Respiratory Flashcards
1
Q
peculiar feature about newborn respiratory physiology
A
obligate nose breathers
2
Q
RV vs. ERV
A
RV is the volume of air remaining after a maximal expiration. ERV is the volume remaining after normal expiration.
3
Q
Characteristic of NRDS
A
Atelectasis. This is because without surfactant, the surface tension of the small alveoli collapse into the large aveoli.
- Lack of surfactant also decreases compliance.
4
Q
When does surfactant appear?
A
Around week 24
5
Q
Asthma physiology
A
Wheezing + tachypnea. Hypoxemia causes tachypnea, which drives PCO2 down.
6
Q
What happens to intrapleural pressure with inspiration?
A
Becomes more negative than it is at rest or during expiration.
7
Q
When airway pressure is equal to atmospheric pressure…
A
This is equilibrium and there is no airflow. ***Volume in the lungs = FRC.
8
Q
What happens to alveolar PO2 with a PE?
A
Alveolar PO2 is equal to the PO2 in inspired air.
9
Q
Blood flow in the systemic vs. pulmonary circulations…
A
Blood flow in the systemic and pulmonary circulations is nearly equal. Pulmonary flow is slightly less than the systemic flow because about 2% of systemic CO bypasses the lungs.
10
Q
Resistance in pulmonary circulation
A
Resistance in the pulmonary circulation is lower than in the systemic circulation.
11
Q
Compared with the apex of the lung, the base of the lung has…
A
a higher pulmonary capillary **PCO2
12
Q
Mean arterial PO2 and PCO2 during exercise…
A
There is no change in mean arterial PO2 or PCO2. This is because ventilation rate increases to match the increased O2 consumption and CO2 production.
BUT venous pCO2 increases.
13
Q
Central chemoreceptor location
A
Medulla. (medullary chemoreceptors).
14
Q
Peripheral chemoreceptor location
A
Carotid and aortic bodies
15
Q
If an area of the lung is not ventilated because of bronchial obstruction, the pulmonary capillary blood serving that area will have a PO2 that is…
A
Equal to mixed venous PO2. This is because pulmonary blood will NOT equilibriate with alveolar PO2 but will have a Po2 equal to that of mixed venous blood.
16
Q
What happens with transporting CO2 from tissues to lungs?
A
CO2 is hydrated to form H+ and HCO3- in RBCs. H+ is buffered inside the RBCs by deoxyhemoglobin, which ACIDIFIES RBCs. HCO3- leaves RBCs in exchange for Cl- and is carried to the lungs in the plasma.
17
Q
Carbonic anhydrase
A
Sits in RBCs and CO2 + H2O H2CO3.
18
Q
What buffers H+ in RBCs?
A
Deoxyhemoglobin
19
Q
hypoxemia
A
Decreased arterial PO2
20
Q
Causes of hypoxemia
A
1) high altitude
2) hypoventilation
3) right to left cardiac shunt
21
Q
Which cause of hypoxemia is associated with an increased AA gradient?
A
Right-to-left cardiac shunt. This is because the shunt “dilutes” the PO2 of the normally oxygenated blood thus decreasing the arterial O2.
22
Q
Causes of hypoxemia with normal A-a gradient?
A
High altitude + hypoventilation
23
Q
Causes of hypoxemia with increased A-a gradient?
A
1) V/Q mismatch
2) Diffusion limitation (fibrosis)
3) right-to-left shunt
24
Q
Why is pH of venous blood only slightly more acidic than the pH of arterial blood?
A
H+ generated from CO2 and H2O is buffered by deoxyhemoglobin in venous blood.
25
Function of J (juxtacapillary) receptors
Receptors located in the alveolar walls, close to the capillaries. Engorgement of pulmonarry capillaries such as with left HF stimulates J receptors, which then cause rapid, shallow breathing.
26
How do you calculate dead space?
Tidal volume x ((arterial PCO2-expired PCO2)/arterial PCO2))
27
Initial development of lungs and when it happens
Lung bud buds off from distal end of respiratory diverticulum during week 4
28
embryonic stage events + timeframe
4-7 weeks
| lung bud --> trachea --> mainstem bronchi --> secondary (lobar) bronchi --> tertiary (segmental) bronchi
29
what do errors in embryonic stage lead to?
TE fistula
30
pseudoglandular stage events + timeframe
5-16 weeks.
| Endodermal tubules --> terminal bronchioles. Surrounded by modest capillary network.
31
Canalicular stage events + timeframe
16-26 weeks.
