FINAL SCHMIDT EXAM Flashcards
1
Q
How open are the vocal cords during normal breathing?
A
Gentle abduction
2
Q
How do you know if someone is whispering? Why?
A
No vibration of the voice box because there is a very wide opening of the vocal cords.
The cords are closed just enough to be able to mouth words.
3
Q
When talking, what do our vocal cords look like?
A
They are close together to allow for vibration. The closeness allows for us to have different pitches.
4
Q
Why is it hard to take a deep breath in the middle of talking?
A
Because cords are very close together during phonation
5
Q
What controls/innervates most of the muscles in the voice box?
A
Inferior laryngeal nerve
6
Q
What is the inferior laryngeal nerve a derivation of?
A
Recurrent laryngeal nerve (could be a complication with thyroid surgery)
7
Q
Can you talk with a dysfunctional/injured laryngeal nerve?
A
You can still get the cords into position tight enough to talk, but you’ll sound abnormal like RFK
8
Q
How does pitch change when the cords tighten?
A
Higher pitch
9
Q
How does pitch change when the cords loosen?
A
Lower pitch
10
Q
Atmospheric pressure is a result of what?
What is this number at sea level?
A
Gravity and weight of all atmosphere between us and outer space
760mmHg @ sea level
11
Q
What is atmospheric pressure of space?
A
0mmHg
12
Q
The more air we have above us, the ____ the atmospheric pressure.
The less air we have above us, the ___ the atmospheric pressure.
A
Higher
Lower
13
Q
At high altitude, barometric pressure is ____ than sea level because _____.
A
Lower
Not at much atmosphere between us and space
14
Q
At low altitude, barometric pressure is _____ because _____
A
Higher
There is more atmosphere above us.
15
Q
Weight of the atmosphere + effect of gravity =
A
Atmospheric pressure
16
Q
What is the most extreme height on earth?
A
Summit of Mount Everest @ 8848 meters, or roughly 9km high
17
Q
What is the barometric pressure on the summit of Mount Everest?
A
253mmHg
18
Q
What is the PiO2 @ the summit of Mount Everest?
A
43mmHg
19
Q
The summit of Mount Everest has an atmospheric pressure of 253mmHg. What is the % of oxygen in the atmosphere here? When might this change?
A
21%
Might change concentration when you are very close to space.
20
Q
What needs to be factored in to the PiO2 no matter where we are or what the pressure is?
A
Water vapor pressure
i.e. if the atmospheric pressure is 253mmHg, take 253-47 and then take 21% of that to get your FiO2.
21
Q
While the FiO2 at the summit of Everest is 43mmHg, how will the arterial PO2 (PaO2) compare?
A
PaO2 will be much lower since there’s a low pressure driving it into the system
22
Q
What is also known as “pressure that is available to push oxygen into blood?”
A
Atmospheric/barometric pressure
23
Q
Why do climbers of Everest only stay at the summit for a few hours at max?
A
They can’t tolerate the low PiO2/atmospheric pressure for very long, as it’s not compatible with life.
They won’t be sprinting with that level of PO2 either, will have to pace themselves.
24
Q
Over time, how do the kidneys help acclimatize to high altitude?
A
When there is low PO2 in the blood, less oxygen gets to the kidney.
Kidney O2 sensors in the inner medulla controls how much EPO we produce.
EPO levels increase, which expands hematocrit to help with oxygen delivery in low pressure environments.
24
Why are there camps on tall mountains along the way to the summit?
Acclimatization to different altitudes
25
When people are first exposed to high altitude, what do they do initially?
How about over a few days/long term adjustment?
Hyperventilate initially
Over a few days: expansion of hematocrit to help with oxygen delivery in low pressure environments.
26
How might someones lungs be different if they grew up in a high altitude environment?
Significantly more surface area for gas exchange in the lungs d/t more alveoli compared to someone who grew up around sea level.
This is why these people are good at running marathons at sea level.. they have a huge advantage due to the increased surface area for gas exchange.
