Exam #2: Hemodynamic Monitoring Flashcards
1
Q
What is a normal stroke volume?
A
60-150
2
Q
What is a normal CVP?
A
2-8
3
Q
What is a normal PAWP?
A
6-12
4
Q
What is normal cardiac output?
A
4-8
5
Q
What is a normal stroke volume index
A
30 - 65
6
Q
What is a normal cardiac output index?
A
2.2-4
7
Q
What is a normal MAP?
A
70-100 (goal is to be >65)
8
Q
What is a normal SpO2?
A
95-100
9
Q
What is a normal mixed venous O2 sat?
A
60-80
10
Q
Hemodynamic Monitoring
A
-Measurement of pressure, flow, and oxygenation within cardiovascular system
11
Q
What is the purpose of Hemodynamic Monitoring?
A
Assesses heart function, fluid balance, and effects of drugs on CO.
12
Q
Hemodynamic Monitoring includes
A
- Systemic and pulmonary arterial pressures
- Central Venous Pressure
- Pulmonary Artery Wedge Pressure
- CO and Cardiac Index
- Stroke volume/Stroke volume index
- Stroke volume variation (SVV)
- SaO2 O2 saturation of arterial blood
- Mixed venous oxygenation saturation (SvO2)
13
Q
What is cardiac output?
A
Volume of blood pumped by the heart in one minute
14
Q
What is Cardiac Index?
A
CO adjusted for body surface area
15
Q
Stroke volume
A
Volume ejected with each heartbeat
16
Q
Stroke volume index
A
SV adjusted for body size
17
Q
What is systemic vascular resistance and pulmonary vascular resistance?
A
Opposition to blood flow by systemic and pulmonary vasculature
18
Q
What determines SV?
A
Preload, afterload and contractility
19
Q
What is preload?
A
Volume of blood within ventricle at the end of diastole.
*read notes on slide!
20
Q
PAWP
A
Reflects left ventricular end-diastolic pressure
21
Q
CVP
A
Reflects right ventricular end-diastolic pressure
22
Q
What is afterload?
A
- Forces opposing ventricular rejection.
- These include SVR and PVR.
23
Q
Afterload: SVR and Arterial Pressure indices of
A
Left ventricular afterload
24
Q
Afterload: PVR and pulmonary arterial pressure indices of
A
Right ventricular afterload
25
Vascular resistance
- Can be systemic or pulmonary
| - Reflect afterload
26
Contractility
- Strength of ventricular contraction
- No direct clinical measure (therefore need to look at PAWP and CO over time)
*Read notes!! Didn’t get to look at them
27
Principles of Invasive Pressure Monitoring
Equipment must be referenced and zero balanced to environment and dynamic response characteristics optimized
28
Principles of Invasive Pressure Monitoring: Referencing
positioning transducer so zero reference point is at level of atria of heart or phlebostatic axis
29
How can you identify the phlebostatic axis?
- Draw two imaginary lines with the patient supine.
- Draw a horizontal line down from the axilla, midway between the anterior and posterior chest walls.
- Draw a vertical line laterally through the fourth intercostal space along the chest wall.
- The phlebostatic axis is the intersection of the two imaginary lines.
*Look at picture
30
Placing the monitor on the phlebostatic axis
- Mark this location on the patient’s chest with a permanent marker.
- Position the port of the stopcock nearest the transducer level at the phlebostatic axis.
- Tape the transducer to the patient’s chest at the phlebostatic axis or mount it on a bedside pole.
31
Principles of Invasive Pressure Monitoring: Zeroing
- Confirms that when pressure within system is zero, monitor reads zero.
- Done by opening reference stopcock to room air
- Done with the initial setup and periodically thereafter
32
Dynamic Response Test (Square Wave Test)
- Optimizing dynamic response characteristics involves checking that the equipment reproduces, without distortion, a signal that changes rapidly.
- Perform a dynamic response test (square wave test) every 8 to 12 hours and when the system is opened to air or the accuracy of the measurements is questioned. It involves activating the fast flush and checking that the equipment reproduces a distortion-free signal.
33
Arterial Blood Pressure Monitoring
- Various indications when continuous BP measurements useful
- Non-tapered Teflon catheter is typically used to cannulate artery (into peripheral artery)
- Suture in place
- Immobilize insertion site
34
Components of Pressure Monitoring System
The catheter, shown entering the radial artery, is connected via pressure (nondistensible) tubing to the transducer. The transducer converts the pressure wave into an electronic signal. The transducer is wired to the electronic monitoring system, which amplifies, conditions, displays, and records the signal. Stopcocks are inserted into the line for specimen withdrawal and for referencing and zero-balancing procedures. A flush system, consisting of a pressurized bag of intravenous fluid, tubing, and a flush device, is inserted into the line. The flush system provides continuous slow (approximately 3 mL/hr) flushing and provides a mechanism for fast flushing of lines.