Terminal bronchioles --> respiratory bronchioles --> alveolar ducts. Surrounded by prominent capillary network.
*increase in airway diameter.
32
When is respiration possible?
Canalicular stage, at 25 weeks
33
Saccular stage events + timeframe
Weeks 26-birth.
| Alveolar ducts --> terminal sacs. Terminal sacs separated by primary septa. Pneumocytes develop.
34
Alveolar stage events + timeframe
Weeks 32-8 years.
| Terminal sacs--> adult alveoli (due to secondary separation)
35
of alveoli at birth and at 8 ye
At birth: 20-70 million
| By 8 years: 300-400 million
36
How does breathing in utero work?
Aspiration and expulsion of amniotic fluid, which leads to increased vascular resistance.
37
Changes in pulmonary vascular resistance at birth.
At birth, fluid gets replaced with air, leading to decreased pulmonary vascular resistance.
38
Pulmonary hypoplasia
Poorly developed bronchial tree with abnormal histology.
39
Which lung does pulmonary hypoplasia usually involve?
Right lung
40
bronchogenic cysts
* Code: Jeep broncho in living room/bronchogenic cysts. Bronchi hanging overhead + guts hanging on top/caused by abnormal budding of the foregut (lung buds arise from the ventral foregut) and dilation of terminal or large bronchi. Metal railing around broncho + round cysts all over car + air tanks in back spraying air everywhere/discrete + round + sharply defined + air-filled densities on CXR. Chelsea on top with drains in her chest + bugs flying into mouth/Drain poorly and cause chronic infections.
* Location: Living room
41
Collapsing pressure equation
P = (2(surface tension))/radius
42
surfactant mechanism
decreases alveolar surface tension, preventing alveolar collapse, DECREASING lung recoil and increasing compliance.
43
Club cell histology
Conciliated; low-columnar/cuboidal with secretory granules.
44
Club cell function
1) Secrete component of surfactant.
2) Degrade toxins
3) Act as reserve cells
45
NRDS presentation on CXR
ground glass
46
L/S ratio predictive of NRDS
less than 1.5
47
Screening tests for fetal lung maturity
1) L/S ratio
2) Foam stability index test
3) surfactant-albumin ratio
48
Sequela of NRDS
1) PDA
2) metabolic acidosis
3) necrotizing enterocolitis
49
NRDS RF's
1) prematurity
2) maternal diabetes (due to increased fetal insulin)
3) C-section delivery
50
Why is C-section a risk factor for NRDS?
Decreased release of fetal glucocorticoids.
51
NRDS management
Maternal steroids before birth; artificial surfactant for infant.
52
Therapeutic O2 can cause...
RIB
Retinopathy of prematurity
Intraventricular hemorrhage
Bronchopulmonary dysplasia
53
Large airways
Nose --> bronchi
54
Small airways
Bronchioles --> terminal bronchioles
55
Function of conducting zone
Warm, humidify and filter airs but no gas exchange (dead space).
56
Extent of cartilage and goblet cells
End of bronchi
57
Epithelium of bronchus
psuedostratified ciliated columnar cells
58
Extent of psuedostratified ciliated columnar cells
Extend to beginning of terminal bronchioles, then transition to cuboidal cells
59
Extent of airway smooth muscle cells
End of terminal bronchioles.
60
Respiratory zone components
Lung parenchyma; respiratory bronchioles + alveolar ducts + alveoli.
61
Histology of respiratory bronchioles
Mostly cuboidal
62
Histology after respiratory bronchioles up to alveoli
simple squamous
63
When do cilia terminate?
Respiratory bronchioles
64
Relation of pulmonary artery to bronchus at each lung hilum
RALS -- Right Anterior; Left Superior
65
Lingula...
left lung
66
If you aspirate a peanut upright where will it end up?
Inferior segment of right inferior lobe.
67
If you aspirate a peanut while supine where will it end up?
superior segment of right inferior lobe
68
central tendon
big tendon in the diaphragm
69
Where does IVC perforate diaphragm?
T8
70
Where does vagus perforate diaphragm?
T10
71
Where does aorta perforate diaphragm?
T12
72
Where does esophagus perforate diaphragm?
T10
73
Where does thoracic duct perforate diaphragm?
T12
74
Where does azygos vein perforate diaphragm?
T12
75
Where does the trachea bifurcate?
T4 (bifourcate)
76
Where does the common carotid bifurcate?
C4 (bifourcate)
77
What innervates the diaphragm?