27
What two countries are high in altitude that give an advantage in endurance sports, per daddy?
Kenya
Ethiopia
28
If someone smokes for 3-4 years, how will their lungs be different than a nonsmoker?
Might not be in the best shape, but won't seem much different than anyone else. (because we have about 3x more lung area than we really need over the course of our life).
28
What is the limiting factor for performance (every day things, sports, etc)? Is it the heart or the lungs?
Why?
Normally is the heart, NOT the lungs.
We have about 3x more lung area than we really need over the course of our life.
29
Is smoking damage more of a short or long term thing?
Long term
30
How do you find out if you're predisposed to altitude sickness?
You don't. You find out when you're up there.
If you find out you have altitude sickness, just don't go up the mountain. Some people elect to go up anyway and die.
31
What is the lowest altitude on earth (per Schmidt, above water)
Death valley (fun fact it's actually the shores of the Dead Sea, but that's not important for the class)
This is the highest barometric pressure on earth (above water)
32
What does water do to atmospheric pressure? Why?
Magnifies increase in barometric pressure as water is heavier than air so more weight is above you
33
At a depth of 33 feet, atmospheric pressure is how many times greater than sea level?
2x
33
At a depth of 66 feet, atmospheric pressure is how many times greater than sea level?
3x
34
At a depth of 100 feet, atmospheric pressure is how many times greater than sea level?
4x
35
At a depth of 133 feet, atmospheric pressure is how many times greater than sea level?
5x
36
At a depth of 166 feet, atmospheric pressure is how many times greater than sea level?
6x
37
At a depth of 200 feet, atmospheric pressure is how many times greater than sea level?
7x
38
At a depth of 300 feet, atmospheric pressure is how many times greater than sea level?
10x
39
At a depth of 400 feet, atmospheric pressure is how many times greater than sea level?
13
39
TYLERISM just in case he does us dirty on the test
An easy way to see how many times atmospheric pressure is amplified at depth starting from sea level is ___
Divide the depth by 33ft, and add 1ATM to the result.
i.e.
400/33 =12.121 +1 = ~13x greater atmospheric pressure
Another example
166/33=5.0303 +1 = 6x greater atmospheric pressure
^Take this amplification number and multiply by 760 to get your barometric pressure
40
When under water, barometric pressure is amplified. What part of the body is exposed to this? What is the implication of this?
The entire body
We need to breathe through a pressurized gas source such as a scuba tank
41
Why is a scuba tank pressurized?
To overcome increased barometric pressure around the breather. It's not just pressurized to have more air in the tank, though that is a benefit
42
A highly pressurized scuba tank will result in what in the diver?
A reflection of this high pressure in the blood gas of divers
43
What happens if someone ascends from the depths of the sea too quickly?
Nitrogen comes out of solution and becomes little air bubbles.. not immediately fatal, but if a couple bubbles mix and form a larger embolus, you're going to have a bad day
44
How can you avoid nitrogen toxicity with sudden decompression?
Don't include nitrogen in the inspired gas mixture - will eliminate decompression sickness.
BUT
Filling a tank with 100% oxygen will result in oxygen toxicity, and also be expensive/explosive
45
Packing a scuba tank with 100% oxygen and inspiring it at 500ft depth will result in ___x greater oxygen on blood gas
40x
760mmHg x 16x =12,160 mmHg
Subtract 47mmHg for water vapor
(figure out from here how this number works out, will come back to fill this in)
46
What are the three sensory divisions of the trigeminal nerve?
V1 – ophthalmic (forehead)
V2 – maxillary (upper mouth/nose)
V3 – mandibular (mandible)
47
Where is the trachea connected?
Base of larynx
48
How long is the trachea?
10-13cm x a few cm wide
49
What is a good gauge for how wide the internal diameter of someones trachea is?
Their thumb width = trachea width
50
Is all of the trachea in the thorax? If not, how much is/isn't?
