Homework Chapter 14
1.)
Where in the central nervous system is the center controlling respirations located?
The respiratory center is located in the medulla oblongata of the brainstem.
2.)
What is the name of the nerve that stimulates the diaphragm? Where does it originate?
The phrenic nerve, which stimulates the diaphragm and originates at the levels of
cervical vertebrae C3, C4, and C5 (keep the diaphragm alive).
3.)
What are the nerves that control the intercostal muscles? Where do they originate?
The intercostal nerves, which control the intercostal muscles, arise from the thoracic
spinal cord.
4.)
Respirations normally are stimulated by what change in the arterial blood gases?
Respirations are normally stimulated by an increase in arterial carbon dioxide level.
5.)
What is the backup system for controlling respirations? What change in the arterial
blood gases triggers this backup system?
The backup system for controlling respirations is the hypoxic drive, which is triggered by
a fall in arterial oxygen levels.
6.)
Patients with long-standing chronic obstructive pulmonary disease (COPD) have what
change in their arterial carbon dioxide levels?
In long standing COPD the arterial carbon dioxide concentration becomes elevated.
7.)
What effect can administration of high concentration oxygen have on a COPD pts
breathing? Why does this happen? Is this a reason to withhold oxygen from a COPD pt?
Why or why not?
High concentrations of oxygen to some COPD pts may depress their respirations.
Because COPD pts retain carbon dioxide and develop high arterial carbon dioxide levels,
over time the respiratory center in the brain becomes desensitized to changes in the
arterial carbon dioxide concentrations. At this point, the hypoxic drive takes over
control of respirations. Giving high concentrations of oxygen to a pt who is breathing in
response to decreases in arterial oxygen levels may satisfy the hypoxic drive and cause
respiratory depression or arrest. However, because oxygen is essential to life any pt who
is hypoxic must receive supplemental oxygen. If a COPD pt receiving high concentration
oxygen develops respiratory depression, his or her breathing should be assisted with
bag-mask device while oxygen continues to be administered.
8.)
Which phase of the respiratory cycle normally requires contraction of the intercostal
muscles and diaphragm?
Inspiration is the active phase of the respiratory cycle, requiring contraction of the
intercostal muscles and diaphragm.
9.)
Which phase of the respiratory cycle does not require contraction of the intercostal
muscles and diaphragm?
Expiration is the passive phase of the respiratory cycle and does not require contraction
of the intercostal muscles or diaphragm.
10.)
During respiration, what effect does contraction of the diaphragm have on the volume
of air in the lungs?
Contraction of the diaphragm increases the volume of the air in the lungs.
11.)
What are the principal anatomic differences between the right and left mainstream
bronchi? Why is this of practical importance in performing endotracheal intubation?
The right mainstream bronchus is shorter and straighter than the left mainstream
bronchus. If an ET is inserted too far, it is more likely to enter the right bronchus than
the left mainstream bronchus.
12.)
What is the tidal volume? What is the normal tidal volume of a 70 kg male?
Tidal volume is the amount of air inhaled or exhaled during a single breath. The tidal
volume of a 70 kg pt is approx. 500 mL.
13.)
What is the minute volume of a pt who has a tidal volume of 500 mL and respirations of
20/minute?
Tidal volume x respiratory rate = minute volume 10,000 mL/min.
14.)
What is anatomic dead space?
Anatomic dead space is the portion of the respiratory tract in which gas exchange with
the blood does not take place.
15.)
What is physiologic dead space?
Physiologic dead space is the area of the respiratory tract where gas exchange should be
occurring but is not because of inadequate alveolar ventilation or inadequate blood flow
through the capillary beds.
16.)
What is atelectasis?
Atelectasis is a localized collapse of the alveoli resulting in a small area of the lung
where gas exchange does not occur.
17.)
What is the normal PaCO2?
Normal PaCP2 is 35-45 mmHg
18.)
What is the normal PaO2?
Normal PaO2 is 80-100 mmHg
19.)
If a pt’s respiratory rate and tidal volume are decreased, what change would you expect
to see in the pt’s PaCO2? What is this condition called?
If respiratory rate and tidal volume are decreases PaCO2 will be increased. This is called
hypoventilation.
20.)
If a pt’s respiratory rate increases and tidal volume decreases, what change would you
expect to see in the pt’s PaCO2? What is this condition called?
If respiratory rate increases and tidal volume decreases, PaCO2 will decrease. This is
called hyperventilation.
21.)
Is cyanosis a late or early sign of hypoxia? Why?
