Resp Flashcards
what is asthma?
chronic inflammatory disease of airway hypersensitivity and variable, reversible obstruction
what are 6 triggers of asthma?
viral/bacterial infection
allergen exposure
exercise
Night/early morning
Cold, damp, dust
Strong emotion
what are 2 medications that can worsen asthma?
Beta blockers
NSAIDs
what are 6 risk factors for asthma?
FHx
Atopic Hx
Low birth weight
not breastfed
Second hand smoke
High concentration allergens - dustmites
what are 5 presentations of asthma?
Diurnal episodic SOB
Dry cough
Chest tightness
Wheeze
Symptoms are reversible with bronchodilators
how is asthma investigated in adults?
1 - eosinophil count raised OR FeNO >50 ppb
2 - spirometry - FEV1 >12% postdilator increase or >10% over predicted normal
3 - PEF 20% variability over 2 weeks
what are the 2 different types of asthma?
Eosinophilic - most common (70%)
non-eosinophilic
what is atopy?
when an individual readily develops IgE against common environmental antigens
what is non-eosinophilic asthma triggered by?
exercise, cold air, stress, smoking, obesity, menstrual cycle
what is eosinophilic asthma triggered by?
allergens
what drug class should you never give to asthmatics?
BETA BLOCKERS
what 4 immune cells are present in asthma?
mast cells
eosinophils
dendritic cells
lymphocytes
what is one feature of a moderate asthma atack?
peak flow 50-70% best/predicted
what are 4 features of a severe asthma attack?
inability to complete sentences
pulse >110
RR >25
PEFR 33-50%
what are 6 features of a life threatening asthma attack?
silent chest, cyanosis, poor rest effort
confusion and exhaustion
Bradycardia
O2 Sats <92%
PEFR <33%
Normal pCO2
what is the management for a mild asthma exacerbation?
INH Salbutamol via spacer
Increased ICS dose/oral prednisolone 40-50mg 5 days
f/u within 48 hours
what is the management of a moderate asthma exacerbation?
Hospital
Nebulised salbutamol back to back
Oral/IV pred/hydrocortisone
what is the management of severe asthma exacerbations?
Hospital
O2
Nebulised ipratropium bromide
IV magnesium sulphate
IV salbutamol
IV aminophylline
intubation and ventilation
what are 3 criterial needed for discharge after an acute asthma exacerbation?
stable on discharge medication for 12-24 hours - no O2 or Nebs
INH technique checked
PEF >75% best or predicted
what are 2 effects of excessive salbutamol administration?
hypokalaemia
Lactic acidosis - due to tachycardia
how is asthma diagnosed with peak flow?
a greater than 15% increase in FEV1 or PEFR following bronchodilator inhalation
how do B2 agonists work?
binds to B2 receptor coupled with Gs protein
=> adenyl cyclase converts ATP to cyclic AMP =>
increases in cyclic AMP leads to bronchodilation
how do muscarinic antagonists work?
act on M3 receptors
prevent Ach from binding => no smooth muscle contraction
what are 6 side effects of corticosteroids?
susceptibility to infection
osteoporosis and muscle wasting
cataracts
diabetes
skin thinning and bruising
growth retardation