Exam 2: Asthma Flashcards
What is the preferred position for spirometry and why?
Sitting because there is less liklihood of syncope
What are the basic PFTs?
1) Airflow spirometry
2) Lung volumes
3) Diffuse capacity of lungs for CO (DLCO)
How is spirometry performed?
1) relax and breath normally
2) take a deep breath in
3) forcefully expire all the air
4) Take another deep breath in
What is forced vital capacity (FVC)?
Taking a deep breath in and blowing air out as fast as possible.
FVC is the total volume of air blown out with maximal effort
Is FVC or FEV1 more useful for obstruction?
FEV1
What is the FEV1/FVC ratio and what is it useful for?
The percentage of FVC in one second.
-Defines the severity of obstruction and assists in differentiating between obstructive and restrictive
What number indicates an obstructive pattern on the FEV1/FVC ratio?
<0.7
There is reversibility on Bronchodilator testing if the FEV1 increases by **% and **mL.
12% and 200mL
What is a positive bronchoprovocation test?
FEV1 decreases by 20%
What does DLCO test?
It measures the ability of the lungs to transfer gas and saturate the hemoglobin (may be misleading if person is anemic and this must be adjusted for hemoglobin level)
What is used as a surrogate for oxygen transfer in DLCO?
CO
What is the technique for DLCO?
The patient inhales a single breath of gas consisting of helium/CO, then expires, and a measurement of the exhalation is taken
What is the result of DLCO when the lungs are healthy?
Little CO is collected during exhalation
What is the result of DLCO when the lungs are diseased?
Less CO diffuses into lungs, higher levels are measuring in exhaled gas
How does obstructive lung disease affect the following: TCL FVC RV FEV1 FEV1/FVC
TCL: increased FVC: Normal RV: Increased FEV1: decreased FEV1/FVC: decreased
How does restrictive lung disease affect the following: TCL FVC RV FEV1 FEV1/FVC
TCL: decreased FVC: decreased RV: decreased FEV1: Decreased FEV1/FVC: normal or increased
What is the normal percentage for Forced Expiratory Flow (FEF)
25-75%
What are the 5 steps to PFT interpretation?
1) Examine the flow-volume curve
2) Examine the FEV1 value
3) examine the FEV1/FVC ratio
4) examine response to bronchodilator
5) examine the DLCO
Why is bronchodilator testing performed?
To test for reversibility and if positive, aids in diagnosis and provides treatment options
What is indicated when the curve of the flow volume curve has a scooped out appearance?
Obstructive pulmonary disease
What is indicated when the slope of a flow/volume curve has an increased slope?
Restrictive lung disease
If the FEV-1 valve is decreased by more than 15-20%, what should you be suspicious of?
Obstructive pulmonary disease
If TLC is increased by 15-20% what should you be suspicious of?
Obstructive disease
If the FEV-1/FVC ratio is decreased to 70% or less, what should you be suspicious of?
Obstructive process
What does it mean if the FEV1-FVC ratio is normal or increased?
There is possibly a restrictive disorder
If FEV-1 increases by 12%/200mL of a bronchodilator, what does this suggest?
Hyperreactive, reversible airways
How frequently should you take lung function measurements?
- At diagnosis
- after 3-6 months of controller treatment (FEV1)
- Periodic assessments at least every 1-2 years
What is the hallmark symptom with asthma?
Inspiratory and expiratory wheezing
What are some of the characteristic triggers of asthma?
URI, exercise, weather, stress, irritant exposures, medications (beta blockers!)
When is wheezing most commonly heard in asthmatics?
Forced expiratory phase
What are the signs of severe obstruction?
Tachypnea, tachycardia, tripod positioning, accessory muscle use, and pulsus paradoxes
What is the ASA triad (Samters triad)?
Sinus disease with nasal polyps, ASA sensitivity, and severe asthma
People who develop upper and lower respiratory reactions to ASA should avoid what medications?
70% of these people also have respiratory reactions to what other substance?
They should avoid NSAIDs
Alcohol
What is the atopic triad?
Atopic dermatitis, allergic rhinitis, and asthma
What is the atopic march?
