Test 2 Flashcards
(458 cards)
1
Q
The heart is a ______________-chambered muscular organ approximately the size of a fist.
A
Four
2
Q
Where is the heart positioned?
A
Mid-mediastinum of the chest, behind the sternum.
3
Q
Approximately ⅔ of the heart lies to the left of the midline of the sternum between which two ribs?
A
2nd and 6th ribs
4
Q
The apex of the heart is formed by the tip of the left ventricle and lies above the diaphragm at the level of the ____________________.
A
5th intercostal space to the left.
5
Q
The base of the heart is formed by the_________________.
A
Atria and projects to the right, lying below the 2nd rib.
6
Q
Posteriorly, where does the heart rest?
A
Level of the 5th to the 8th thoracic vertebrae.
7
Q
Externally, surface grooves called _________________ mark the boundaries of the heart chambers.
A
Sulci
8
Q
The heart is enclosed in a sac called the _________________.
A
Pericardium
9
Q
A thin layer of fluid called the _____________________ separates the two layers of the serous pericardium.
A
Pericardial fluid
10
Q
Tough, loose-fitting outer layer and inelastic sac surrounding the heart.
A
Fibrous pericardium
11
Q
Serous pericardium consists of what two layers?
A
- Visceral layer
- Parietal layer
12
Q
Which layer of serous pericardium is the inner lining of the fibrous pericardium?
A
Parietal layer
13
Q
Which layer of the pericardium covers the outer surface of the heart and great vessels?
A
Visceral layer
14
Q
Inflammation of the pericardium.
A
Pericarditis
15
Q
An abnormal amount of fluid can accumulate between the layers of the pericardium resulting in a ________________________.
A
Pericardial effusion
16
Q
What is a cardiac tamponade?
A
When excess pericardial fluid compresses the heart muscle, leading to a serious decrease in blood flow to the body. This, ultimately, may lead to shock and death.
17
Q
Cardiac tamponade ultimately may lead to _____________________.
A
- Shock
- Death
18
Q
The heart wall consist of three layers. What are they?
A
- Outer epicardium
- Middle myocardium
- Inner endocardium
19
Q
A cardiac tamponade should be suspected in patients presenting with: (8)
A
Beck’s Triad
- Muffled heart sounds
- Hypotension
- Jugular venous distention
- Pulsus paradoxus
- Tachycardia
- Tachypnea
- Narrowing pulse pressure
- Severe dyspnea
20
Q
Which layer of the heart composes the bulk of the heart muscle?
A
Myocardium
21
Q
The heart consists of how many valves and chambers?
A
8!!!
22
Q
Each AV ring is composed of dense connective tissue termed annulus fibrosus cordis which encircles the bases of the pulmonary trunk, aorta, and heart valves and electrically isolates the aorta from ______________.
A
The ventricles
23
Q
____________ are two thin-walled “cups” of myocardial tissue that contribute little to the total pumping activity of the heart.
A
Atrial chambers
24
Q
The vascular system has two major subdivisions: What are they?
A
- Systemic circulation
- Pulmonary circulation
25
What’s the other name for **epicardium?**
Visceral layer
26
What does CPR mimic?
Cardiac output
27
Which type of pericardium consists of two layers?
Serous pericardium
28
Can electrical impulses be transmitted through the heart muscle and connective tissue from the atria to the ventricles?
No.
29
What is regurgitation?
Back flow of blood through a malfunctioning leaky valve.
30
The two atrial chambers are separated by ________________________.
An interatrial wall or septum.
31
On the **right side** of the interatrial septum is an oval depression called the ______________.
Fossa ovalis cordis
32
Two lower chambers of the heart make up the bulk of the heart's muscle mass and does most of the pumping that circulates the blood.
Ventricles
33
The right and left ventricles are separated by a muscle wall called _________________________.
Interventricular septum
34
The AV valves close during systole, what does this prevent?
Back flow of blood into the atria.
35
The free ends of the AV valves are anchored to papillary muscles of the endocardium by the _____________________.
Chordae tendineae cordis
36
During systole, _________________ prevents the AV valves from swinging upward into the atria.
Papillary muscle
37
Damage to the either the chordae tendineae cordis or the papillary muscles can impair the function of the __________.
AV valves and cause leakage upward into the atria.
38
What is stenosis?
Pathologic narrowing or constriction of a valve outlet.
39
What happens with mitral stenosis?
High pressure in the left atrium back up into the pulmonary circulation. Those high pressures can cause:
**-Pulmonary edema**
**-Diastolic murmur**
40
_________________ prevent backflow of blood into the ventricles during **systole**
Semilunar valves
41
Two main coronary arteries, one in the right and one in the left, arise from the ___________________________.
Root of the aorta right underneath the semilunar valves.
42
When does blood flow through the coronary arteries?
Only during diastole when the semilunar valves are closed.
43
Partial obstruction of a coronary artery can lead to _______________________.
Tissue ischemia (decreased oxygen supply)
44
Complete obstruction of a coronary artery may cause _______________________.
- Tissue death
- Myocardial infarction
45
________________________ is the name given to three types of CAD.
Acute Coronary Syndrome
46
What are the 3 names of the acute artery disease types?
- Unstable angina or angina pectoris
- Non-ST segment elevation myocardial infarction (NSTEMI)
- ST segment elevation myocardial infarction (STEMI)
47
What condition remains responsible for approximately one-third of all deaths in people over age 35?
Heart disease
48
What are classic signs of tissue ischemia?
- Chest pain
- SOB
**Resulting in a clinical condition called _angina pectoris._**
49
What are classic signs of an MI? (5)
- Pain or tightness in the chest, back, arms, neck.
- Fatigue
- Lightheadedness
- Abnormal heart beat
- Anxiety
50
Nearly how many middle aged men and women in the USA will develop a CHD?
Men: 1/2
Women: 1/3
51
Coronary veins gather together into large vessel called the ___________________.
Coronary sinus
52
The coronary sinus empties into the ___________________.
Right atrium
53
Where does the thebesian veins empty?
Into all of the heart chambers.
54
Any deoxygenated blood coming from the thebesian veins that enters the left atrium or ventricle lowers the overall oxygen content of the _______________.
Systemic circulation
55
Because the thebesian veins bypass or shunt around the pulmonary circulation as part of the normal anatomy, this phenomenon is called an ______________.
Anatomic shunt
56
Normal anatomic shunts account for approximately ______% of total cardiac output.
2-3%
57
The performance of the heart as a pump depends on its ability to:
- Initiate and conduct electrical impulses
- Synchronously contract the heart's muscle quickly and efficiently
58
The ability of cells to respond to electrical, chemical or mechanical stimulation.
