Asthma Flashcards
define asthma?
it is a chronic inflammatory airway disease characterized by variable reversible airway obstruction, airway hyperresponsiveness, and bronchial inflammation.
what kind of hypersensitivity is asthma?
type 1 hypersensitivity
what genetic factors might precede asthma?
- Family history
- atopy
- antenatal factors
- maternal smoking
- exposure to allergens
what environmental factors might precede asthma?
- House dust mites
- pollen
- pets
- smoking
- viral infection
- occupational allergens
- made worst by beta blockers and NSAIDS
what is the epidemiology of asthma?
- affects 10% of kids
- affects 5% of adults
- prevalence is increasing
presenting symptoms of asthma?
- episodic history
- wheeze
- breathlessness
- cough
precipitating factors?
- cold
- viral infection
- drugs
- exercise
- emotions
what are the signs of asthma on physical exercise?
- reduced PEFR
- tachypnoea
- use of accessory muscles
- prolonged expiratory phase
- hyperinflated chest
signs of moderate asthma?
PEFR 50-75% best or predicted
Speech normal
RR < 25 / min
Pulse < 110 bpm
signs of severe asthma?
PEFR 33 - 50% best or predicted
Can’t complete sentences
RR > 25/min
Pulse > 110 bpm
signs of life-threatening asthma?
PEFR < 33% best or predicted Oxygen sats < 92% Silent chest, cyanosis or feeble respiratory effort Bradycardia, dysrhythmia or hypotension Exhaustion, confusion or coma Normocapnia/ PH less than 7.35
investigations for acute asthma?
o Peak flow o Pulse oximetry o ABG o CXR - to exclude other diagnoses (e.g. pneumonia, pneumothorax) o FBC - raised WCC if infective exacerbation o CRP o U&Es o Blood and sputum cultures
investigations for asthma?
- o Peak flow o Pulse oximetry o ABG o CXR - to exclude other diagnoses (e.g. pneumonia, pneumothorax) o FBC - raised WCC if infective exacerbation o CRP o U&Es o Blood and sputum cultures
investigations for chronic asthma?
- spirometry and reversibility test
- FeNO
- An FEV1/FVC ratio of <0.7 indicates obstructive pathology
- criteria for reversibility is a change of 12% after use of a bronchodilator
management for acute asthma?
- ABCDE
- resus
- Monitor O2 sats, ABG and PEFR
- High-flow oxygen
- Salbutamol nebulizer
- Ipratropium bromide nebulized
- Steroid therapy
- if no improvement then refer to ITU
