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
Describe cough in TB
over 2 to 3 weeks; initially dry, later productive
CXR findings in TB?
hilar lymphadenopathy
effusion
pulmonary infiltrates
calcification
CXR findings in reactivation TB?
Upper lobe cavitating lesion
What is the gold standard test for active TB?
Sputum culture
Sputum analysis is a key investigation in TB.
What are the 3 possible tests?
1) Sputum microscopy
2) Culture (gold standard)
3) NAAT
What stain identifies the TB bacilli with sputum microscopy?
Acid-fast stain (Ziehl-Neelsen stain) identifies the bacilli.
What 4 drugs are used in the management of TB?
1) rifampicin
2) isoniazid
3) pyrazinamide
4) ethambutol
Which TB drug is a potent liver enzyme inducer?
Rifampicin
What are 3 side effects of rifampicin?
1) hepatitis
2) orange bodily secretions
3) flu-like symptoms
Which TB drug is a liver enzyme inhibitor?
Isoniazid
What are 3 key side effects of isoniazid?
1) peripheral neuropathy
2) hepatitis
3) agranulocytosis
How can peripheral neuropathy be prevented during treatment with isoniazid?
Pyridoxine (B6)
Which TB drug increases risk of gout?
Pyrazinamide - causes hyperuricaemia
Which TB drug requires checking visual acuity before starting?
Ethambutol - can cause optic neuritis
What immunodeficiency is known to cause bronchiectasis?
Hypogammaglobulinaemia
What is the primary test used to assess drug sensitivities in TB?
Sputum culture
How is a diagnosis of epiglottitis made?
Direct visualisation performed by senior, airway trained staff
Symptom control in non-CF bronchiectasis?
Inspiratory muscle training + postural drainage
Mx of latent TB?
3 months of isoniazid (with pyridoxine) and rifampicin,
or
6 months of isoniazid (with pyridoxine)
What is used to assess drug sensitivities in TB
Sputum culture
What are the 2 most common causes of bilateral hilar lymphadenopathy?
1) TB
2) Sarcoidosis
What may be seen on CXR in a patient with latent TB?
Calcified Ghon complex
What are the main 2 indications for surgery in bronchiectasis?
1) uncontrolled haemoptysis
2) localised disease.
What are the 3 most common organisms causing post splenectomy sepsis?
1) strep. pneumoniae
2) h. influenzae
3) meningococci
at what age should spirometry be offered to children with ?asthma
> 5 y/o
What FEV1 improvement following bronchodilator therapy indicates asthma?
> 12%
Stepwise mx of asthma in those <5 y/o?
1) SABA
2) Trial of low dose paediatric ICS for 8 weeks
3) SABA + ICS + LTRA
4) Refer to specialist
What are the next steps following the 8 week ICS trial period for asthma in children <5?
1) If symptoms resolved but then recurred in <4w after stopping ICS treatment –> restart ICS at a paediatric low dose as first-line maintenance therapy
2) If symptoms resolved but then recurred in >4w after stopping ICS treatment –> repeat the 8‑week trial of a paediatric moderate dose of ICS
3) If no improvement –> alternative diagnosis
Stepwise management of asthma in children aged 5-16?
1) SABA
2) SABA + low dose ICS
3) SABA + low dose ICS + LTRA
4) Stop LTRA and start LABA
5) Switch ICS/LABA for a MART regimen that includes a paediatric low-dose ICS
6) Increase ICS dose (either continuing on a MART regimen or changing to a fixed dose of an ICS and a LABA, with a SABA)
7) Specialist advice
What should long-acting beta-2 agonists (e.g. salmeterol) always be prescribed with?
Corticosteroid
What is maintenance and reliever therapy (MART)?
A form of combined ICS and LABA treatment in which a single inhaler, containing both ICS and a fast-acting LABA, is used for both daily maintenance therapy and the relief of symptoms as required.
Pre-school wheeze can be separated into what 2 categories?
1) Episodic viral wheeze
2) Multiple trigger wheeze
What is episodic viral wheeze?
Child only wheezes when has a viral URTI and is symptom free inbetween episodes.
What is multiple trigger wheeze?
As well as viral URTIs, other factors appear to trigger the wheeze such as exercise, allergens and cigarette smoke
Is episodic viral wheeze associated with an increased risk of asthma?
No
Is multiple trigger wheeze associated with an increased risk of asthma?
Yes
Mx of viral induced wheeze?
Symptomatic only:
1st –> SABA or anticholinergic via spacer
2nd –> LTRA
What lifestyle advice should be given to parents regarding pre-school wheeze?
Parents who are smokers should be strongly encouraged to stop.
Management of multiple trigger wheeze?
Trial of either inhaled corticosteroids or a LTRA (montelukast), typically for 4-8 weeks.
Inheritance of CF?
Autosomal recessive
What mutation is seen in CF?
Mutation in CFTR gene on chromosome 7
What is the most common variant of the CFTR mutation in CF?
Delta-F508 mutation
What is the normal role of the CFTR gene?
Codes for CFTR protein
This is a chloride channel found on epithelial cells.