Excitability
59
What can increase myocardial excitability? (3)
- Electrolyte imbalances
- Congenital cardiac anomalies
- Certain drugs
**Can lead to cardiac arrhythmias**
60
The unique ability of the cardiac muscle to initiate a spontaneous electrical impulse (depolarization and repolarization).
Inherent rhythmicity or automaticity
61
What are the heart's primary pacemakers?
**- SA node**
- AV node
62
An electrical impulse from any source other than a normal heart pacemaker is considered what?
Abnormal or ectopic heartbeat
63
The ability of the myocardial tissue to spread and conduct electrical impulses.
Conductivity
64
Abnormal conductivity can affect ______________________.
Timing of the chamber contractions and decrease cardiac efficiency.
65
_________________, in response to an electrical impulse, is the primary function of the myocardium.
Contractility
66
The period during which the myocardium cannot be stimulated is called ____________________.
The refractory period.
It lasts approximately 250 ms, nearly as long as the heart contraction or systole.
67
Individual cardiac fibers are enclosed in a membrane called the _________________.
Sarcolemma
68
Cardiac fibers are separated by irregular transverse thickenings of the sarcolemma called ___________________.
Intercalated discs
69
Explain Starling's law of the heart, also known as Frank-Starling law.
The more a cardiac fiber is stretched, the greater the tension it generates when contracted.
70
Where does the systemic circulation begin and end?
**Begins:** Aorta on the left ventricle
**Ends:** Right atrium
71
Where does the pulmonary circulation begin and end?
**Begins:** Pulmonary artery out of the right ventricle
**Ends:** Left atrium
72
Venous or deoxygenated blood from the head and upper extremities enters the right atrium from the _______.
SVC
73
Venous blood from the abdomen and lower body enters from the ______.
IVC
74
_____________________ are the only arteries in the blood that carry deoxygenated or venous blood.
Pulmonary arteries
75
The systemic circulation has three major components. What are they?
- Arterial sytem
- Venous system
- Capillary system
76
This system consists of large, highly elastic, low-resistance arteries and small, muscular arterioles or vary resistance.
Arterial system
77
What is referred as conductance vessels?
Large arteries
78
What is referred as resistance vessels?
Small arterioles
79
What plays a major role in the distribution and regulation of blood pressure?
Arterioles
80
________ controls blood flow into the capillaries.
Arterioles
81
_________________ are commonly referred as exchange vessels.
Capillaries
82
This system maintains a constant exchange of nutrients and waste products for cells and tissues of the body.
Capillary system
83
Cardiac Output equation
CO= HR x SV
84
P wave represents ___________________.
Atrial depolarization
85
T wave represents ___________.
Ventricular repolarization
86
The left atrium pumps blood into the left ventricle and the blood is then pumped to the body through the _____.
AORTA!
87
Blood flows into the network by an _________ and out through a ________. Direct communication between these vessels is called _______.
Blood flows into the network by an **arteriole** and out through a **venule.**
Direct communication between these vessels is called **arteriovenous anastomosis.**
88
Capillaries have smooth muscle rings at their proximal ends called ____.
Precapillary sphincters
89
What happens when precapillary sphincters contract and relax?
- Contraction: decreases blood flow locally
- Relaxation: Increases local perfusion
90
_________ and ___________ allow precise control over the direction and amount of blood flow to a given organ or area of tissue.
Sphincters and bypasses
91
This system consist of small, expandable venules and veins and larger, more elastic veins.
Venous system
92
At any given time, the veins and venules hold approximately __________ of the body's total blood volume.
2/3
93
The components of the venous system, especially the small, expandable venules and veins are termed _____.
Capacitance vessels
94
What must the venous system overcome to return blood to the heart?
Gravity
95
What four mechanisms aid the venous return to the heart?
1. Sympathetic venous tone
2. Skeletal muscle pumping or "milking"
3. Cardiac suction
_4. Thoracic pressure differences caused by respiratory efforts; often called the thoracic pump_
96
Why is thoracic pressure differences caused by respiratory efforts; often called the thoracic pump so important to RTs?
Artificial ventilation with positive pressure reverses normal thoracic pressure gradients.
97
Does PPV assists with venous return?
No, it impedes it.
98
What type of patients are vulnerable to a reduction in CO when PPV is applied to the lungs?
Hypovalemic or in cardiac failure
99
The right side of the heart generates a systolic pressure of ___________ to drive blood through the **low-resistance, low-pressure pulmonary circulation.**
25 mm Hg
100
The left side of the heart generates systolic pressures of _________ to propel blood through the **high pressure, high-resistance systemic circulation.**
120 mm Hg
101
Blood flow through the vascular system is opposed by what?
Frictional forces
102
The sum of all frictional forces opposing blood flow through the systemic circulation is called ___________.
SVR - Systemic Vascular Resistance
103
The beginning pressure of the systemic circulation is the ________.
Mean Aortic Pressure
104
The ending pressure of the systemic circulation is the ________.
Right atrial pressure or CVP
105
Resistance to blood flow in the pulmonary circulation is approximately _______ of that of the systemic circulation.
One-tenth
106
Is pulmonary circulation characterized as a low-pressure, low resistance or high-pressure, high resistance system?
Low-pressure, low resistance system
107
Is systemic circulation characterized as a low-pressure, low resistance or high-pressure, high resistance system?
High-pressure, high resistance system
108
What is the priority of the cardiovascular system?
Maintain perfusion pressures to tissues and organs at functional levels, even under changing conditions.
109
MAP is directly related to the ______________ and inversely related to _______________.
MAP is directly related to the volume of blood in the vascular system and inversely related to its capacity.
**MAP = Volume/Capacity**
110
**MAP (Mean Arterial Pressure) Equation**
MAP = CO x SVR
111
In a normal adult, MAP ranges from ____.
80-100 mm Hg
112
MAP is regulated by changing what?
Either changing the volume of circulating blood, the capacity of the vascular system or **both**
113
Does **vasoconstriction** cause BP to increase or decrease?
Increase
114
Does **vasodilation** cause BP to increase or decrease?
Decrease
115
Vascular space decreases when ____ occurs.
Vasoconstriction
116
Vascular space increases when ____ occurs.
Vasodilation
117
Define vasoconstriction.
Constriction of the smooth muscles in the peripheral blood vessels.
118
Define vasodilation.
Constriction of the smooth muscles in the arterioles.
119
What happens when MAP decreases below **60 mm Hg?**
Perfusion to the brain and kidney are severely compromised and organ failure may occur in minutes.
120
The MAP is one of the first variables that is monitored in __________.
