Test 3 Flashcards
(318 cards)
1
Q
Ch. 11: Hemodynamic Monitoring
Your intubated patient just had a central venous line placed & you notice increased PIP on the ventilator, what is likely the problem?
A
The patient has a PNEUMOTHORAX, they need a chest tube.
2
Q
Ch. 11: Hemodynamic Monitoring
Pulmonary capillary wedge pressure (PCWP) is also known as ______.
A
Pulmonary Artery Occlusion Pressure (PAOP)
3
Q
Ch. 11: Hemodynamic Monitoring
_________ are commonly used to determine overall fluid balance.
A
CVP and PAOP
4
Q
Ch. 11: Hemodynamic Monitoring
What is the primary indication for hemodynamic monitoring?
A
The management of critically ill patients who demonstrate evidence of compromised cardiovascular function.
5
Q
Ch. 11: Hemodynamic Monitoring
Hemodynamic measuring can be used for the diagnosis and treatment of life-threatening conditions such as: (9)
A
- Shock
- Heart failure
- Pulmonary hypertension
- Complicated myocardial infarction
- ARDS
- Chest trauma
- Severe burn injury
- Severe dehydration
- After cardiac surgery
6
Q
Ch. 11: Hemodynamic Monitoring
What are some examples of invasive hemodynamic measuring?
A
- Systemic arterial pressure
- Central venous pressure
- Pulmonary artery pressure
- Arterial and mixed-venous blood gases
- Cardiac output
7
Q
Ch. 11: Hemodynamic Monitoring
The outputs of the right and left ventricle are ultimately influenced by what four factors?
A
- Heart rate
- Preload
- Contractility
- Afterload
8
Q
Ch. 11: Hemodynamic Monitoring
Heart rates can range from _________ in a normal healthy adult.
A
50-200 bpm
9
Q
Ch. 11: Hemodynamic Monitoring
The filling pressure of the ventricle at the end of ventricular diastole.
A
Preload
10
Q
Ch. 11: Hemodynamic Monitoring
How is preload estimated?
A
Measuring end-diastolic pressures (EDPs)
11
Q
Ch. 11: Hemodynamic Monitoring
The amount of blood present in the ventricle at the end of ventricular diastole depends on _____.
A
The level of venous return and the compliance of the ventricle.
12
Q
Ch. 11: Hemodynamic Monitoring
Which of the following reflects the length of ventricular muscle fibers and thus the ability of these fibers to generate the necessary tension in the next ventricular contraction?
a. Afterload
b. Preload
c. Contractility
d. None of the above
A
b. Preload
13
Q
Ch. 11: Hemodynamic Monitoring
This principle states in most basic terms that the heart pumps what it receives.
A
Frank-Starling mechanism
14
Q
Ch. 11: Hemodynamic Monitoring
The force that the ventricles generates during each cardiac cycle.
A
Contractility
15
Q
Ch. 11: Hemodynamic Monitoring
How can contractility be measured?
A
By using the EF (ejection fraction)
16
Q
Ch. 11: Hemodynamic Monitoring
The impendance that the left and right ventricles must overcome to eject blood in the great vessels.
A
Afterload
17
Q
Ch. 11: Hemodynamic Monitoring
________ is used to describe the afterload that the left ventricle must overcome to eject blood into the systemic circulation.
A
Systemic Vascular Resistance
18
Q
Ch. 11: Hemodynamic Monitoring
________ is used to describe the afterload that the right ventricle must overcome to eject blood into the pulmonary circulation.
A
Pulmonary Vascular Resistance
19
Q
Ch. 11: Hemodynamic Monitoring
What is the normal values for CVP and what is the measurement used for?
A
2-6 mm Hg, used to estimate right ventricular preload; also for drug and fluid administration
20
Q
Ch. 11: Hemodynamic Monitoring
What are some associated problems with inserting a pulmonary artery catheter in the internal jugular?
A
- Pneumothorax
- Hemothorax
21
Q
Ch. 11: Hemodynamic Monitoring
What are some associated problems with inserting a pulmonary artery catheter in the subclavian?
A
- Severe thrombocytopenia (difficulty to control bleeding)
- Pneumothorax (more frequently than with internal jugular)
- Hemothorax
22
Q
Ch. 11: Hemodynamic Monitoring
What are some associated problems with inserting a pulmonary artery catheter in the femoral?
A
- Phlebitis
- Catheter tip may migrate with movement of the leg
23
Q
Ch. 11: Hemodynamic Monitoring
What are some associated problems with inserting a pulmonary artery catheter in the antecubital (elbow)? (3)
A
- Phlebitis
- Catheter tip may migrate with movement of the arm
- Difficult site for catheter advancement
24
Q
Ch. 11: Hemodynamic Monitoring
The standard adult pulmonary artery catheter is ____ cm in length.
A
110
25
_Ch. 11: Hemodynamic Monitoring_
The standard adult pulmonary artery catheter is available in what two sizes?
7 & 8
26
_Ch. 11: Hemodynamic Monitoring_
Catheters placed in the _____________ are generally called central venous lines.
- Right atria
- Vena cava
27
_Ch. 11: Hemodynamic Monitoring_
_________ in any patient with a intravascular line should alert the clinician to infectious complications.
Fever
28
_Ch. 11: Hemodynamic Monitoring_
Direct measurement of the systemic arterial pressure requires the insertion of a catheter into a ______.
Peripheral artery, such as the radial, brachial or femoral arteries
29
_Ch. 11: Hemodynamic Monitoring_
What must be performed before a radial artery catheter is inserted?
Modified Allens Test
30
_Ch. 11: Hemodynamic Monitoring_
**Systemic Artery Catheterization**
What is the most common cause of decreased perfusion?
Thrombus formation, which occludes the catheter tip
31
_Ch. 11: Hemodynamic Monitoring_
**What is the formula?**
Mean Arterial Blood Pressure (MAP)
(Systolic pressure + Diastolic pressure) divided by 3.
32
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range?**
Stroke Volume
60-100 mL
33
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range?**
Mean Pulmonary Artery Pressure
10-20 mm Hg
34
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range and what is the measurement used for?**
PAOP/PCWP
5-12 mm Hg, used to estimate left ventricular filling and preload.
35
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range?**
Cardiac Output
4-8 L/min
36
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range?**
PvO2
40 mm Hg
37
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range?**
PaO2
80-100
38
_Ch. 11: Hemodynamic Monitoring_
What are some pathological conditions that are associated with increased PVR?
