Asthma Flashcards
epidemiology in US
-Affects 8–10% of the population
-Annual Data:
-10 million office visits
-1.8 million ED visits
-> 3500 deaths
-Slightly more common in boys (< 14 years old) and in women
-One MC chronic diseases worldwide
-~300 million affected individuals
-Prevalence increasing in many countries, especially in children
-A major cause of school/work absence
asthma is increasing every year in the US
-In 2016: adults and children with asthma was 26.5 million
-Since 2001, asthma prevalence increased at a rate of 1.5% each year, to 8.3% in 2016
-As of 2016, the average asthma prevalence was:
-Highest in children 12-14 years old
-Higher in women than men
-Higher in blacks than whites
burden
-A high economic and personal burden exists for people with asthma
-During 2008-2013, asthma was responsible for $3 billion in losses due to missed work and school days, $29 billion due to asthma-related mortality, and $50.3 billion in medical costs.
-Between 2008-2013, asthma resulted in an estimated loss of 1.8 days from work each year, and 2.3 days from school each year, per person
asthma
-chronic inflammatory disorder of airways
-Chronic inflammation causes associated airflow obstruction (bronchoconstriction, airway hyperresponsiveness and airway edema)
-Symptoms: recurrent coughing, wheezing, breathlessness and chest tightness
-Involves widespread, variable airflow limitation (often reversible, either spontaneously or with treatment)
pathophysiology
-Chronic inflammatory disorder of airways:
-Hypertrophy of bronchial smooth muscle and mucous glands
-Plugging of small airways with thick mucous
-Airway inflammation-> ds chronicity -> airway hyper-responsiveness, airflow limitation, and respiratory symptoms
-allergic inflammation, eosinophilic inflammation, mucus overproduction -> narrowing -> many different places to intervene
risk factors for development of asthma
-Genetic characteristics
-Environmental exposures
-Contributing factors
genetic characteristics
-Atopy:
-Predisposition to develop IgE in response to environmental allergens
-High IgE: more likely to have allergic response
-2-3x risk if have parent with asthma
asthma triggers
-A definitive cause of the inflammatory process leading to asthma has not yet been established
-Several factors, including both genetic and environmental, are thought to play a role in asthma
non-atopic vs atopic
-non-atopic:
-Ozone
-Smoke
-Particulate matter
-Infection
-Some medications(aspirin, beta blockers, ACE inhibitors)
-Cold, dry air
-atopic:
-House dust mite
-Pollen
-Ragweed
-Cockroach
-Mold
-Pet dander/saliva
-Foods (peanuts, soy, shellfish, milk)
-Natural oils and fragrances
allergic and nonallergic phenotypes
-most commonly discussed phenotypes of asthma -> allergic and nonallergic
-many pts with asthma display characteristics of both phenotypes, including an increase in type 2 inflammation
allergic (atopic or extrinsic)
-triggers- allergic rxn to inhaled allergens (dust mite allergen, pet dander, pollen and mold
-age at development- usually begins in childhood
-symptoms- many similarities with non allergic -> coughing, wheezing, SOB, hyperventilation, chest tightness
-inflammatory process- can be similar to nonallergic -> increased TH2 cells, mast cell activation and infiltration of eosinophils
nonallergic (nonatopic or intrinsic)
-triggers- factors not related to allergies (anxiety, stress, exercise, cold or dry air, hyperventilation, tobacco smoke, viruses or other irritants)
-age at development- tends to develop in adults (>35 years of age)
-symptoms- many similarities with non allergic -> coughing, wheezing, SOB, hyperventilation, chest tightness
-inflammatory process- can be similar to nonallergic -> increased TH2 cells, mast cell activation and infiltration of eosinophils
diagnosing asthma: medical hx
-Symptoms
-Patterns to Symptoms (freq at night, seasonal)
-Severity (impact on life)
-Past Medical History
-Family History
diagnosing asthma: physical exam
-Wheezing
-Hyper-expansion of the thorax
-Increased nasal secretions or nasal polyps (sign of type 2 inflammation)
-Atopic dermatitis (sign of type 2 inflammation) or other allergic skin conditions
-During severe asthma exacerbations, airflow may be too limited to produce wheezing -> only dx clue on auscultation may be globally reduced breath sounds with prolonged expiration
-ABG changes
diagnosing asthma: spirometry
-Testing of lung function
-Determines presence and extent of airflow obstruction & if reversible
-Airflow obstruction- Reduced FEV1/FVC ratio (< 90% pred)
-Reversibility- Increase of ≥ 12% and 200 ml in FEV1
flow volume loops: obstructive vs restrictive
-obstructive:
-loop shifts left -> volumes are > than normal
-FEV1 decreases more than FVC (lower FEV1/FVC
-restrictive:
-loops shifts to right
-volumes are < normal
-FEV1 and FVC decrease in proportion (normal or even elevated FEV1/FVC
assessing asthma control and adjusting therapy NAEPP EPR-3: pts >= 12 years of age
-OCS- oral corticosteroids- this is bad!
asthma control test chart
-its really important you are asking the right questions….asthma is very under appreciated
-many people report being fine and doctors too -> but in reality they are not well controlled
medications to tx asthma: how to use a spray inhaler
-health care provider should evaluate inhaler technique at each visit
-stand up, breathe out
-as you start to breathe in -> push down on top of inhaler -> keep breathing in slowly
-hold your breathe for 10s
-breath out
-pMDI- hardest to use
-first thing you do when pt is being txed and are uncontrolled -> ask them to use inhaler in front of you -> if they are doing it perfectly….then consider stepping up
