RESP Flashcards
1
Q
17-25 weeks gestational age is what period of lung development?
A
Canalicular
2
Q
26-35 weeks gestational age is what period of lung development?
A
Saccular
3
Q
36 weeks gestational age - adolescence is what period of lung development?
A
Alveolar
4
Q
7-16 weeks gestational age is what period of lung development?
A
Pseudoglandular
5
Q
Which period of lung development do acini form?
A
Canalicular (17-25 weeks)
6
Q
Surfactant production occurs during what period of lung development?
A
Saccular (26-35 weeks)
7
Q
Which cells create surfactant?
A
type II epithelial cells of the lung
8
Q
How many times does the respiratory tree branch?
A
24
9
Q
What is the primary unit of the lung?
A
pulmonary lobule
10
Q
What makes up a pulmonary lobule?
A
1 terminal bronchiole and 2 acinus (respiratory bronchiole and alveoli)
11
Q
What is an acinus?
A
respiratory bronchiole and alveoli (working unit of the lung)
12
Q
What are the 2 sources of blood supply to the lungs?
A
pulmonary arterial (major) and systemic arterial (bronchial arteries from aorta)
13
Q
What is the lung volume at which thoracic cavity recoil (outward) and lung recoil (inward) are equal?
A
functional residual capacity (FRC)
14
Q
Compliance =
A
C = change in V/change in P
15
Q
Surfactant: at low lung volumes (small radius), increase or decrease surface tension?
A
decrease
16
Q
Surfactant: at high lung volumes (high radius), increase or decrease surface tension?
A
increase
17
Q
Surfactant is mainly made up of what molecule?
A
DPPC (dipalmitoyl phosphatidyl choline; a lipid)
18
Q
Without surfactant, gas will preferentially redistribute into which alveoli, small or large?
A
large (lower P)
19
Q
At lung apices: intrapleural pressure more negative or less negative?
A
more negative (-10 at apex, -2 at base)
20
Q
Where is the highest transmural pressure in the lung: apices or bases?
A
apices (more negative intrapleural pressure (out), so in - - out = bigger number); thus volumes highest at apices
21
Q
What is the change in compliance related to the phase of breathing (inspiration vs expiration) called?
A
hysteresis
22
Q
Time constant is the time required to fill what % of volume?
A
63%
23
Q
Time constant T =
A
T = R x C
24
Q
What is the Law of Laplace?
A
P = 2T/R (pressure, tension, radius)
25
What is Poiseuille's law?
Q = pie*Pr^4/8nl (pressure, radius, n = viscosity, l = length); applies to laminar flow
26
Changing the viscosity of gas: important for laminar or turbulent flow?
laminar flow (Poiseuille's law)
27
Changing density of gas: important for laminar or turbulent flow?
turbulent flow
28
Large airways: turbulent or laminar flow?
turbulent
29
Helium/heliox effects what property of gas?
density
30
Heliox/helium decreases the density of: turbulent or laminar flowing gas?
turbulent (large airways)
31
What is a normal A-a gradient?
3-8 mmHg
32
What are the 5 causes of hypoxemia?
V/Q mismatch, R to L shunt, diffusion defect, hypoventilation, decreased FiO2 (altitude)
33
Which causes of hypoxemia have an increased A-a gradient?
V/Q mismatch, shunt, diffusion defect
34
Ventilation: higher at apices or bases?
bases
35
Flow (Q): higher at apices or bases?
bases
36
What area of the lung has the highest V/Q ratio, apices or bases?
apices
37
What is carbonic acid?
H2CO3
38
Most of CO2 in the blood is in what form?
H2CO3
39
How long does it take kidneys to compensate acid/base status?
At least 6 hours
40
What do kidneys excrete during acidosis?
NH4+ (ammonium)
41
What is ammonia?
NH3
42
What is ammonium?
NH4+
43
For every 10 mmHg increase in PaCO2, HCO3- increases by how much?
4 mEq/L
44
What is the RQ for lipids?
0.7
45
What is the RQ for carbohydrates?
1.0
46
What is the RQ for protein?
0.8
47
What is a normal time constant?
0.1-0.2 seconds
48
What is PAO2 at sea level and FiO2 0.21?
100 mmHg
49
What is Patm? (atmospheric pressure at sea level)
760 mmHg
50
What is PH20? (at sea level)
47 mmHg
51
What is P50 (hemoglobin dissociation curve)?
PaO2 at which hemoglobin is 50% saturated with O2
52
What is the normal P50?
27 mmHg
53
A leftward shift on the oxyhemoglobin curve: increase or decrease P50?
decrease
54
A rightward shift on the oxyhemoglobin curve: increase or decrease P50?
increase
55
Which "effect" describes that the affinity of hemoglobin for oxygen changes depending on H+/CO2 concentration?