Septic patients
121
Define prolonged hypotension.
MAP of less than 60-65 mm Hg.
122
What is the cardiovascular system responsible for?
Transporting metabolites to and from the tissues under various conditions and demands.
123
Stroke Volume Equation.
SV = EDV-ESV
124
EDV ranges for normal persons.
110-120 mL
125
What is ECGs primarily used for?
To help evaluate a patient with signs/symptoms of cardiac disease.
126
What are some reasons why the Dr. would order an ECG? (6)
Patients complaining of:
- Chest pain
- SOB
- Dyspnea with palpations
- Weakness
- Lethargy
- Syncope
127
**What is this called?**
Stimulation of the polarized cells cause an influx of Na+ into the interior portion of the cell.
Depolarization
128
Depolarization causes the cardiac muscle cells to _____.
Contract
129
Which part of the body is most sensitive to changes in the local metabolite levels?
Brain
130
The total amount of blood pumped by the heart per minute.
Cardiac output
131
SV is affected primarily by intrinsic control of what three factors?
1. Preload
2. Afterload
3. Contractility
132
The heart **does not** eject all of the blood it contains during systole. Instead, a volume called the ____, remains inside the **ventricles.**
End-systolic volume
133
**EF equation**
EF = SV/EDV x 100
134
An increase in SV occurs when either...
- EDV increases
- ESV decreases
135
A decrease in SV occurs when either...
- EDV decreases
- ESV increases
136
_______ in preload (EDV) and _____ in ESV result in increased SV in the healthy heart.
**Increases** in preload (EDV) and **decreases** in ESV result in increased SV in the healthy heart.
137
____ in afterload can decrease SV, especially in the failing heart by increasing the ESV.
**Increases** in afterload can decrease SV, especially in the failing heart by increasing the ESV.
138
Drugs that increase contractility of the heart muscle are called __.
Positive inotropes
139
Drugs that decrease contractility of the heart muscle are called __.
Negative inotropes
140
___ and ____ impair myocardial function and decrease cardiac contractility and CO.
- Profound hypoxia
- Acidosis
141
The impulse-conducting system cells have the ability to stimulate the heart without ______.
Influence of the nervous system
142
A rapid return of the cell to the "polarized" position.
Repolarization
143
The impulse-conducting system has three type of cardiac cells capable of electrical excitation:
- Pacemaker cells (SA and AV node)
- Specialized rapidly conducting tissues (Purkinje fibers)
- Atrial and ventricular muscle cells
144
The ability of cardiac cells to depolarize without stimulation.
Automaticity
145
The impulse-conducting system is responsible for what?
Initiating the heartbeat and controlling the heart rate. Also coordinates the contraction of the heart chambers.
146
Where is the SA node located?
In the upper portion of the right atrium.
147
______ has the greatest degree of automaticity and paces the heart.
SA node
148
A defect in the impulse-conducting system may lead to:
- Inadequate CO
- Decreased tissue perfusion
149
Define ectopic beat.
Any heartbeat originating outside of the SA node.
150
The SA node is innervated by the ___.
Autonomic nervous system
- Sympathetic and parasympathetic nervous system influence HR.
151
The electrical impulse generated by the SA node travels across the right atrium through intraatrial pathways, to left atrium by the way of ___.
Bachmann bundle
152
____ is the backup pacemaker of the heart.
AV node
153
AV node paces ventricular activity at what rate?
40-60 beats/min
154
Where is the AV node located?
Intraventricular septum
155
Why is the eletrical impulse temporarily delayed at the **AV node?**
To allow the ventricles time to fill with blood.
156
Normally the QRS complex is shorter than _____.
0.12 second
157
In the first degree heart block, the PR interval is longer than _____.
0.12 second
158
Type II heart block is seen as a series of _________.
Nonconducted P waves followed by a P wave that is conducted to the ventricles.
159
Treatment is usually **not** needed for first-degree heart block if the patient is able to ____.
Maintain adequate BP
160
Ventricular tachycardia is a run of _________________.
3 or more PVCs.
161
When atrial muscles quivers in an irregular pattern that does not result in a coordinated contraction.
Atrial fibrillation
162
Where is V1 placed?
4th intercostal space to the right of the sternum.
163
Where is V6 placed?
5th intercostal space at the midaxillary line
164
The wave of depolarization in the atria is seen as the _____ on an ECG.
P wave
165
What's the size of the P wave?
- 2.5 mm high
- 3 mm long
166
What may cause the P wave to enlarge to a larger height and length?
Atrial hypertrophy
167
Why is atrial repolarization not seen on an ECG?
It's obscured by the electrical activity occurring in the ventricles at the same time.
168
Ventricular depolarization is seen as the ____ on an ECG.
QRS complex
169
Why is the QRS complex much larger than the P wave?
Muscle mass of the ventricles is greater than the atria.
170
**QRS complex**
The first wave of the complex is negative (downward), it's labeled the _____.
Q wave
171
**QRS complex**
The initial positive (upward) deflection is referred as the ____.
R wave
172
**QRS complex**
The next negative deflection after the R wave is labeled the ___.
S wave
173
What wave represents ventricular repolarization?
T wave
174
Typical PR interval is ________ long.
0.12 to 0.20 seconds
175
_____ refers to the distance (time) between the start of atrial depolarization and the start of ventricular depolarization.
PR interval
176
What does a PR interval longer than 0.20 seconds represents?
The impulse is abnormally delayed at the AV node and a “block” is present.
177
_____ represents the times from the end of ventricular depolarization to the start of ventricular repolarization.
ST segment
178
Cells that conduct the electrical impulse throughout the heart.
Conducting cells
179
Cells that contract in response to electrical stimuli and pump blood
Myocardial cells
180
Specialized cells that have a high degree of automaticity and provide electrical power for the heart
Pacemaker cells
181
What does an inverted T wave suggest?
Ischemia of the heart muscle
182
Abnormal configuration of the T wave occurs with _____.
Electrolyte abnormalities such as hyperkalemia (where the T wave take a “peaked” or sharper than normal appearance)
183
What is the most life-threatening arrhythmia?
Ventricular fibrillation
184
Treatment for V-fib (4)
- Rapid defibrillation
- CPR
- Administration of O2 and anti antiarrhythmic medications
**Immediate reversal of underlying cause**
185
Erratic quivering of the ventricular muscle mass that cause CO to drop to **zero**
Ventricular fibrillation
186
Glossy irregular fluctuations with a zigzag pattern describes what ECG pattern?
Ventricular fibrillation
187
Serious condition that is characterized by a disassociation between the electrical and mechanical activity of the heart.
