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Flashcards in Hemodynamic Monitoring Deck (75):
1

How far is an esophageal stethoscope inserted into the esophagus?

28-30cm. This allows us to hear heart sounds and BS internally.

2

What are precordial and esophageal stethoscopes useful for?

Continuous assessment of heart and breath sounds. Very sensitive monitor for bronchospasm and changes in pediatric patients

3

How often should we have a regular stethoscope available?

At all times

4

What 4 general things are continually evaluated?

Oxygenation, ventilation, circulation, and temperature

5

Considerations in deciding what type of monitoring to use

1) Indication
2) Risk/benefit
3) Complications
4) Alternatives
5) Cost
6) Skill level

6

Types of hemodynamic monitoring used

EKG, BP (NIBP and IABP), CVP, PAP, PCWP, TEE, stethoscope

7

What can the EKG tell you?

Heart rate, arrhythmias, Ischemia, electrolyte imbalances, pacemaker function

8

Aspects of the 3 Lead EKG

Electrodes used: RA, LA, LL
Leads: I, II, III
Number of views of the heart: 3

9

Aspects of the 5 lead EKG

Electrodes used: RA, LA, RL, LL, chest
Leads: I, II III, AVL, AVR, AVF, V lead
Number of views of the heart: 7

10

Value of the length and width of each EKG box

.1mV and .04s

11

How to calculate HR based on EKG lead

1500/# boxes between R waves

12

How should the gain be set in order to accurately assess the ST segment?

At standardization (1mV signal gives a rise of 10mm). This setting also fixes the ratio of the QRS complex to the ST segment size so that a 1mm change in the ST segment can be accurately assessed. If the wrong gain setting is used, ST changes may be under or over-diagnosed.

13

What filtering mode should the EKG be on for accurate ST assessment?

Diagnostic mode. Filtering out the low end of frequency bandwith (which can happen on monitor mode) can lead to ST distortion (either elevation OR depression)

14

5 main indicators of acute ischemia

ST elevation ( >1mm), ST depression ( >1mm), flipped Ts, peaked Ts, development of Q waves

15

Posterior / inferior wall ischemia is seen in these leads and is due to a blockage in this artery

II, III, AVF
Right coronary

16

Lateral wall ischemia is seen in these leadsand is due to a blockage in this artery

I, AVL, V5-6
Left circumflex coronary artery

17

Anterior wall ischemia is seen in these leadsand is due to a blockage in this artery

I, AVL, V1-4
Left coronary artery

18

Anterioseptal wall ischemia is seen in these leads and is due to a blockage in this artery

V1-4
Left anterior descending coronary artery

19

This part of BP correlates to the point of the most demand on the heart

SBP

20

The pulse pressure changes as you move from where to where

From the central arterial system to the periphery. The pulse pressure widens due to wave reflections in the vasculature.

21

These factors can cause a falsely high NIBP reading

Cuff too small, cuff below the level of the heart, loose cuff, arterial stiffness (HTN, PVD)

22

These factors can cause a falsely low NIBP reading

Cuff too large, cuff above the level of the heart, poor tissue perfusion, deflation is too rapid

23

Fals NIBP reading can also occur with

Cardiac dysrhythmia, tremors/shivering/ and improper cuff placement

24

This type of NIBP reading only gives you SBP

Palpation. It measures the return of arterial pulse during deflation. This is simple, inexpensive, and underestimates the SBP.

25

This NIBP reading only gives you SBP but measures it fairly reliably

Doppler. Measures it by a shift in frequency of sound waves that is reflected by RBCs moving through an artery.

26

This NIBP method estimates both SBP and DBP

Auscultation with a sphygmomanometer. Measures BP by auscultation Karotkoff sounds created by turbulent blood flow though the artery created by the mechanical deformation from the BP cuff. This method is unreliable in patients with HTN.

27

Changes in SBP correlate with changes in ____

Myocardial O2 demand.

28

Automated cuffs work by this mechanism

Oscillometry

29

Complications of NIBP measurement

Ulnar nerve damage, compartment syndrome, edema of the extremity, bruising / petechiae, pain, interference of IV flow, altered timing of IV drug administration

30

Indications for IABP monitoring

1) Deliberate hypotension
2) Risk of rapid BP changes
3) Wide swings in BP intra-op
4) Rapid fluid shifts
5) Titration of vasoactive drugs
6) End organ disease
7) Repeated blood sampling
8) NIBP measurement failure

31

What test has to be done before radial a-line placement?

Allen's test

32

Rate that NS moves through the a-line system to prevent clot formation

1-3mL/hr

33

How can a-line dynamics and accuracy be improved?

Remove bubbles, calibrate at the level of the heart, limit tube length and number of stop-cocks, use non-compliant stiff tubing, and make sure the mass of the fluid used is small

34

Where should the a-line be calibrated?

Supine patients- midaxillary line (right atrium)
Sitting patients- level of the ear / circle of willis because we are concerned about CBF

35

Rate of a-line upstroke tells you about

Contractility

36

Rate of a-line downstroke tells you about

SVR

37

Exaggerated variations in a-line tracing size with respirations indicates

Hypovolemia

38

The area under the a-line curve tells you

MAP

39

The dicrotic notch indicates the closure of this valve

Aortic valve

40

What happens to IABP readings as they move further into the periphery?

