Paediatric Respiratory

Question 1

What is the inheritance pattern for CF

Answer 1

Autosomal recessive

Question 2

What is the most common CF mutation? What is the most severe?

Answer 2

The most common form is F508del (50%)
Most severe = G551D (11%)

Question 3

What is the pathophysiology of CF?

Answer 3

Mutations in CFTR gene cause defected chloride channels. Chloride is normally released where water follows and hence creating a mucus where cilia will perform a sweeping motion that moves the mucus out of the airways. in del F508, the protein is misfolded, preventing it from being expressed on the membrane. in CF, there is reduced volume being excreted and its hyper viscosity makes it difficult to clear and hence builds up. This impairment of airway clearance increases the risk for infection which would cause inflammation and hence lung damage worsening the situation. This also affects the GI system as the mucus prevents the release of enzymes from the pancreas leading to pancreatic insufficiency, pancreatitis, and reduced absorption =>absorption symptoms)

Question 4

What is an early indication of CF in the neonate?

Answer 4

Meconium Ileus

Question 5

How is CF screened and how is it diagnosed?

Answer 5

Heel prick blood spot test in neonates for screening
Diagnosis is usually done via sweat test as CF causes increased Na and Cl secretion making sweat salty. A sweat chloride concentration >60mmol/L confirms the diagnosis. Alternatively, CF can be confirmed via genetic screening of mutations affecting the CFTR gene

Question 6

What are the main clinical features of CF. Start with giving some for the newborn and then the ones for older children. Go system by system.

Answer 6

Newborn: Meconium ileus, prolonged neonatal jaundice, faltering growth and steatorrhea (from malabsorption), recurrent chest infections.

Older:
Resp: Recurrent chest infections => bronchiectasis, hemoptysis, and pneumothorax
GI: Pancreatic insufficiency (+thick mucus) => malabsorption => steatorrhoea + Distal Intestinal Obstruction Syndrome. (meconium ileus => distention, constipation, and vomiting)
Endocrine: Pancreatic insufficiency also allows for Cf-related Diabetes Mellitus
Hepatic: Hepatomegaly on palpation (may progress to cirrhosis and portal hypertension)
Genital: Male infertility

Question 7

A blood test is conducted on a patient with CF. Results show markedly raised glucose levels. Why is this occurring and how is this treated? How does this usually present

Answer 7

CF causes pancreatic insufficiency => preventing the action of insulin => CF-related Diabetes. They typically present with failure to gain weight. Treated with insulin

Question 8

A male CF patient asks you about getting a child. What do you tell them?
How would this affect females?

Answer 8

CF causes male infertility due to complete bilateral absence of the Vas Deference but sperm can still be harvested.

With females it is subfertility due to cilia along fallopian tubes being impacted as well as inhospitable cervical mucus.

Question 9

What is the psychological aspect of CF

Answer 9

Mainly it is difficult to balance treatment burden with necessity of care
1) parental distress due to burden of care on children.
2) Non-compliance in teenagers
3) Chronic non-curable illness

Question 10

What is your full management plan of CF

Answer 10

1) Input from MDT concerning all aspects of care
2) Psychology input key
3) Resp -> Resp Physio 2/day, Mucolytics (DNase/hypertonic saline), Antibiotic prophylaxis (flucloxacillin)
4) Dietary input: Give Oral Enteric-coated pancreatic replacement therapy AND fat-soluble vitamin supplements (ADEK)
5) CFTR modulators: 1 potentiator (Ivacaftor) and 2 correctors (Tezacaftor and Elexacaftor) for Trikafta (triple therapy).

Question 11

Is croup a URTI or LRTI? What are the symptoms of an URTI and LRTI?

Answer 11

Croup or laryngotracheobronchitis is an URTI => sore throat, low grade fever, sore throat
LRTI (pneumonia, bronchitis, bronchiectasis) => Wheezing, fever, chest pain/tightness

Question 12

What is the most common pathogen that may cause croup? Any others?

Answer 12

Parainfluenza (75%). Others include influenza, adenovirus, RSV, and COVID-19

Question 13

What are the clinical features of croup

Answer 13

URTI => sore throat, low grade fever, sore throat
Characteristic features: Inspiratory stridor (subglottal laryngitis/narrowing), hoarseness of voice/crying, and seal-like barking cough
In more severe cases, it may also cause hypoxemia (sx of resp distress), suprasternal recession, pulsus paradoxis

Question 14

What is pulsus paradoxis?

Answer 14

It is the pathological drop of >10mmHg of systolic BP during inspiration

Question 15

Why should you not examine a throat of a child with suspected croup

Answer 15

Any agitation even from inserting a line (unless absolutely necessary) may cause complete airway obstruction

Question 16

What are the differential diagnoses for stridor?