Atopic dermatitis, food allergy, allergic rhinitis, asthma
What are the spirometry findings that support diagnosis of asthma?
- FEV1 <80%
- FEV1/FVC is normal to decreased relative to predicted values
- Reversibility >12% in FEV1 with bronchodilator
What FEV1/FVC ratio is the gold standard for COPD diagnosis?
<70%
What symptoms are classified as intermittent asthma?
- Symptoms less than 2 days per week
- No nighttime awakenings if aged 0-4
- If 5 or older, less than 2 nighttime awakening per month
What PFT findings are consistent with intermittent asthma?
- Normal PFTs in between exacerbations
- FEV1 >80%
- Normal FEV1/FVC ratio
- normal activity
- <2 days/weeks SABA use to control symptoms
What symptoms classify mild persistent asthma?
- Symptoms more than 2 days/week but not daily
- 1-2 nighttime awakenings per month if aged -4
- 3-4 nighttime awakenings per month if 5 and older
What are the PFT findings consistent with mild persistent asthma?
- FEV1>80%
- FEV1/FVC normal
- Minor activity limitation
- > 2 days per week SABA use to control symptoms
What FEV1/FVC value is normal for 5-19 year olds?
> 80%
What symptoms classify moderate persistent asthma?
- daily symptoms
- 3-4 nighttime awakenings per month if aged 0-4
- more than once a week nighttime awakenings if 5 and older
What are the PFT findings consistent with moderate persistent asthma?
- FEV1 60-80%
- FEV1/FVC reduced by 5%
- some activity limitation
- daily SABA use to control symptoms
What symptoms classify severe persistent asthma?
Symptoms throughout the day
- greater than once weekly nighttime awakenings for those aged 0-4
- Nightly awakenings for those 5 and older
What are the PFT findings with severe persistent asthma?
- FEV1< 60%
- FEV1/FVC reduced by >5%
- Extreme physical activity limitation
- SABA used several times daily
What are the medication options for asthma treatment? (8)
SABA, LABA, ICS, LTRA, monoclonal antibodies, methylxanthines, mast cell stabilizers, and anticholinergics
What LTRA is used in patients aged 0-4?
Montelukast
What are the two monoclonal antibodies used to treat asthma?
Omalizumab (anti-IgG) and Benralizumab (anti-IL5 receptor a)
What kind of drug is theophylline?
Methylxanthines
What is Step one in treatment of asthma?
SABA PRN (used in all stages)
What is Step 2 in treatment of asthma?
Low dose ICS daily
OR
LRTA or Cromolyn
What is Step 3 in treatment of asthma?
-medium dose ICS (all stages)
OR
Low dose ICS and LABA (if >5yo) or LTRA
What is Step 4 in treatment of asthma?
-medium dose ICS and LABA (Or LTRA in 0-4yo)
OR
Medium dose ICS and LTRA
What is Step 5 in treatment of asthma?
-High dose ICS and LABA (or LRTA in 0-4yo)
What is Step 6 in treatment of asthma?
-high dose ICS and LABA(or LRTA in 0-4yo) and oral steroids
What should you consider adding to step 5 and 6 in asthma treatment in patients older than 12 with allergies?
Omalizumab
What should you consider adding in asthma treatment in patients older than 12 with severe eosinophilia asthma?
Benralizumab
What drug may be used on conjunction with ICS in aged older than 5, but serum levels must be monitored closely?
Theophylline
What does green mean on a peak flow meter?
Peak flow rate is >80 with means asthma is in good control
What does yellow mean on a peak flow meter?
Peak flow rate is 50-80% and patient should take SABA and medications
What does red mean on a peal flow meter?
Peak flow rate is <50% and patient needs to go to the ED
What may be initial finding on ABGs in a patient with asthma?
Respiratory Alkalosis because they are hyperventilating and blowing off CO2
What are the 3 main treatment options of asthma exacerbation?
1) O2
2) SABA/SVN: Albuterol and ipratropium bromide (repeat PEF and SVN may be repeated or continuous)
- Systemic corticosteroids (prenisolone)