Most of the trachea is intrathoracic, while 4cm is extrathoracic (at the top of the chest in the neck)
This means 4cm is extra thoracic, while 6-9cm is intrathoracic
51
What is the trachea made out of?
Annular ligaments, which is connective tissue that connects cartilage pieces together
51
Why is cartilage useful in the trachea?
Bends and isn't brittle, won't be broken but it can be crushed. It's resilient
52
How many annular ligaments (trachea) are there in the average adult?
20
52
How many bronchopulmonary segments do we have in each mainstem?
R - 10
L - 8
Note: In the left, we have 4 segments that fuse to make two during development, resulting in 8 adult segments.
53
Which mainstream is larger - left or right? Why?
Right - the right lung is larger in general
54
Which mainstem is longer - left or right? Why?
Left mainstem is more narrow and is longer as well @4-6cm. The heart is positioned here, so this mainstem routes air past the heart.
55
Which mainstem branches immediately?
Right mainstem branches immediately
56
From vertical, what is the angle of the right mainstem?
25 degrees
57
From vertical, what is the angle of the left mainstem?
45 degrees - more horizontal
58
What is the total bifurcation angle of the right and left mainstem?
70 degree angle between mainstems
59
At the start of the bifurcation of the trachea, what is the last piece of cartilage called?
Carina
60
What are the two types of invasive surgical airways?
Tracheostomy
Cricothyrotomy
61
Where can a tracheostomy be done?
any portion of the trachea exposed in the extra thoracic area, so around 4cm
62
Where can a Cricothyrotomy be done?
between thyroid and cricoid cartilages at the *median cricothyroid ligament*
^Note this is a little higher than we did on pigs.. maybe this ligament goes deep to the thyroid cartilage and pops up between the thyroid cartilage and cricoid cartilage?
63
What is the problem with invasive airways?
They bypass the beginning of the respiratory system, which bypasses humidification & warming.
50% air goes through the nose normally, so it's important in humidification/warming.
In skipping this, the patients lungs can dry out.
63
What can we do to prevent lungs from drying out with invasive airways?
Humidify inspired air, especially with longer term procedures.
64
What things can make the trachea longer/shorter? What happens to diameter?
Extending the neck (putting head back) stretches the trachea, making it longer.
Making flexible tubes longer makes them more narrow as well (internal diameter reduced).
Putting chin to chest shortens the trachea and makes the diameter larger.. which doesn't help us since we can't intubate people like this.
65
When we inflate the pressure cuff of an ETT, where can we feel the balloon inflate?
Sternal notch/angle at the top of the sternum. The balloon should be right under this area within the trachea.
66
What three regions are included in the upper airway?
Nasopharynx
Oropharynx
Laryngealpharynx
67
What is the larynx, and where is it connected superiorly?
Cartilaginous structure that floats in the middle of the neck. It's connected to the hyoid bone superiorly, which is secured/clamped through ligaments and skeletal muscles, specifically the pharyngeal muscles.
68
What is the structure of tracheal cartilage, and what is another name for this piece of cartilage?
Annular ligaments
Not continuous, C shaped, have a small opening in the back (facing the esophagus)
69
What two useful things result from the small opening in the back of annular ligaments?
Helps swallow
Helps cough up gunk
70
How does the small opening in the back of annular ligaments help people swallow?
"We can put big things in the esophagus!" - Schmidt
Makes sense to have a space here to allow for that
71
How does the small opening in the back of annular ligaments help clear secretions?
The connective tissue in the back of the annular ligament/trachea gets an infolding, which divides the trachea into two areas. This creates a high velocity to get rid of junk we want to get rid of.
72
How does gunk come from the lungs into the upper trachea before we cough it up?
We have cilia and goblet cells. Cilia sweep the gunk up, while goblet cells produce mucous. Cilia do a good job, but sometimes you need a good cough to get it all out.
73
How fast does the air move when we cough, roughly?
