VALLEY: ECG/CVP/PAP/BP Monitoring Flashcards
1
Q
What is Einthoven’s triangle?
A
Einthoven’s triangle is a representation of the placement of the three standard limb leads.
2
Q
Where are the leads placed for lead I?
A
left arm positive, right arm negative, left leg ground
3
Q
Where are the leads placed for Lead II?
A
right arm negative, left leg positive, left arm ground;
4
Q
Where are the leads placed for Lead III?
A
left arm negative, left leg positive, right arm ground.
5
Q
Where are the leads placed for lead VS?
A
The positive electrode for lead VS is placed between the middavicular line and the lateral chest line in the 5th. intercostal space. The negative electrode is placed on the left or right arm.
6
Q
What two monitors detect cardiac dysrhythmias?
A
(1) Stethoscope
(2) electrocardiogram
7
Q
List five reasons for using the electrocardiogram?
A
(1) Detect cardiac dysrhythmias (leads I or II).
(2) detect myocardial ischemia,
(3) detect electrolyte abnormalities
(4) calculate heart rate
(5) detect pacemaker malfunction.
8
Q
The ECG is recorded on ruled paper. What is the size of the smallest square? Each small division on an ECG tracing, when measured horizontally between the fine lines, represents how many seconds?
A
The smallest unit is l mm tall by 1 mm wide.Each mm corresponds to 0.04 seconds.
9
Q
How many millivolts (mV) are generated on the skin by electrocardiographic (ECG) signals? How many microvolts
(V) is this?
A
ECG potentials on the skin are on the order of l millivolt ( m V) , which is l,000 microvolts
10
Q
Is currently the standard for monitoring patients with suspected myocardial ischemia
A
A 5-cable (5-lead) ECG monitoring In the five-electrode (S-cable) monitoring system, the four limb electrodes, LA, RA,
LL, and RL placed at their corresponding monitoring locations allow any of the six bipolar limb leads (I, II, III, aVR, aVL, and a VF) to be obtained, and a fifth chest electrode can be placed in any of the standard
precordial V 1 to V6. locations.
11
Q
Describe the proper placement of RA, LA,
A
Proper placement of the RA electrode is over the outer right clavicle and of the LA electrode is over the outer left clavicle..
12
Q
The LL electrode is placed near the
A
left iliac crest or midway between the costal margin and left iliac crest along the anterior axillary line.
13
Q
The RL electrode may be placed at any
A
convenient location on the body
14
Q
Which unipolar lead in the S-lea monitoring system is preferred when arrhythmias are anticipated?
A
In the 5-lead system, VI is preferred for special arrhythmia monitoring
15
Q
Which unipolar leads are preferred for monitoring ischemia?
A
V3 to V5 are the preferred leads for monitoring ischemia
16
Q
List six indications for using a central venous catheter?
A
- to measure central venous venous pressure
- for rapid infusion of fluids,
(3) for transvenous pacemaker insertion
(4) for parenteral alimentation
(5) for chemotherapy, (
6) to remove air if there is a high risk for venous air embolism
17
Q
What jugular vein, right or left, is most often preferred for cannulation for CVP? why?
A
The right internal jugular is preferred because of its straight course to the SVC.
18
Q
Where is the thoracic duct?
A
Left IJ
19
Q
3 risk for LJ vein for CVC
A
- Vascular erosion
- Pleural effusions
- PUNCTURE OF THORACIC DUCT
20
Q
Where should the tip of the CVC be located?
A
Just above the junction of the Superior vena cava and the Right atrium
21
Q
When the central venous pressure (CVP)line is inserted via the right internal jugular, the tip of the catheter on x-ray will be seen at the level of what thoracic vertebra?
A
Radiography will show the catheter tip positioned below the inferior border of the clavicles and above the T4 to T5 interspace.
22
Q
Why should the zero point of the manometer or transducer be positioned exactly for measurement of central venous pressure?
A
So low venous pressures are to be measured accurately and reproducibly.
23
Q
The a wave is the result of
A
right atrial contraction
24
Q
The c wave is caused by a
A
slight elevation of the tricuspid valve into the right atrium during ventricular contraction
25
The v wave is due to
blood flow into the right atrium before the tricuspid valve opens.
26
Think about a central venous pressure (CVP} waveform: What do x-descent and y-descent indicate?
x-descent occur during ventricular systole and represents atrial relaxation with downward displacement of the tricuspid valve.