- Pulmonary hypertension
- Pulmonary embolus
- Congestive heart failure
39
_Ch. 11: Hemodynamic Monitoring_
Does inhaled nitric oxide increase or decrease PVR and PA systolic pressures?
Dilates the pulmonary vasculature, decreasing PVR and PA systolic pressures.
40
_Ch. 11: Hemodynamic Monitoring_
The volume of blood that is pumped by the heart per minute and is usually expressed as L/min or mL/min
Cardiac Output
41
_Ch. 11: Hemodynamic Monitoring_
The volume of blood pumped by the heart per beat is usually expressed as L/beat or mL/beat.
Stroke Volume
42
_Ch. 11: Hemodynamic Monitoring_
What are some reasons why you would see an **elevated right atrial pressure?** (6)
1. Volume overload
2. Right ventricular failure
3. Tricuspid stenosis or regurgitation
4. Cardiac tamponade
5. Constrictive pericarditis
6. Chronic left ventricular failure
43
_Ch. 11: Hemodynamic Monitoring_
What are some reasons why you would see a **low RAP or PAOP?**
Hypovalemia
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_Ch. 11: Hemodynamic Monitoring_
What are some reasons why you would see an **elevated PAOP?** (6)
1. Volume overload
2. Left ventricle failure
3. Mitral stenosis or regurgitation
4. Cardiac tamponade
5. Constrictive pericarditis
6. High PEEP
45
_Ch. 11: Hemodynamic Monitoring_
Left atrial pressures ranges from ___.
5-12 mm Hg
46
_Ch. 11: Hemodynamic Monitoring_
RAP and ____ are the same thing!
CVP
47
_Ch. 11: Hemodynamic Monitoring_
The following factors can increase the risk for infections in patients with arterial lines: (3)
- Insertion of the arterial line by surgical cutdown
- Altered host defense
- Prolonged cannulation (>4 days)
48
_Ch. 11: Hemodynamic Monitoring_
Risk factors for Catheter-Associated Pulmonary Artery Rupture (6)
- Age >60 years
- Pulmonary hypertension
- Improper balloon inflation
- Improper catheter positioning
- Cardiopulmonary bypass surgery
- Anticoagulation therapy
49
_Ch. 11: Hemodynamic Monitoring_
What is the difference between the systolic and diastolic pressures called?
Pulse pressure
50
_Ch. 11: Hemodynamic Monitoring_
An increase in diastolic pressure is associated with _____.
**Diastolic pressure is affected by vascular tone.**
Vasoconstriction
50
_Ch. 11: Hemodynamic Monitoring_
An decrease in diastolic pressure is associated with _____.
**Diastolic pressure is affected by vascular tone.**
Vasodilation
51
_Ch. 11: Hemodynamic Monitoring_
The **resting** heart rate of a healthy adult is typically ___.
60-100 bpm
52
_Ch. 11: Hemodynamic Monitoring_
Bradycardia is associated with _________ in parasympathetic tone and _____________ in sympathetic tone.
Bradycardia is associated with **increases** in parasympathetic tone and **decreases** in sympathetic tone.
53
_Ch. 11: Hemodynamic Monitoring_
Tachycardia is associated with _________ in parasympathetic tone and _____________ in sympathetic tone.
Tachycardia is associated with **decreases** in parasympathetic tone and **increases** in sympathetic tone.
54
_Ch. 11: Hemodynamic Monitoring_
Increases in afterload are generally associated with _______ in cardiac output.
a. Increases
b. Decreases
b. Decreases in cardiac output
55
_Ch. 11: Hemodynamic Monitoring_
Decreases in afterload are associated with _________ in cardiac output.
Increases
56
_Ch. 11: Hemodynamic Monitoring_
What two things leads to an increase in PVR and SVR?
Systemic and pulmonary hypertension
**In both cases, the CO will be reduced.**
57
_Ch. 11: Hemodynamic Monitoring_
Administering a systemic ____________ will reduce SVR and result in an increase in CO.
Vasodilator
58
_Ch. 11: Hemodynamic Monitoring_
Administering a pulmonary ____________ will reduce PVR and result in an increase in CO.
Vasodilator
59
_Ch. 11: Hemodynamic Monitoring_
Why is the radial artery the most commonly used site systemic arterial catheterization?
Easy accessibility and collateral circulation to the hand from the ulnar artery.
60
_Ch. 11: Hemodynamic Monitoring_
Prolonged or frequent flushing of the arterial line should be avoided because ____.
This can lead to the inadvertent administration of large amounts of flush volume to the patient
61
_Ch. 11: Hemodynamic Monitoring_
**Systemic Artery Catheterization**
What should be suspected when pallor distal to the insertion site occurs?
Distal ischemia, particularly if it accompanied by pain and paresthesia in the affected limb.
62
_Ch. 11: Hemodynamic Monitoring_
An decrease in diastolic pressure is associated with _____.
Vasodilation
62
_Ch. 11: Hemodynamic Monitoring_
What are the two techniques that can be done to insert a systemic arterial catheter?
1. Percutaneous technique
2. Surgical cut down technique
63
_Ch. 11: Hemodynamic Monitoring_
**Systemic Artery Catheterization**
The catheter should be percutaneously inserted at what degree angle?
Approximately 30-degree angle
64
_Ch. 11: Hemodynamic Monitoring_
**Systemic Artery Catheterization**
Maintenance of the arterial line requires the use of a ____.
Continuous pressurized flush mechanism to irrigate the catheter with a heparinized solution at a low flow (2-3 mL/h).
65
_Ch. 11: Hemodynamic Monitoring_
**Systemic Artery Catheterization**
The catheter is removed if there is evidence of ___.
Local infection or the presence of distal ischemia.
66
_Ch. 11: Hemodynamic Monitoring_
Difficulty withdrawing blood or persistence of damped tracings should alert the clinician to possible complications like ___.
The presence of air bubbles in the line or occlusion of the catheterized artery.
67
_Ch. 11: Hemodynamic Monitoring_
**Systemic Artery Catheterization**
_______ is a distinct possibility if the line is left open.
Hematoma
68
_Ch. 11: Hemodynamic Monitoring_
During ____________ or _________, when the triscuspid valve is **closed**, the pressure measured in the right atrium or vena cava reflects the RAP.