Pulseless Electrical Activity
188
What is one of the hallmarks of VT in general?
Third-degree AV block because ventricles are beating independently of the atria
189
VT is considered “sustained” if it lasts longer than _____.
30 seconds
190
What are some conditions that can produce atrial flutter? (6)
- Rheumatic heart disease
- Coronary heart disease
- Pulmonary embolism
- Stress
- Renal failure
- Hypoxemia
191
_____ is an ECG characterized by a saw-tooth baseline pattern.
Atrial flutter
192
The standard ECG is calibrated so that ______ causes an upward deflection of 10 small boxes or 2 large large boxes on the vertical axis.
1 mV
193
What is the size of the large ECG boxes?
5x5 mm
193
What is the size of the small ECG boxes?
1x1 mm
194
Each large box represents ____ second.
0.20 second
195
Each small box represents ____ second.
0.04 second
196
A negative QRS complex in lead I is consistent with right-axis deviation, which is often caused by ____.
Cor pulmonale
197
The six chest or precordial leads are called ______.
- V1
- V2
- V3
- V4
- V5
- V6
198
What represents the time in which the impulse begins in the SA node and travels across the atria to the AV node, where it is briefly held before passing on to the ventricles?
PR interval
199
_______ is isoelectric and seen as a **flat line** that is not above or below the neutral baseline.
ST segment
200
An elevated or depressed ST segment is common with _____.
- Cardiac ischemia
- MI
201
Speficially, a **depressed** ST segment is a common finding with _______.
Cardiac ischemia such as occurs in angina
202
Speficially, a **elevated** ST segment is a common finding with _______.
Certain types of MIs
203
The PR is normal if its not longer than how many boxes?
1 large box (0.2 seconds)
204
How to measure PR interval.
Start of P wave and start of QRS complex.
205
The ST segment should be flat and at least no more than ________ above or below the baseline.
1 mm
206
_________ is identified to asses the regularity of the rhythm.
R-R rhythm
207
If the variation between the R-R intervals exceeds **0.12 second** , abnormal conduction called a "__________________" exists.
Bundle branch block.
208
Treatment for sinus tachyacardia.
Eliminate the underlying cause, such as pain relievers, fever reducers, fluids or oxygen
209
Some causes of sinus tach.
- Anxiety
- Pain
- Fever
- Hypovolemia
- Hypoxemia
210
Sinus brady is most often caused by: (3)
-Hypothermia
- Abnormalities in SA node
- Intense athletic conditioning
211
Medication to treat sinus brady:
Atropine
212
Sinus arrhythmia is common and recognized by the _____.
Irregular spacing between QRS complexes
213
**Treatment:**
Most sinus arrhythmias are ____.
Benign and don't need treatment.
214
First degree heart block is common after an _____ .
MI that damages AV node or may be a complication of certain medications like digoxin and beta blockers.
215
First degree heart block indicates _____.
The impulse from the SA node is getting through the ventricles but is delayed in passing through the AV node of bundle of His.
216
Other names for **Type 1** Second-Degree Heart Block
- Wenckebach
- Morbitz type I
217
Treatment for type I second-degree heart block
Not needed bc it usually doesn't impair CO or cause symptoms
218
Treatment for type II second-degree heart block
Atropine until pacemaker can be inserted
219
_________ heart block is the most serious of the different types of heart blocks.
Third-degree
220
Third-degree heart block indicates _________.
The conduction system between the atria and ventricles are completed blocked and impulse conducted in the SA node are not conducted to the ventricles.
221
No relationship between the P wave and QRS complex.
P-P intervals an R-R intervals are regular but they have no correlation with one another.
Third-degree heart block
222
Third-degree heart block is often caused by
MI or drug toxicity
223
Treatment for Third-degree heart block. (3)
Addressing the underlying cause (MI) and medication to speed up the ventricles and temporary external pacemaker until a permanent one can be placed.
224
Limb leads are called ___ .
- I
- II
- III
- aVr
- aVL
- aVf
225
**Third-degree heart block**
The QRS complexes are normal in configuration if the ventricles are paced by the AV node. What happens if they are paced by an abnormal site in the myocardium?
QRS complex may be abnormally wide, consistent with a bundle branch block
226
Atrial flutter is the rapid depolarization of the atria resulting from an ectopic focus that depolarizes at a rate of _________.
250-350 bpm
227
What is the HR for ventricular tachycardia?
100-250 bpm
228
Name a medication that may cause sinus arrhythmia
Digoxin
229
Mobitz type II heart block requires treatment in most cases because the reduction in ventricular rate causes ____.
Decrease in blood pressure
230
What medication may help with a Mobitz type II heart block?
Atropine
231
With third-degree heart block, most commonly, the atria are paced by the SA and the ventricles are paced by the _____.
AV node
232
What are the causes of pulseless electrical activity?
**7 H's**
- Hypovalemia
- Hypoxia
- Hyperkalemia
- Hypokalemia
- Hypothermia
- Hypoglycemia
- Hydrogen ion (acidosis)
**6 Ts**
- Trauma (most common)
- Tension pneumothorax
- Toxins
- Tamponade (cardiac)
- Thrombosis (coronary)
- Thrombosis (pulmonary)
233
What is the drug of choice for sinus bradycardia?
Atropine
234
What is the drug of choice to correct PVCs?
Lidocaine
235
Systemic venous blood returns to the right atrium via __________.
SVC/IVC
236
**Blood flow through the Heart**
- SVC/IVC
- Right atrium
- Tricuspid valve
- Right ventricle
- Pulmonary semilunar valve
- Pulmonary arteries
- Lungs
- Pulmonary veins
- Left atrium
- Biscuspid/Mitral valve
- Left ventricle
- Aortic valve
- Aorta
- Body
237
Going from left to right, the ___ wave begins the ECG.
P wave (atrial depolarization)
238
Blood flows through the coronary arteries only during ______.
Diastole when the semilunar valves are closed.
239
The pressure gradient between the left and right side of the heart helps ___.
The suction effect in returning venous blood to the right side of the heart.
240
The beginning pressure of the pulmonary circulation is the ________.
Mean PA pressure
241
The ending pressure of the pulmonary circulation is the ________.
Left Atrial Pressure
242
The results of SEPSISPAM study suggest that a MAP target of ________ is usually sufficient in patients with septic shock, but a higher MAP, around _______ may be preferable in patients with chronic arterial hypertension.
The results of SEPSISPAM study suggest that a MAP target of **65-75** is usually sufficient in patients with septic shock, but a higher MAP, around **75-85** may be preferable in patients with chronic arterial hypertension.
243
During the resting phase or diastole, the ventricles fill to a volume called ______.