27
Think about a central venous pressure (CVP} waveform: What do y-descent indicate?
The y-descent occurs during diastole and represent early ventricular filling through the open tricuspid valve.
28
What is the normal CVP reading
0-11 mmHg
29
What are four early signs of increased central venous pressure?
(l) distended peripheral veins,
(2) increased right heart filling pressures
(3) increased heart rate
(4) bounding peripheral pulses
30
What are three late signs of increased central venous
pressure?
(1) systemic edema,
(2) S-3 gallop
(3} decreased pulmonary compliance.
31
What three pathological conditions may cause an elevated central venous pressure (CVP) to occur?
Pulmonary hypertension, right heart failure, or left heart failure.
32
What two situations would cause the CVP reading be higher than the PCWP?
presence of: (l) right ventricular failure, possibly secondary to pulmonary hypertension, or (2) pulmonary embolus
33
What is the most common complication of central venous cannulation?
Infection.
34
What is the incidence of pneumothorax during subclavian vein cannulation?
1%.
35
What confirms entry of the catheter into the internal jugular vein?
Return of desaturated venous blood
36
What five sites are acceptable for inserting a pulmonary catheter?
( l) right internal jugular; (2) external jugular;
(3) subclavian; (4) antecubital- preferably basilic, and (5) femoral veins.
37
What site should not be used for insertion of a pulmonary artery catheter?
Left internal jugular
38
With right internal jugular insertion of a pulmonary artery (Swan-Ganz} catheter, what is the distance to the right atrium and pressure transduced there?
right ventricle, pulmonary artery, and
the wedge position? What pressures will
you normally see when the tip of the
catheter is at each of these locations?
Right atrium: 18-22 cm and 6-8 mm-Hg;
39
With right internal jugular insertion of a pulmonary artery (Swan-Ganz} catheter, what is the distance to the right Ventricle and pressure transduced there?
right ventricle: 28- 32 cm and 25/0 mm-Hg;
40
With right internal jugular insertion of a pulmonary artery (Swan-Ganz} catheter, what is the distance to the pulmonary artery and pressure transduced there?
pulmonary artery: 40- 50 cm and 25/12 mm-Hg;
41
With right internal jugular insertion of a pulmonary artery (Swan-Ganz} catheter, what is the distance to the pulmonary WEDGE and pressure transduced there?
pulmonary wedge: 45- 50 cm and 2-12 mm-Hg
42
Specify six indications for a pulmonary artery catheter.
(1) patients with known cardiovascular disease;
(2) cross clamping of the thoracic aorta is anticipated;
(3)respiratory failure;
(4)suspected or diagnosed pulmonary emboli
(5) pts w/previous cardiac surgery
6) when pneumonectomy
43
You listed six indications for a pulmonary artery catheter previously. State six more indications.
Sepsis
Significant fluid shifts
pulmonary HTN, or PVR
Cor pulmonale
Treated with bleomycin
Continuous inotropes and vasodilators.
44
Give three (3) contraindications to use of a pulmonary artery catheter.
Relative contraindications
( l) complete left bundle branch block,
2) Wolff-Parkinson-White syndrome
(3) Ebstein's malformation
45
What ejection fraction and cardiac index are suggestive of poor left ventricular function and hence an indication for a
pulmonary artery catheter?
Ejection fraction <0.4; cardiac index <2. l \/min
46
What is the most severe complication of a pulmonary artery catheter?
Pulmonary artery perforation and hemorrhage
47
What three actions should be taken to treat pulmonary artery perforation and hemorrhage?
(l) Replace volume, (
2) use positive end-expiratory pressure, and (
3) isolate involved lung with a double-lumen tube or advance a single lumen tube into the nonhemorrhaging lung
48
What is the most common complication with the insertion of a Swan·Ganz catheter?
Arrhythmias as the catheter goes through the right ventricle
49
What drug is used to treat arrhythmias that occur during the placement of a Swan-Ganz catheter?
Lidocaine.
50
What is the most commonly used size of a swan-Ganz catheter?
7Fr
51
What are two causes of a Swan-Ganz catheter not reaching the pulmonary artery?
1. Perforation
2. Coiling
52
What is the range of normal pulmonary artery systolic/diastolic pressures?