Cyanosis is a late sign of hypoxia and occurs because the pts must have 5 mg/dL of their
hemoglobin not bound to oxygen. Because the normal hemoglobin concentration is
approx.. 15 mg/dL a pt must have desaturated 1/3 of their hemoglobin before cyanosis
occurs.
22.)
What is usually the earliest sign that a pt is hypoxic?
Restlessness and anxiety
23.)
What is the most common cause of an obstructed airway in an unconscious person? If
you attempt to ventilate an unconscious person and the chest does not rise, what
should be your first action?
The tongue is the most common obstruction in an unconscious person. Reposition pt’s
head to ensure the tongue is not obstructing the airway
24.)
If a pt reacts to placement of an oral airway by coughing and gagging, what should be
done?
The airway adjunct should be removed
25.)
If a pt will not tolerate an oral airway, but is not alert enough to manage his or her own
airway unassisted, what device should be used?
An NPA should be inserted when the pt cannot tolerate an OPA and needs intervention
26.)
How do you distinguish between a partial airway obstruction with poor air exchange
and a partial airway obstruction with good air exchange? How do you manage a partial
obstruction with good air exchange? How do you manage a partial obstruction with
poor air exchange?
Pt with partial airway obstruction with poor air exchange will not be able to talk, cough,
or exchange air adequately. This pt should be treated with abdominal thrusts to attempt
to dislodge the obstruction. Pt with a partial airway obstruction with good air exchange
will be able to talk, cough, and exchange enough air to stay awake and orientated. This
pt should be encouraged to cough, given supplemental oxygen and transported to the
ED.
27.)
What oxygen mask should be used with a young adult who is having an acute asthma
attack? Why?
Nonrebreather mask with high flow oxygen will best help correct the hypoxia produced
by the asthma attack. Asthma is a reversible obstructive pulmonary disease that results
in episodes of inadequate alveolar ventilation.
28.)
Why is the Venturi mask the preferred oxygen administration device for a COPD pt who
presents in mild to moderate respiratory distress? (Explain in terms of how the Venturi
mask controls the pt’s FiO2)
Venturi mask aka air-environment mask, provides precise control over pt’s FiO2 level.
Because some pts with long standing COPD may be breathing in response to decreases
in their arterial oxygen concentrations, giving high concentrations of oxygen may
depress their respirations. The Venturi mask allows controlled increases in the FiO2 level
to find the concentration that corrects hypoxia without depressing respirations.
29.)
If a COPD pt who is receiving oxygen experiences depressed respirations, what should
you do?
Assist their respirations with bag-mask device
30.)
Should a person who has ingested a caustic agent be intubated with a dual-lumen
airway? Why?
No, because the pt’s esophagus will be burned, insertion of a dual-lumen device could
cause esophageal perforations
31.)
Should a person with a history of cirrhosis of the liver or chronic alcohol abuse be
intubated with a dual-lumen airway? Why?
No, pts with chronic alcoholism or cirrhosis of the liver may have developed formation
of esophageal varices and passing a tube through the esophagus may lead to massive
upper gastrointestinal tract bleeding
32.)
What is the maximum period of time that should elapse during an intubation attempt
before ventilating?
No more than 30 seconds should pass before ventilating a pt during an intubation
attempt
33.)
Since it is difficult to keep track of time during an intubation attempt, what method is
used to determine when the patient needs to be ventilated?
The person attempting to intubate should hold their breath, when they need to breathe
the pt needs to be ventilated. If pt is perfusing adequately then a pulse ox monitor may
also be used to determine if there is a change in pt status and it ventilation is needed
and intubation attempt should cease
34.)
How can you estimate the correct endotracheal tube size to use when intubating a
pediatric pt?
Age/4 +4 += Uncuffed ET tube size Age/4 +3 = Cuffed ET tube size
35.)
After intubating a pt endotracheally, you auscultate the chest and discover absent
breath sounds on the left. What is the most likely cause of this problem, and how do
you solve it?
Tube is probably in the right mainstream bronchus, deflate cuff and pull back tube until
sounds are equal bilaterally
36.)
How do you determine the correct amount of air to place in the cuff of the endotracheal
tube?
Cuff of ET tube should be inflated approx. 6-10 mL of air. Periodically assess the pilot
balloon to ensure the distal cuff is adequately inflated. Cuff is adequately inflated when
air cannot leak out
37.)
When you are intubating a pt endotracheally, how do you know that the tube is in the
trachea?
