Approach To Asthma Flashcards
Asthma broad overview
Chronic inflammatory disease of the airway due to hyper responsiveness of the airway
- symptoms initially are variable, reversible and recurring.
- overtime with no treatment, symptoms become irreversible and scar tissue takes over
- smooth muscle hypertrophied and hyperplasia
Is a type 1 hypersensitivity reaction
- type 2 helper T cells release IL-4/5
- mast cells releases histamines, leukotrienes and prostaglandins
Causes bronchoconstriction which decreases airflow and increases resistance
Types of asthma
Atopic/ allergic asthma
- most common kind of asthma
- most are diagnosed in people before age of 7 (75%)
Most resolve by puberty
Nonatopic asthma
- infection induced asthma
- primarily diagnosed as adults
Drug-induced asthma
- caused by aspirin in patients with rhinitis and nasal polyps
- primarily diagnosed as adults
Occupational asthma
- causes by fumes or gases
- primarily diagnosed as adults
Asthma triad
Personal history of allergies
Eczema
Asthma symptoms
these 3 usually occur together
Wheezy bronchitis/ reactive airway disease
Found in 1-4 year old children that have wheezing due to viral URIs
- looks like asthma, but is technically not since asthma is a chronic illness not acute
- this resolves on its own by 5 usually, however if it doesnt then it can be considered asthma
History associated with asthma
Symptoms
- dyspnea (especially with exertion)
- wheezing (sometimes is audible but it is always heard on auscultation)
- coughing (especially at night)
- cyanosis
symptoms come in waves, hence “asthma attack”
Physical exam
- tachypnea/tachycardia
- possibly normal vitals in some patients
- decreased inspiration:expiration ratio (1:2 -> 1:4) this is similar to COPD
- wheezing can be inspiratory only, or both inspiratory and Expiratory
- possible hyper resonance when percussing
- substernal and intercostal retractions (stomach sucks in when breathing)
- accessory muscle overuse (very clear to see)
NOTE: severe asthma attacks can show no wheezing on auscultation, so wheezing alone is not enough to diagnose
Tripod position
Found in patients with emphysema or severe asthma
Patients need to hunch over to breath properly
Pulsus paradoxus
Found in patients with asthma but also in a lot of other disorders
Systolic BP drops by > 10mmHg during inspiration
Ways to diagnosis asthma
1) Spirometers/PFTs are the best inital diagnostic tests to use
- is very dependent on patient effort so you must know that the patient can take orders
- FEV1 will decrease (<80% predicted)
- FEVs/FVC is decreased (<70% predicted)
2) If spirometers shows possible asthma, give SABA (albuterol) and then retest
- asthma should show symptoms improve after
- if symptoms dont improve, COPD
3) Peak flow monitoring
- note this isnt the best to diagnose asthma by itself
- very effort dependent again
4) X-rays
- shows flattening of diaphragm and increased lung volumes (however these findings just prove is some sort of obstructive disorder, not asthma entirely)
5) methacholine challenge test
6) biopsy/pathology
- shows Curschmann spirals
- muscle hypertrophy
- Charcot-Leyden crystals
Treatment of asthma
1) Avoid triggers
2) Treat underlying causes of asthma
Acute asthma attacks = SABA every 1-6 hrs and prednisone for 5-10 days
*always try to step down if possible* Step 1 (mild intermittent): - just SABA
Step 2 (mild chronic) - prednisone
Step 3 (moderate chronic) - LABA or SABA & prednisone
Step 4 (severe chronic) - LABA + medium dose glucocorticoids