Paediatric Respiratory

Question 1

Bronchiolitis

Answer 1

Bronchiolitis describes inflammation and infection in the bronchioles, the small airways of the lungs.

This is usually caused by a virus. Respiratory syncytial virus (RSV) is the most common cause.

Bronchiolitis is very common in winter. Bronchiolitis is generally considered to occur in children under 1 year. It is most common in children under 6 months. It can rarely be diagnosed in children up to 2 years of age, particularly in ex-premature babies with chronic lung disease.

When a virus affects the airways of adults, the swelling and mucus are proportionally so small that it has little noticeable effect on breathing. The airways of infants are very small to begin with, and when there is even the smallest amount of inflammation and mucus in the airway it has a significant effect on the infants ability to circulate air to the alveoli and back out. This causes the harsh breath sounds, wheeze and crackles heard on auscultation when listening to a bronchiolitic baby’s chest.

Question 2

Presentation of bronchiolitis

Answer 2

Coryzal symptoms. These are the typical symptoms of a viral upper respiratory tract infection: running or snotty nose, sneezing, mucus in throat and watery eyes.
Signs of respiratory distress
Dyspnoea (heavy laboured breathing)
Tachypnoea (fast breathing)
Poor feeding
Mild fever (under 39ºC)
Apnoeas are episodes where the child stops breathing
Wheeze and crackles on auscultation

Question 3

Signs of respiratory distress

Answer 3

One of the foundations of paediatrics is being able to spot the signs of respiratory distress:

Raised respiratory rate
Use of accessory muscles of breathing, such as the sternocleidomastoid, abdominal and intercostal muscles
Intercostal and subcostal recessions
Nasal flaring
Head bobbing
Tracheal tugging
Cyanosis (due to low oxygen saturation)
Abnormal airway noises

TOM TIP: You should become very confident in listing and spotting the signs of respiratory distress. This is very important when treating children, to distinguish between a well child and an unwell child. Your examiners will expect you to know the signs like the back of your hand.

Question 4

Abnormal airway noises

Answer 4

Wheezing is a whistling sound caused by narrowed airways, typically heard during expiration
Grunting is caused by exhaling with the glottis partially closed to increase positive end-expiratory pressure
Stridor is a high pitched inspiratory noise caused by obstruction of the upper airway, for example in croup

Question 5

Typical RSV course

Answer 5

Bronchiolitis usually starts as an upper respiratory tract infection (URTI) with coryzal symptoms. From this point around half get better spontaneously. The other half develop chest symptoms over the first 1-2 days following the onset of coryzal symptoms. Symptoms are generally at their worst on day 3 or 4. Symptoms usually last 7 to 10 days total and most patients fully recover within 2 – 3 weeks. Children who have had bronchiolitis as infants are more likely to have viral induced wheeze during childhood.

Question 6

Admission with bronchiolitis

Answer 6

Most infants can be managed at home with advice about when to seek further medical attention. Reasons for admission include:

Aged under 3 months or any pre-existing condition such as prematurity, Downs syndrome or cystic fibrosis
50 – 75% or less of their normal intake of milk
Clinical dehydration
Respiratory rate above 70
Oxygen saturations below 92%
Moderate to severe respiratory distress, such as deep recessions or head bobbing
Apnoeas
Parents not confident in their ability to manage at home or difficulty accessing medical help from home

Question 7

Managing bronchiolitis

Answer 7

Typically patients only require supportive management. This involves:

Ensuring adequate intake. This could be orally, via NG tube or IV fluids depending on the severity. It is important to avoid overfeeding as a full stomach will restrict breathing. Start with small frequent feeds and gradually increase them as tolerated.
Saline nasal drops and nasal suctioning can help clear nasal secretions, particularly prior to feeding
Supplementary oxygen if the oxygen saturations remain below 92%
Ventilatory support if required
There is little evidence for treatments such as nebulised saline, bronchodilators, steroids and antibiotics.