100mph
74
Having the same amount of air flowing through a divided tube rather than an undivided tube ____ air flow
Increases - this is the purpose of the infolding of the annular ligaments when we cough
75
What is the largest ligament going across the front of the larynx, and what does it do?
Thyrohyoid membrane - connects the top of the thyroid cartilage to the hyoid bone.
75
In the larynx, what is the one full circle piece of cartilage that is continuous?
Cricoid cartilage
76
What is the most narrow point of the airway in a patient younger than 10y/o?
Cricoid cartilage
77
What is the most narrow part of the airway in a patient older than 10 years old?
Volcal cords
78
What's another name for vocal cords?
Transglottis space
79
When might putting pressure on the cricoid cartilage not work for reducing aspiration?
Maybe if someone had severe trauma that severed the cricoid cartilage and make it an incomplete ring. Without a full ring, pressure could not be applied.
80
Can you reduce aspiration risk by putting pressure on tracheal cartilage?
No, it's not a full ring, won't help
81
The cricothyroid muscle connects the front of the thyroid cartilage to the rear of the cricoid cartilage. When it contracts, what happens?
The voice box is pulled down
82
The vocal cords are attached to the laryngeal prominence. What happens when this is pulled down (cricothyroid muscle contracts)?
Cords are tightened, making breathing a little harder since there's tension
83
Slide to study attachment points of laryngeal muscles for self study, he kind of skipped over this slide
84
What is the opening between the vocal cords called?
Rima glottidis
OR
Rima glottis
84
How many sets of laryngeal muscles are there?
6
85
What is the only laryngeal muscle that is fully exterior of the larynx?
What effect does it have on the rima glottidis?
What is the action on the vocal folds?
#1 Cricothyroid muscle
No effect on the rima glottidis
Tightens the vocal folds
86
What laryngeal muscle is parallel with the vocal cords?
What effect does it have on the rima glottidis?
What is the action on the vocal folds?
Is it similar to another laryngeal muscle?
#2 vocalis muscle
None
Tightens the vocal folds
Similar to the cricothyroid muscle, just a different location.
87
What laryngeal muscle is attached to the thyroid cartilage and the back part of the arytenoid cartilage?
What effect does it have on the rima glottidis?
What is the action on the vocal folds?
Thyroarytenoid muscle #3
Closes rima glottidis due to the arytenoid having an axis to swivel/rotate
Contraction causes adduction (comes closer together) the vocal cords
88
When the Thyroarytenoid muscle contracts, which way does the left arytenoid cartilage spin?
How about the right?
Left - spins clockwise
Right - spins counterclockwise
89
Which laryngeal muscle transverses the space between the two arytenoid cartilages? What can we think of this as?
What effect does it have on the rima glottidis?
What is the action on the vocal folds?
What does the function of this muscles actions depend on?
Transverse arytenoid muscle #4; think of it as a cylinder that is flexible/bendable
Closes the rima glottidis
Contraction adducts (makes closer together) the vocal cords
Function depends on these structures being flexible*
89
Which laryngeal muscle connects the cricoid to the arytenoid cartilage?
Where does it connect to the cricoid cartilage?
What effect does it have on the rima glottidis?
What is the action on the vocal folds?
Posterior cricoarytenoid muscle #5
Connects to the medial posterior side of the cricoid cartilage
Contraction OPENS the rima glottidis
Contraction abducts the vocal folds, meaning it makes them wider.
90
When the posterior cricoarytenoid muscle contracts, which way does the arytenoid cartilage spin (both left and right side)?
Right - clockwise
Left - counter clockwise
91
How many laryngeal muscles serve to open the vocal cords?
Only one set of six laryngeal muscles open the vocal folds. That muscle is the Posterior cricoarytenoid muscle.
92
If someone has a bad set of posterior cricoarytenoid muscles, what happens to them?
They have a terrible time breathing d/t not being able to keep the airway open.
93
Which laryngeal muscle connects to the lateral side of the arytenoid cartilage?
What effect does it have on the rima glottidis?