Bohr effect
56
Which "effect" describes that the affinity of hemoglobin for carbon dioxide/H+ depends on O2 in the blood ?
Haldane effect
57
V/Q > 1?
wasted ventilation
58
V/Q <1?
venous admixture (physiologic shunt)
59
In a normal breath, what % of each tidal volume is anatomic dead space?
25%
60
Dead space ventilation: increases or decreases with tachypnea?
increases
61
What is the equation to estimate dead space?
Vd/Vt = (PaCO2 - PetCO2)/PaCO2
62
Intrapulmonary shunt fraction equation?
Qs/Qt = (CcO2 - CaO2)/(CcO2 - CvO2)
63
What is the normal intrapulmonary shunt fraction %?
10%
64
Blood remains in a pulmonary capillary for how long?
0.75 seconds
65
Pulmonary capillary blood approximates alveolar oxygen in how much time (normally)?
0.25 seconds
66
For every 10 mmHg increase in PaCO2, pH changes by how much?
0.08 units
67
For every 10 mEq/L change in base excess, pH changes by how much?
0.15 units
68
OI (oxygenation index) =
OI = MAP x FiO2 / PaO2
69
Oxyhemoglobin reflects which light, 660nm or 900nm?
660nm (red)
70
Pulse oximetry utilizes which two wavelengths of light?
red (660 nm) and near-infrared (900nm)
71
What oxygen saturation would be expected in carbon monoxide poisoning and why?
Normal (overestimated) due to carboxyhemoglobin reflecting light similarly to oxyhemoglobin (at red 660nm)
72
What oxygen saturation would be expected in methemoglobinemia and why?
80-85% because MetHb absorbs both 660nm and 900nm equally
73
Oxyhemoglobin reflects which wavelength in a pulse oximeter?
660nm (red)
74
Which type of capnometer uses a light-emitting detector?
mainstream capnometer
75
Which type of capnometer continuously aspirates a small amount of gas?
sidestream capnometer
76
Which type of capnometer adds dead space to a ventilator circuit?
mainstream capnometer
77
What is the normal PaCO2 - PetCO2 gradient?
2-5 mmHg
78
PALS guidelines recommend targeting what etCO2 goal in CPR?
>15 mmHg
79
Diagnosis: infant with ineffective respiratory efforts at rest that improve during crying?
choanal atresia (crying is mouth breathing)
80
What causes atypical expiratory stridor in infancy?
subglottic cysts
81
What is the most common etiologic agent of croup?
Parainfluenza type I
82
What are the most common etiologic agents of bacterial tracheitis (croup superinfection)?
S aureus, Moraxella
83
What age group is effected by retropharyngeal abscesses (RPA)?
under age 5 years
84
What age group is effected by peritonsillar abscesses (PTA)?
school age to adolescent
85
What organism is implicated in Lemierre disease?
Fusobacterium necrophorum
86
What is Lemierre disease?
septic thrombophlebitis of the internal jugular vein
87
What is the most common etiologic agent of acute epiglottitis?
Haemophilus influenzae type B
88
What causes laryngeal papillomatosis?
HPV
89
Acquired subglottic stenosis: improve or no?
unlikely to improve
90
Obstruction at what level of the airway causes stertor?
supraglottic obstruction
91
Obstruction at what level of the airway causes high-pitched stridor and weak voice?
laryngeal obstruction
92
Obstruction at what level of the airway causes high-pitched stridor and hoarse voice?
subglottic obstruction
93
How do you size for an appropriate nasopharyngeal airway?
from nostril to tragus
94
A needle cricothyrotomy can be performed with what gauge angiocaths?
14 or 16 gauge
95
A needle cricothyrotomy is performed by inserting a needle between which 2 structures?
thyroid cartilage and cricoid cartilage (in the cricoid membrane)
96
What medications should be avoided in asthmatics?
beta blockers, aspirin, NSAIDs
97
What is Omalizumab?
anti-IgE antibody (allergic asthma treatment)
98
What is pulsus paradoxus?
exaggeration (>10 mmHg) in normal decrease in SBP during inspiration (RV fills so LV small, increased afterload to LV)
99
How does magnesium work in asthma?
Prevents calcium intake into smooth muscle cells and prevents mast cell degranulation
100
How does aminophylline work in asthma?
Nonselective PDE inhibition and inhibits adenosine-induced bronchoconstriction
101
What is levalbuterol (vs albuterol)?
R-albuterol only (vs albuterol, a stereoisomer mix of R- and S)
102
Which is the therapeutically active stereoisomer of albuterol, R or S?
R (levalbuterol)
103
Consider tapering steroids if used for what duration?
>2 weeks
104
If using magnesium drip for asthma, what is the goal magnesium level?
4 mg/dL
105
Flow is turbulent when the Reynolds number (Re) is what?
