Respiratory Conditions Flashcards
Which gene is defective in cystic fibrosis?
The cystic fibrosis transmembrane regulator gene on chromosome 7
How common is cystic fibrosis in Caucasians?
1 in 2500 live births, carrier rate 1 in 25
True / False - Testing for cystic fibrosis is routinely done as part of the newborn heel-prick test?
True
Which age group is most commonly affected by bronchiolitis?
0-9 months. It is rare after 1 year.
Which organism causes over 80% of cases of bronchiolitis?
Respiratory syncytial virus
What is the treatment for bronchiolitis?
Supportive - keep hydrated and maintain saturations with humidified oxygen. CPAP or ventilation only required in a very small number of severe cases.
What might be given to high-risk, pre-term infants to reduce their risk of hospital admission from bronchiolitis?
Monoclonal antibody to RSV (palivizumab) given monthly by IM injection
What are the classical symptoms of croup?
Barking cough
Stridor
Which virus causes croup?
Parainfluenza virus
True / False: A throat examination should be performed on a child with croup to check for exudates on the tonsils
FALSE - It’s important not to distress a child with croup as this can make it much worse so NEVER look in their throat
What is the management of croup?
- Do not distress the child
- Humidified oxygen
- Oral steroids (dexamethasone)
- Nebulised budesonide
- Nebulised adrenaline may be required
- Intubation in extremis (about 2% of children)
Which organism causes acute epiglottitis?
Haemophilus influenza B
True / False: Whooping cough (pertussis) is highly infectious
True
What age group are affected by croup?
6 months to 6 years
Which organisms are responsible for causing pneumonia throughout childhood?
Neonate = Group B streptococcus Infancy = Viral infection especially RSV Childhood = Strep. pneumoniae, mycoplasma pnemonia, haemophilus influenza
True / False: Asthma causes clubbing
False
When should a patient with chronic asthma be advised to check their peak flow?
At least morning and evening, and preferably again during the day as well
What sort of picture on a peak flow diary would indicate an asthmatic patient?
Variability of >20% between morning and evening readings on 3 or more days of the week for 2 weeks
What is the most common chronic respiratory disorder in children?
Asthma
What is the nature of the wheeze in asthma?
Widespread, polyphonic
In asthmatics, are peak flow values generally lower in the morning or in the evening?
Morning
What is the step-wise approach to asthma management in children?
1) Short-acting beta-2 agonist
2) Add inhaled steroid e.g. beclametasone 200ug daily
* **Before proceeding to step 3, check inhaler technique and ensure correct diagnosis
3) Add long-acting beta-2 agonist e.g. Salmeterol…if this works but still symptomatic, continue LABA but increase steroid to 400ug daily. If no response from LABA, stop it, increase steroid to 400ug and consider trial of Motelukast or theophylline
4) Increase dose of inhaled steroid to 800ug
5) Add daily oral steroid e.g. prednisolone, and continue high dose inhaled steroid…refer to paediatrician!
Give an example of a long-acting beta-2 agonist added in at Step 3 of asthma management in children
Salmeterol
What is theophylline and what is it’s mechanism of action?
A methylxanthine - Normally, adenosine binds to it’s receptor and causes smooth muscle contraction due to inhibition of cAMP by phosphodiesterases…Methyxanthines block the adenosine receptor, thus increasing the amount of cAMP and causing muscle relaxation
What are the features of acute, severe asthma?
Unable to complete sentences, or too breathless to talk or feed
PEF 33-50% best or predicted
SpO2 less than 92%
HR over 140bpm (age 2-5) or 125bpm (over 5yr olds)
RR over 40 (age 2-5) or 30 (over 5yr olds)
What are the feature of acute, life threatening asthma?
Any of the following features in a child with severe asthma:
- Silent chest
- Cyanosis
- Poor respiratory effort
- Hypotension
- Exhaustion
- Confusion
- PEF less than 33% best or predicted
What is viral induced wheeze?
Wheezing episode associated with viral URTI, typically affecting the under 5 year olds. It is NON-ATOPIC (c.f. asthma)
3 year old has a wheeze associated with coryza and low-grade fever. No hx of atopy. What is the most likely diagnosis?
Viral induced wheeze - The viral URTI and absence of atopy is indicative of VIW instead of asthma
What might be heard on auscultation of the chest in bronchiolitis?
Fine end-inspiratory crackles
Expiratory wheeze
Which infants are particularly at risk of severe bronchiolitis?
Premature
Chronic lung disease
Passive smokers
True / False: Steroids are not indicated in bronchiolitis, but bronchodilators are
FALSE - Neither of these have been shown to improve outcomes in bronchiolitis so NEITHER are indicated
What is the technical name for croup?
Laryngotracheaobronchitis
What is the underlying pathology in bronchiolitis?
Inflammation of the small airways (bronchioles)
What is the underlying pathology in croup?
Inflammation of the upper airway and increased secretions causing upper airway obstruction
What causes the stridor in croup?
Subglottis oedema causing tracheal narrowing
True / Flase: Epiglottitis is common in the UK
False - Children are vaccinated against HiB so it’s uncommon
What are some clinical features of epiglottis?
Very acute onset
Fever, toxic looking child - they look unwell!
Child is open mouthed to help open the away
Drooling
Intensely painful throat - child cannot speak or swallow
Inspiratory stridor, respiratory distress
NO cough
What is the management of epiglottis?
- Sit child upright, do not examine throat, do not distress
- Alert senior paediatrician, ENT surgeon, anaesthetist
- ITU admission and intubation
- Antibiotics: Ceftriaxone or cefataxime…usually a 3-5 day course
- Extubation usually after 24 hours
What is the most common life-limiting condition affecting Caucasians?
Cystic fibrosis
Give some key clinical features of cystic fibrosis in neonates and children
Faltering growth Meconium ileus Recurrent infections Bronchiectasis Clubbing Diabetes mellitus Steatorrhoea
What is the goal standard test for diagnosis of cystic fibrosis?
Sweat test looking for raised chloride ion levels
What is the prognosis of cystic fibrosis?
Medial survival is now about 40 years old
What is a key infective organism which affects patients with cystic fibrosis?
Pseudomonas
What is the causative organism in whooping cough?
Bordetella pertussis
True / False: Montelukast is part of the management of acute asthma
False - Leukotriene antagonists have no place in the management of acute asthma. They are only useful in chronic.
Can the pertussis vaccination be given to pregnant women?
Yes - It is an inactivated vaccine
What is the incubation period of pertussis?
10-14 days
What are the clinical features of whooping cough?
Coryza
‘Whooping’ cough (caused by inspiration against closed glottis) worse at night
Vomiting after coughs
Epistaxis and subconjunctival haemorrhage may result from vigorous coughing
Apnoeas in neonates
What investigations might be carried out in pertussis?
Pernasal swab
Lymphocytosis on WCC
What are the key differences in features between epiglottitis and croup?
Croup: Harsh loud cough, hoarse voice, child will appear more ‘well’
Epiglottitis: NO cough, muffled voice, toxic looking child