Channel pumps Cl- into secretions –> this helps draw water into secretions –> thins secretions.
What are the 3 consequences of the CF mutation?
1) Thick pancreatic and biliary secretions that cause blockage of the ducts, resulting in a lack of digestive enzymes such as pancreatic lipase in the digestive tract
2) Low volume thick airway secretions that reduce airway clearance, resulting in bacterial colonisation and susceptibility to airway infections
3) Congenital bilateral absence of the vas deferens in males
What causes pancreatic enzyme insufficiency in CF?
Thick pancreatic and biliary secretions cause blockage of the ducts, resulting in a lack of digestive enzymes such as pancreatic lipase in the digestive tract.
How can CF cause neonatal jaundice?
CF can cause cholestasis
How can CF present in neonates? (3)
1) Meconium ileus
2) Prolonged neonatal jaundice
3) Failure to thrive
When are the majority of cases of CF picked up?
Heelprick test at birth
Clinical features of CF?
Neonates:
- meconium ileus
- prolonged neonatal jaundice
- failure to thrive
Infancy:
- recurrent LRTIs
- pancreatic insufficiency: steatorrhoea
Childhood:
- rectal prolapse
- nasal polyps (strongly suspect CF in children presenting with nasal polyps)
- sinusitis
Adolescence:
- pancreatic insufficiency: diabetes mellitus
- chronic lung disease e.g. bronchiectasis
- Distal intestinal obstruction syndrome (DIOS)
- gallstones
- liver cirrhosis
- pancreatitis (from blockage of pancreatic ducts)
What causes nasal polyps in CF?
Thickened secretions in sinuses can lead to recurrent infection and subsequent nasal polyps due to chronic inflammation.
Why may finger clubbing be seen in CF?
Due to bronchiectasis
How can a diagnosis of CF be made?
1) Fitting clinical history
2) Positive chloride sweat test
There are three key methods for establishing a diagnosis of CF that you should remember for your exams.
What are they?
1) Newborn blood spot testing –> performed on all children shortly after birth and picks up most cases
2) Sweat test –> gold standard
3) Genetic testing for CFTR gene –> can be performed during pregnancy by amniocentesis or chorionic villous sampling, or as a blood test after birth
What happens in the sweat test for CF?
1) Pilocarpine is applied to a patch of skin.
2) Electrodes are placed either side of the patch and a small current is passed between the electrodes.
3) This causes the skin to sweat.
4) The sweat is absorbed with lab issued gauze or filter paper and sent to the lab for testing for the chloride concentration.
5) Increased chloride –> CF
What is the diagnostic chloride concentration for cystic fibrosis?
> 60 mmol/l
Relevant bedside investigations in CF?
1) Urine dip: for glucose in case of diabetes
2) Lung function testing: an obstructive picture is most common but can be restrictive, mixed or normal
What prophylactic Abx do patients with CF take long term to prevent staph. aureus infections?
Flucloxacillin
What can pseudomonas colonisation be treated with in CF?
Long term nebulised antibiotics such as tobramycin. Oral ciprofloxacin is also used.
What is involved in the management of respiratory manifestations in CF?
1) Twice-daily chest physiotherapy: to increase airway secretion clearance to reduce airway obstruction and minimise risk of infection.
2) Prophylactic antibiotics and antibiotics for acute exacerbations.
3) Inhaled bronchodilators
4) Mucolytics (oral or inhaled): hypertonic saline or dornase alfa
What is the role of hypertonic saline in CF?
Hypertonic saline can aid airway clearance (and can be used at time of physiotherapy to further aid clearance)(limited evidence to support use in under 12 yrs).
How is pancreatic insufficiency in CF usually managed?
Pancreatic enzymes (creon)
What are the fat soluble vitamins?
ADEK
How long should all courses of Abx in CF last?
2 weeks
Respiratory complications of CF?
1) Bronchiectasis
2) Recurrent infections
3) Cor pulmonale from pulmonary HTN and right heart strain
4) Haemoptysis (can be large volume and life-threatening)
5) Pneumothorax
6) Nasal polyps
7) Respiratory failure will eventually occur
8) Allergic bronchopulmonary aspergillosis (ABPA)
What can ABPA initially be treated with?
Oral prednisolone
Inheritance of primary ciliary dyskinesia?
Autosomal recessive
What is PCD also known as?
Kartagener’s syndrome
What does Kartagener’s syndrome have a strong association with?
Consanguinity
What is Kartagner’s triad?
1) Situs inversus
2) Paranasal sinusitis
3) Bronchiectasis
Also subfertility
How do patients with Kartagener’s syndrome typically present?
Recurrent respiratory tract infections
What is the key investigation for establishing the diagnosis of PCD?
Take a sample of the ciliated epithelium of the upper airway and examine the action of the cilia –> sample can be obtained through nasal brushing or bronchoscopy.
Management of Kartagener’s syndrome?
Management is similar to cystic fibrosis and bronchiectasis with daily physiotherapy, a high calorie diet and antibiotics.
What are 2 problematic bacteria in lung problems in CF?
1) Staph. aureus (gram +ve)
2) Pseudomonas aeruginosa (gram -ve)