15-30 / 4-12 mmHg
53
Your pulmonary catheter is properly wedged and a large V wave appears. What is the cause?
mitral regurgitation
54
What three measures are taken to increase the accuracy and precision of the cardiac outputs measured by thermodilution?
Triplicate determinations are averaged to increase precision
the variability of cardiac output measurements can be reduced by performing the measurement at end-inspiration or at end-expiration;
(3) ensuring that the rate of injection and volume of injectate are constant.
55
Most cardiac output computers delay the time between each repeat measurement by
60 to 90 seconds
56
What interferes with cardiac output determinations
using the thermodilution method?
Electrocautery interferes with thermodilution measurements.
57
Avoid measurements of cardiac output using the thermodilution method during
electrocautery.
58
Is the area under a thermodilution curve directly related or inversely related to cardiac output?
Cardiac output is inversely proportional to the area under the thermodilution curve.
59
The smaller the area under the curve, the
greater the cardiac output.
60
if the area under a patient's thermodilution curve is getting
smaller, cardiac output is
increasing
61
False high thermodilution cardiac output determinations occur when the injectate volume is
too small.
62
False low determinations occur when injectate volume is
too large.
63
The area under the curve will be larger if a ________so cardiac output will be
greater volume is injected; falsely low.
64
The area under the curve will be smaller if a __________so cardiac output will be
a smaller volume is injected; falsely high
65
Insufficiency of either of what two valve may lead to a falsely high thermodilution cardiac output reading?
Insufficiency (regurgitation} of either the TRICUSPID valve or PULMONIC valve may be associated with falsely high thermodilution cardiac output readings.
66
The patient with tricuspid valve regurgitation
has a thermodilution cardiac output reading of 5 liters per minute. Is this reading accurate, falsely high, or
falsely low?
This reading is falsely high. Tricuspid regurgitation may produce a falsely elevated thermodilution cardiac output.
67
Recall also that insufficiency of the pulmonic valve may produce a
falsely elevated cardiac output
68
If you inject 10 ml of cold normal saline when the cardiac output computer is set for 5 ml, will calculated cardiac output be higher or lower than actual cardiac output?
Calculated cardiac output will be lower than the true cardiac output
69
What is the relationship of the following parameters: preload, LVEDV, PAOP, LVEDP, and LADP?
In the absence of mitral stenosis or pulmonary hypertension, PAOP = LADP = LVEDP = LVEDV = preload
70
Any of the pulmonary artery catheter measurements are equivalent indirect indicators of _______in the absence
of
preload; mitral stenosis or pulmonary hypertension
71
Does pulmonary capillary wedge pressure (PCWP) overestimate, underestimate, or accurately reflect left ventricular end-diastolic pressure (LVEDP) in the patient with mitral valve stenosis?
Since stenosis of the mitral valve impedes the flow of blood into the left ventricle, LVEDP is truly lower than PCWP. Hence, PCWP overestimates LVEDP in the patient with mitral valve stenosis.
72
Left ventricular end-diastolic pressure (LVEDP) is______related to PCWP
directly related to PCWP assuming an open conduit from the catheter tip to the left ventricle.
73
Does pulmonary capillary wedge pressure (PCWP) overestimate, underestimate, or accurately reflect
left ventricular end-diastolic pressure (LVEDP) in the patient with mitral valve insufficiency?
Pulmonary capillary wedge pressure accurately assesses left ventricular end-diastolic pressure in the patient with mitral insufficiency.
74
_______is not a factor that can lead to a false estimate of left ventricular end-diastolic pressure by the pulmonary capillary wedge pressure.
Mitra! insufficiency
75
Identify three situations in which pulmonary capillary wedge pressure (PCWP) will be greater than left ventricular end-diastolic pressure (LVEDP)?
in patients who have
mitral stenosis
elevated alveolar pressure
pulmonary venous obstruction.
76
Pulmonary capillary wedge pressure (PCWP) will be less than left ventricular end-diastolic pressure in patients who
have what valve problem? Explain.
PCWP will underestimate LVEDP in patients with aortic regurgitation.The blood flowing back into the left ventricle from the aorta during diastole closes the mitral valve before systole actually begins. More blood enters
the left ventricle through the aortic valve after the mitral valve closes; hence, the true end-diastolic pressure cannot be detected by the wedged pulmonary artery catheter because the mitral valve is closed.