C3,C4,C5 (Phrenic nerve, C3,C4C5 keeps the diaphragm alive). This explains why pain can be referred to shoulder (C5) and trapezius ridge (C3,4)
78
Typical tidal volume
500 mL
79
What can you not measure by spirometry
1) RV
2) FRC
3) *TLC
80
Dead space equation
FA 633
81
physiologic dead space
anatomic dead space + alveolar dead space
82
Largest contributor to alveolar dead space
Apex of lung
83
anatomic dead space
dead space of conducting airways
84
Pathologic dead space
ventilated but not perfused
85
Minute ventilation equation
Vt x RR
86
alveolar ventilation
VA = (Vt-Vd) x RR
87
Normal dead space volume
150 mL/breath
88
Why is system pressure atmospheric at FRC?
Inward pull of lung is balanced by outward pull of chest wall.
89
When is PVR at minimum?
FRC
90
When is alveolar pressure at FRC?
0
91
compliance expression
deltaV/deltaP. Change in lung volume for a change in pressure.
92
When is compliance increased?
1) emphysema
2) normal aging
* surfactant increases compliance.
93
Hysteresis
Concept that lung inflation curve follows a different curve than lung deflation curve due to need to overcome surface tension forces in inflation.
94
Taut form of hemoglobin
Deoxygenated; low affinity for O2, thus promoting release/unloading.
95
Relaxed form of hemoglobin
High affinity for O2 (300x). Hb exhibits positive cooperatively and negative allostery.
96
Cl affect of hemoglobin
Favors taut form over relaxed form.
97
Fetal Hb structure
2alpha and 2gamma
98
Why does fetal Hb have higher O2 affinity?
Decreased affinity of HbF for 2,3BPG
99
Oxidized Hb
decreased O2 affinity but increased cyanide affinity
100
What do you use to induce methemoglobinemia?
Nitrites, followed by thiosulfate.
101
Other things that can cause methemoglobin
benzocaine
102
carboxyhemoglobin
Hb bound to CO
103
left shift vs. right shift
Right shift = decreased affinity
| Left shift = increased affinity
104
CO poisoning management
100% O2 + hyperbaric O2
105
O2 content of blood equation
= (1.34 x Hb x SaO2) + (0.003 x PaO2
106
normal Hb amount in blood
15 g/dL
107
normally 1 g Hb can bind...
1.34 mL O2
108
O2 binding capacity =
20.1 mL O2/dL blood
109
physiologic effects of decreased Hb on
1) arterial O2 content
2) O2 saturation
3) PaO2
1) decreased
2) no change
3) no change
110
Calculating O2 delivery to tissues
= CO x O2 content of blood
111
CO poisoning effect on total O2 content
Decreased
112
Anemia effect on...
1) Hb concentration
2) %O2 sat of Hb
3) dissolved O2 (PaO2)
4) total O2 content
1) decreased
2) normal
3) normal
4) decreased
113
Polycythemia effect on
1) Hb concentration
2) %O2 sat of Hb
3) dissolved O2 (PaO2)
4) total O2 content
1) increased
2) normal
3) normal
4) increased
114
V/Q mismatch
Either shunt physiology or dead space.
115
Examples of low V/Q
1) chronic bronchitis
2) asthma
3) hepatopulmonary syndrome
4) acute pulmonary edema
116
Perfusion limited gases
1) O2 (normal health)
2) CO2
3) N2O
117
Perfusion limited gas characteristics
1) Gas equilibrates early along the length of the capillary.
| 2) Diffusion can only be increased if blood flow increases.
118
Diffusion limited gases
1) O2 (emphysema, fibrosis)
| 2) CO
119
Diffusion limited gas graph + characteristic
Linear. Gas does not equilibrate by the time blood reaches the end of the capillary.
120
Diffusion equation
FA 613
121
What is the underlying diffusion problem with emphysema?
Decreased area for diffusion
122
DLCO
Extent to which oxygen passes from air sacs of lungs into blood.
123
Hypoxia
Decreased O2 delivery to tissue
124
Causes of hypoxia
1) decreased CO
2) hypoxemia
3) anemia
4) CO poisoning
125
Causes of ischemia
1) impeded arterial flow
| 2) decreased venous drainage
126
V/Q at apex of lung
3 (wasted ventilation), both perfusion and ventilation are reduced, but perfusion is reduced to a greater extent
127
Lung zones
Zone 1 is apex, 2 is middle lobe, 3 is base
128
V/Q at base of lung
0.6 (wasted perfusion)
129
When is ventilation greatest?
base of the lung
130
When is perfusion greatest?
base of the lung
131
Pa,PA,PV in Zone 1
PA greater than Pa greater than Pv
132
Pa,PA,PV in Zone 2
Pa greater than PA greater than PV
133
Pa,PA,PV in Zone 3
Pa greater than Pv greater than PA
134
What happens to V/Q with exercise?