What is the action on the vocal folds?
Lateral cricoarytenoid muscle #6
Contraction closes the rima glottidis
Adducts (brings closer together) the vocal cords when contracted.
94
Which way does the lateral cricoarytenoid muscle spin the arytenoid cartilage when contracted? (both left and right)
Right - counter clockwise
Left - clockwise
95
Why do airplanes cruise at high altitudes?
Better fuel economy as the air is less dense, leading to less friction on the airframe.
96
Jet airplanes fly higher than Mount Everest. How come all the passengers just don't die?
Airplanes are pressurized to mimic the conditions at 8,000ft. (Guyton table 44-1)
97
What is the barometric pressure at 30,000ft?
~226mmHg
97
Why don't airplanes pressurize to sea level?
More pressure = more danger (both in inspired values and explosion)
97
If an airplane is pressurized, why wouldn't you want someone with bad lungs or a bad heart to fly?
The barometric pressure is = to that at 8000ft, so oxygen content is still a little lower.
Hypoxic pulmonary vasoconstriction will be present. If vessels constrict, the right heart will have to work harder. This can exacerbate lung/heart issues.
98
When airplanes depressurize, oxygen masks drop from the ceiling. How do these work?
There is a metal box filled with chemicals that when pulled, produces heat (exothermic) and oxygen. This oxygen is more concentrated than the environment, which helps you survive until reaching a safe altitude/atmospheric pressure. The bag won't inflate, but has enough oxygen to keep you alive.
PS put your mask on before helping other people.. can't help people if you're dead
99
If there is sudden decompression of an airplane at 40,000ft, what is the PO2? What is concerning about this?
PO2 29mmHg
Gas exchange will happen in reverse (from capillaries to the lower concentration in the cabin), leading to rapid consciousness loss. Sure, can hold your breath, but not for long.
100
Do pilots get the little air mask from the ceiling?
No, they have a compressed 100% oxygen canister with them with a tight mask, providing oxygen + pressurization. This is why facial hair is prohibited in aviation jobs requiring flying pressurized airplanes.
101
After decompression of an airplane, gas exchange happens in reverse and oxygen is sucked out of the capillaries to the environment.
What about oxygen on hemoglobin?
Oxygen is pulled off of hemoglobin
102
Regarding the metal box that produces oxygen for passengers after sudden decompression in an aircraft - what is bad/dangerous about the way it produces oxygen?
It's an exothermic reaction. If this goes off at a bad time, can cause fire/explosions. All of these metal boxes are next to each other, which further compounds the danger. They need to be maintained regularly.
103
What are scuba tanks typically filled with and why?
Compressed atmospheric air, not 100% oxygen.
Reasons: Cheap, and it isn't 100% oxygen meaning that there is no risk of explosion or fire.
104
Nitrogen is insoluble and there is not much space for it in the blood.
We have some in the blood. What pressure is this equal to, and what is the number associated?
80% atmospheric pressure = nitrogen
At sea level, the partial pressure of N in the alveoli will be = to the partial pressure in the blood. 569mmHg = PaN2
As pressure increases, there is still 80% nitrogen in the blood, which is why at depths the nitrogen concentration gets so high in the blood. Nitrogen gets pushed into the blood.
105
What are the two concerns with nitrogen toxicity? Which one is a bigger concern?
AMS & coming back to the surface rapidly
Rapidly resurfacing = most concerning d/t decompression sickness
106
What happens with sudden decompression sickness? (think scuba)
Pressures adjust - only way for this to happen is for nitrogen coming out of solution (blood) and forming small air emboli within the circulatory system. Can lead to a very bad day if some of these bubbles combine and travel to the left coronary artery. Some places will tolerate nitrogen, and others are lethal.
"That's it for 'ya." - Schmidt
107
How do you prevent decompression sickness?
Ascend slowly from the ocean, make it gradual.
108
If there is an emergency requiring rapid ascent while scubaing, what do you need to do to prevent decompression sickness?