Ventricular systole or atrial diastole
69
_Ch. 11: Hemodynamic Monitoring_
At the end of _______ and ________, when the triscuspid valve is **open**, the pressure measured in the right atrium reflects the **RVP.**
Ventricular diastole and atrial systole
70
_Ch. 11: Hemodynamic Monitoring_
Pressure measurements are usually performed during which phase of the respiratory cycle? The transducer is zeroed at the level of the _____.
Exhalation when the patient is supine. The transducer is zeroed at the level of the _right atrium._
71
_Ch. 11: Hemodynamic Monitoring_
CVP catheters are usually inserted percutaneously into a large central vein such as:
- Internal jugular
- Peripherally through the medial basilic or lateral cephalic vein
72
_Ch. 11: Hemodynamic Monitoring_
What are the most common problems encountered with the insertion of the CVP catheters? (6)
**1. Pneumothorax is the most common complication!!!**
2. Hemothorax
3. Vessel damage
4. Infection
5. Thrombosis
6. Bleeding
73
_Ch. 11: Hemodynamic Monitoring_
How is the placement of a CVP catheter usually confirmed?
Radiography
74
_Ch. 11: Hemodynamic Monitoring_
The balloon-tipped, flow-directed catheter is also referred to as ____.
Swan-Ganz catheter or PAC (pulmonary artery catheter)
75
_Ch. 11: Hemodynamic Monitoring_
Remember that the french size (7 or 8) divided by ____ equals the **external** diameter of the catheter in millimeters.
Pi, 3.14
76
_Ch. 11: Hemodynamic Monitoring_
Both adult and pediatric catheters are marked at ___ increments.
10-cm
77
_Ch. 11: Hemodynamic Monitoring_
**Pulmonary Artery Catheterization**
A pressurized flush must run through catheter at a rate of ________ to prevent clot formation within the catheter's lumen.
1-5 mL/h
78
_Ch. 11: Hemodynamic Monitoring_
**Pulmonary Artery Catheterization**
A triple-lumen catheter can be used to measure ___.
Right atrial pressures and for administering IV medications.
79
_Ch. 11: Hemodynamic Monitoring_
**Pulmonary Artery Catheterization**
Thermodilution catheters incorporate a thermistor connector, which contains electrical wires that connect to a thermistor approximately ______ from the tip of the catheter.
1.5 inches (3cm)
80
_Ch. 11: Hemodynamic Monitoring_
**Pulmonary Artery Catheterization**
When measuring CO using the thermodilution technique, __________ is injected through the catheter's **third (proximal) lumen,** which is positioned at the level of the right atrium.
a bolus of saline or 5% dextrose (cold or room temperature)
81
_Ch. 11: Hemodynamic Monitoring_
**Pulmonary Artery Catheterization**
How is CO measured using the thermodilution technique?
Change in temperature sensed by the thermistor near the tip of the catheter as the injected saline mixes with the patient's pulmonary blood flow.
82
_Ch. 11: Hemodynamic Monitoring_
**Pulmonary Artery Catheterization**
Positioning the catheter can be accomplished by ____.
Fluoroscopy or by monitoring the pressure tracings generated as the catheter is slowly advanced into the right side of the heart and PA.
83
_Ch. 11: Hemodynamic Monitoring_
The mean PAOP may exceed the PA diastolic pressure in patients with ____.
Mitral stenosis or mitral regurgitation
83
_Ch. 11: Hemodynamic Monitoring_
A wide pulse pressure is associated with __.
Increased SV and decreased arterial compliance
84
_Ch. 11: Hemodynamic Monitoring_
A narrow pulse pressure is associated with ___.
Decreased SV and increased arterial compliance
85
_Ch. 11: Hemodynamic Monitoring_
**Pulmonary Artery Catheterization**
Loss of respiratory fluctuations may indicate that ___.
- The stopcock is closed between th catheter
- The pressure transducer or the tube is kinked
- Blood clot or air is present in the tubing.
86
_Ch. 11: Hemodynamic Monitoring_
**Pulmonary Artery Catheterization**
It is important inflate the balloon to avoid endocardial or PA damage. What is the balloon volume for adults?
1.5 mL.
The catheter is slowly advanced until it wedges into a small PA.
86
_Ch. 11: Hemodynamic Monitoring_
**Complications associated with PAC (pulmonary artery catheterization)**
What are the causes of infection?
Nonsterile technique or irritation of the wound
86
_Ch. 11: Hemodynamic Monitoring_
**Complications associated with PAC (pulmonary artery catheterization)**
What is the cause of a air embolism?
Air entering vessel during insertion
86
_Ch. 11: Hemodynamic Monitoring_
**Complications associated with PAC (pulmonary artery catheterization)**
What is the cause of a access vessel?
Irritation of vessel by catheter or nonsterile insertion technique or phlebitis
86
_Ch. 11: Hemodynamic Monitoring_
**Complications associated with PAC (pulmonary artery catheterization)**
What are the causes of cardiac arrhythmias?
- PAC
- PVC
- V tach
- V fib
- A flutter
- A fib
Heart valve or endocardium irritation by the catheter
86
_Ch. 11: Hemodynamic Monitoring_
**Complications associated with PAC (pulmonary artery catheterization)**
What is the cause of a pulmonary infarction? (4)
1. Overinflation of catheter balloon
2. Prolonged wedging
3. Clots formed in or near the catheter
4. Catheter advancement into a small artery
87
_Ch. 11: Hemodynamic Monitoring_
**Complications associated with PAC (pulmonary artery catheterization)**
What is the cause of a damped waveform? (6)
1. Air in line
2. Clot in the system
3. Kinks in line
4. Catheter tip against vessel wall
5. Overwedging
6. Blood on the transducer
88
_Ch. 11: Hemodynamic Monitoring_
**Complications associated with PAC (pulmonary artery catheterization)**
What is the cause of catheter whip or fling?
- High CO
- Abnormal vessel diameter
89
_Ch. 11: Hemodynamic Monitoring_
**Complications associated with PAC (pulmonary artery catheterization)**
What is the cause of a pulmonary artery rupture or perforation?
Overinflation of catheter balloon
90
_Ch. 11: Hemodynamic Monitoring_
**Complications associated with PAC (pulmonary artery catheterization)**
What is the cause of a balloon rupture - air embolism?
