Day 2 Flashcards
Symptoms and signs of asthma
(4)
Symptoms
cough: often worse at night
dyspnoea
expiratory wheeze on auscultation
reduced peak expiratory flow rate (PEFR)
Risk factors for developing asthma
- personal or family history of atopy
- mantenatal factors: maternal smoking, viral infection during pregnancy (especially RSV)
- low birth weight
- not being breastfed
- maternal smoking around child
- exposure to high concentrations of allergens (e.g. house dust mite)
- air pollution
- ‘hygiene hypothesis’
What is the “hygiene hypothesis”
Reduced exposure to infectious agents in childhood prevents normal development of the immune system resulting in a Th2 predominant response
Asthma brings sensitivity to which medication?
aspirin
What type of sensitivity reaction is asthma?
Type 1
Focusing on atopy, patients with asthma also suffer from other IgE-mediated atopic conditions such as:
- atopic dermatitis (eczema)
- allergic rhinitis (hay fever)
How is asthma investigated?
- Spirometry
- Fractional exhaled nitric oxide (FeNO)
- chest x-ray
What are the typical spirometry results seen in asthma + COPD conditions?
Typical results in asthma
FEV1 - significantly reduced
FVC - normal
FEV1% (FEV1/FVC) < 70%
How does Fractional exhaled nitric oxide (FeNO) testing work?
Fractional exhaled nitric oxide (FeNO)
- nitric oxide is produced by 3 types of nitric oxide synthases (NOS).
- one of the types is inducible (iNOS) and levels tend to rise in inflammatory cells, particularly eosinophils
- levels of NO therefore typically correlate with levels of inflammation.
Which drugs are used to treat asthma?
- Short-acting beta-agonists (SABA)
- Inhaled corticosteroids (ICS)
- Long-acting beta-agonists (LABA)
- Leukotriene receptor antagonists
Epidemiology of bronchiolitis (3)
- most common cause of a serious lower respiratory tract infection in < 1yr olds (90% are 1-9 months, with a peak incidence of 3-6 months).
- Maternal IgG provides protection to newborns against RSV
- higher incidence in winter
Features of bronchiolitis
(6)
Features
- coryzal symptoms (including mild fever) precede:
- dry cough
- increasing breathlessness
- wheezing, fine inspiratory crackles (not always present)
- feeding difficulties associated with increasing dyspnoea
- interfering with feeding, often a reason for hospital admission is low weight
NICE recommend immediate referral if they have any of the following:
(6)
NICE recommend immediate referral if they have any of the following:
- apnoea (observed or reported)
- child looks seriously unwell to a healthcare professional
- severe respiratory distress, for example grunting, marked chest recession, or a respiratory rate of over 70 breaths/minute
- central cyanosis
- persistent oxygen saturation of less than 92% when breathing air.
In a GP setting NICE recommend that clinicians ‘consider’ referring to hospital if any of the following apply:
- a respiratory rate of over 60 breaths/minute
- difficulty with breastfeeding or inadequate oral fluid intake (50-75% of usual volume ‘taking account of risk factors and using clinical judgement’)
- clinical dehydration.
What is Croup
What is the main characterisation?
Which pathogen is the main cause?
(3)
Croup is a form of upper respiratory tract infection seen in infants and toddlers.
It is characterised by stridor which is caused by a combination of laryngeal oedema and secretions.
Parainfluenza viruses account for the majority of cases.
Epidemiology of Croup
(2)
peak incidence at 6 months - 3 years
more common in autumn
What are the features of Croup?
(4)
- stridor
- barking cough (worse at night)
- fever
- coryzal symptoms
What are the characteristics of “mild” croup?
(4)
- Occasional barking cough
- No audible stridor at rest
- No or mild suprasternal and/or intercostal recession
- The child is happy and is prepared to eat, drink, and play
What are the characteristics of “moderate” croup?
(5)
- Frequent barking cough
- Easily audible stridor at rest
- Suprasternal and sternal wall retraction at rest
- No or little distress or agitation
- The child can be placated and is interested in its surroundings
What are the characteristics of “severe” croup?
(5)
- Frequent barking cough
- Prominent inspiratory (and occasionally, expiratory) stridor at rest
- Marked sternal wall retractions
- Significant distress and agitation, or lethargy or restlessness (a sign of hypoxaemia)
- Tachycardia occurs with more severe obstructive symptoms and hypoxaemia
CKS suggest admitting any child with moderate or severe croup.
Other features which should prompt admission include:
(3)
- < 6 months of age
- known upper airway abnormalities (e.g. Laryngomalacia, Down’s syndrome)
- uncertainty about diagnosis (important differentials include acute epiglottitis, bacterial tracheitis, peritonsillar abscess and foreign body inhalation)
Investigations for croup
(3)
- the vast majority of children are diagnosed clinically
however, if a chest x-ray is done:
- a posterior-anterior view will show subglottic narrowing, commonly called the ‘steeple sign’
- in contrast, a lateral view in acute epiglottis will show swelling of the epiglottis - the ‘thumb sign’
Management of croup
(4)
- CKS recommend giving a single dose of oral dexamethasone (0.15mg/kg) to all children regardless of severity
Emergency treatment:
- high-flow oxygen
- nebulised adrenaline