Asthma Flashcards
1
Q
What is the airway pathology associated with asthma?
A
- Chronic inflammation **** the cornerstone
- Eventual airway remodeling and fibrosis d/t chronic inflammation
- Airway wall edema
- Mucus gland hypertrophy
- Mucus hypersecretion/plugging
- Smooth muscle hypertrophy
- Bronchoconstriction
- Airway hyperresponsiveness
2
Q
What are the symptoms of asthma?
A
yspnea, wheezing, chest tightness, cough
3
Q
Adult starts wheezing, what is your ddx?
A
COPD, asthma, vocal cord dysfunction
VCD is inspiratory. They can be discracted from it but it’s true pathology
4
Q
Criteria for Dx of Asthma
A
- Presence of episodic sx of airflow obstruction / airway hyperresponsiveness
- Objective assessment - one of the following
- at least partially reversible w/SABA
- increase in FEV1, of > 12% from baseline
- increase in predicted FEV1, of > 10% points from baseline
- increase PEF of > 20% (or 60 l/min) from baseline
- Diurnal variation in PEF (measured 2x daily) of >10%
- at least partially reversible w/SABA
5
Q
What is FEV1?
A
Forced Expiratory Volume in 1 second
6
Q
What is FVC?
A
Forced Vital Capacity (total volume of full exhalation after full inhalation)
7
Q
FEV1/FVC normal values for 20-39yo
A
80%
8
Q
FEV1/FVC normal value for 40-59yo
A
75%
9
Q
FEV1/FVC normal value for 60-80yo
A
70%
10
Q
Mild (intermittent or persistent) asthma: what is their FEV1/FVC?
A
may be normal
11
Q
Pts w/moderate persisten asthma: what is their FEV1/FVC?
A
5% less than normal
12
Q
Severe persistent asthma: what is their FEV1/FVC?
A
>5% less than normal
13
Q
Goals of chronic asthma mgmt
A
Reduction of impairment
Reduction of risk
14
Q
How can impairment d/t chronic asthma be reduced?
A
- Minimizing intensity and frequency of symptoms
- _<_2 days/week SABA use
- _<_2 nights/month with symptoms
- Maintenance of normal activity
- Optimization of lung function
- Improved patient satisfaction
15
Q
How can risk d/t chronic asthma be reduced?
A
- Prevention of exacerbations
- Preservation of lung function
- Tolerance of medications with minimal adverse effects
16
Q
Characteristics of mild intermittent asthma
A
- Sx ≤ 2d/ wk
- Noct sx ≤ 2d/mo
- FEV1>80%, 0-1 exac/yr
17
Q
Characteristics of mild persistent asthma
A
- Sx 3-6d/wk
- Noct sx 3-4d/mo
- FEV1>80%, _>_1 exac/yr
18
Q
Characteristics of moderate persistent asthma
A
- Daily sx
- Noct sx >1d/wk
- FEV1>60%, _>_1 exac/yr
19
Q
Characteristics of severe persistent asthma
A
- Constant sx
- Noct sx often nightly
- FEV1 ≤60%
- Frequent exacerbations
20
Q
Initial Tx: mild intermittent
A
no daily meds
SABA prn
21
Q
Initial tx: mild persistent asthma
A
Preferred: low-dose ICS
Alternative: Cromolyn, LTRA, Nedocromil, Theophyline
22
Q
Initial Tx: Moderate persistent asthma
A
Preferred: Low-dose ICS + LABA OR Medium Dose ICS
Alternative: Low-dose ICS + either LTRA, Theophyline, or Zileuton
23
Q
Initial Tx: Severe persistent asthma (step 4)
A
Preferred: Medium-dose ICS + LABA
Alternative: Medium-dose ICS + either LTRA, Theopyline, or Zileuton
24
Q
Initial Tx: Severe persistent asthma (step 5)
A
Preferred: High-dose ICS + LABA
AND
Consider Omalizumab for pts who have allergies
25
What is Step 6 for asthma?