Loss of catheter balloon elasticity or overinflation
91
_Ch. 11: Hemodynamic Monitoring_
**Complications associated with PAC (pulmonary artery catheterization)**
What is the cause of catheter knotting?
Excessive catheter movement
92
_Ch. 11: Hemodynamic Monitoring_
______ is most often associated with prolonged duration of catheterization because the balloon will typically lose its elasticity with exposure to blood.
Balloon rupture
93
_Ch. 11: Hemodynamic Monitoring_
**PAC (pulmonary artery catheterization)**
It is important that the balloon is inflated for only 15-30 secs when measured PAOP, particularly in patients with ______.
Pulmonary hypertension
94
_Ch. 11: Hemodynamic Monitoring_
What is the normal range systolic pressure for adults?
90 to 140 mm Hg
95
_Ch. 11: Hemodynamic Monitoring_
What is the normal range diastolic pressure for adults?
60 to 90 mm Hg
96
_Ch. 11: Hemodynamic Monitoring_
What is the normal range mean arterial pressure for adults?
70 to 100 mm Hg
97
_Ch. 11: Hemodynamic Monitoring_
It is generally accepted that systemic hypertension exists when _________.
- Systolic pressure is greater than 140 mm Hg
- Diastolic pressure is greater than 90 mm Hg
97
_Ch. 11: Hemodynamic Monitoring_
Systemic hypotension is associated with ___.
- Systolic pressures less than 100 mm Hg
- Diastolic pressures less than 60 mm Hg
97
_Ch. 11: Hemodynamic Monitoring_
The typical adult can maintain an adequate CO at heart rates of ___.
40-50 beats/min as long as SV increases proportionally.
98
_Ch. 11: Hemodynamic Monitoring_
Does systemic pressures increase or decrease as the site moves away from the heart?
Increases
More evident in young children than adults.
99
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range?**
Oxygen Consumption (VO2)
200-300 mL/min
100
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range?**
Oxygen Transport (DO2)
500-1000 mL/min
101
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range?**
Stroke Index (SI)
35-55 mL/beat
102
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range?**
Cardiac index
2.5-4 L/min/m2
103
_Ch. 11: Hemodynamic Monitoring_
**How is it measured?**
PAOP (pulmonary artery occlusion pressure)
Measured from PA catheter in the occlusion position (balloon inflated)
104
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range and how is measured?**
PAP
**Systolic:** 15-35 mm Hg
**Diastolic:** 5-15 mm Hg
Measured from PA catheter
105
_Ch. 11: Hemodynamic Monitoring_
**What is the normal range and what is it used for?**
MPAP (mean pulmonary artery pressure)
10-20 mm Hg, used to calculate PVR
106
_Ch. 11: Hemodynamic Monitoring_
Identification of the right ventricular pressure waveform during continuous monitoring indicates that the catheter has slipped into the right ventricle. How would reposition it back in the PA?
Reinflating the balloon and allowing blood flow to carry the catheter back into the PA.
107
_Ch. 11: Hemodynamic Monitoring_
The balloon should be inflated for short periods when measuring ___.
PAOP
108
_Ch. 11: Hemodynamic Monitoring_
What are some reasons why you would see an **elevated RAP or PAOP?**
Hypervolemia or ventricular failure
109
_Ch. 11: Hemodynamic Monitoring_
What plays an important role in the assessment of pulmonary hydrostatic pressure in the formation of pulmonary edema?
PAOP
110
_Ch. 11: Hemodynamic Monitoring_
The finding of bilateral infiltrates on a CXR and a PAOP greater than 25 mm Hg suggests the presence of ________ resulting from _____.
Cardiogenic pulmonary edema resulting from left-sided heart failure.
111
_Ch. 11: Hemodynamic Monitoring_
The finding of bilateral infiltrates on a CXR with a normal PAOP would indicate ___.
Presence of noncardiogenic pulmonary edema and suggests the presence of **ARDS.**
112
_Ch. 11: Hemodynamic Monitoring_
With spontaneous breathing, the intraplueral pressure decreases during inspiration, causing the PA wave pattern to ___.
Descend
113
_Ch. 11: Hemodynamic Monitoring_
With spontaneous exhalation, the intraplueral pressure increases causing the PA wave pattern to ___.
Rise
114
_Ch. 11: Hemodynamic Monitoring_
PA pressure is measured during which phase of the respiratory cycle?
End expiration
115
_Ch. 11: Hemodynamic Monitoring_
What have been shown to minimize the hemodynamic effects of positive intrathoracic pressure and help maintain right heart preload and cardiac output?
Lower mean inspiratory pressures present with IMW and PSV
116
_Ch. 11: Hemodynamic Monitoring_
What ventilator mode decreases cardiac index and thus DO2?
Pressure control inverse ratio ventilation (PC-IRV)
117
_Ch. 11: Hemodynamic Monitoring_
What can produce erroneously elevated pressure readings?
Use of PEEP, either applied or inadvertent, a levels greater than 15 cm H2O
118
_Ch. 11: Hemodynamic Monitoring_
Cardiac Output Equation
SV x HR
118
_Ch. 11: Hemodynamic Monitoring_
a.) Cardiac Index Equation
b.) What is the normal range?
a.) CO/BSA
b.) 2.5 to 4.0 L/min/m2
119
_Ch. 11: Hemodynamic Monitoring_
Stroke Index Equation
SV/BSA
120
_Ch. 11: Hemodynamic Monitoring_
Decreases in either HR or SV can cause reductions in ___.
CO
121
_Ch. 11: Hemodynamic Monitoring_
Decreases in SV are associated with ___.
Reduced preload or contractility of the heart or with an abnormally high afterload.
122
_Ch. 11: Hemodynamic Monitoring_
**Something to know:**
Tachycardia can lead to decreases in ventricualar filling and can ultimately result in ________.
CO reductions
123
_Ch. 11: Hemodynamic Monitoring_
Increases in SV are associated with ___.
Increased in preload and contractility and with reductions of afterload.
124
_Ch. 11: Hemodynamic Monitoring_
SaO2 is normally about __.
97-98%
125
_Ch. 11: Hemodynamic Monitoring_
CaO2 of a normal healthy individual is _____.
20 vol% (200 mL/L of whole blood)
126
_Ch. 11: Hemodynamic Monitoring_
SvO2 of a normal healthy individual is _____.