With increased CO, apical capillaries vasodilator, V/Q approaches 1.
135
Relative forms of CO2 transport
1) HCO3- (90%)
2) carbaminohemoglobin (HbCO2) (5%)
3) dissolved CO2 (5%)
136
carbaminohemoglobin
CO2 bound to Hb at N-terminus of globin (not heme)
137
Haldane effect
In lungs, oxygenation of Hb promotes dissociation of H+ from Hb. This shifts equilibrium toward CO2 formation; therefore, CO2 is released from RBCs. (shifts equation to the left)
138
Bohr effect
In peripheral tissue, increased H+ from tissue metabolism shifts curve to right, unloading O2.
139
Pulmonary vasculature response to high altitude
Chronic hypoxic pulmonary vasoconstriction results in pulmonary HTN + RVH.
140
Renal response to high altitude
Increased renal excretion of HCO3- to compensate for respiratory alkalosis (this is why acetazolamide is also given for altitude sickness).
141
Rhinosinusitis pathophys
Obstruction of sinus drainage into the nasal cavity, leading to inflammation and pain over affected area
142
Sinuses typically affected in rhinosusitis and drainage
Maxillary sinuses, which drain into the middle meatus.
143
Common bacterial causes of rhinosinusits
S Pneumonia + H influenza + M cattarhalis
144
Most common area for epistaxis
Anterior segment of nostril (Kiesselach plexus)
145
Life-threatening hemorrhages location?
Posterior segment (sphenopalatine artery)
146
Sphenopalatine branches from...
Maxillary artery
147
Field cancerization
Carcinogen damages wide mucosal area leading to multiple tumors
148
Virchow triad
Stasis + hyper coagulability + endothelial damage
149
Endothelial damage and thrombosis mechanism
Exposed collagen triggers clotting cascade
150
D-dimer characteristics as a test
High sensitivity, low specificity
151
Homan sign
Sign of DVT. Dorsiflexion of foot --> calf pain.
152
Acute management of DVTs
unfractionated heparin or low-molecular weight heparins
153
DVT prophylaxis
unfractionated heparin or low-molecular weight heparins
154
DVT long-term prevention
warfarin + rivaroxaban
155
Imaging test of choice for DVTs
compression ultrasound
156
acid-base disturbance with PEs
Respiratory alkalosis (tachypnic)
157
What composes lines of Zahn?
areas of pink = platelets, fibrin
| red = RBCs
158
Fat emboli triad
hypoxemia + neurologic abnormalities + petechial rash
159
amniotic fluid emboli association
DIC
160
Imaging test of choice for PE
CT pulmonary angiography
161
Cardiac sequela of obstructive lung disease
Chronic hypoxic pulmonary vasoconstriction can lead to cur pulmonale
162
Reid index
Thickness of mucosal gland layer to thickness of war between epithelium and cartilage. (NOT just surface area ratio)
163
Chronic bronchitis diagnosis
Productive cough for greater than 3 months (don't need to consecutive) for over 2 consecutive years.
164
CXR in chronic bronchitis
Normal (mucus buildup is etiology)
165
Centriacinar vs. panacinar emphysema location
centriacinar usually in upper lobes, panacinar frequently in lower lobes.
166
emphysema pathophys
Increased elastase activity leads to loss of elastic fibers leading to increased lung compliance.
167
Breathing pattern in emphysema
Exhalation through pursed lips to increase airway pressure and prevent airway collapse.
168
recoil and compliance in emphysema
Increased compliance, decreased recoil
169
CXR finding in asthma
Peribronchial cuffing
170
Inspiratory/expiratory ratio in asthma
Decreased
171
Bronchiectasis pathophys + presentation
Chronic necrotizing infection of bronchi leading to permanently dilated airways + purulent sputum + recurrent infections + hemoptysis + digital clubbing
172
FEV1/FVC in restrictive lung disease
greater than or equal to 80%
173
ILD characteristics
Decreased diffusing capacity + increased A-a gradient
174
Pulmonary langerhans cell histiocytosis (eosinophilic granuloma)
...