Distal pulse amplification!
This causes increased SBP, decreased DBP, and increased pulse pressure. MAP remains unchanged. The dicrotic notch becomes less and less apparent and appears later in the tracing (takes longer for the pressure wave to reach the transducer).

41

Complications of IABP measurement

Nerve damage, hemorrhage/hematoma, retained guidewire, infection, thrombosis, air embolus, arterial aneurysm, vasospasm (usually self-limiting), skin necrosis, loss of digits

42

Are fluids able to be given faster through a PIV or central line?

PIV

43

Indications for getting central access

Need more vascular access (unable to get enough PIVs) and need to rapidly give fluids, give vasoactive meds, monitor CVP, assess fluid status/blood volume, sample venous blood, remove air emboli, pulmonary artery access, insertion of transvenous pacing leads

44

Why is the right IJ preferred to the left

It provides a more direct route to the heart and the dome of the lung is higher on the left

45

Typical central venous catheter size

7 french
20cm

46

If anesthesia places a central line, is placement confirmed with an x-ray?

No, it is confirmed with blood aspiration from all 3 ports. X-ray is taken after surgery.

47

Where should the tip of the central line be located?

Just above the RA at the SVC/RA junction and parallel to the vessel walls. Should be at the level of the 3rd rib or the T4/5 interspace or the level of the carina or R mainstem bronchus.

48

When is a central line contraindicated?

R atrial tumor
Injection at site of desired placement

49

Central line risks

Thrombo-embolism, air embolism, guidewire embolism, carotid puncture, hematoma, dysrhythmia, pneumo/hemothorax, vascular damage, cardiac tamponade, infection

50

What does CVP measure?

CVP measures the RAP (because it's right at the RA junction), which is a measure of preload

51

Normal RA pressure in a spontaneously breathing patient is ______ and it rises by _______ during mechanical ventilation

1-7mmHg
3-5mmHg

52

How is RVEDP measure with CVP tracing?

The a wave at end-expiration, which correlates with maximal filling of the right ventricle.

53

What is the a wave?

Contraction of the right atrium, which results in increased RAP.

54

The a wave follows this on the EKG

The p wave.

55

This CVP wave is the atrial kick

The a wave

56

What is the c wave a reflection of?

Isovolumetric contraction of the right ventricle, resulting in the bulging back of the tricuspid valve into the RA

57

The c waves follows this waveform on the EKG

The QRS complex. The c wave occurs in early systole

58

The x descent occurs during

Mid-systole. The x descent follows the c wave.

59

The v wave reflects what?

Venous return into the RA against a closed tricuspid valve

60

When does the V wave occur during the cardiac cycle and EKG?

At the end of systole with the tricuspid valve still closed, and it occurs just after the T wave.

61

What does the y descent reflect?

Passive ventricular filling after ventricular relaxation. The y descent reflects a fall in RAP due to this. This is referred to the "diastolic collapse in atrial pressure"

62

Size of pulmonary artery catheters and number of lumels

7-9 french
110cm
4 lumens (distal is for PAP, second is 30cm proximal for CVP, third is for balloon, and fourth is for the thermistor wires)

63

Indications for PAP monitoring

1) Unstable cardiac patients
2) LV dysfunction
3) Pulmonary HTN
4) ARDS/resp failure
5) Shock/sepsis
6) ARF
7) CAD
8) Valvular disease
9) Surgical procedures, such as cardiac, aortic, or OB

64

Complications of pulmonary artery catheters

Arrhythmias (v-fib, RBBB, complete heart block)***
PA rupture****
Balloon rupture
Pulmonary infarction
Thromboembolism/air embolism
Pneumothorax
Catheter knotting
Damage to cardiac structures (valves)
Infection (endocarditis)

65

Relative contraindications to a PA catheter

WPW syndrome
Complete LBBB

66

Distance from right IJ to various structures

SVC/RA junction- 15cm
RA- 15-25cm
RV- 25-35cm
PA- 35-45
PA Wedge 45-50

If you go beyond these measurements and don't see the proper waveform, you may be coiling the catheter

67

When might the a wave be larger than normal

Mitral/tricuspid stenosis

68

When might the v wave be larger than normal?

Mitral/tricuspid insufficiency, causing blood to reflux into the atrium during systole. Remember that the v wave reflects atrial filling during late systole

69

Ways that we can measure CO

Thermodilution, continuous thermodilution, ultrasound, TEE, pulse contour, and mixed venous oximetry

70

"a" waves may be lost with

a-fib or ventricular pacing

71

Giant a waves ("Cannon" a waves) may be caused by

Junctional rhythms, complete HB, mitral stenosis, diastolic dysfunction, myocardial ischemia, ventricular hypertrophy

72

Large V waves may be caused by

Mitral/tricuspid regurgitation
Acute increase in intravascular volume

73

7 things you can observe with TEE

1) CO
2) Ventricular wall characteristics and motion
3) Valve structure and function
4) Measurement of EDV and ESV
5) Blood blow characteristics
6) Intracardiac masses
7) Intracardiac air

74

When is the use of TEE indicated?

1) Pericardial tamponade (for trauma)
2) Unusual causes of acute hypotension
3) PE
4) Aortic dissection
5) Myocardial ischemia
6) Valvular dysfunction

Overall, if someone is still very unstable and unresponsive to our treatments, we can use TEE to get a better overall picture of our patients- checking to see what the actual structural problem might be

75

Complications of TEE

Esophageal trauma
Dysphagia
Hoarseness
Dysrhythmias

Most complications are reported in awake patients