Question 8

Ventilatory support for children

Answer 8

As breathing gets harder, the child gets more tired and less able to adequately ventilate themselves. They may require ventilatory support to maintain their breathing. This is stepped up until they are adequately ventilated:

High-flow humidified oxygen via tight nasal cannula (i.e. “Airvo” or “Optiflow”). 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.
Continuous positive airway pressure (CPAP). This involves using a sealed nasal cannula that performs in a similar way to Airvo or Optiflow, but can deliver much higher and more controlled pressures.
Intubation and ventilation. This involves inserting an endotracheal tube into the trachea to fully control ventilation.

Question 9

Assessing ventilation

Answer 9

Capillary blood gases are useful in severe respiratory distress and in monitoring children who are having ventilatory support.

The most helpful signs of poor ventilation are:

Rising pCO2, showing that the airways have collapsed and can’t clear waste carbon dioxide.
Falling pH, showing that CO2 is building up and they are not able to buffer the acidosis this creates. This is a respiratory acidosis. If they are also hypoxic, this is classed as type 2 respiratory failure.

Question 10

Palivizumab

Answer 10

Palivizumab is a monoclonal antibody that targets the respiratory syncytial virus. A monthly injection is given as prevention against bronchiolitis caused by RSV. It is given to high risk babies, such as ex-premature and those with congenital heart disease.

It is not a true vaccine as it does not stimulate the infant’s immune system. It provides passive protection by circulating the body until the virus is encountered, as which point it works as an antibody against the virus, activating the immune system to fight the virus. The levels of circulating antibodies decrease over time, which is why a monthly injection is required.

Question 11

Viral-induced wheeze

Answer 11

Viral-induced wheeze describes is an acute wheezy illness caused by a viral infection. Small children (typically under 3 years) have small airways. When these small airways encounter a virus (commonly RSV or rhinovirus) they develop a small amount of inflammation and oedema, swelling the walls of the airways and restricting the space for air to flow. This inflammation also triggers the smooth muscles of the airways to constrict, further narrowing the space in the airway.

This swelling and constriction of the airway caused by a virus has little noticeable effect on the larger airways of an older child or adult, however due to the small diameter of a child’s airway, the slight narrowing leads to a proportionally larger restriction in airflow. This is described by Poiseuille’s law, which states that flow rate is proportional to the radius of the tube to the power of four. Therefore, halving the diameter of the tube decreases flow rate by 16 fold.

Air flowing through these narrow airways causes a wheeze, and the restricted ventilation leads to respiratory distress. For some reason, certain children are much more prone to this airway swelling than others. There seems to be a hereditary element, so when assessing a wheezy child ask about a family history of viral-induced wheeze. These children are at higher risk of developing asthma in later life.

Question 12

Viral Induced Wheeze or Asthma?

Answer 12

The distinction between a viral-induced wheeze and asthma is not definitive. Generally, typical features of viral-induced wheeze (as opposed to asthma) are:

Presenting before 3 years of age
No atopic history
Only occurs during viral infections
Asthma can also be triggered by viral or bacterial infections, however it also has other triggers, such as exercise, cold weather, dust and strong emotions. Asthma is historically a clinical diagnosis, and the diagnosis is based on the presence of typical signs and symptoms along with variable and reversible airflow obstruction.

Question 13

Presentation of viral-induced wheeze

Answer 13

Evidence of a viral illness (fever, cough and coryzal symptoms) for 1-2 days preceding the onset of:

Shortness of breath
Signs of respiratory distress
Expiratory wheeze throughout the chest
TOM TIP: Neither viral-induced wheeze or asthma cause a focal wheeze. If you hear a focal wheeze be very cautious and investigate further for a focal airway obstruction such as an inhaled foreign body or tumour. These patients will require an urgent senior review.

Question 14

Managing viral-induced wheeze

Answer 14

Management of viral-induced wheeze is the same as acute asthma in children.