End- diastolic volume
244
If the EDV remains constant while the ESV increases, the SV _____.
Decreases
245
Factors that increase HR are called ____.
Positive chronotropic factors
245
Factors that decrease HR are called ____.
Negative chronotropic factors
245
When the pumping efficiency of the heart is so low that CO is inadequate to meet tissue needs, the heart is said to be in ___.
CHF
246
What is this?
Normal Sinus Rhythm
247
What is this?
Sinus Tachycardia
**Common causes:**
- Fever
- Pain
- Anxiety
- Hypoxemia
- Hypovalemia
248
What is this?
Sinus Bradycardia
**Common causes:**
- Hypothermia
- Abnormalities in the SA node
- Intense athletic conditioning
249
What is this?
Sinus Arrhythmia
**Common causes:**
- May occur with the effects of breathing on the heart or as side effect to medications like digoxin
250
What is this?
Second-degree Heart Block type II
**Common causes:**
Most often the result of serious problems such as MI or ischemia
251
What is this?
First-degree heart block
**Common causes:**
Following an MI that damages the AV node or a complication of certain meds like digoxin or beta blockers
252
What is this?
Third-degree heart block
**Common causes:**
Often caused by MI or drug toxicity and it may render the heart unable to meet the normal metabolic demands of the body.
253
What is this?
Atrial Flutter
**Common causes:**
- Rheumatic heart disease
- Coronary heart disease
- Pulmonary embolism
- Stress
- Renal failure
- Hypoxemia
- Hypertension
254
What is this?
Atrial Fibrillation
**Common causes:**
Similar to atrial flutter
255
What is this?
PVCs
**Common causes:**
- Stress
- Caffeine intake
- Nicotine use
- Electrolyte imbalance
256
What is this?
Ventricular fibrillation
**Common causes:**
Similar to VT
257
What is this?
Ventricular tachycardia
**Common causes:**
- MI
- CAD
- Hypertensive heart disease
- Untreated OSA
258
**Which one is less work?**
a. Pressure triggering
b. Flow triggering
b. Flow triggering
259
The mechanism the ventilator uses to begin inspiration is the ____.
Triggering mechanism
260
The ventilator can initiate a set breath after a set time (time triggering), or the patient can trigger the machine (patient triggering) based on ______.
Pressure, flow or volume changes
261
What are the most **common** triggering variables?
Pressure and flow
262
What does the trigger variable do?
Begins inspiration
263
What does the limit variable?
Limits the pressure, volume, flow or time during inspiration but does not end the breath
264
What does the cycle variable do?
Ends the inspiratory phase and begins exhalation
265
The baseline variable is the _______ before a breath is triggered.
End-expiratory baseline (usually pressure)
266
The number of mandatory breaths delivered by the ventilator is based on what?
The length of the TCT.
267
When does a patient-triggered breath occur?
When the ventilator detects changes in pressure, flow or volume.
268
What are the two most common patient triggering mechanisms?
Pressure and flow
269
This setting determines the pressure or flow change required to trigger the ventilator.
Patient-effort control
270
The sensitivity level for pressure triggering usually is set at ____.
About -1 cmH2O
271
_________ occurs when the ventilator detects a drop in flow through the patient circuit during exhalation.
Flow triggering
272
Describe pressure limiting.
Allows pressure to rise to a certain level but not exceed it.
273
Describe volume triggering.
Volume triggering occurs when the ventilator detects a small drop in volume in the patient circuit during exhalation.
274
Inspiration is timed from when to when?
Beginning of the inspiratory flow to the beginning of the expiratory flow.
275
Describe limit variable.
The maximum value that a variable can attain (pressure, flow, volume or time).
276
Does reaching a set limit variable end inspiration?
NO!
277
Infant ventilators often _________ the inspiratory phase, but _________ inspiration.
Infant ventilators often **pressure limit** the inspiratory phase, but **time cycle** inspiration.
278
A breath is considered _________ if the inspiratory phase end when a predetermined time has elapsed.
Time cycled
279
Can ventilators use more than one limiting feature at a time?
Yes.
280
When gas flow from the ventilator to the patient reaches but does not exceed a maximum value before the end of inspiration, the ventilator is ____.
Flow limited
281
Maximum safety pressure is typically by the operator to a value of _______.
10 cmH2O above the average peak inspiratory pressure.
282
Ventilator manufacturers usually set internal maximum safety pressure at ______.
120 cmH2O
283
The variable that a ventilator uses to end inspiration is called ___.
Cycling mechanism
284
Can more than one cycling variable be used at a given time by the ventilator to end inspiration?
NO. **Only one of four can be used**
285
The ventilator measures the cycle variable during _______ and uses this information to govern when the ventilator will end gas flow.
Inspiration
286
When the inspiratory phase is terminated when set a set volume has been delivered.
Volume-cycled
287
When is plateau pressure measured?
End-inspiration
288
Inspiration ends when a set pressure threshold is reached at the mouth or upper airway.
Pressure-cycled
289
What is the most common cycling mechanism in the pressure support mode?
Flow
290
What can it mean if the volume of gas delivered to the patient may be less than the set volume?
May be a leak in the system
291
What is an advantage of pressure cycled ventilators?
They limit peak airway pressures
291
What are some disadvantages of pressure cycled ventilators?
- They deliver variable and generally lower tidal volumes when reductions in compliances and increases in resistance occurs
291
Inflation hold is designed to _____.
Maintain air in the lungs at the end of inspiration, before the exhalation valve opens.
291
What does the inflation hold do the I-time and E-time?
- Increases inspiratory time
- Reduces expiratory time
291
The expiratory phase encompasses the period from the _________.
The expiratory phase encompasses the period from the **end of inspiration to the beginning of the next breath.**
291
The baseline variable is the parameter that generally is controlled during _____.
Exhalation
291
If an adequate amount of time is not provided for exhalation what can occur?
Airtrapping, hyperinflation, leading to auto-PEEP or intrinsic PEEP.
291
When the ventilator cycles into the expiratory phase once the flow has decreased to a predetermined value during inspiration.
Flow cycling ventilation
**Volume, pressure and time vary according to changes in lung characteristics**
291
The inspiratory pause is occasionally used to _______.
Increase peripheral distribution of gas and improve oxygenation.
291
What is the most practical choice to use as a baseline variable?
Pressure
291
Define baseline pressure.
The pressure level from which a ventilator breath begins.
291
Plateau pressure is used to calculate _______.
Static compliance
291
Baseline pressure can be zero (atmospheric) which is called _____.
Zero-end expiratory pressure
291
Baseline pressure can be positive (above zero) which is called _____.