Visually see the tube pass through the vocal cords. Adequate chest rise and fall with
each ventilation, hear breath sounds in lungs bilaterally when pt is ventilated, you do
not hear sounds over the epigastrium, and proper ETCO2 35-45 mmHg.
38.)
What is the most common complication of endotracheal suctioning? How can it be
prevented?
Most common complication is hypoxia. To prevent hypoxia preoxygenate the pt and
limit the time of suctioning.
39.)
What is the maximum time for which a pt’s trachea should be suctioned without
oxygenating?
No longer than 15 seconds
40.)
What is the correct position in which to place a pt’s head during an endotracheal
intubation attempt?
The pts head should be placed in the sniffing position. Do not hyperextend the neck.
41.)
Why should an unconscious pt be intubated endotracheally before placing a gastric
tube?
A gastric tube holds the gastroesophegeal sphincter open, increasing the risk of
regurgitation of gastric contents and aspirations. Since an unconscious person cannot
protect their airway an endotracheal tube must be placed prior to an OG tube.
42.)
Why should instrumentation of the nose be avoided in pt’s with mid-face trauma or
signs of a possible basilar skull fracture (CSF, otorrhea, CSF rhinorrhea, Battle’s sign, and
periorbital ecchymosis)?
Mid-face trauma or basilar skull fracture may be associated with injury to the cribriform
plate at the top of the nasal cavity. If the cribriform plate is fractured an instrument can
pass through into the cranial cavity and enter the brain.
43.)
What percentage of oxygen is delivered by a bag-mask and reservoir with oxygen
flowing at 15 L/min?
BVM with supplemental oxygen will deliver 90-100% oxygen
44.)
What is the only reliable indicator that rescue breathing is inflating the lungs?
Chest rise is the only reliable indicator that proper ventilation is being delivered
45.)
What term is used to describe dyspnea that is more severe when the pt is lying down, or
inversely is relieved when the pt sits or stands?
Orthopnea is the condition when dyspnea is more severe when pt is lying down
46.)
List four signs of respiratory distress (increased work of breathing).
Nasal flaring, movement of the larynx and trachea up and down as the pt breathes, use
of respiratory accessory muscles (muscles of the neck and upper chest), retractions
between the ribs, at the top of sternum, or over the epigastrium as the pt inhales.
47.)
Why is a rigid (Yankauer) catheter the preferred device for suctioning the secretions of a
pt whose upper airway is obstructed with blood or vomitus?
Soft suction catheters clog to easily when the thickness of blood and vomitus
48.)
What term describes a crackling sensation under the skin of the chest wall or neck
caused by leakage of air into the soft tissues?
Subcutaneous emphysema
49.)
A blood gas report shows a pt’s PaCO2 to be elevated. What is the most common reason
that a pt will develop increased arterial CO2 concentration? How can this problem be
corrected?
The most common reason is inadequate respiratory rate or tidal volume. This problem
can be corrected by assisting the pt’s ventilations with BVM.
50.)
A pt is receiving oxygenation and ventilation via bag-mask device and an endotracheal
tube. The blood gas report shows a PaO2 of 120 mmHg and a PaCO2 of 50 mmHg. What
do these findings indicate about the pt’s oxygenation and ventilation?
PaCO2 of 50 mmHg indicates the pt is not being ventilated adequately, but the PaO2 of
120 mmHg indicated that the pt is receiving adequate oxygen on the supplemental
oxygen.
51.)
You respond to a report of a “man down” to find a 62 y/o male who is unconscious and
unresponsive. Your initial assessment reveals that he is apneic and deeply cyanotic, but
a pulse is present. Should you intubate him immediately or ventilate and oxygenate him
first? Why?
He has already become too deoxygenated, so he needs to be oxygenated and ventilated
first using a BVM prior to ET is attempted.
52.)
What is the difference between the mechanism of action of a depolarizing and a nondepolarizing neuromuscular blocker?
Depolarizing neuromuscular blocker cause the muscles to depolarize and hold them in a
depolarized state, preventing further contraction. Nondepolarizing neuromuscular
blockers block the Ach receptors on skeletal muscles, preventing them from
depolarizing and contracting.
53.)
What effect do neuromuscular blockers have on level of consciousness?
Neuromuscular blockers have no effect on level of consciousness.
54.)
What is the implication of the effect of neuromuscular blockers on level of
consciousness when these agents are used to facilitate intubation?
Pt’s that receive a neuromuscular blocker to facilitate endotracheal intubation should
be sedated first with a benzodiazepine. If this is not done, the pt will be completely
paralyzed and unable to breathe while remaining fully conscious.