In-Class lecture material - Slocum Flashcards
(47 cards)
ATS recommends that every pt with dyspnea be evaluated for what 3 domains?
- sensory - intensity and quaility
- affective - unpleasantness or distress
- impact or burden - what level of impairment
Causes of wide A-aDO2
- V/Q mismatch
- Qs/Qt
- Diffusion abnormalities
what are the stages of spirometry classification of COPD
Gold 1 (mild) = FEV1 gr than 80% Gold 2 (moderate) = FEv1 50% to <80% Gold 3 (severe) = FEV1, 30-<50% Gold 4 (very severe) = FEV1 <30%
Medical Research Council Dyspnea Scale
Grade 0 = breathless w/strenuous exercise
Grade 1 = SOB when hurrying on level or walking up slight hill
Grade 2 = On level ground, walk slower than normal cuz of breathlessness or have to stop for breath
Grade 3 = Stop for breath after 100 yds on level ground
Grade 4 = Too breathless to leave home, get breathless when dressing
What are the reasons for Dyspnea in COPD?
- Increased dead space - -Increased PaCO2
- Altered V/Q relationships - hypoxemia
- Airflow obstruction
- reduced mechanical advantage of diagragm
How does the volume/flow loop change in COPD?
During expiration (top half) the loop is scooped off indicating air is not flowing out as much. as efficiently
Normally, tidal flow volume loops expand in both direction during exercise. In emphysema, the decreased expiratory time (because of increased respiratory rate during exercise) results in more air trapping and increases the FRC, shifting the tidal flow-volume loop curves to the left, a phenomenon called dynamic hyperinflation
what are some common causes of hypoxemia with normal A-a gradient?
Alveoli are working fine, but you’re not inhaling enough O2. can be due to:
- hypoventilation (narcotics, neuromuscular weakness, obesity)
- high attitude
Can be treated with O2
what are some causes of hypoxemia with high A-a gradient?
Either due to 1)Alveoli cant get O2 to blood or 2) Blood is not going to working alveoli. Can be due to:
- Pneumonia
- PE
- Chronic bronchitis
- Pulm edema
what are the two common mechanism of creating a high A-a gradient?
- Fibrosis (loss of alveoli for diffusion, increased A-a gradient V/Q mismatch, hypoxemia
- Shunt (blood not flowing past alveoli with O2: anatomic shunting or physiologic shunting)
What are some examples of extrathoracic airway obstruction?
Obstruction upstream of the lungs.
- laryngeal inducable laryngeal obstruction, or laryngeal tumors.
Explain the changes seen in a flow loop due to a extrathoracic airway obstruction.
Normal expiratory flow loop, but when they try to inhale, the flow loop truncates (can’t generate flow). The reason is: if you exhale you create an intrathoracic/intraluminal pressure below the obstruction that is greater than Atm, as the diaphragm descends.
In other words, Extrathoracic airway obstruction is an INSPIRATORY problem.
Explain how the flow loop changes due to an intrathoracic obstruction (e.g. tumor in large airway)
when you inspire you create negative pressure inside thorax, and atm becomes significantly greater, thus inspiration is normal, but when you try to exhale you have to generate increased pressure than atm and this will result in a collapse of airway and thus truncate the expiratory flow loop.
in sum: intrathoracic obstruction is an expiratory problem
In order to qualify as significant response to a bronchodilator, what two criteria must be met after administration of an bronchodilator?
- 12% increase in VC or FEV1
2. 200cc increase in either VC or FEV1
which Gold Stages of dyspnea are oral PDE4 inhibitors (Roflumilast) and Theophyline used for?
Gold 3 and 4. stages before that are managed with ICS, SABA, SAMA, LABA and LAMA, any combo of those
Pts with COPD are often prescribed abx for which organisms?
H.Flu or morexella.
For milder and younger COPD pts with FEV1>50% and age <65 what abx are commonly used?
- Doxycycline
- TMP-SMX
- Cephalosproin
- Advanced macrolides (azithro or clarithro)
For sicker and older COPD pts which abx are commonly used?
- Amoxi-clav
- Fluoroquinolones
In COPD pts what are criteria that which indicates supplemental O2
- PaO2 <56 t(7.3 Kpa) OR SpO2 <89% measure twice over a 3 week period of time
- PaO2 >56 <60 t (7.3 kPa) any time with evidence of: Pulm HTN, CHF, Polycythemia Hct >55%
How is mild COPD treated?
Either SABA or SAMA prn often ordered together as Combivent (difference between COPD and asthma is ICS indications)
How is moderate COPD treated?
LABA or LAMA
How is severe COPD treated?
ICS+LABA or ICS +LAMA (never use ICS alone in COPD)
-can be w/wo Roflumilast or theophylline
How is very severe COPD treated?
ICS+LABA or ICS+LAMA or ICS +LAMA +LABA
w/wo roflumilast or theophylline
What is the 6 minute test?
Assesses distance walked over 6 minutes as a sub-maximal test of aerobic capacity/endurance.
-Pt on room air walks for 6 mins and measure how far they can walk. Then let them rest for about 20 mins. And then give them O2 via nasal canula and again do the 6MWT and see if they do better.
Inhalers and other meds are used to treat symptoms which decreases hospitalization and increases quality of life. What two factors is known to increase longevity in a COPD pts?
- STOP smoking
- Supplemental O2