175
Hypersensitivity pneumonitis hypersensitivity type
Mixed type III/IV
176
Hypersensitivity pneumonitis presentation
Dyspnea + cough + chest tightness + headache
177
Pneumoconioses cardiac sequela
Increased risk of cor pulmonale
178
asbestosis professional RF's
Shipbuilding + roofing + plumbing
179
Pathognomonic finding of asbestosis
"Ivory white" calcified, supra diaphragmatic and pleural plaques.
180
asbestosis association
Increased risk of pleural effusions
181
Lung region affected in asbestosis
Lower lobes
182
Lung region affected in asbestosis in berylliosis
Upper lobes
183
Potential treatment for berylliosis
Occasionally responsive to steroids (granulomatous)
184
Coal workers' pneumoconiosis findings
inflammation + fibrosis
185
Coal workers' pneumoconiosis lung region affected
Upper lobes
186
Silicosis professional RF's
Foundries + sandblasting + mines
187
Silicosis pathophys
Macrophages respond to silica and release fibrogenic factors, leading to fibrosis
188
Silicosis and increased TB risk pathophys
Silica disrupts phagolysosomes and impairs macrophages, thus increasing susceptibility to TB.
189
Silicosis lung region affected
Upper lobes
190
PaO2/FIO2 in ARDS
decreased
191
ARDS and fluid overload
no evidence of HF or fluid overload
192
ARDS associations
SPARTAS: Sepsis, Pancreatitis, Pneumonia, Aspiration, uRemia, Trauma, Amniotic fluid embolism, Shock
193
ARDS pathophys
endothelial damage leads to increased alveolar capillary permeability, leading to protein-rich leakage into alveoli, leading to diffuse alveolar damage and noncardiogenic pulmonary edema.
194
ARDS management
Mechanical ventilation with low tidal volumes, address underlying cause.
195
Initial ARDS damage pathophys
Release of neutrophilic substances toxic to alveolar wall --> activation of coagulation cascade --> oxygen derived free radicals
196
PaO2 in sleep apnea
Decreased at night, normal during day
197
Sleep apnea definition
Repeated cessation of breathing greater than 10 seconds during sleep.
198
Sudden death in sleep apnea pathophys
Nocturnal hypoxia --> systemic/pulmonary HTN --> arrhythmias (atrial fibrillation/fluter)
199
OSA etiology in adults and kids
Adults --> excess paraparyngeal tissue.
| Kids --> adenotonsillar hypertrophy
200
Central sleep apnea
No respiratory effort due to CNS injury/toxicity, HF, opioids
201
Obesity hypoventilation syndrome labs
Decreased PaO2 and increased PaCO2 during sleep; increased PaCO2 during waking hours (retention).
202
Normal mean pulmonary artery pressure
10-14 mm Hg
203
Pulmonary HTN defined as..
greater than 35 mm Hg at rest
204
Arterial sequela of pulmonary HTN
Pulmonary arteries..
1) Arteriosclerosis
2) medial hypertrophy
3) intimal fibrosis
205
Heritable PAH genetics
Inactivating mutation in BMPR2 gene
206
BMPR2 gene function
normally inhibits vascular smooth muscle proliferation
207
Other causes of PAH
1) Amphetamines + cocaine
2) connective tissue disease
3) HIV infection
4) portal HTN
5) congenital heart disease
6) schistosomiasis
208
ID associated with PAH...
schistosomiasis
209
Microthrombi and pulmonary HTN mechanism
recurrent micro thrombi lead to decreased cross-sectional area of pulmonary vascular bed
210
fremitus
Vibratory sensation transmitted through the lungs.
211
Fremitus
1) Increased pathophys
2) decreased pathophys
1) Denser or inflamed lung tissue, eg pneumonia
| 2) air or fluid in pleural spaces, eg COPD or asthma
212
tracheal deviation with atelectasis (bronchial obstruction)
Toward side of lesion
213
Simple pneumo
1) breath sounds
2) percussion
3) fremitus
1) decreased
2) hyperresonant
3) decreased
214
tracheal deviation in simple pneumo
None
215
tracheal deviation in tension pneumo
Away from side of lesion
216
Simple pneumo
1) breath sounds
2) percussion
3) fremitus
1) decreased
2) hyper resonant
3) decreased
217
Consolidation (lobar pneumonia, pulmonary edema)
1) breath sounds
2) percussion
3) fremitus
1) bronchial breath sounds; late inspiratory crackles
2) dull
3) ***increased
218
typical organisms in lobar pneumonia
1) s pneumo most frequently
2) legionella
3) klebsiella
219
Lobar pneumonia characteristics
Intra-alveolar exudate leading to consolidation; may involve entire lobe or lung.