75%
127
_Ch. 11: Hemodynamic Monitoring_
CvO2 of a normal healthy individual is _____.
15 vol% (150 mL/L of whole blood)
128
_Ch. 11: Hemodynamic Monitoring_
EF values of _____ are considered normal for healthy adults.
0.5 - 0.7
129
_Ch. 11: Hemodynamic Monitoring_
The portion of the cardiac output that does not participate in gas exchange with alveolar air.
Shunt
130
_Ch. 11: Hemodynamic Monitoring_
___ represents the total amount of O2 that is carried in the blood to the tissues each minute.
DO2 (Oxygen Delivery)
131
_Ch. 11: Hemodynamic Monitoring_
Under normal circumstances DO2 is approximately _____.
1000 mL/min or about 550 to 650 mL/min/m2.
132
_Ch. 11: Hemodynamic Monitoring_
SVR may be ___________ if blood viscosity increases, as occurs in **polycythemia**
Increased
133
Normal SVR ranges from ____.
900 - 1500 dyne x seconds x cm -5
134
When changes in the FiO2 are initially made for adult patients, ABGs should be measured within ______.
15 minutes, some clincians choose to obtain a sample after 30 minutes.
134
_____ is used to estimate the force of the pulse.
Pulse pressure (systemic)
134
**What is the normal value?**
PaO2/PAO2
0.8-1.0
134
**Ch. 13: Improving Oxygenation**
The strategy used to treat hypoxia should focus on ___.
Its cause
134
**Ch. 13: Improving Oxygenation**
What are the different types of hypoxia? (4)
**1.Hypoxemic hypoxia:**
- low PaO2
- ascent to altitude
- hypoventilation)
**2. Anemic hypoxia:**
- lower than normal RBC
- abnormal Hgb
- carbon monoxide poisoning
**3. Circulatory hypoxia:**
- reduced CO
- decreased tissue perfusion
**4. Histotoxic hypoxia:**
- cyanide poisoning
134
Hypoxia vs. hypoxemia
**Hypoxia:** Reduction of O2 in the tissues
**Hypoxemia:** Reduction in partial pressure of O2 in the blood. (PaO2 <80%, SaO2 <95%)
134
______ provides information about cardiac performance.
Stroke Volume
134
____________ is used to calcaulate systemic resistance and used in hemodynamic monitoring when giving vasoactive drugs.
Mean Arterial Blood Pressure
134
What are the most important factors tha influence vascular resistance?
The caliber of the blood vessels and the viscosity of the blood.
134
**What is the normal value?**
PaO2
80-100 mm Hg
134
Treatment of circulatory hypoxia typically involves ___.
Fluid resuscitation and pharmalogical interventions, which normalizes CO.
**Drugs that increase ventricular contractility or decrease vascular resistance.**
134
Normal PVR ranges from ____.
100 to 250 dyne x seconds x cm -5
134
**Ch. 13: Improving Oxygenation**
Improving the ventilatory status of a patient with hypercapnic respiratory failure can be accomplished by ____.
1. Improving alveolar ventilation
2. Reducing physiological dead space
3. Reducing CO2 production
134
_______________ are among the most difficult to oxygenate and manage in the ICU.
Patients with ARDS
134
When hypoventilaion causes hypoxemia, _______ generally improves oxygenation.
Increasing minute ventilation
134
List some ways to improve oxygenation. (4)
1. Supplemental oxygen
2. PEEP
3. CPAP
4. Patient positioning (proning)
134
**What is the normal value?**
P(A-a)O2
5-10 mm Hg (FiO2: 0.21)
30-60 mm Hg (FiO2: 1.0)
134
**What is the normal value?**
VO2
250 mL/min
134
Every attempt should be made to prevent complications associated with O2 toxicity by administering an FiO2 below _____.
0.6 while maintainin PaO2 between 60-90 and CaO2 near normal (20 mL/dL)
134
**What is the normal value?**
PAO2
100 - 673 mm Hg
FiO2 range: 0.21-1.0
134
**What is the normal value?**
PaO2/FiO2
380-475
134
Breathing 100% oxygen can lead to ____.
Absorption atelectasis and increase intrapulmonary shunting which worsens hypoxemia.
134
What type of disease process have a large discrepancy between SpO2 and PaO2?
COPD
134
Define Paw.
Average pressure above baseline during a total respiratory cycle.
134
If PaO2 remains very low while the patient is breathing an enriched O2 mixture, _____ is present. (3)
1. Signficant shunting
2. V/Q abnormailities
3. Diffusion defects
134
Something to know!
Beside increasing FiO2, another way to increase PaO2 is by ____.
Increasing the Paw (mean alveoalar pressure).
134
As total PEEP _______, paw (mean alveoalar pressure) increases.
a. increases
b. decreases
c. remains constant
a. increases
134
What are some factors that affect Paw (mean alveoalar pressure) during positive pressure ventilation? (5)
- PIP
- Total PEEP
- I/E ratios
- RR
- Inspiratory flow pattern
134
Other than increasing PEEP, what are the other ways to increase Paw (mean alveoalar pressure)? (2)
- High-frequency oscillatory ventilation
- APRV
134
What is the goal of using PEEP?
Recruit collapsed alveoli while avoiding overdistention of already open alveoli.
134
Other than increasing PEEP, what are the other ways to increase Paw (mean alveoalar pressure)? (3)
- High-frequency oscillatory ventilation
- APRV
- At one point, IRV was used too.
134
What are some pathological conditions are associated with an increased shunt fraction? (5)
1. Atelectasis
2. Pulmonary edema
3. Pneumonia
4. Pneumothorax
5. Complete airway obstruction
134
What are the goals of PEEP/CPAP therapy? (4)
1. Maintain a PaO2 60 mm Hg or greater and SpO2 at 90% or greater, at an acceptable pH
2. Recruit alveoli and maintain them at a aerated state
3. Restore FRC
4. Enhance tissue oxygenation
134
How can IRV be accomplished with VC-CMV?
Using a descending waveform to lengthen Ti or setting longer I-time if the ventilator is time cycled.
Ti can also be lengthened by adding inspiratory pause and slowing inspiratory flows.
134
**Inverse Ratio Ventilation**
The rationale behind increasing Ti is to ___.
Recruit lung units and avoid overinflating normal units.