Positive end-expiratory pressure
291
Define capnography.
The measurement of carbon dioxide concentrations in respired gas.
291
_____________ involves the display of exhaled CO2 numerically without a waveform.
Capnometry
291
_________ describes the continuous display of CO2 concentrations as a graphic waveform called a *capnogram*
Capnography
291
**Capnography/Capnometry Indications (8)**
1. Monitoring severity of pulmonary disease and evaluating response to therapy
2. Use as an adjunct to verify tracheal rather than esophageal intubation has taken place.
3. Graphic evaluation of the integrity of the patient-ventilatory interface
4. Monitoring the adequacy of pulmonary and coronary blood flow
5. Screening patients for pulmonary embolism
6. Detection of CO2 rebreathing and the waning effects of neuromuscular blockade
7. Monitoring CO2 elimination
8. Optimization of mechanical ventilation.
292
Expiratory hold, or end-expiratory pause, is a maneuver transiently performed at ___________.
End-exhalation
293
An accurate reading of end-expiratory pressure is impossible to obtain if ________.
Patient is breathing spontaneously
294
What is the purpose of an expiratory hold?
Measure pressure associated with air trapped in the lungs at the end of expiration.
295
What does the expiratory retard maneuver mimic?
Pursed-lip breathing, by adding a degree of resistance during exhalation.
296
An elevated plateau pressure indicates a high probability of ___.
ARDS
297
What are some treatment options for atrial flutter? (4)
- Digoxin
- Beta blockers
- Calcium channel blockers
**Occasionally, electrical cardioversion is required.**
298
What are some treatment options for atrial fibrillation?
- Anticoagulant medications
- Beta blockers
- Calcium channel blockers
- Anti-arrthymia medications
**Patients who dont respond to drug therapy: synchronized cardioversion or ablation**
298
What are some treatment options for PEA?
- Emergency life support
- Immediate reversal of underlying cause
299
What determines how fast the inspired gas will be delivered to the patient?
Flow setting
300
Which ramp provides a progressive increase in flow?
Ascending ramp
301
Constant flow patterns are also called ___.
Rectangular or square waveforms
302
What does higher flows do to the I-time?
Shortens it and may result in higher peak pressures and poor gas distribution
303
Explain what slower flows can do for I-time.
May reduce peak pressures, improve gas distribution and increase airway pressure at the expense of increase I-time.
304
Shorter expiratory times can lead to _____.
Air trapping and using a longer I-time may also cause cardiovascular effects.
305
Flow is usually set to deliver inspiration in about ____.
1 second **(Range: 0.8-1.2 seconds)**
306
An I/E ratio of 1:2 or less is typically recommended. This can be achieved with initial peak flow setting of about ______.
60 L/min (range: 40-80 L/min)
307
A long I-time (requiring 3-4 time constants) has been shown to improve ventilation in nonhomogenous lungs such a those seen in ____.
ARDS
308
Are fast or slow flows better for patients with increased resistance such as COPD?
Fast flows!
309
Robin and colleagues reported that using flow rates up to _____ can improve gas exchange in patients with COPD by providing a longer E-time.
100 L/min
310
It is important to recognize that flows that are too high can result in _____.
Uneven distribution of inspired air in the lung and also cause persistent tachypnea in addition to increased PIP.
311
What are the most common flow patterns used clinically?
- Constant flow waveforms
- Descending waveforms
312
Which waveform provides the shortest I-time of all available flow patterns?
Constant flow rate
313
Descending ramp is used with what vent mode?
Pressure control
314
With a descending pattern, flow is the greatest at ______________.
Beginning of inspiration, when patient flow demand is the highest.
315
This pattern produces a tapered flow at the end of inspiratory phase.
Sine flow pattern
316
It is important to remember that in situations where Pplat is critical, _____________ can reduce peak pressures and increase Paw.
Descending ramp
317
When initiating MV, most clinicians will chose to start with a **descending ramp or constant waveform** for what reasons? (4)
1. Mean airway pressure is higher with descending flow waveforms
2. PIP is higher with ascending flow waveforms.
3. Descending waveforms improve gas distribution
4. Descending waveforms improve arterial oxygenation.
318
What flow pattern may be useful for patients with hypoxemia and low lung compliance?
Descending flow pattern, by maintaining low peak pressure and high Paw and improving gas distribution.
319
______________ produces a lower Paw compared with a descending flow pattern and **may be useful in ventilation with patients with severe hypotension and cardiac instability.**
Constant flow pattern
320
What flow pattern would be best for patients with increased airway resistance?
Descending pattern
321
It is important to know that ventilator circuits, expiratory valves and bacterial filters placed on the expiratory side of the patient circuit can produce a certain amount of expiratory retard because ____.
They cause resistance to flow
322
What is this and how would you fix it?
Overdistention of the lungs.
**Decrease pressure or volume based on the mode**
323
What is this waveform called?
Flow - Sinusoidal
324
What is this waveform called?
Flow - Exponential (decay)
325
What is this waveform called?
Flow and volume- Ascending ramp
326
What is this waveform called?
Flow - Descending ramp
327
What is this waveform called?
Flow and pressure - Rectangular, square, constant waveform
328
What is this waveform called?
Pressure - Exponential rise
329
What is this waveform called?
Volume - sinusoidal
330
What does this indicate?
Air leak
331
What does this indicate?
Presence of auto-PEEP
332
What does this indicate?
**Note the diminished peak expiratory flow and the scooped-out concave shape of the expiratory F-V curve.**
COPD
333
Chemical devices that rely on disposable colorimetric detector provide ________ estimates of exhaled CO2.
Qualitative
334
Spectroscopic devices provide _______ data on the concentration of expired CO2.
Quantitative
335
_______ are handheld devices composed of specially treated filter paper in a plastic casing that can be attached to a patient's ET tube.
Chemical (colorimetric) capnometers
336
In some cases,ET placement in the trachea rather than the stomach may be difficult to determine because patient's gastric CO2 may be elevated due to:
- Receiving mouth-to-mouth breathing
- Having recently ingested a carbonated drink and the presence of antacids
337
IR spectroscopy is based on the principle that ________.
Molecules containing more than one element absorb IR light in a characteristically manner.
338
CO2 absorbs IR radiation maximally at ____.
4.6 µm
339
Which type of sampling is attached directly to the ET tube?
Mainstream sampling
340
In __________ sampling devices, gas from the airway is extracted through a narrow plastic tube to the measuring chamber.
Sidestream sampling devices
341
The PetCO2 is dependent on ____.
Alveolar PCO2.
Influenced by CO2 production and effectiveness of ventilation
342
The production of CO2 is primarily determined by ____.
