Asthma Flashcards
Asthma
A chronic inflammatory condition of airways
Main two parameters in asthma
- Reversible airway obstruction
- Bronchial hyper-reactivity
Pathogenesis of asthma
- Trigger – not known in many (intrinsic)
- Release of mediators
- Inflammation leading to airway obstruction
- Bronchial hyper-reactivity
- Increased response to environmental triggers
pathology of asthma
- Smooth muscle contraction
- Mucosal oedema
- Mucous plus
- Denuded epithelium
common triggers of asthma
- Infection
- Tobacco smoke & cooking fumes
- Occupational – wood dust, grain dust, flour
- House hold – dust, pets, mould, cockroach
- Food – allergies, preservatives, colouring
- Drugs – aspirin, NSAIDs, beta blockers
- Exercise
- Emotion
Asthma clinical features
- Recurrent episodes of
o Wheezing
o Breathlessness
o Chest tightness
o Coughing - Particularly at night or in the early morning
- Variable airflow obstruction, reversible either
spontaneously or with treatment
what features confirm asthma
- Airflow limitation
- Reversibility
what devices can be used to confirm the Dx of asthma
Peak flow meter
Spirometry
how to confirm obstructive nature of the disease
FEV1/FVC <70%
To assess the reversibility of bronchoconstriction in asthma
repeat FEV1 after salbutamol nebulizer
FEV1 levels after bronchodilator in asthma
> 12%
PEFR value in asthma after bronchodilator
increased by 60 L/min or 20% or previous
value
PEFR diurnal variation of asthma
> 10%
other Ix done on asthma
- WBC/DC
- CXR-AP
- PEFR
o Monitoring the disease
o Assessing the response to drugs
o Occupational asthma – to confirm the
relationship with work
Main principle of Rx of asthma
to avoid allergens
Main pharmacological principles in Mx of asthma
- Influence bronchial smooth muscles
- Reduce inflammations
- Inhibit release of mediators
- Inhibit production of mediators
which drug classes influence bronchial smooth muscles
Beta receptor agonists
anticholinergics
Xanthines
Sympathetic beta receptor agonists
Short acting – salbutamol, terbutaline
Long acting – salmeterol, formeterol
Parasympathetic – anticholinergics
Short acting – ipratropium
Long acting - tiotropium
Xanthines
theophyllines
what can be done to reduce inflammation in asthma
o Glucocorticoids (inhaled)
Beclamethasone
Budesonide
Fluticasone
o Glucocorticoids (oral or IV)
inhibiting release of mediators in asthma
Mast cell stabilizers – sodium cromoglycate
Inhibiting production of mediators in asthma
Leukotriene modifiers – montelukast
the two tracks of asthma Mx
Controller + preferred reliever
Controller+ alternative reliever
the preferred reliever
low dose ICS- formeterol combo
alternative reliever
SABA
Step 1 and 2 of track 1 in asthma Mx
preferred reliever as needed
Step 3 of track 1 in asthma Mx
low dose ICS- formoterol for both maintenance and reliever therapy (MART)
Step 4 of track 1 in asthma Mx
medium dose ICS- formoterol as maintenance
low dose ICS- formoterol as reliever
Step 1 of track 2 in asthma Mx
SABA as needed for reliever
low dose ICS whenever SABA is taken
Step 2 of track 2 in asthma Mx
Maintenance low dose ICS controller and SABA as needed as the reliever
Step 3 of track 2 in asthma Mx
low dose maintenance ICS- LABA controller
SABA as needed as the reliever
Step 4 of track 2 in asthma Mx
medium/ high dose maintenance ICS- LABA as the controller
SABA as reliever
Step 5 asthma Mx both tracks
refer to phenotypic investigations +/- add on therapy
Acute exacerbations of bronchial asthma
admit the patient and give a bed
Assess the severity of the episode
PaCO2 normal in life threatening asthma but raised PaCO2 in near fatal asthma
Connect to a monitor, measure the oxygen saturation
Administer high flow oxygen
Give oxygen driven nebulization with salbutamol 5mg every 15-30 minutes
Add ipratropium bromide 500 micrograms nebulized every 6 hours
Monitor the response
Give hydrocortisone 200mg IV
difference between acute severe asthma and life threatening asthma
Acute severe asthma Inabiity to complete a single sentence in one breath
RR>25/min
HR >110/min
PEFR between 33-50% of best or predicted
Life threatening asthma
Exhausted, confused or comatose
Poor respiratory effort
Bradycardia and hypotension
Cyanosis, SpO2<92%, PaCO2< 8kPa, silent chest
PEFR <33% of expected or predicted
PaCO2 levels in life-threatening asthma
PaCO2 normal
Near fatal asthma PaCO2 levels
Raised
Dose of ipratropium bromide in Mx of acute exacerbation of bronchial asthma
500mcg nebulized every 6 hours
If the patient is not responding to initial treatment consider adding
IV Magnesium sulphate
IV salbutamol
Exclude pneumothorax
ABG and ICU care
SABA
Salbutamol
Side effects of SABA
tremors
Which patients gets categorized into steps 1-2 of track 1 of asthma Mx
Sx less than 4-5 days in a week
Which patients gets categorized into steps 3 of track 1 of asthma Mx
Sx most days, or walking w asthma once a week or more
Which patients gets categorized into steps 4 of track 1 of asthma Mx
Daily Sx, or walking with asthma once a week or more, and low lung function
Which patients gets categorized into step 1of track 2 of asthma Mx
Sx less than twice a month
Which patients gets categorized into step 2 of track 2 of asthma Mx
Sx twice a month, or more, but less than 4-5 days a week
Which patients gets categorized into step 3 of track 2 of asthma Mx
Sx most days, or walking with asthma once a week or more
Which patients gets categorized into step 4 of track 2 of asthma Mx
Daily Sx or walking with asthma once a week or more and low lung function
ARDS of inhaled corticosteroids
oral candidiasis
stunted growth in children
ICS examples
Beclometasone
dipropionate
Fluticasone
Propionate
LABA examples
Salmeterol
Leukotriene receptor antagonists example
Monteleukast