Keeping alveoli open for extended periods may reduce shunt and V/Q mismatch.
134
Explain IRV (Inverse Ratio Ventilation)
Inspiratory time is longer than expiratory time.
134
**Inverse Ratio Ventilation**
What increases the risk for lung damage with this mode?
- Dynamic hyperinflation
- Increased Paw (CO may decrease)
134
IRV can be used with what mode of ventilation?
- Pressure control
- Volume control
134
How can IRV be accomplished with VC-CMV?
Using a descending waveform to lengthen Ti or setting longer I-time if the ventilator is time cycled.
Ti can also be lengthened by adding inspiratory pause and slowing inspiratory flows.
134
Indications for PEEP Therapy (6)
- Bilateral infiltrates
- Recurrent atelectasis with low FRC
- Reduced lung compliance
- P/F ratio <300 for ARDS
- Refractory hypoxemia: PaO2 increases <10 mm Hg with FiO2 increase of 0.2
- PaO2 <60 mm Hg on FiO2 >0.5
134
_Ch. 11: Hemodynamic Monitoring_
Increases in afterload are associated with _________ in cardiac output.
Decreases
135
When properly inserted, the proximal lumen of the PAC will be positioned in the:
Right atrium
136
The proximal lumen can be used for all of the following **except:**
Monitoring wedge pressures
137
SVR equation
([MAP-CVP]/CO) x 80
138
PVR equation
([MPAP-PAOP]/CO) x 80
139
Pulmonary artery pressures can be monitored continuously through _____.
The _distal_ lumen of a PA catheter
140
The RAP can be monitored continuously through _____.
The _proximal_ lumen of a PA catheter or through CVP line.
141
Which of the following could be used to estimate left ventricular end -diastolic pressure? (2)
- PAOP
- PA diastolic pressure
142
Pulmonary hypertension will have which of the following effects?
Increase afterload of the right side of the heart
143
If the transducer level is lower than the tip of the catheter during pulmonary arterty pressure monitoring, _____.
The readings will be falsely high.
144
The dicrotic notch of the pulmonary artery waveform may disappear in all of the following conditions except:
Measurements obtained from a femoral artery.
145
Patients receiving noninvasive CPAP should have a PaO2/FiO2 ratio greater than ___.
200 mm Hg and have a stable cardiovascular status.
146
What are some hazards and complications of mask CPAP? (7)
- Vomiting
- Aspiration
- Skin necrosis
- Discomfort
- CO2 retention
- Increased WOB
- Cerebral hemorrhage at high CPAP levels
147
What are some hazards and complications of nasal CPAP? (4)
- Gastric distention
- Pressure necrosis
- Swelling of nasal mucosa
- Abrasion of the posterior pharynx
148
Pressures of up to _____ can be administered with nasal CPAP.
15 centimeters of water
149
______ acheives expiratory pressure by creating a resistance to gas flow through an orifice.
Flow resistor
150
**Ch. 13: Flow Resistor**
As the diameter of the orifices _decreases_ in size, the pressure level applied _____.
a. Increases
b. Decreases
a. Increases
151
**Ch. 13: Flow Resistor**
As the diameter of the orifices _increases_ in size, the pressure level applied _____.
a. Increases
b. Decreases
b. Decreases
151
**Ch. 13: Flow Resistor**
Changes in expiratory gas flow also affect expiratory pressure applied with a flow resistor. The pressure is ____ dependent.
Flow
152
**Ch. 13: Flow Resistor**
Explain the relationship between pressure and flow.
The higher the expired gas flow, the higher the expiratory pressure generated and vice versa.
153
Therapeutic PEEP is used for what?
Treatment of refractory hypoxemia caused by increased intrapulmonary shunting and V/Q mismatch accompanied by a decreased FRC and pulmonary compliance.
153
What are some disorders that may benefit from the use of PEEP? (3)
**1. ARDS**
2. Cardiogenic pulmonary edema in adults and children
3. Bilateral, diffuse pneumonia
153
_______ PEEP is the level at which the maximum beneficial effects of PEEP occur.
Optimal PEEP
153
With __________, a constant pressure is provided throughout expiration regardless of the rate of gas flow.
Threshold resistors
153
In most situations it is appropriate to use a minimum level of PEEP to help preserve a patient's normal FRC.
3-5 cmH2O
153
Therapeutic PEEP is ______ or greater.
5 cmH2O or greater
153
The expiratory valves on most ventilators behave as ______.
Threshold resistors
153
True of False.
Patients with ARDS do not benefit from mechanical ventilatory support without PEEP.
True
153
What is the primary difference between using CPAP vs. PEEP?
Patient provides the WOB at all times during CPAP.
153
Continous flow CPAP is a open or closed system?
Closed
153
Demand-flow spontaneous CPAP is a open or closed system?
Open
154
**Ch. 21: Long-Term Ventilation**
Patients requiring LTMV can be divided into 2 groups:
1. Those recovering from an acute illness and unable to maintain adequate ventilation for prolonged periods
2. Those with chronic progressive cardiopulmonary disorders
- Ventilatory muscle disorders
- Alveolar hypoventilation
- Obstructive lung disease
- Restrictive lung disease
- Cardiac disease
155
**Ch. 21: Long-Term Ventilation**
Long-term ventilator assisted patients are defined by the American College of Chest Physicians as ppl requiring MV for at least ___.
6 hrs per day for 21 days or more
156
**Ch. 21: Long-Term Ventilation**
VAIs in specialized units located within a hospital typically have the following characteristics: 6
- Longer hospital stays
- Lower hospital mortality rates
- Higher weaning rates
- Higher liklihood of being discharged to their homes
- Longer life expectancy after discharge
- Greater independence in daily activities
157
Which site does not have the resources to treat acutely ill patients and are not ideal for weaning patient from ventilation?
LTC sites, like SNF and single-family homes
158
Individuals who are considered candidates for long-term mechanical ventilation in the home or in extended care facilities must be clinically and physiologically stable to the degree that they are free from any medical complications for at least _________.
2 weeks before discharge
159
**Ch. 21: Long-Term Ventilation**
What type of patients may require a higher level of care?
COPD and younger children
160
The major factor affecting the cost of home care is ______.
The need for professional or skilled caregivers
161
The goal of the discharge planning team is to ______.
Identify all patient care issues that need to be addressed before discharge and develop a plan of care to facilitate transfer.