Find a Hyperbaric chamber (high pressure environment that releases pressure gradually).
109
What was the movie Schmidt asked about where there was a space station on mars that Arnold Schwarzenegger was on that had a scene where there was a decompression in the space station?
The scene had skin bubbling.. what was that about?
Total recall
Nitrogen coming out of solution and going under the skin. Essentially, this is what boiling blood is.
^It's the same as boiling water.. liquid turns to gas, gas escapes the solution
110
A standard hyperbaric chamber simulates how many ATMs?
What about a military one?
3x atmospheric pressure
Military can go much higher, but is very expensive and not really needed.. also dangerous because more pressure = bigger bomb
110
Where might there be a hyperbaric chamber that is more like a room for several people (and not called a hyperbaric chamber, just similar)?
What's the downside?
Oil rigs in the gulf have active divers all the time. Regularly going to deep depths? Might be easier to just live at high pressure so the body doesn't have to adjust between dives.
Downside: Expensive (both to build and to ensure practically a bomb on an oil rig).
111
What are hyperbaric chambers useful for?
Treatment of rapid decompression
Diabetic wound care (problem with circulatory/immune system)
112
What is required by the immune system for oxidative stress?
Oxygen
112
Why do diabetics have issues with wound healing? (long sorry)
Uncontrolled blood sugar lead to sticky vessels, and the immune system destroys things that don't need to be destroyed while not destroying actual contaminants.
As CV system gets destroyed, the ability to heal woulds gets destroyed as well as oxygen delivery isn't as good.
Note that oxygen is required by the immune system. Hyperbaric chambers (or FiO2 100%) can help push air into blood, leading to beneficial oxidative stress. Bacteria/viruses don't have protection available for this, and they die.
113
Where might a hyperbaric chamber be found?
Large academic hospitals. They are large, expensive, and are an insurance risk, so smaller hospitals are unlikely to carry these.
Luckily, some are portable and can be moved by semi trucks.
114
What prominent pop star had a hyperbaric chamber in his house?
Michael Jackson, as quoted by the tabloids/national enquirer
114
For a multi person hyperbaric chamber room, why isn't the whole room pumped with 100% oxygen?
Expensive, not really needed.. Bomb/flammable as well
Instead, little bubble head masks are put on each person. Oxygen levels are adjusted within their bubble by a nurse on staff.
115
In the blood, oxygen is relatively ____. It likes to be carried on ____.
Insoluble
Hemoglobin
116
How can you increase the amount of oxygen blood carries past the point that hemoglobin can carry?
Increase PAO2 (alveolar) with a FiO2 above .21, or use a hyperbaric chamber (more environmental pressure)
^Or both. This extra oxygen is pushed into the dissolved form.
116
What FiO2 do we frequently use in the OR, and why?
0.30
With general anesthesia, hypoxic pulmonary vasoconstriction and airway reactivity is goofed up. Meaning, some air might be going to areas that won't have good gas exchange.
Using a higher FiO2 compensates for the loss of HPV in general anesthesia.
117
Here's a graph to study and memorize
118
Other than oxygen and nitrogen, what gas do we have to worry about increasing while diving?
CO2 - can cause problems with vast excess
119
What are the four dangerous oxygen molecules that can be formed in the body?
Superoxide (O2-)
Peroxynitrite (OONO-)
Hydrogen Peroxide (H2O2)
Nitric Oxide (NO)
120
What does superoxide do?
Has an extra electron that is unpaired and very reactive. This means it can degrade lots of compounds in the body (not great)
121
What is nitric oxide good for?
What is the problem if you have too much in the body?
Good for relaxing blood vessels
Too much in the presence of other compounds? Will form extraordinarily dangerous compounds such as peroxynitrite (OONO-)
122
Why is Peroxynitrite (OONO-) bad, and where does it come from?