*Look at picture on slide 15
35
Arterial Pressure Monitoring
Read Notes on Slide 16
36
What does the diacritic notch indicate?
Aortic valve closure
37
Arterial Pressure Monitoring: Alarms
High and low pressure alarms are set based on the patient’s current status and then activated
38
Arterial Pressure Monitoring: Risks/complications
- Hemorrhage
- Infection
- Thrombus formation
- Neurovascular impairment
- Loss of limb
*Read notes on slide 17!!
39
Arterial Pressure Monitoring: Continuous flush irrigation system
- Delivers 3 mL of saline/hour: maintains line patency and limits thrombus formation
- Assess neurovascular status distal to arterial insertion site hourly
*READ NOTES
40
Arterial Pressure-Based CO Monitoring
- Calculates continuous CO and CCI
- Used to assess patient’s ability to respond to fluids
- Uses arterial waveform characteristics and patient demographic data to calculate SV and pulse rate (PR) to calculate CCO/CCI, and SV/SVI every 20 seconds
*READ NOTES
41
Slide 20
Look at notes!
42
Pulmonary Artery Pressure Monitoring
- Guides management of patients with complicated cardiopulmonary problems
- PA diastolic (PAD) pressure and PAWP are sensitive indicators of heart function and fluid volume status
- Allows for precise manipulation of preload
*READ NOTES
43
PA flow-directed catheter: Types of ports
- Distal lumen port in PA
- Balloon inflated to measure PAWP
- Two proximal lumens to measure CVP, inject fluid for CO, draw blood, administer fluids or drugs
- Thermistor port distally
*READ NOTES AND ADD WHAT EACH PORT DOES INTO FLASHCARDS!
44
PULMONARY ARTERY Pressure Monitoring: Specialized Features include
- Atrial electrode
- Fiberoptic sensor for mixed venous O2 saturation
- Continuous measurement of right ventricular volume and EF
- Continuous CO monitoring
- Additional ports for IV access
*ADD NOTES FOR WHAT EACH OF THESE DO
45
PA Waveforms during insertion
- Change in pulmonary artery pressure (PAP) waveform to pulmonary artery wedge pressure (PAWP) waveform with balloon inflation.
- The balloon is inflated while observing the bedside monitor for change in the waveform.
- Balloon inflation (arrow) in patient with a normal PAWP.
46
When are these measurements obtained: PA
At the end of expiration
47
When are these measurements obtained: PAWP?
Slowly inflate balloon with air until PA waveform changes to PAWP waveform
48
Pulmonary Artery Pressure Monitoring: When measurements are obtained, do not
Inflate for more than four respiratory cycles or 8-15 seconds
*Read notes on slide!!!
49
Pulmonary Artery Pressure tracing
- Before inflation, the PA pressure tracing on the monitor looks similar to an arterial tracing.
- There is a distinct systolic peak, dicrotic notch, and a diastolic low point.
- As the waveform becomes “wedged,” the tracing changes shape and amplitude.
50
What is the effect of an overinflated balloon?
- Balloon inflation (arrow) in patient with elevated wedge pressure. Overwedging of balloon (balloon has been overinflated). The danger of overinflating the balloon is that the pulmonary artery (PA) vessel may rupture from the pressure of the balloon.
- This is suspected when the waveform looks “wedged” spontaneously, when <1 mL is needed to wedge the tracing, or an “overwedge” tracing is obtained.
51
Central Venous Pressure Monitoring
- Measurement of the right ventricular preload -> reflects fluid volume
- Similar to PAWP waveforms
- Measured as a mean pressure at the end of expiration
52
CVP Monitoring is obtained from
- Central Venous Catheter
| - PA catheter
53
An elevated CVP indicates
Right ventricular failure or volume overload
54
A low CVP indicates
Hypovolemia
55
Question on test from slide 30!!
...
56
Measuring Cardiac Output: Continuous Cardiac Output
- PA catheter with thermal filament located in right atrium
- Senses change in temperature of blood as it passes through right ventricle
- Measures every 30–60 seconds
- Reflects average CO for past 3–6 minutes
*Add notes from this slide!!
57
Measuring Cardiac Output: Intermittent bolus thermodilution
- Inject saline or D5W into proximal lumen of PA catheter
- Thermistor sensor detects differences in blood temperature and calculates CO
- Uses average of three measurements
*Read notes!
58
When you get cardiac output, what can be calculated?
SVR, SVRI, SV, and SVI calculated when CO is measured
59
Increased SVR indicates
Vasoconstriction
*Read notes from slide
60
Decreased SVR indicates
Vasodilation
61
How to measure Venous Oxygen Saturation?
PA and CVP catheters can be used:
- CVP measures central venous oxygen saturation (ScvO2)
- PA measures mixed venous oxygen saturation (SvO2)
62
Venous Oxygen Saturation determines
- Adequacy of tissue oxygenation.
| - Tells you how well the body is using the oxygen that it has. (If its high, the body is not using it well)
63
SvO2/ScvO2 reflects
Balance between oxygenation of arterial blood, tissue perfusion and tissue oxygen consumption.