162
Ventilation can be provided by IPPV to patients with a _____.
TT
163
IPPV is indicated for ______.
Patients who have persistent symptomatic hypoventilation and those who don't meet the criteria for NIV or are unable to tolerate it or NPV.
164
Generally, a tracheotomy is performed as soon as possible after the need for extended intubation is verified, and it appears the patient is likely to benefit from the procedure. It's likely occurs when the patient is stabilized on the ventilator in an acute care hospital within about ______.
7 days of the onset of respiratory failure or sooner in neurologically impaired patients.
165
True or false.
Simple technology should be the goal of the ventilator election when it is possible.
True
166
What are the most important factors in choosing a ventilator? (5)
1. Reliability
2. Safety
3. Versatility
4. User-friendly
5. Easy patient cycling
167
Approximately _____ of patients who transferred to long-term care facilities on mechanical ventilation, have some type of neurological disorder, which is generally the primary cause of their ventilator dependence.
45%
168
Psychological problems in VAI can be attributed to a host of causes, including the following: (7)
- Severity of illness
- Longevity of illness
- Multiple medications
- Sleep disruption
- Delirium
**- Anxiety**
**- Depression**
169
What type of ventilation can provide support to a patient without requiring an artificial airway; thus patient can speak eat and drink while avoiding the complications associated with artificial airways?
Negative pressure ventilation
170
Negative pressure ventilation is preferable for what type of patients?
Patient with disorders, such as neuromuscular disease, spinal cord injuries, chest wall disorders, or central hypoventilation syndrome
171
When would negative pressure ventilation not be recommended?
If excessive airway secretions, decreased pulmonary compliance, or increased airway resistance are present or if the patient is at risk for aspiration, negative pressure ventilation is not recommended.
172
What are several disadvantages of tank ventilators/iron lungs?
They are large and cumbersome and make bronchial drainage, IV therapy and physical contact with the patient difficult.
173
A rigid shell that is placed over the patient's chest, touching the upper abdomen.
Chest Cuirass
174
A rigid chest grid that attaches to a flat back plate.
The body suit
175
Advantages/Disadvantages of the Body Suit
**Advantages:**
- More portable than the tank ventilation
- Patient can sleep in their own bed
**Disadvantages:**
- Less efficient
- Hard to completely seal
- It restricts movement so it can cause muscular and joint pain
176
The rocking bed and pneumobelt are not appropriate for what patient type? (3)
- Obese
- Severe chest wall deformities
- Intrinsic lung disease
177
The rocking bed is a motorized bed that continuously moves in a _________.
Longitudinal plane
178
In what cases is the rocking bed shown to be effective? (2)
- Bilateral diaphragmatic paralysis
- Muscular dystrophy
179
The rocking bed supports ventilation by rhythmically moving through an arch of _____.
40-60 degrees
180
The rocking bed has a rocking rate of ____.
12-22 times/min
181
What are some conditions in which the rocking bed is not effective and should be used with caution? (5)
- Obesity
- Excessively thin patients
- Severe chest wall deformities
- Infants
- Intrinsic lung disease
182
What position should the patient be in to use the pneumobelt?
Seated position
183
The pneumobelt (also known as intermittent abdominal pressure ventilator) is ineffective if the head is lower than _____________.
30 degrees from horizontal
184
Is the pneumobelt powerful?
No.
185
Who could benefit from diaphragmatic pacing?
- Patients with respiratory failure caused by high spinal cord lesions
- Central hypoventilation
186
The phrenic nerve is electrically stimulated through surgically implanted phrenic electrodes.
Diaphragmatic pacing
187
**Diaphragmatic pacing**
Some patients experience ______.
Disadvantages
Obstructive apnea and a drop in SpO2 during sleep.
This device does not have alarms.
Cost around $300k
188
What is the treatment for OSA?
CPAP via face or nasal mask
189
**Continuous Positive Airway Pressure for Obstructive Sleep Apnea**
The decision to use CPAP depends on ____.
The degree of the upper airway obstruction and patient muscle strength.
190
**Continuous Positive Airway Pressure for Obstructive Sleep Apnea**
For those patients who have adequate respiratory muscle strength, and do not require mechanical ventilation, but become hypercapnic or hypoxemic during sleep, ________ maybe all that is necessary to alleviate hypoxemia and alveolar collapse.
Nasal CPAP
191
Who may benefit from glossopharyngeal breathing (also known as frog breathing)? (2)
- Postpolio syndrome
- Spinal cord injuries
191
What is the purpose of assisted coughing?
Increase expiratory gas flow
192
What is the purpose mechanical oscillation?
Assist in mobilization of secretions
193
A technique in which rapid pressure pulses are applied to the chest wall or upper airway.
High-frequency mechanical oscillation
193
Contraindications of MI-E. (2)
- Emphysema
- Pulmonary disorders that predispose a patient to barotrauma
194
For speech to occur, tracheal pressures of approximately ______ are required to vibrate the vocal cords and produce a quality voice.
2 cm H2O
195
Which speaking valve is currently the only valve that has approval from the US?
Passy-Muir
196
What are solutions for aerophagia - gastric distention caused by CPAP or NIV therapy? (4)
- Lower PIP
- Use PSV
- Alter sleep position
- Use abdominal strap
197
**Something to Know**
When the circuits are changed LESS frequently, the risk for VAP ____.
Decreases
198
**Provide the equation for the following:**
DO2
CO x CaO2
199
**Provide the equation for the following:**
VO2
CO x (CaO2 - CvO2)
200
**Provide the equation for the following:**
CaO2
([Hb x 1.34] x SaO2) + (0.003 mL/dL x PaO2)
201
**Provide the equation for the following:**
PiO2
FiO2 (PB - PH2O)
202
**Provide the equation for the following:**
CvO2
([Hb x 1.34] x SvO2) + (0.003 mL/dL x PvO2)
203
**Noncardiogenic** pulmonary edema is also known as _____.
ARDS
204
At what shunt percentages does the clinician start to consider mechanical ventilation?
15-20%
205
_____% shunt **absolutely** calls for mechanical ventilation.
30
206
**Compare & Contrast**
CPAP vs. PEEP
**PEEP:**
- Invasively applied via ventilation
**CPAP:**
- Noninvasive via face or nasal mask
*but, there are essentially the same thing.*
207
Oxygen Delivery is the product of ________.