**Preferred:** High dose ICS + LABA + PO corticosteroid
AND
Consider Omalizumab for pts who have allergies
26
If a patient with asthma has coexisting allergic rhinitis, what is the recommended maintenance drug?
LTRA instead of ICS
27
How should exercise indduced bronchoconstriction / asthma be treated?
* Pretreat w/ SABA or MCS
* Beware of masking symptoms. Consider controller
* Warm up period in cold weather. Scarves, warm clothes.
28
How should asthma be managed during pregnancy?
* Albuterol = preferred bronchodilator
* ICS = preferred controller. Budesonide (Pulmacort) is preferred.
* No Singulaire
* Risk of poor control outweighs risk of med adverse effects
29
Metered Dose Inhalers (MDI): how to use
* Shake the inhaler well before use; remove cap
* Exhale away from inhaler
* Bring the inhaler to your mouth.
* Place it in your mouth between your teeth and close you mouth around it.
* Start to breathe in **slowly**.
* Press the top of you inhaler once and keep breathing in slowly until you have taken a full breath.
* Remove the inhaler from your mouth, and hold your breath for about 10 seconds, then breathe out.
30
Diskus (Dry powder inhaler): how to use
* Hold Diskus in palm of hand (sandwich)
* Push thumb grip until it clicks into place
* Slide lever away from you
* Place it in your mouth between your teeth and close you mouth around it.
* Start to breathe in **deeply and rapidly**.
* Remove the inhaler from your mouth, and hold your breath for about 10 seconds, then breathe out.
* Always check the number in the dose counter window to see how many doses are left
31
Twisthaler (Dry powder inhaler): how to use
* Twist white cap counter clockwise
* Exhale away from Twisthaler
* Hold horizontally
* Place it in your mouth between your teeth and close you mouth around it.
* Start to breathe in **deeply and rapidly**.
* Remove the inhaler from your mouth, and hold your breath for about 10 seconds, then breathe out.
* Replace cap and twist clockwise.
* Make sure it clicks to completely close it.
* Rinse mouth and gargle
32
Spacers: benefit
* Enhanced drug delivery, highly recommended with ICS for pediatrics
* Canister holds drug in place. Can inhale at own pace – good for pedi who may not have high lung capacity
33
What controller medications are available for asthma tx?
* Inhaled Corticosteroids
* Leukotriene receptor antagonists (montelukast)
* Long acting bronchodilators (b2-agonists)
* Mast cell stabilizers (cromolyn and nedocromil) *more in pedi*
* Methylxanthines (theophylline)
* Biologics (omalizumab, trial therapies) *new frontier*
34
What rescue meds are available for asthma tx?
* short acting bronchodilators (b2-agonists, antichol) *preferentially SABA, sometimes antichols, sometimes combo*
* corticosteroids: oral, IV
35
Benefits of ICS
* The cornerstone of “controller” therapy:
* Decrease inflammation
* Decrease AHR
* Reduce risk of exacerbations
* Reduce symptoms
* More effective than LTRA for most stages
36
When would you use an oral steroid with asthma?
acute exacerbation and severe dz
37
Side effects of ICS
* Inhaled: Thrush, dysphonia *- thrush can be severe and refractory even to good technique*
* Oral (or high ICS with frequent OCS): cataracts, adrenal suppression, hyperglycemia, osteoporosis, skin fragility
*If refractory to other methods, but reserved d/t side effects*
38
When are mast cell stabilizers used?
* Frequently used in children, less in adults:
* Seasonal, cold-induced sx
* Exercise induced asthma
* Mild to moderate anti-inflammatory effect
*Not really used w/adults at all*
39
Mast cell stabilizer MOA
* Prevents degranulation of mast cells
* ↓ release of pro-inflammatory cytokines
40
Side effects of mast cell stabilizers
* Mild throat irritation, cough
* Metallic taste
41
Mast cell stabilizers: agents
* Cromolyn sodium
* Nedocromil sodium
42
How do endogenous leukotrienes contribute to asthma?