220
typical organisms in bronchopneumonia
1) s pneumo
2) s aureus
3) H flu
4) klebsiella
221
bronchopneumonia characteristics
1) Acute inflammatory infiltrates from bronchioles into adjacent alveoli
2) patchy distribution involving more than 1 lobe
222
typical organisms in interstitial (atypical) pneumonia
1) mycoplasma
2) chlamydia
3) legionella
4) RSV
5) CMV
6) influenza
7) adenovirus
223
interstitial (atypical) pneumonia characteristics
Diffuse patchy inflammation localized to interstitial areas at alveolar walls; diffuse distribution involving one or more than one lobe.
224
lung abscess etiology
1) aspiration
| 2) bronchial obstruction (eg cancer)
225
lung abscess treatment
Clindamycin
226
Location of aspiration when upright
Basal segments of right lower lobe
227
Location of aspiration when supine
Posterior segments of right upper lobe or superior segment of right lower lobe
228
Sequela of mesothelioma
1) hemorrhagic pleural effusion (exudative)
| 2) pleural thickening
229
caveat about mesothelioma
Smoking is not a risk factor
230
mesothelioma markers
Cytokeratin + calretinin positive
231
area affected in Horner syndrome
Superior cervical ganglion
232
pan coast tumor associations
1) hoarseness
2) horner's
3) SVC syndrome
4) sensorimotor deficit
233
Physical exam findings in SVC syndrome
1) facial plethora
2) blanching after fingertip pressure
3) JVD
4) upper extremity edema
234
SVC syndrome etiology
1) Pancoast tumor
| 2) thrombosis from indwelling catheter
235
SVC syndrome sequela pathophys
Raised ICP --> headaches, dizziness + increased risk of aneurysm/rupture of intracranial arteries.
236
Coin lesion on CXR...
lung cancer
237
non calcified nodule on CXR...
lung cancer
238
lung cancer mets
adrenals + brain + bone + liver
239
most common mets to lung
Breast, colon, prostate, bladder
240
lung cancer caveat
mets more common than primary neoplasms
241
small cell management
chemo +/- radiation
242
small cell origin
neoplasm of neuroendocrine Kulchitsky cells
243
adenocarcinoma genetics
Activating mutations in KRAS + EGFR + ALK.
244
adenocarcinoma association
Hypertrophic osteoarthropathy
245
CXR of adenocarcinoma in situ
hazy infiltrates similar to pneumonia.
246
adenocarcinoma in situ also known as...
bronchioloalveolar subtype
247
SCC location
hilar mass arising from bronchus
248
large cell carcinoma management
Less responsive to chemo; surgery.
249
large cell carcinoma marker
Can secrete beta-hCG
250
bronchial carcinoid tumor prognosis
Excellent; mets rare
251
bronchial carcinoid presentation
Symptoms due to mass effect or carcinoid syndrome (flushing, diarrhea, wheezing).
252
bronchial histology
Nests of neuroendocrine cells + chromogranin A positive.
253
First generation antihistamines
1) Diphenhydramine
2) dimenhydrinate
3) chlorpheniramine
254
Second generation antihistamines
1) Loratadine
2) fexofenadine
3) desloratadine
4) cetirizine
255
Guaifenesin caveat
just thins respiratory secretions; doesn't suppress cough reflex.
256
N-acetylcysteine MOA
disrupts disulfide bonds
257
N-acetylcysteine use
Liquefying mucus in COPD
258
Dextromethorphan mechanism
1) antagonizes NMDA glutamate receptors
| 2) synthetic codeine analog
259
abuse potential of dextromethorphan?
Mild
260
pseudoephedrine mechanism
alpha-adrenergic agonist
261
pseudoephedrine SE's
HTN + CNS stimulation/anxiety
262
Pulmonary HTN drugs
1) bosentan
2) sildenafil
3) epoprostenol, iloprost
263
Bosnian mechanism
Competitively antagonizes endothelin-e receptors
264
How can sildenafil be used for pulmonary HTN?
By inhibiting cGMP, prolongs vasodilatory effect of NO.