Metabolic rate
343
What are some things that can **increase** metabolic rate and VO2?
- Fever
- Sepsis
- Hyperthyroidism
- Seizures
344
What are some things that can **decrease** metabolic rate and VO2?
- Hypothermia
- Sedation
- Starvation
345
The PetCO2 is normally ________ lower than the PaCO2.
about 4-6 mm Hg
346
Failure of the capnogram to return to baseline indicates ______.
Rebreathing of exhaled gas
347
_______ devices increase the amount of deadspace added to the ventilator circuit.
Mainstream devices
348
During capnography, what should be recorded?
**Ventilatory variables:**
VT, RR, PEEP, I/E, PIP, FiO2
**Hemdynamic variables:**
Systemic and pulmonary pressures, CO, shunt, V/Q imbalances
349
__________ may lead to a false-negative capnography result.
Low CO
350
Gastric PCO2 is usually equal to ___.
Room air
351
______ is associated with low PetCO 2 and should not be confused with esophageal intubation.
Low perfusions of the lungs
352
**What is the critical value range?**
MIP
-20 to 0
353
**What is the critical value range?**
MEP
<40
354
**What is the critical value range?**
VC
<10-15
355
**What is the critical value range?**
VT
<5
356
**What is the critical value range?**
Respiratory rate
>35 breaths/min
357
**What is the critical value range?**
FEV1
<10
358
**What is the critical value range?**
PEF
75-100
359
The PetCO2 for tidal breathing should be approximately ________.
4-6 mm Hg
360
PetCO2 is elevated for what type of patients?
- COPD
- Left sided heart failure (CHF)
- Pulmonary embolism caused by an increase in physiological dead space.
361
What disease process shows an increased gradient between PaCO2 and expired PC2 at the end of maximal exhalation?
Pulmonary emobolism
COPD and LHF does not show a difference.
362
Exhaled NO is currently used as a marker for _________.
Airway inflammation associated with asthma
363
Conditions associated with reductions of Exhaled NO: (5)
- Systemic hypertension
- Pulmonary hypertension
- CF
- Sickle cell anemia
- Ciliary dyskinesis
364
Conditions associated with elevated levels of Exhaled NO: (9)
- Asthma
- Bronchiectasis
- Airway viral infections
- Alveolitis
- Allergic rhinitis
- Pulmonary sarcoidosis
- Chronic bronchitis
- Systemic sclerosis
- Pneumonia
365
The most common method used to quantify the level of exhaled NO is _____.
Chemiluninescence
366
Exhaled NO can be detected in exhaled gas in the range of ___.
7.8 to 41.1 ppb
367
The single breath CO2 is produce by the ______.
Integration of airway and CO2 concentration; it is presented on a breath-to-breath basis.
368
The mode of ventilation is determined by what three factors?
- Type of breath
- Targeted control variable
- Timing of breath delivery
369
Mandatory breaths are breaths for which the ventilator controls the:
- Timing
- VT
- Inspiratory pressure
370
For spontaneous breaths, what does the patient control?
- Timing
- VT
**Volume and pressure not set by clinician; based on patient demand**
371
Describe assisted breaths.
All or part of the breath is generated by the ventilator
372
What does it mean if the airway pressure rises above the baseline during inspiration?
The breath is assisted
373
What is the primary advantage of volume-controlled ventilation?
Guarantees a specific volume delivery and volume of expired gas.
374
What is the goal of volume-controlled ventilation?
Maintain a certain level of PaCO2
375
What vent mode is a protective lung strategy that is more comfortable for patients who can breath spontaneously?
Pressure control
376
**Guess the mode**
Either time-triggered or patient-triggered breaths are mandatory breaths; the patient is not generating any spontaneous breaths.
CMV
377
**Guess the mode**
The patient is allowed to breath spontaneous breaths between mandatory breaths.
IMV
378
**Guess the mode**
All breaths are spontaneous and therefore patient triggered.
CSV
379
When the breaths are patient triggered during CMV, the breaths are described as ____.
Assisted ventilation
380
When breaths are time-triggered, the breaths are described as ___.
Controlled ventilation
381
**CMV**
Breaths can be _____ or ____ triggered.
Time or patient-triggered
382
Controlled (time-triggered) ventilation is only appropriate when ____.
A patient cannot make an effort to breathe.
383
The maximum pressure limit during PC-CMV is typically set at ________ above the target or set pressure.
Approximately +10 cmH2O
384
**Advantages of CMV** (4)
- Set minimum VE with volume-targeted breaths
- May synchronize with patient efforts
- Patient can establish rate
- Full support for patient who are not spontaneously breathing
385
**Disadvantages of CMV** (6)
- Muscle atrophy may result.
- May not be tolerated in awake patients
- Asynchrony if flow and sensitivity not set correctly
- High mean airway pressure and related complications
- VE may decrease with changes in compliance or resistance
- Respiratory alkalosis if # of patient-triggered breaths is too high
386
**Advantages of IMV** (6)
- May lower mean airway pressure
- Used for weaning
- May reduce alkalosis
- Full or partial support can be adjusted to meet patient needs
- Sedation not required
- Variable WOB may maintain muscle strength
387
**Disadvantages of IMV**
- IMV and PSV may increase mean airway pressure
- May increase weaning time
- Asynchrony
- WOB may increase as mandatory rate is reduced
- Acute hypoventilation can occur with low RR
388
A pressure support breath is a _______ triggered, _________ limited, ________ cycled breath.
Patient triggered, pressure limited, flow cycled
389
A dual control mode that provides pressure-limited ventilation with volume delivery targeted for every breath.
Pressure augmentation (VAPS)
390
A key criterion for pressure augmentation is the ____.
Ability to initiate breaths, patient must also have a consistent RR.
391
What do you set in VC?
- Flow
- VT
- PEEP
- FiO2
- RR
392
What do you set in PC?
- I-time
- Inspiratory pressure
- PEEP
FIO2
- RR
393
PRVC delivers pressure breaths that are _________ triggered, _________ targeted and ______ cycled.
- Patient or time-triggered
- Volume-targeted
- Time-cycled
394
**What mode does this describe?**
If the volume delivered is less than the set VT, the ventilator increases pressure progressively over several breaths until the set and the targeted VT are about equal.
Pressure-Regulated Volume control (PRVC)
395
Volume support ventilation (VSV) is very similar to ____.
PRVC
396
Unlike PRVC, VSV is _____ cycled.
Flow
397
Mandatory Minute Ventilation has been used primarily for ____.
Weaning patients off the ventilator
398
Explain MVV.