* Product of the arachadonic acid metabolic pathway
* Potent proinflammatory effects: LTB4
* Potent _bronchoconstrictor_ effects: LTC4, LTD4
* Increase mucus production while impeding mucociliary clearance
* Promote vascular permeability
* Receptors on respiratory mucosa, including nasal mucosa
43
How do leukotriene inhibitors work?
* Zileuton inhibits leukotriene production, while LTRAs (Montelukast, zafirlukast) inhibit receptors → mild bronchodilator/anti-inflammatory effects
44
Side effects of leukotriene inhibitors
* *mostly well tolerated*
* Mildly elevated LFTs
* +/- Mild sedation (give in evening)
45
Main limiting factor of leukotrien inhibitors?
main limiting factor is not SEs, but whether accomplishes goal
46
How do beta 2 agonists work?
* Stimulate β2-adrenergic receptor --\> smooth muscle bronchodilation
* Decreased sensitivity of β2 receptor with age
47
When do you use LABAs?
Only in combo with ICS!
## Footnote
*many given combo first now - but you should start w/ICS to avoid risks, per speaker*
48
Onset and duration of SABAs
rapid onset (minutes), 4-6h duration
49
Onset and duration of LABAs
variable onset (2-5min formoterol, \>20min salmeterol), 12h duration
50
Side effects of beta agonists
* Common: Tachycardia, tremor, nervousness (β1 effect)
* Hypokalemia *– if given very frequently, e.g., in acute setting*
* Vasodilation: stimulation of β2-receptor on vascular smooth muscle
* mild hypoxia (pulmonary vasodilatation --\> shunt)
* Hypotension
* Reflex tachycardia
* increased cardiac output
51
Methylxanthines (Theophylline): how does it work & why is it not often used?
* *good drug, works for many, but many issues w/it*
* Multiple mechanisms (BD, anti-inflammatory, etc)
* Narrow therapeutic window – monitoring essential
* Multiple drug interactions
* High occurrence of side effects/toxicity
52
Anti-IgEs: what are the agents?
omalizumab (Xolair)
53
How do Anti-IgEs work?
* Monoclonal Ab blocking binding of IgE to receptors on mast cells and basophils *– e.g., allergic to dust mites*
* Injections every 2-4 wks, small risk of anaphylaxis
54
Who is at high risk for acute exacerbations of asthma?
* Prior ICU/intubation
* _\>_ 2 hospitalizations or \>3 ED visits in past year
* High SABA use
* Poor symptom perception *– don’t recognize until crisis point. PFMs at home can be helpful in training.*
* Low SE status, urban residence
* Comorbid drug use, psychiatric disease, heart/lung disease
55
Characteristics of mild / moderate asthma exacerbation
* SOB with activity that may limit some normal activities
* Usually treated at home; may require UV or ED
* PEF\>40% personal best
* Symptoms relieved temporarily with SABA use
56
Tx for mild / moderate exacerbation
* Frequent SABA
* Oral systemic steroids
* 40-60mg “bursts”
* 5-10 days
* \<1wk course no need to taper *– commonly taper but not necessary*
* Should expect improvement in 24-48hrs
57
Characteristics of severe/life threatening exacerbation
* SOB at rest, unable to converse
* Requires hospitalization, possibly ICU
* PEF\<40% personal best
* Incomplete improvement with SABA
58
Tx of severe/life threatening exacerbation
* Oral/IV steroids
* ~40-80mg/d equivalent
* Oral = IV if absorbed
* No data for higher doses *– unless absorption problem*
* Frequent SABA/SAMA, possibly continuous SABA
* IV Magnesium
* Heliox *–inhaled helium & oxygen. Improves laminar flow through tight airway*
* Careful ventilator management
59
Important co-morbidities in asthma (may lead to exacerbation)
* Rhinosinusitis (and consider evaluation for ABPA/AF disease)
* GERD *- often missed*
* Sleep disordered breathing
* Depression
* Anxiety
* Obesity
* Cardiac disease
60
Two important factors to monitor in deciding asthma therapy
severity
control
61
What must asthma Tx include
First line pharm therapy + constant education, prevention, trigger control, and co-morbid management to optimize care