77
In Aortic Regurgitation, The blood flowing back into the left ventricle from the aorta during diastole •
closes the mitral valve before systole actually begins.
78
Does pulmonary artery diastolic pressure reflect left ventricular end -diastolic pressure (left ventricular preload)?
Yes. Pulmonary artery diastolic pressure is used often as an alternative to pulmonary capillary wedge pressure to estimate left ventricular filling pressure (preload)
79
After administration of a 200 ml intravenous (IV) bolus of crystalloid solution, pulmonary artery systolic/diastolic
pressures increase from 22/6 mm Hg to 40/25 mm Hg. ls this a normal o abnormal response?
The increase in pulmonary artery pressures to 40/25
mm Hg after infusion of a 200 ml bolus of fluid is abnormal.pulmonary artery pressures of 40/25 mm Hg are clearly elevated abnormally.
80
While a small increase in pulmonary artery pressure is expected with increased volume why?
(Starling's law: increased right ventricular preload >increased right ventricular output·> increased pulmonary artery pressure),
81
After administration of a 200 ml intravenous (IV) bolus of crystalloid solution, pulmonary artery systolic/diastolic
pressures increase from 22/6 mm Hg to 40/25 mm Hg. What is the most likely reason for this change in pulmonary blood pressures in response to this IV volume?
The most likely explanation for the large increase in pulmonary artery diastolic pressure is a decrease in left ventricular compliance (diastolic dysfunction).
82
With decreased left ventricular compliance,
a small increase in left ventricular volume will produce a
large increase in left ventricular end-diastolic pressure (LVEDP}. The increased LVEDP is reflected by the increase in pulmonary artery pressure.
83
After administration of a 200 ml intravenous (IV) bolus of crystalloidsolution, pulmonary artery systolic/ diastolic pressures increase from 22/6 mm Hg to 40/25 mm Hg. A decrease in left ventricular compliance is the most
likely explanation for this observation. What is another possible reason for this change in pulmonary blood pressures in response to this IV volume?
Systolic dysfunction (decreased myocardial contractility; heart failure) is the second explanation.
84
With systolic dysfunction, left ventricular preload
is markedly____why?
elevated because of the decrease in stroke volume (remember: if the left ventricle does not pump blood forward, it remains behind)
85
With systolic dysfunction and elevated LV preload you would see what changes in the BP
Systolic Hypotension
86
A large increase in pressure for a small change in
volume suggests a
decrease in left ventricular compliance
87
Increase in pulmonary artery pressure following a small bolus due to 5 possible causes
1. Increased LV compliance
2. Decreased LV compliance
3. Normal response to an increase preload
4. Systolic dysfunction
5. Indeterminable/
88
Where could a central venous or pulmonary artery catheter be inserted in the patient with superior vena cava
syndrome?
femoral vein
89
______that is due to superior vena cava syndrome often times necessitates venous access through the lower extremity.
Edema
90
What three (3) valuable cardiovascular parameters are obtained from an arterial line?
l) left ventricular volume, (2) left ventricular function, and (3) systemic vascular resistance.
91
How will an arterial line tracing change if air gets into the line?
pattern is dampened.
92
Where is the proper placement of the pressure transducer in a sitting position?
At the base of the ear
93
In intra-arterial waveform monitoring, what is the dicrotic notch due to?
Closure of the aortic valve
94
What condition or situations result in an abnormal arterial waveform with a false elevation of systolic pressure
A decreased arterial compliance or a decreased transducer system frequency (ringing or overshoot) produce distortion of the arterial waveform. Results in overestimation of systolic blood pressure
95
What factors may cause damping of the arterial pressure transducer system?
The presence of air bubbles in the tubing, thrombus formation in the catheter, or inadvertent kinking of the catheter may overly damp the system.
96
Damping refers to
how quickly a system comes to rest after being set in
motion.
97
What effect does system damping have on arterial blood pressure readings?
Losses of the dicrotic notch and fine details in the waveform indicate an overly damped system.
98
Overdamping results in what in terms of SBP and DBP and MAP?
underestimation of systolic blood pressure overestimation of diastolic pressure; MAP remains fairly accurate.
99
Your patient requires arterial cannulation: list 6 arterial cannulation sites, in order of preference.
