiveness is expected to be present if a 250mL fluid bolus increases the stroke volume in excess of what %?

Answer 57

10% | general rule

Question 58

Why is there variation in pulse contour when a patient is "dry" and on PPV

Answer 58

A positive pressure breath compresses the pulmonary vasculature and augments LV filling > increased stroke volume At the same time, it impedes RV filling So you have an initial increase in SV, followed by a decrease SV due to that previous decrease in RV filling

Question 59

What are 6 situations where pulse contour analysis won't provide reliable data?

Answer 59

1. spontaneous ventilation 2. use of peep 3. small tidal volumes 4. open chest 5. dysrhythmias 6. RV dysfunction

Question 60

Which conditions limit the reliability of the esophageal Doppler monitor? (select 2): - hypovolemia - aortic stenosis - aortic cross-clamp placement - esophageal disease

Answer 60

Aortic stenosis (or insuffiency) and aortic cross clamp

Question 61

position of TEE probe

Answer 61

~ 35cm from the incisors (T5-6)

Question 62

Relative contraindication to TEE

Answer 62

esophagel disease (varices) ## Footnote risk of traumatic injury

Question 63

Relative contraindication to TEE

Answer 63

esophagel disease (varices) ## Footnote risk of traumatic injury

Question 64

When preparing to transition off CPB, the SvO2 decreases from 64% to 56%. What are the MOST likely etiologies of this finding (select 2): -light anesthesia -initiation of dobutamine infusion -anemia -hypothermia

Answer 64

Anemia & light anesthesia ## Footnote SvO2 is reduced by things that increase o2 consumption (light ansethesia) or decrease o2 delivery (anemia) Hypothermia reduces O2 consumpution and would increase SvO2 Dobutamine infusion would increase O2 delivery and increase SvO2

Question 65

When preparing to transition off CPB, the SvO2 decreases from 64% to 56%. What are the MOST likely etiologies of this finding (select 2): -light anesthesia -initiation of dobutamine infusion -anemia -hypothermia

Answer 65

Anemia & light anesthesia ## Footnote SvO2 is reduced by things that increase o2 consumption (light ansethesia) or decrease o2 delivery (anemia) Hypothermia reduces O2 consumpution and would increase SvO2 Dobutamine infusion would increase O2 delivery and increase SvO2

Question 66

Which components of the CVP waveform correlate with ventricular systole (select 2): -c wave -y descent -a wave -x descent

Answer 66

c wave and x descent (a wave and y descent correlate with ventricular diastole) (peak of the v wave correlates with the shift from ventricular systole to diastole)

Question 67

Match each component of the CVP waveform to its corresponding mechanical event: -c wave, v wave, a wave, x descent -RA passive filling, RV cx, RA cx, RA relaxation

Answer 67

a wave → RA contraction (active filling) c wave → RV contraction x descent → Right atrial relaxation v wave → passive filling of the right atrium y descent → right atrium empties through an open tricuspid valve

Question 68

What conditions increase the amplitude of the v wave on the CVP waveform? (select 2): -complete heart block -RV hypertrophy -papillary muscle ischemia -TR

Answer 68

TR & papillary muscle ischmia V wave = passive filling of the right atrium → during TR, a portion of the RV volume flows back retrograte across the incompetent tricuspid valve. →papillary muscle ischemia can cause TR.