Asthma Flashcards
define asthma
a disease characterized by increased responsiveness of the airways to various stimuli and manifested by widespread narrowing of the airways that changes in severity either spontaneously or as a result of therapy
what changes are seen in the airways of a chronic asthmatic
inflammation and edema
mucus and plasma exudation
epithelial shedding and damage
list extrinsic asthma triggers
infection
irritants (smoke)
allergen (dust, pollen)
weather change
list intrinsic asthma triggers
exercise
stress
name 4 patterns of asthma
- infrequent episodic asthma
- frequent episodic asthma
- persistent asthma
- chronic cough
what tests can be used in the dx of asthma
oximetry blood--> CBC, blood bases (aminophylline level) xray pulmonary function allergy testing
how do you manage an acute episode of asthma –general
oxygen
fluids
bronchodilators (relax the muscle spasm)
anti inflammatory agents (reduce the airway wall edema and mucous secretion)
what inhaled beta agonists can be used in the management of an acute asthma episode
- salbutamol 5mg and 3 ml saline up to q15min
2. salbutamol by MDI, 6 puffs through spacer q5min
what oral steroids can be used in the management of an acute asthma episode
prednisone 1mg/kg q12h
what IV steroids can be used in the management of an acute asthma episode
- methylprednisone 1mg/kg load then 0.5 mg/kg q6h
2. hydrocortisone 4mg/kg/dose q4-6h
what IV bronchodilators can be used in the management of an acute asthma episode?
aminophylline 6mg/kg load then 1mg/kg/hr infusion–> monitor levels
what factors can be used to gauge how well a childs asthma is controlled
daytime symptoms night time symptoms physical activity exacerbations absence from school or work need for a short acting beta 2 agonist FEV1 or PEF PEF diurnal variant
what are the aims of chronic asthma therapy
minimize symptoms
allow a normal lifestyle
normalise pulmonary function
how do you manage asthma in the long term?
avoid triggers like allergens and smoking
- -no open fires in home
- -animals kept outside
medications
education
describe the canadian asthma guidelines asthma treatment continuum
early on, start with just enviro control/education/follow up plus a fast acting bronchodilator on demand
progress to adding inhaled corticosteroids at low/med/high doses
after you start adding a low or mod dose inhaled corticosteroid, consider add on therapy
if patient continues to fail with bronchodilator plus high dose inhaled corticosteroids and add on therapy, consider prednisone
why are inhaled medications the most appropriate for astha
local effect
high therapeutic ration
what devices would you use to admin asthma drugs in an infant
MDI plus spacer with mask
Wet nebulizer
what devices would you use to admin asthma drugs in a toddler
MDI plus spacer with mask for under 3-4 years old
MDI plus spacer with mouthpiece for over 3-4 years old
what devices would you use to admin asthma drugs in a child older than 4
MDI plus spacer with mouthpiece
dry powder inhaler device
what are the three pieces of info docs should provide to asthma patients and their parents
- simple explanation of disease and therapy
- when to alter meds
- when to seek medical attention
what asthma med combats episodic airway constriction?
bronchodilators–> BETA-2 AGONISTS, theophylline, anticholinergics
what asthma meds combat the chronic asthma effects of mucous/inflammation/edema etc
antiinflammatories–> CORTICOSTEROIDS, methotrexate etc
what changes are seen in the airways of people with asthma
typically affects airways 0.5 - 2 mm range
bronchial muscle hyperplasia
inflammatory cell (eosinophilic) infiltrate
edematous and thickened disrupted epithelium, loss of ciliated cells
luminal obstruction from mucous and cell debris
increased mucous secreting cells in bronchial walls
asthma is associated with a family history of what?
atopy
“hyperallergic”
what are risk factors for asthma
BPD
bronchiolitis
what affects the dose delivered to the lung by a nebulizer?
particle size
minute ventilation
entrainment of air
nasal vs oral inhalation
what is the peripheral lunch deposition from a nebulizer in a child and an adult
adult 6%
infant 1-2%
symptoms of asthma attacks
dyspnea
chest pain
cough (nocturnal/early morning with or without vomiting)
what are the chest signs of an asthma attack
tachypnea retractions accessory muscle use hyperinflation wheezing cyanosis respiratory failure subcutaneous emphysema
what are the systemic signs of an asthma attack
tachycardia
pulsus paradoxus
anxiety
exhaustion