64
Venous Oxygen Saturation: it is useful to assess what?
hemodynamic status and response to treatment/activity
65
↓ In SvO2/ScvO2 could indicate
- ↓ Arterial oxygenation
- Low CO
- Low hemoglobin level
- ↑ Oxygen consumption or extraction
*Read notes on slide for more info!!
66
↑ In SvO2/ScvO2 could indicate
- Clinical improvement (e.g., improved arterial oxygen saturation)
- Worsening clinical condition (e.g., sepsis)
*Read notes on slide!!
67
Complications with PA catheters include
- Infection and sepsis
- Air embolus
- Pulmonary infarction or PA rupture
- Ventricular dysrhythmias
68
Complications with PA Catheters: Infection and Sepsis
- Asepsis for insertion and maintenance
| - Change flush bag, pressure tubing, transducer, and stopcock every 96 hours
69
Complications with PA Catheters: Air embolus
(e. g., disconnection)
- Monitor for balloon integrity
- Luer-Lok connections; alarms on
*Read notes on slide
70
Complications of PA Catheters: Pulmonary infarction or PA rupture management
- Do not inflate balloon with >1.5 mL
- Monitor waveforms continuously
- Maintain continuous flush system
*read notes on slide
71
Complications of PA Catheters: Ventricular Dysrhythmias
- Monitor during insertion and removal
| - Also for migration of PA catheter
72
Noninvasive Arterial Oxygenation Monitoring: Pulse Oximetry
- Continuous method of determining arterial oxygenation (SpO2)
- Normal 95%–100%**
- Accurate measurements may be difficult—consider forehead or earlobe
- Used to evaluate effectiveness of O2 therapy
*Read notes!
73
Nursing Management: Obtain baseline observational data
- General appearance
- Level of consciousness
- Skin color/temperature
- Vital signs
- Peripheral pulses
- Urine output
*Read notes !
74
Other nursing management includes
- Correlate baseline data with data obtained from biotechnology (e.g., ECG; arterial, CVP, PA, and PAWP pressures; SvO2/ScvO2)
- Monitor trends to evaluate the whole clincial picture
75
Circulatory Assist Devices
Decrease ventricular workload and improve organ perfusion when drug therapy fails.
76
Circulatory Assist Devices provide interim support when:
- Recovering from acute injury
- Stabilizing before surgical repair
- Awaiting cardiac transplant
77
Intraaortic Balloon Pump
- Provides temporary assistance by reducing afterload
| - Temporary use only
78
What are the benefits of intraaortic balloon pump?
- ↓ Ventricular workload
- ↑ Myocardial perfusion
- Augment circulation
79
Intraaortic Balloon Pump consists of
- Sausage-shaped balloon
- Pump that inflates and deflates balloon
- Control panel for synchronizing balloon inflation to cardiac cycle
- Fail-safe features
*READ NOTES AND LOOK AT PROCEDURE ON YOUTUBE
80
Intraaortic Balloon Pump: Procedure
- Balloon inserted into femoral artery and placed in thoracic aorta
- Confirm placement with x-ray
- Inflate balloon with helium in conjunction with ECG
*READ NOTES ON SLIDE
81
Complications of IABP therapy
- Vascular injuries
- Thrombus and embolus formation
- Thrombocytopenia (d/t endothelial damage)
- Ischemia to periphery, kidneys, bowel
- Infection
- Mechanical Complications
*READ NOTES ON THIS SLIDE
82
Complications of IABP: Mechanical Complications
- Improper timing of balloon inflation
- Balloon leak
- Malfunction of balloon or console
*READ NOTES ON SLIDE
83
To decrease risk of IABP therapy
- Frequent assessments
- Keep patient immobile and limited to side-lying or supine positions with HOB <45 degrees
*READ NOTES ON SLIDE
84
How do you wean off IABP?
By gradually reducing assist ration
85
Ventricular Assist Devices
- Short- and long-term support
- Allows more mobility than IABP
- Inserted into path of flowing blood to augment or replace action of ventricle
- Can be Internal or external
- Can be Left, right, or biventricular
86
VADs can
- Be implanted (e.g., peritoneum) or positioned externally
| - Provide biventricular support
87
Indications for VAD
- Failure to wean from bypass
- Failure after MI
- Bridge while awaiting transplant
88
VAD’s: Cannula sites depend on
Type of device used
89
Nursing Management: VADs
1. Similar to care for patient with IABP including:
- Frequent assessments and observe for complications
- Patient may be mobile and will require an activity plan
- In-depth teaching if discharged to home
2. Many patients die or choose to terminate device, causing death -> emotional support for patient and caregiver is essential
*Read notes
90
Nursing Management for CADs: Goal
- Recovery through ventricular improvement
- Heart transplantation
- Artificial heart implantation
