Resp Flashcards
what is asthma?
“Chronic respiratory condition associated with airway inflammation and hyper-responsiveness” leading to episodes of bronchoconstriction where airways narrow and obstruct airflow to lungs
what is the pathophysiology of asthma?
type 1 hypersensitivity reaction immediately where allergens react with IgE causing mast degranulation to release histamine leading to bronchoconstriction
then comes the type 4 hypersensitivity late phase where mediators and cytokines cause inflammation in airways
what are some risk factors for asthma?
- genetics, low birth weight, parental smoking
- personal or FHx
- antenatal factors: maternal smoking, viral infection during pregnancy
- exposure to high concentrations of allergens
- hygiene hypothesis
what are some key points in the history of asthma?
- env triggers: exercise, allergens, weather, infections, medications
- dry cough, wheeze b/L, chest tightness, SOB
- episodic, worse at night, family history
- frequent hospital admissions
what are some key examination findings of asthma?
*normal inbetween attacks
- finger clubbing (not for asthma, CF or bronchiectasis)
- chest shape - hyperinflated chest
- chest symmetry
- breath sounds
- crepitations (not only asthma)
- wheeze!!
- tonsillar enlargement - infection
how is asthma investigated?
- fractional inhaled NO
- over 5y spirometry, bronchodilator with reversibility
- bronchial challenge
- CXR
what is the aim of asthma management?
good symptom control with full school attendance, no sleep disturbance, <2 a week of daytime sx, no limitation on daily activities, SABA <2/ week and normal lung function
how is asthma managed?
- SABA —> ICS —> add on therapy like ICS+ LABA —> increase ICS —> stop LABA and add montelukast —> oral steroids and resp paediatrician
- then potential monoclonal antibody therapy with Omalizumab for those with persistent poor control and raised IgE
- general Mx
- spacer use
- question compliance
- LABA given as combination inhaler with ICS
- asthma management plan!
- inhaler technique review with asthma or practice nurse
how do you define mild/ moderate asthma exacerbation?
SpO2 - >92%
talking in full sentences
wheeze audible
no accessory muscle use
RR <30
how do you define severe asthma exacerbation?
SpO2 <92%
PEFR 33-50%
too breathless to feed or talk
use of accessory muscles
audible wheeze
RR> 30
how do you define life threatening asthma?
SpO2 <92%
PEFR <33%
silent chest
altered consciousness
cyanosis
how is an asthma exacerbation managed?
- Oxygen
- salbutamol can be given with O2 *make sure it is asthma as salbutamol increases HR so could exacerbate conditions.
- 3 day course of oral prednisolone (if vomiting or unwell IV hydrocortisone)
- Ipatropium and reassess
- Mg IV
- Escalate!
how do you ensure a safe discharge post exacerbation of asthma?
bronchodilators taken with spacer every 4h, SATS over 94%, inhaler technique assessed and taught, asthma management plan updated and explained to parents, GP review within 2 days after discharge
what is the pathophysiology of bronchiectasis?
- Abnormal dilatation of the airways with associated destruction of bronchial tissue
- Inflammatory response to severe infection leads to structural damage within the bronchial walls, which causes dilatation, scarring as a result
- This reduces the number of cilia within the bronchi which predisposes them to further infections
what are some common causes of bronchiectasis?
- CF
- post-infectious due to strep pneumonia
- immunodeficiency
- primary ciliary dyskinesia
- post-obstructive foreign body
- congenital syndromes
what are some key points in a history for bronchiectasis?
- Chronic productive cough
- purulent sputum expectoration
- chest pain
- wheeze
- SOB on exertion
- haemoptysis
- recurrent or persistent LRTI
what are some complications of bronchiectasis?
- recurrent infection
- life-threatening haemoptysis
- lung abscess
- pneumothorax
- poor growth and development
how do you investigate bronchiectasis?
diagnose and find cause
- CXR: bronchial wall thickening, airway dilatation
- high resolution CT
- bronchoscopy
- lung function
- underlying cause: chloride sweat test, FBC, immunoglobulin, HIV, microbiology
what is the gold standard of investigating bronchiectasis and what do you see?
high resolution CT gold standard
- bronchial wall thickening
- diameter of bronchus larger than accompanying bronchial artery (signet ring sign)
- visible peripheral bronchi
what is bronchiolitis?
viral infection of bronchioles, smallest air passages in lungs, commonly caused by respiratory syncytial virus (RSV)
what is the pathophysiology of bronchiolitis and what physiological changes take place as a result?
- RSV causes
- proliferation of goblet cells causing excess mucus production
- IgE-mediated type 1 allergic reaction causing inflammation
- Bronchiolar constriction
- Infiltration of lymphocytes causing submucosal oedema
- Infiltration of cytokines and chemokines
what are some risk factors for bronchiolitis?
breast fed for less than 2 months
smoke exposure (parents smoke)
having siblings who attend nursery or school (increased virus exposure)
chronic lung disease due to prematurity
what are some key features of bronchiolitis?
*affects children under 2
- winter and spring hospitalisations
- increasing sx over 2-5 days
- low grade fever
- nasal congestion
- rhinorrhoea
- cough
- feeding difficulty
what examination findings might you detect in bronchiolitis?
- tachypnoea
- grunting
- nasal flaring
- intercostal, subcostal or supraclavicular recessions
- inspiratory crackles
- expiratory wheeze
- hyper-inflated chest
- cyanosis or pallor