265
epoprostenol, iloprost SE's
flushing + jaw pain
266
epoprostenol, iloprost MOA
PGI2 (prostacyclin)
267
formoterol
like salmeterol
268
salmeterol, formoterol AE's
tremor + arrhythmia
269
1st line for chronic asthma
fluticasone, budesonide (inhaled corticosteroids0
270
fluticasone, budesonide MOA
1) inhibit synthesis of virtually all cytokines
| 2) inactivate NF-kappaB
271
NF-kappaB
TF that induces production of TNF-alpha and other proinflammatory agents
272
tiotropium vs. ipratropium
tiotropium is long acting
273
methacoline receptor
M3 agonist
274
best treatment for aspirin-induced asthma
Montelukast, zafirlukast
275
Montelukast, zafirlukast mechanism
block leukotriene receptors (CysLT1)
276
Zileuton SE
hepatotoxic
277
Zileuton MOA
5-lipoxygenase inhibitor
278
Omalizumab clinical use
allergic asthma with increased IgE levels resistant to inhaled steroids and LABAs
279
theophylline MOA
bronchodilator via phosphodiesterase inhibition, leading to increased cAMP levels due to decreased cAMP hydrolysis
280
theophylline caveats
1) limited usage due to narrow therapeutic index (cardiotoxic + neurotoxic)
2) adenosine
281
Phosphodiesterase (PDE)
cAMP --> AMP
282
cAMP respiratory mechanism
bronchodilator
283
molecules that cause bronchoconstriction
1) ACh
| 2) adenosine
284
Phospholipase A2 in arachidonic acid pathway
Converts membrane phospholipids to arachidonic acids
285
What activates COX-2?
NF-kB
286
5-lipoxygenase
Arachidonic acid --> 5-HPETE (eicosanoid)
287
COX-1 action in arachidonic acid pathway
arachidonic acid --> cyclic endoperoxides
288
arachidonic acid pathway
1) membrane phospholipids --> arachidonic acid --> 5-HPETE --> Leukotrienes
2) membrane phospholipids --> arachidonic acid --> cyclic endoperoxides --> prostacyclin + PGs + thromboxane
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Leukotrienes that increase bronchial tone
1) LTC4
2) LTD4
3) LTE4
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Dinoprostone
PGE2
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Alprostadil
PGE1
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Carboprost
PGF2alpha
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thromboxane actions
1) increase platelet aggregation
| 2) increase vascular tone
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PGE1 actions
Decreases vascular tone
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PGE2 actions
Increases uterine tone
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PGF2alpha actions
Increases uterine tone
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Prostacyclin (PGI2) action
1) decreases platelet aggregation
| 2) decreases vascular tone
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Pulmonary hypertension characteristic finding
Coronary sinus dilation is a characteristic finding (coronary sinus contains venous blood and communicates freely with the RA and therefore may become dilated secondary to any factor that causes right atrial dilatation).
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Causes of transudate
1) increased hydrostatic pressure
| 2) decreased oncotic pressure
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examples of transudate
1) nephrotic syndrome
| 2) cirrhosis
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Conditions that cause exudate
1) malignancy
2) pneumonia
3) collagen vascular disease
4) trauma
* states of increased vascular permeability.
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chylothorax
AKA lymphatic effusion
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Cause of lymphatic effusion
thoracic duct injury from trauma or malignancy
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lymphatic effusion presentation
1) Milky-appearing fluid
| 2) increased TGs
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Pneumothorax
1) breath sounds
2) percussion
3) fremitus
1) diminished
2) hyperresonant
3) decreased
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Cause of secondary spontaneous pneumo
1) Diseased lung (eg bullae in emphysema, infections).
| 2) mechanical ventilation with use of high pressures leading to barotrauma.
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Tension pneumothorax
Can be any of other types. Air enters pleural space but cannot exit. Increased trapped air leads to tension pneumothorax.
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tension pneumo management
Immediate needle decompression + chest tube placement.
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tracheal deviation in tension pneumo
Trachea deviates away from affected lung.
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Phases of lobar pneumonia
Hippo with cold in lawn chair/congestion. Red lungs + covered in blood vessels + francis’s climbing all over it/1) congestion (first 24 hrs): red, heavy and boggy lobe + vascular dilation + alveolar exudate contains mostly bacteria.
red hippo in lawn chair/red hepatization. Red lungs + newts crawling around everywhere + big RBCs on the ground + lawn chair covered in fibrin/2) red hepatization (2-3 days): red, firm lobe (liver-like consistency + alveolar exudate contains erythrocytes + neutrophils + fibrin.
Grey hippo in lawn chair/grey hepatization. Grey lobe + disintegrating RBCs on ground + lawn chair covered in fibrin + newts crawling around/3) grey hepatization (4-6 days): gray-brown firm lobe + RBCs disintegrate + alveolar exudate contains neutrophils and fibrin.
