Revision - Respiratory Flashcards
What age does croup typically affect?
6m to 3y
Peak incidence is at 2 years of age.
Typical symptoms seen in croup?
1) Barking cough
2) Stridor
3) Low grade fever
What time of year is croup more common?
Autumn
What is the classic cause of croup?
Parainfluenza virus
What did croup USED to be caused by?
Diptheria
What scoring system for croup can helps to categorise children based on their presenting clinical features?
Westley Croup Score
1) Mild: 0-2
2) Moderate: 3-5
3) Severe: 6-11
4) Impending respiratory failure: 12-17
What does management of croup involve in primary care (mild illness)?
Supportive
Single dose of oral dexamethasone
Dose of dex given in croup?
0.15 mg/kg
What 2 medications are used in the management of severe croup?
1) Oral dex/pred
2) Nebulised adrenaline
What is the most common causative organism of acute epiglottitis?
Hib –> think unvaccinated children!
Abx given in epiglottitis ?
Broad spectrum e.g. ceftriaxone
What is a common complication of epiglottitis?
The development of an epiglottic abscess (a collection of pus around the epiglottis) –> can threaten airway.
What is whooping cough also known as?
Pertussis
What organism causes whooping cough?
Bordetella pertussis
Who is vaccianted against whooping cough?
Children and pregnant women are vaccinated against pertussis.
The vaccine becomes less effective a few years after each dose.
What age is the pertussis vaccination given?
2, 3, and 4 months of age, with a booster at 3 years and 4 months.
Pathophysiology of pertussis?
The bacteria attach to the respiratory epithelium and produce toxins which paralyse the cilia and promote inflammation, impairing the clearance of respiratory secretions, which leads to a cough.
What is a paroxysmal cough?
These involve sudden and recurring attacks of coughing with cough free periods in between (seen in pertussis).
Cause of loud inspiratory whoop in pertussis?
Caused by forced inspiration against a closed glottis.
1st line investigation for diagnosis of pertussis if the cough is less than 2 weeks in duration?
Nasopharyngeal or nasal swab with PCR testing or bacterial culture.
1st line investigation for diagnosis of pertussis if the cough is >2 weeks in duration?
<5 y/o –> Anti-pertussis toxin IgG seology
5-16 y/o –> Anti-pertussis toxin detection in oral fluid
What will a FBC show in pertussis?
Lymphocytosis
When are abx given in whooping cough?
If onset of cough is <21 days
1st line mx of pertussis if the onset of the cough is <21 days?
1st –> oral macrolide e.g. clarithromycin
2nd –> oral co-trimoxazole
Who should be notified in pertussis?
Pertussis is a notifiable disease. Therefore Public Health need to be notified of each case.
How long should patients with pertussis avoid schools/nursery for?
48h after starting abx
Or 21 days from symptom onset if no abx
Complications of whooping cough?
1) subconjunctival haemorrhage
2) pneumonia
3) bronchiectasis
4) seizures
Give 2 key differentials of a wheeze in children
1) asthma
2) bronchiolitis
What is the main pathogen causing bronchiolitis?
RSV
What age does bronchiolitis typically affect?
<2y/o
Most common in infants <6m
What is a key differential for bronchiolitis that must not be missed?
HF
1st line investigation in bronchiolitis?
Nasopharyngeal aspirate or throat swab –> RSV rapid testing and viral cultures.
What is bronchiolitis obliterans?
A potential complication of bronchioilitis
Airways become permanently damaged due to inflammation and fibrosis
How long does bronchiolitis typically last?
Bronchiolitis usually lasts 7-10 days.
What is ‘grunting’?
Grunting is caused by exhaling with the glottis partially closed to increase positive end-expiratory pressure.
What is the stepwise approach to ventilatory support in infants?
1) High-flow humidified oxygen via tight nasal cannula (i.e. “Airvo” or “Optiflow”)
2) Continuous positive airway pressure (CPAP)
3) Intubation & ventilation
What does ‘high flow humidified oxygen’ involve?
Delivered via a tight nasal cannula.
This delivers air and oxygen continuously with some added pressure, helping to oxygenate the lungs and prevent the airways from collapsing.
It adds “positive end-expiratory pressure” (PEEP) to maintain the airway at the end of expiration.
What drug may be indicated in the prevention of bronchiolitis?
Palivizumab (monoclonal antibody).
A monthly injection is given as prevention against bronchiolitis caused by RSV.
Which babies is the Palivizumab injection given to?
It is given to high risk babies, such as ex-premature and those with congenital heart disease.
What does bronchiectasis commonly occur as a result of in children?
CF
What is primary ciliary dyskinesia (PCD)?
Autosomal recessive disorder leading to either reduced efficacy or complete inaction of bronchial cilia.
How can PCD predispose to bronchiectasis?
PCD causes problems with mucociliary clearance leading to increased susceptibility to low-grade infections and irritation from foreign particulates.
What are the most typical organisms causing post-infectious bronchiectasis? (7)
1) Strep. pneumoniae
2) Staph. aureus
3) Adenovirus
4) Measles
5) Influenza virus
6) Bordetella pertussis
7) Mycobacterium tuberculosis
What is Young’s syndrome?
1) bronchiectasis
2) reduced fertility
3) rhinosinusitis
Different patterns seen on HRCT can occur with different aetiologies.
What aetiologies would the following patterns indicate:
a) Bilateral upper lobe bronchiectasis
b) Unilateral upper lobe bronchiectasis
c) Focal bronchiectasis (lower lobe)
a) CF
b) Post-TB infection
c) Foreign body inhalation
Management options in bronchiectasis?
1) Chest physiotherapy
2) Exacerbations and antibiotics
3) Bronchodilators (if have wheeze)
4) Follow up regularly
What are the 3 most commonly isolated organisms causing bronchiectasis exacerbations?
1) H. influenzae
2) Strep. pneumoniae
3) Moraxella catarrhalis
What type of organism is Mycobacterium tuberculosis?
Aerobic, acid-fast bacilli