Ventilator provides whatever part of minute ventilation the patient is unable to accomplish by increasing breathing rate or the preset pressure.
399
What alarms are typically set for MVV?
- Low VT
- High RR
**Because these parameters suggest an increased WOB.**
400
**Proportional Assist Ventilation**
The amount of pressure the ventilator produces depends on what two factors?
- The amount of inspiratory flow and volume demanded by the patient's effort
- The degree of amplification selected by the clinician
401
PAV is a ______ system.
Positive feedback
402
What are some factors that may contribute to extubation failure? (14)
- Type of patient (medical vs. surgical)
- Older age
- Severity of illness at weaning onset
- Repeated or traumatic intubations
- Use of continuous IV sedation
- Duration of mechanical ventilation
- Female gender
- Anemia
- Need for transport out of the ICU
- Initial severity of illness
- Indication for MV
- Protocol-directed weaning
- Mode of ventilator support before extubation
- Duration or # of SBTs before extubation
403
**Physiological Parameters for Weaning and Extubation of Adults**
VC
>15 mL/kg
404
**Physiological Parameters for Weaning and Extubation of Adults**
VE
<10-15 L/min
405
**Physiological Parameters for Weaning and Extubation of Adults**
VT
>4-6 mL/kg (IBW)
406
**Physiological Parameters for Weaning and Extubation of Adults**
Frequency (RR)
<35 breaths/min
407
**Physiological Parameters for Weaning and Extubation of Adults**
RSBI
<60-105 breaths/min/L
408
**Physiological Parameters for Weaning and Extubation of Adults**
Ventilatory pattern
Synchronous and stable
409
**Physiological Parameters for Weaning and Extubation of Adults**
Pimax
< -20 to -30 cmH2O
410
**Physiological Parameters for Weaning and Extubation of Adults**
P 0.1
>6cmH2O
411
The set up for T-piece weaning includes:
- Heated humidifier with a large reservoir
412
With pressure support ventilation, what does the patient control? (3)
- RR
- Timing
- Depth of each breath (VT)
413
In general, there is a pressure support level of _________ for patients who meet weaning criteria.
5-15 cmH2O
414
ATC was designed to specifically do what?
Reduce WOB associated with increased ET resistance
415
What three key points have evolved as criteria for weaning?
1. The problem that caused the patient to require ventilation has been resolved
2. Certain measurable criteria should be assessed to help establish a patient's readiness for discontinuation of ventilation
3. SBT should be performed to establish readiness for weaning
416
**Physical signs and measurements of increased WOB (9)**
- Use of accessory muscles
- Asynchronous breathing
- Nasal flaring
- Diaphoresis
- Anxiety
- Tachypnea
- Substernal and intercostal retractions
- Measured WOB >15% of total O2 consumption
- Measured WOB >1.8 kg/m/min
417
**Clinical Signs and Symptom Indicating Problems During a SBT (7)**
- Deterioration of arterial blood gas values and O2 saturations measured by pulse oximeter (SpO2)
- Diaphoresis
- Sudden onset PVCs
- VT decreases below 250-300 mL
- BP changing significantly (a drop of 20 mmHg systolic, a rise of 30 mm Hg systolic, systolic values above 180 mm Hg, a change of 10 mm Hg diastolic)
- HR increasing 20% or exceeds 140 bpm
- Anxious
418
**Criteria for Instituting NIV after Failure to Wean From Invasive MV in Extubated Patients (8)**
- Optimum nutritional status
- Functioning GI tract
- Low FiO requirements
- Minimal airway secretions
- Hemodynamic stability
- Strong cough reflex
- Can tolerate SBT for 10-15 mins
- Resolved problem leading to respiratory failure
419
**Hazards and Complications of Removal of the ET tube (11)**
- Hypoxemia
- Hypercapnia from airway obstruction
- Tracheal, vocal card, laryngeal edema
- Laryngospasm
- Bronchospasm
- Aspiration
- Respiratory muscle weakness
- Hypoventilation
- Excessive WOB
- Postextubation pulmonary edema
- Development of atelectasis
420
How does nutrition play a role in the weaning process?
Overfeeding of carbohydrate calories leads to increased CO2 production.
421
Ultimately, the most important beneficial outcome of a tracheostomy is ___.
The potential to facilitate discontinuation of MV support.
422
What are some patient types that may benefit from a tracheostomy? (5)
- Those who require high levels of sedation to tolerate ETs
- Those with marginal respiratory mechanics and who may have tachypnea as a result
- Those in whom lower resistance may reduce the risk for muscle overload
- Those who may gain psychological benefit from the ability to eat, talk and have greater mobility.
- Those for whom increased motility may aid physical therapy efforts
423
What type of patients are less likely to tolerate T-piece weaning? (3)
- Underlying heart disease
- Severe muscle weakness
- Inclined to panic due to psychological problems or preexisting lung conditions.
424
What begins, sustains, ends and determines the characteristics of the expiratory portion of each breath?
Phase variable
425
What are the two settings used for APRV?
1. Time 1 (T1) controls the time high pressure is applied.
2. Time 2 (T2) controls the release time, or time low pressure is applied
426
HFOV assists with _______________ and is most often used for ______.
HFOV assists with inspiration and exhalation and is most often used for infant lungs, can also be used for ARDS.
427
______________ is controlled by an electronically operated valve that measures flow passing through the ventilator circuit during a specific interval.
Volume limiting
428
High PVR is usually associated with ___.
Hypoxemia
429
Which system act as a reservoir for the circulatory system?
Venous system
430
Which system allows for precise control over the direction and amount of blood flow to a given organ or area of tissue?
Capillary system
431
Higher than normal PetCO2 can be caused by: (3)
- Respiratory center depression
- Muscular paralysis
- COPD
432
Lower than normal PetCO2 can be caused by: (3)
- Pulmonary embolism
- Excessive PEEP
- Any disorder marked by pulmonary hypoperfusion
433
"Curare cleft" **during phase III** is a positive sign that a paralyzed patient is _____.
receiving insufficient NMBAs.
434
Changes in the contour of the capnogram can be used to detect: (7)
- Increases in dead space ventilation
- Hyperventilation/Hypoventilation
- Apnea or periodic breathing
- CO2 rebreathing
- Inadequate NMBAs
- Detect esophageal intubation
- Monitor the effectiveness of gas exchange during CPR
435
What **ventilator mode** uses two pressures and was originally used to improve oxygenation?
APRV
436
Where does electrical impulse travel the fastest?
Purkinje fibers
437
**What is this mode of ventilation?**
- Patient-triggered
- Pressure-limited
- Flow-cycled
Pressure support ventilation