Answer 16

Croup
Epiglottitis (acutely unwell, H. influenzae, high grade fever, supraglottic laryngitis)
Spasmodic croup (allergy => sudden)
Diptheria laryngitis (acutely unwell, diptheria)
Foreign body aspiration

Question 17

What imaging would you conduct for ddx of inspiratory stridor? What do you expect to find?

Answer 17

Xray neck and chest AP and lateral. There should be narrowing of the ariway shown via Steeple sign.

Question 18

A patient presents to you with a barking cough. What are your investigations and management?

Answer 18

Ix: Xray nach and chest AP and lateral with steeple sign, PCR for detection, FBC with differentials and CRP, Blood gas

Management: Keep patient comfortable in an upright position and provide supportive therapy
Give all patients a single dose of Dexamethasone PO (or IV if necessary)
In severe cases, nebulized racemic epinephrine

Question 19

What are atopic diseases? give 2 examples

Answer 19

Eczema, hayfever
It is the predisposition to develop an allergic reaction to otherwise harmless environmental substances

Question 20

What is asthma?
What are the main RFs?

Answer 20

Chronic inflammation of the airways or bronchioles causing narrowing and wheeze

RFs: Family hx of asthma
Family/personal history of atopic disease
Smoking and anything suggesting a dust-filled home (carpets, plush toys)
Obesity
Post-infection (bacterial or viral)

Question 21

Why is it easier to diagnose asthma above the age of 5

Answer 21

Ability to do pulmonary function tests

Question 22

A patient comes in with a wheeze. What are your differentials by age?

Answer 22

<1 = Bronchiolitis
>1 = Viral induced wheeze
>5 = Athma

Question 23

Why wouldnt you prescribe salbutamol to a patient with bronchiolitis (<1)

Answer 23

Shows no improvement as salbutamol receptors tend to becomes more active and in higher concentrations to use the medication after the age of 1

Question 24

What are important history taking questions for asthma/allergy (as many as you can quickly)

Answer 24

1) Number of times to the GP
a) Chest infection? recurrent? given antibiotics?
b) Given bronchodilator (salbutamol) or steroids before?
2) Cough: Worse at night? or morning?
3) SOB: On exertion? simple activities? Trigger?
4) Sleep: Wheeze during sleep, awakening with cough or wheeze?
5) Aspiration risk: GORD (acid aspiration), food aspiration => infection risk
6) Triggers: Smoking at home, pets, atopy, carpets, soft toys
7) What are your triggers

Question 25

How would you diagnose Asthma (include investigations)

Answer 25

Full and thorough history
Pulmonary function test (Spirometry with peak expiratory flow)
Chest X-ray
Pulse oximetry

Question 26

What is the significance of spirometry in asthma.

Answer 26

Asthma is an obstructive lung disease therefore it has a low FEV1/FVC ratio (Forced expiratory volume in 1 sec and forced vital capacity). A high ratio => low FVC would indicate restrictive lung disease

Question 27

How would you treat an acute exacerbation of asthma (not an emergency)

Answer 27

Give oxygen if sats <90 (<93 if emergency as usual)
Salbutamol via spacer at 6 puffs if <6 and 10 if >6 given 1 minute apart
Prednisolone PO 1mg/kg

Question 28

What would you prescribe to a newly diagnosed asthma patient for maintenance?
Regarding spacers, what would you use if they were
<5
>5
Teen complaining of not wanted to be embarrassed when taking it before their soccer game (give 2)

Answer 28

Education!!!
Salbutamol (blue inhaler) with spacer as needed
Baclomethasone 1-2/day (brown inhaler)
<5: Aerochamber spacer
>5: Volumetric spacer
Teen: Turbohaler, Diskus inhaler, beath actuated inhaler (attached already)
Nice note: Mention Single breath and hold technique during education

Question 29

What is the Asthma action plan

Answer 29

It divides up the treatment of asthma based on symptoms. Good tool for education. Green, orange, and red (more details on ipad)

Question 30

During an acute asthma exacerbation, what symptoms (give numbers for SPO2, PEF, HR, and RR) do you expect to see? What are some red flags that may indicate that this is becoming life threatening (use common sense and you can get everything)

Answer 30

SPO2 <93%
PEF <50 (<33 in emergency)
HR >125 (slightly higher if younger)
RR > 30 (slightly higher if younger)
RED FLAGS: confusion, silent chest, cyanosis, poor resp effort (giving up from exhaustion)

Question 31

What ipratropium bromide? When is it given? How is it administered in an emergency? With what (give the dose of the other medication)

Answer 31

It is an anticholinergic agent which opens airways in the lungs. It is given to asthmatics in an acute emergency. Given together with salbutamol up to 3 times.
Salbutamol dosages
<5 = 2.5 mg/kg
5-11= 2.5-5mg/kg
>11 = 5 mg/kg