- Cardiac Outut
- Arteral O2 content
208
Mixed venous values can be higher than normal patients with _______ hypoxia.
Histotoxic
Also in situations in which intrapulmonary shunting occurs.
209
EF values less than **0.3** are associated with _____.
Compromised cardiovascular function and imminent heart failure
210
Pulse Pressure Equation
Systolic pressure - Diastolic pressure
211
Arterial-to-venous oxygen content difference
C(A-a) O2
212
How is BP measured?
- Blood pressure cuff
- Arterial line
213
How is CO measured?
By thermodilution or dye dilution
214
How is PvO2 measured?
From blood from the distal port of the PA catheter
215
_____ is used as an index of tissue oxygenation.
C(A-a) O2
216
What does a reduced DO2 indicate?
Decrease in cardiac output or arterial O2 content
217
What is the goal when selecting an appropriate PEEP/CPAP setting for a patient?
Achieving a CPAP/PEEP level that produces maximum beneficial effects and is not associated with profound cardiopulmonary side effect.
218
For adults, PEEP is increased in increments of ______.
3-5 cm H2O
219
Practitioners agree that a target PaO2 of _______ and SpO2 of _______ are acceptable for adult patients.
Practitioners agree that a target PaO2 of **60 mm Hg** and SpO2 of **90** are acceptable for adult patients.
220
It is important to use PEEP that avoids over distention while maintaining alveolar latency and preventing alveoli from collapsing during exhalation of a VT.
Something to know.
221
Sites for Ventilator Dependent patients
- Acute care sites
- Intermediate care sites
- Long-term care sites
222
Acute Care Sites (4)
- Intensive care units
- Specialized respiratory care units
- Generalized medical-surgical care units
- Long-term acute care hospitals
223
What are the 5 major factors that have added to the upsurge of ventilator-assisted individuals?
1. Continued advances in pulmonary medicine
2. Increased emphasis on earlier discharge from acute care hospitals
3. NIV is a alternative to invasive ventilation
4. Simple and more versatile equipment is available for home use.
5. Increase in medical equipment agencies.
224
Intermediate Care Sites (3)
- Subacute units
- Long-term care hospitals
- Rehabilitation hospitals
(Patient may still require a high level of PEEP or FiO2)
225
Long-Term Care Sites (3)
- Skilled Nursing Facilities
- Congregate Living Centers
- Single-family Homes
**These sites are not ideal for weaning a patient from ventilation.**
226
A discharge plan should contain the basic components of ________. (4)
- Assessment
- Education
- Training
- Plan of Care
227
What are some complications of long-term positive pressure ventilation?
- Pulmonary complications
- Complications to the cardiovascular system, the airway, GI tract and neurological complications
- Problems associated with immobility
- Psychological dysfunction
228
**Complications of the Airway in LTMV**
Nasopharyngeal injury
- SInusitis
- Otitis
- Injury to the nasal septum
- Ulceration to the mouth, lips and pharynx
229
**Complications of the Airway in LTMV**
Laryngeal injury (3)
- Damage to the laryngeal cartilages
- Glottic and subglottic stenosis
- Vocal cord injury or paralysis
230
**Complications of the Airway in LTMV**
Tracheal injury (4)
- Infection or bleeding of the stoma
- Granuloma formation
- Tracheal stenosis , malacia or dilation
- Tracheoinnominate or tracheoesophageal fistula formation
231
Pneumbelt is also known as ____.
Intermittent abdominal pressure ventilator
232
Which two NIV devices both move abdominal contents and diaphragm to aid in breathing?
- Rocking beds
- Pneumobelt
233
All of the following are realistic goals of MV except:
To reverse the disease process
234
A technique of applying abdominal thrusts or compression to the patient's anterior chest wall during the expiratory phase of breathing.
Assisted coughing
235
**Speaking with Tracheostomy Tubes during Ventilation:**
With cuff deflation positive pressure ventilation, air is allowed to flow around the cuff and through the vocal cords during the __________ cycle of the ventilator.
Inspiratory
236
According to the criteria for patient selection, which of the following conditions would be most suitable for successful home care ventilation?
A patient with progressive muscular dystrophy
237
Which of the following NPV is most efficient for providing ventilatory assistance but is cumbersome?
Full-body chamber
238
During a PAOP measurement, if you leave the balloon inflated, what complication could this cause?
Myocardial infarction
239
Pulse pressure is influenced by ______.
Stroke volume and arterial compliance
240
How are PAOP measurements obtained?
By inflating the balloon of the PA catheter until it occludes a small PA and wedges to block blood flow past the catheter tip.
241
_____ and _____ can be measured intermittently during PAOP determinations.
Left atrial and ventricular pressures
242
**Fick's Principle**
What is the formula?
Q = VO2/(CaO2-CvO2) x 10
243
DO2 is increased in situations in which cardiac output or arterial content O2 is elevated. What is an example?
Septic shock
244
DO2 is decreased in situations in which cardiac output or arterial content O2 is reduced. What is an example?
Hemorrhage
245
Shunting is normally ______% of cardiac output.
2-3
246
_____ provides an estimate of ventricular contractility.
Ejection fraction
247
What are some instances in which PVR is increased?
- Periods of alveolar hypoxia
- Cases where high intraalveolar pressures are generated
- Low CO by causing derecruitment of pulmonary vessels
248
SVR ____________ during systemic vasodilation, such as moderate hypoxemia or after the administration of systemic vasodilators such as nitroglycerin or hydralazine.
decreases
249
What is MAP (mean arterial blood pressure) used for?
To calculate systemic vascular resistance; used in hemodynamic monitoring when giving vasoactive drugs.
250
Overdistention and repeated collapse and re-expansion of the alveoli are associated with ____.
Ventilator-Induced Injury
251
Which of the following complications is most common following long-term placements of systemic arterial catheterization?
Infection and tissue ischemia distal to the catheter
252
The third lumen of a pulmonary artery catheter is used to measure which of the following?
Cardiac output
253
The respiratory therapist is assisting a physician inserting a pulmonary artery catheter in a patient when it is noted that a _dampened or continuous low-pressure waveform_ is displayed on the oscilloscope. This indicates which of the following?
The balloon may still be inflated or the catheter may be wedged.
254
Which of the following is the primary mechanism by which PEEP increases PaO2, and improves compliance?
Recruitment of collapsed alveoli