>2500
106
Mechanical ventilation for asthma: goal I:E ratio?
1:4 or higher
107
Dynamic compliance =
dynamic compliance = TV/(PIP - PEEP)
108
What OI values constitute mild ARDS (PALICC 2015)?
4-7 (<8)
109
What OI values constitute moderate ARDS (PALICC 2015)?
8-15 (<16)
110
What OI values constitute severe ARDS (PALICC 2015)?
>/= 16
111
Starling equation Jv =
Jv = K[(Pc - Pi) - σ(πc - πi)]
112
Blood flow from which vessels contribute to the physiologic intrapulmonary shunt?
thebesian veins (cardiac veins), bronchial veins
113
End of the acute phase of ARDS sees formation of what?
hyaline membrane
114
The subacute phase of ARDS involves what?
fibroblast proliferation
115
What biomarker indicates fibroproliferation in ARDS?
type III procollagen
116
Plateau pressure should be limited to what in ARDS?
117
What is driving pressure?
Driving pressure = Plateau pressure - PEEP
118
What goal driving pressure is desirable in ARDS?
<14-18
119
A deadspace fraction (Vd/Vt) of what indicates higher mortality in ARDS?
>25%
120
How to set mPaw in HFOV?
4-8 cmH2O above mPaw on conventional vent
121
How does Hz/frequency relate to Vt in HFOV?
Higher Hz (higher frequency) = lower Vt
122
What starting dP/amplitude in HFOV?
35-40 cmH2O
123
How to set Phigh in APRV?
plateau pressure in CMV
124
How to set Tlow in APRV?
set at time it takes for expiratory flow to fall to 50% of peak expiratory flow
125
What is the only FDA-approved antiviral for RSV?
Ribavirin
126
Palivizumab is a MAB directed against what?
RSV-F glycoprotein
127
Palivizumab should be given for how many doses in a season?
5 doses
128
Palivizumab should be given how frequently?
monthly
129
Palivizumab should be redosed after what major insult?
CPB
130
When is the RSV season for Palivizumab?
November to March
131
Premature infants born at what gestational age need Palivizumab?
<29 weeks
132
What is the predominant immunoglobulin in the upper respiratory tract?
IgA
133
HUS is associated with which common respiratory pathogen?
S pneumo
134
Which S pneumo strains are associated with HUS?
neuraminidase-producing strains
135
Diagnosis: newborn with respiratory distress and peripheral eosinophilia?
Chlamydia trachomatis
136
What toxin is present in most CA-MRSA isolates (but not HA-MRSA)?
PVL (panton valentine leukocidin)
137
In cases of toxic shock by GAS, Clindamycin is added to inhibit what?
production of (streptococcal pyrogenic) exotoxins A (SPE-A) and B (SPE-B)
138
What is the treatment for Bordetella pertussis?
erythromycin or azithromycin
139
Mechanism of action of oseltamivir?
neuraminidase inhibitor
140
What medication is contraindicated in influenza?
aspirin (Reye syndrome)
141
What two organ systems are implicated in Reye syndrome?
brain and liver
142
What medication is used in severe adenovirus (especially in HSCT)?
cidofovir
143
Diagnosis: cardiorespiratory illness, rodent/mouse feces, southwest US?
hantavirus
144
Malignant effusion: exudative or transudative?
exudative
145
ARDS effusion: exudative or transudative?
exudative
146
Heart failure effusion: exudative or transudative?
transudative
147
What pH of pleural fluid indicates exudative effusion?
<7.2
148
What pH of pleural fluid indicates it is likely to get better with antibiotics alone?
>7.3
149
What is the global V/Q ratio of the lung?
0.8
150
Anatomical dead space normally represents what percent of a normal breath?
30%
151
What is the volume at which airway closure begins to occur?
closing capacity (CC)
152
In obstructive lung physiology, ideal PEEP is set at what value?
80% of intrinsic (auto) PEEP
153
What is the normal I:E ratio?
1:3 or 1:4
154
A NIF (negative inspiratory force) of what value is reassuring for extubation?
30 cmH2O
155
The optimal ventilator circuit would have low/high resistance and low/high compliance?
low resistance, low compliance
156
In HFOV, when choosing Hz/f, do you want to set it highest or lowest for weight?
set highest f possible
157
Why is it not feasible for an older child to breath spontaneously while on HFOV?
a child's (compared to neonate) inspiratory flow demand exceeds bias flow
158
Consider transitioning back to CMV when Paw on HFOV reaches what value?
Paw
159
Flow-volume loop: dynamic extrathoracic obstruction?
inspiratory limb flattening
160
Flow-volume loop: dynamic intrathoracic obstruction?
expiratory limb flattening
161
Flow-volume loop: fixed obstruction?
inspiratory and expiratory flattening
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