( l) radial artery,
(2) ulnar artery,
(3) brachial artery,
4) axillary artery,
(5) femoral artery
(6) dorsalis pedis artery
100
The most commonly selected site for arterial cannulation;
Radial artery
101
More difficult to cannulate owing to its deeper and more tortuous course;
Ulnar artery
102
Is the primary arterial supply of hand blood flow.
the ulnar artery
103
Large and easily identifiable in the antecubital fossa; insertion site is medial to biceps tendon;
Brachial Artery
104
Insertion site is medial to biceps tendon;
Brachial Artery
105
Artery cannulation , Median nerve damage is possible.
Brachial Artery
106
Artery Cannulation where the insertion site is at the junction of the pectoral and deltoid muscles - special kits are now available
Axillary Artery
107
Nerve damage can result from hematoma or traumatic cannulation.
Axillary
108
Provides easy access in low flow state; is and there is potential for retro· peritoneal hemorrhage
the femoral artery
109
Artery prone to pseudoaneurysm and formation of atheroma,
The Femoral artery
110
Artery with potential for retro-peritoneal hemorrhage
The Femoral artery .
111
Artery the farthest distance from the aorta,,
Dorsalis Pedis Artery
112
Arterial waveforms are most distorted with this artery cannulation.
Dorsalis Pedis Artery
113
Leading to higher systolic pressure estimate because farthest away from the aorta.
Dorsalis Pedis Artery
114
What are 3 factors that can cause an arterial line to develop thrombosis (catheter related) ?
Duration of catheterization
Catheter size 18 vs 20
Catheter material
115
Teflon vs polypropylene which causes less radial artery thrombosis
Telfon
116
What are 3 OTHER factors that can cause an arterial line to develop thrombosis ? 3Ps
Proximal emboli
Prolonged shock
Pre-existing vascular disease.
117
Inaccuracy of blood pressure measurements by sphygmomanometry is most often due to what?
Improper cuff size
118
What is the recommended bladder width in cuff used for indirect blood pressure monitoring?
40% of the circumference of the extremity
119
A bladder width of 40% of the circumference corresponds to approximately
120% to 150% of the diameter of the extremity
120
What is the recommended bladder length in the cuff used for indirect blood pressure monitoring? Is this controversial?
at least 80% of the extremity
121
Bladder length controversial (Dorsch)
According to Dorsch, the length of the cuff has little effect on the accuracy of the indirect blood pressure measurement, as long as the bladder in the cuff encircles at least 40% to 50% of the extremity's circumference.
122
What is the recommended bladder length in the cuff used for indirect blood pressure monitoring on the arm of the
obese patient?
at least 75% of the arm circumference- ideally the entire arm circumference-should be used on the arm of the obese patient
123
A standard cuff is used to take blood pressure measurement from an obese patient's forearm; will the readings accurately reflect actual blood pressure?
No, forearm blood pressure measurements with a standard cuff overestimate both systolic and diastolic pressures in the obese patient.
124
Is the blood pressure reading erroneously high or erroneously low when the cuff is too narrow or wrapped loosely?
The blood pressure reading is erroneously high when the cuff is too narrow or is wrapped loosely.
125
As a properly·sized noninvasive blood pressure cuff is moved more distally along an extremity, for example from the arm to the forearm, how do measured systolic and diastolic pressures change
pressure cuff is moved more distally (peripherally) along an extremity, the systolic pressure tends to increase whereas the diastolic pressure tends to decrease
126
A patient has an arterial line in the right arm and a blood pressure cuff on the left arm; the left arm is 20 cm higher than the right arm. If the blood pressure from the arterial line is 120/80, what is the pressure from the cuff on the left arm? (Assume the a·line has been properly
calibrated to the phlebostatic axis.)
The blood pressure from the cuff on the left arm is 105/65. For each 10 cm of vertical height above or below the level of the heart, 7.5 mm-Hg should be subtracted from or added to, respectively, the blood pressure
readings
127
For every inch, above or below the heart,
subtract or add 1.80 mm-Hg
128
The phlebostatic axis approximates the position of the
for the right lateral decubitus
position, at fourth intercostal space midsternum; for the left lateral
decubitus position, at fourth intercostal space at the left parasternal border.
right atrium.
129
In the supine position, where is the phlebostatic axis?
the phlebostatic axis is the fourth intercostal space,
midanteroposterior level (not midaxillary line);