Hippo dancing around/4) resolution: restoration of normal architecture + enzymatic digestion of the exudate.
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methemoglobinemia presentation
dizziness + dyspnea + confusion + seizures + coma
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Complication of nitric oxide administered for pulmonary HTN disease of newborn
methemoglobinemia
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Systemic mastocytosis
o Code: Scott Massed: huge cat spewing acid from its mouth behind him/mast cell proliferation in the bone marrow and in other organs, resulting in increased histamine secretion gastric acid hypersecretion. Scott looking like below + flushed face + itching himself intensely + booting everywhere/presentation = pruritis + rash + flushing + GI symptoms (abdominal cramps, nausea, vomiting). Huge nests at top of all the sail boat masts + intestines in the nests/small bowel biopsy = nests of mast cells within the mucosa.
o Location: Boat yard, end of dock near exit from Royal River
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Worsening SOB + malaise + continued respiratory symptoms in a patient with pneumonia
pulmonary effusion
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CXR of pulmonary effusion
blunting of costophrenic angle + air fluid level.
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Physical exam findings of pleural effusion
pleural friction rub on auscultation.
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Characteristic finding in severe PAH
Lesions can progress to form plexiform lesions (interlacing tufts os mall vascular channels)
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presentation of IPF
insidious onset of dyspnea on exertion + dry cough present for more than 3 months + bibasilar rales clubbing + diffuse reticular opacities.
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inflammatory mediators of chronic bronchitis
monocytes + CD8+ T cells + neutrophil infiltration
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cough productive of yellow sputum...
chronic bronchitis
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common pathogen in smokers with chronic bronchitis
H flu
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sputum findings in bronchial asthma
Luke in corner and it’s hailing on him + eoss goddesses wrapped around all the hanging spiral/sputum findings = **eosinophils, which are recruited and activated by IL-5 secreted by TH2 type helper T-cells.
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bronchiectasis association
hypertrophic osteoarthropathy (HOA)
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leukocoria
White reflex
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leukocoria associations
1) retinoblastoma
| 2) congenital cataracts
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ARDS on CXR
bilateral radiographic opacities
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Brain abscess RF's
endocarditis + bronchiectasis + IV drug use
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lung abscess presentato
indolent + fever + night sweats + weight loss + cough productive of foul-smelling sputum (indicative of anaerobes).
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How do enteric bacteria (e coli + klebsiella + enterococci) cause hepatic abscesses?
Ascend biliary tract
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other route of infection to hepatic abscess
portal vein pyemia
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How does staph aureus cause hepatic abscesses?
Francis with a blow dart gun shooting seeds at liver/another route of infection = hematogenous seeding of the liver with staph aureus.
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pneumoconiosis associated with insulation...
asbestosis/mesothelioma
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Mesothelioma histology
tumor cells with long, slender microvilli + abundant tonofilaments
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typical pneumonia
♣ Code: Margaret Lawrence: she’s sweating profusely + coughing up sputum all over her chest/presentation = high fever + lobar consolidation + productive sputum. Newts crawling around floor everywhere/these symptoms result from the primary responding immune cell, the neutrophil, which enters area, releases pyrogenic products (fever), causes innocent bystander damage to lung, and creates abscesses (lobar consolidation). /usually EXTRACELLULAR organisms, gram-negatives (1) s. pneumo + 2) H. influ + 3) M. cattarhalis + 4) S. aureus). /lobar infiltrate. Steph in a track suit flashing her tits + prostitutes sitting at table/treatment = empirical ceftriaxone + azithromycine.
♣ Location: Conference room in library first floor
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typical pneumonia treatment
ceftriaxone + azithromycine
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neonatal atypical pneumonia presentation
crackles + wheeze
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cold agglutinins
antibodies (usually IgM) produced in response to certain kinds of infection such as m. pneumoniae.
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Relation between lung volume and pulmonary vascular resistance
o Code: huge massive U/graph is U shaped. /This is because high lung volumes (eg following inspiration) increase PVR due to the longitudinal stretching of alveolar capillaries by the expanding alveoli. Decreased lung volumes also increase PVR due to decreased radial traction from adjacent tissues on the large extra-alveolar vessels. /thus, PVR is lowest at the FRC.
o Location: Above DIA
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What can you use to measure FRC and RV?
helium dilution technique
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Lamellar body or granule
Phospholipids are stored in lamellar bodies and serve as pulmonary surfactant.