Can interact and mutate DNA, damaging cells, and leading to cancer
Superoxide (O2-) + Nitric Oxide (NO) = Peroxynitrite (OONO-)
^Note that this won't form if there are small concentrations of superoxide and nitric oxide. This is only a problem if there is a LARGE amount of nitric oxide and superoxide.
123
Hydrogen peroxide (H2O2) can be formed in the body. What does it do?
Reactive oxygen species (ROS) used as an antiseptic, helps with infections.
Body uses this in some places such as macrophages and immune killer cells. These sells generate it and pump it into something it wants to degrade.
123
What can break down hydrogen peroxide or other peroxides?
Peroxidases
124
What can degrade superoxide (O2-)?
Superoxide dismutase
125
What can form or degrade hydrogen peroxide depending on which way the chemical equation is running?
Catalase
126
What does a good job scavenging excess reactive oxygen species (ROS)?
Acetylcysteine
127
What is ROS?
Reactive oxygen species
127
What does acetylcysteine smell and taste like?
"funny" - Schmidt
128
What is N-Acetylcysteine?
A supplement used to cut down on liver damage from Tylenol overdose.
It is over the counter, but the FDA wants to regulate it and make it prescription only for whatever reason.
Good at destroying dangerous oxygen compounds such as superoxide, peroxynitrite, hydrogen peroxide, and nitric oxide.
129
Why is Tylenol overdose an issue for the body?
Overwhelms the livers ability to degrade the toxin that results from CYP450 metabolism of Tylenol. All liver damage is reactive oxygen species (ROS) related.
A compound such as N-Acetylcysteine can scavenge the ROS and save lots of liver.
130
What is an iron lung?
Oldschool way of ventilating someone who doesn't have adequate respiratory muscle.
Cylinder with a cap on the end, and a rubber/leather diaphragm that fits around the patients upper body/neck. This creates a pressure seal between the tank and the environment. The diaphragm of the iron lung is pulled outward, creating a negative pressure, which sucks air into the patients mouth/lungs assuming the airway is open.
131
When did the iron lung become popular?
1960s with polio, which is an infection that destroys the ability of the nervous system to communicate with skeletal muscle (which is needed to breathe).
132
What is the benefit of the iron lung over positive pressure ventilation?
Less trauma, and is closer to how the body normally works as opposed to PPV
133
What is the alveolar gas equation?
Note: He said we don't need this, but just throwing it out there.
134
What information must be known to use the alveolar gas equation?
Respiratory quotient/respiratory exchange ratio, which is a ratio of how much O2 is used and how much CO2 is produced. It's not 1 for 1, but is close.
135
What can you calculate without even taking a blood draw by using the alveolar gas equation?
Arterial PCO2
136
Who is this guy?
Christopher Reeves, he has a trach with PPV, he died in a couple years from pulmonary problems as a result from PPV.
Meanwhile, our Polio man on the left lived in his iron lung for 40-50 years. He was the last known living iron (lung) man living in Dallas. He was at parkland and obtained a law degree while inside the iron lung, where he then practiced as a lawyer. Spare parts were a problem.
137
How does the lung normally fill itself?
Diaphragm contracts, reduces pleural pressure, and the walls of the lungs are pulled closer to the chest wall, or down when the diaphragm drops. This pulls air in in an even manner.
138
When breathing with negative pressure breathing, how do the alveoli fill?
Alveoli closest to the superficial border of the lung will fill first because they're closer to the negative pressure that is pulling air into the lung.
This results in deeper alveoli getting stretched out mores than the more superficial alveoli.
139
When using PPV, how does the filling of alveoli change?
Alveoli closest to the large airway are filled first, while deeper alveoli push on alveoli between them and the border of the lungs, resulting in less air being in the deeper alveoli. This is the reverse of normal breathing.
140
Why would someone choose PPV over an iron lung?
PPV is mobile, while the iron lung is fixed. That being said, the iron lung is closer to normal breathing.
141
What two issues were common in polio victims?
Mobility issues + comfort issues
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
170
171
172
173
174
175
176
177
178
179
180
181