Question 15

Presentation of acute asthma

Answer 15

An acute exacerbation of asthma is characterised by a rapid deterioration in the symptoms of asthma. This could be triggered by any of the typical asthma triggers, such as infection, exercise or cold weather.

Presentation

Progressively worsening shortness of breath
Signs of respiratory distress
Fast respiratory rate (tachypnoea)
Expiratory wheeze on auscultation heard throughout the chest
The chest can sound “tight” on auscultation, with reduced air entry
A silent chest is an ominous sign. This is where the airways are so tight it is not possible for the child to move enough air through the airways to create a wheeze. This might be associated with reduce respiratory effort due to fatigue. A less experienced practitioner may think because there is no respiratory distress and no wheeze the child is not as unwell, however in reality this a silent chest is life threatening.

Question 16

Severity of acute asthma

Answer 16

It is important to assess the severity of asthma to guide how aggressively they need to be treated. The table below is adapted from the BTS / SIGN guidelines from 2016.

Moderate
Peak flow > 50 % predicted
Normal speech
No features listed across

Severe
Peak flow < 50% predicted
Saturations < 92%
Unable to complete sentences in one breath
Signs of respiratory distress
Respiratory rate:
> 40 in 1-5 years
> 30 in > 5 years
Heart rate:
> 140 in 1-5 years
> 125 in > 5 years

Life Threatening
Peak flow < 33% predicted
Saturations < 92%
Exhaustion and poor respiratory effort
Hypotension
Silent chest
Cyanosis
Altered consciousness / confusion

Question 17

Managing acute asthma

Answer 17

Staples of management in acute viral induced wheeze or asthma are:

Supplementary oxygen if required (i.e. oxygen saturations less than 94% or working hard)
Bronchodilators (e.g. salbutamol, ipratropium and magnesium sulphate)
Steroids to reduce airway inflammation: prednisone (orally) or hydrocortisone (intravenous)
Antibiotics only if a bacterial cause is suspected (e.g. amoxicillin or erythromycin)

Bronchodilators are stepped up as required:

Inhaled or nebulised salbutamol (a beta-2 agonist)
Inhaled or nebulised ipratropium bromide (an anti-muscarinic)
IV magnesium sulphate
IV aminophylline

Mild cases can be managed as an outpatient with regular salbutamol inhalers via a spacer (e.g. 4-6 puffs every 4 hours).

Moderate to severe cases require a stepwise approach working upwards until control is achieved:

Salbutamol inhalers via a spacer device: starting with 10 puffs every 2 hours
Nebulisers with salbutamol / ipratropium bromide
Oral prednisone (e.g. 1mg per kg of body weight once a day for 3 days)
IV hydrocortisone
IV magnesium sulphate
IV salbutamol
IV aminophylline
If you haven’t got control by this point the situation is very serious. Call an anaesthetist and the intensive care unit. They may need intubation and ventilation. This call should be made earlier to give the best chance of successfully intubating them before the airway becomes too constricted.

Once control is established: you can gradually work your way back down the ladder as they get better:

Review the child prior to the next dose of their bronchodilator.
Look for evidence of cyanosis (central or peripheral), tracheal tug, subcostal recessions, hypoxia, tachypnoea or wheeze on auscultation.
If they look well, consider stepping down the number and frequency of the intervention.
A typical step down regime of inhaled salbutamol is 10 puffs 2 hourly then 10 puffs 4 hourly then 6 puffs 4 hourly then 4 puffs 6 hourly.
Consider monitoring the serum potassium when on high doses of salbutamol as it causes potassium to be absorbed from the blood into the cells.

It is also worth noting that salbutamol causes tachycardia and a tremor.

Question 18

Discharge after acute asthma

Answer 18

Generally, discharge can be considered when the child well on 6 puffs 4 hourly of salbutamol. They can be prescribed a reducing regime of salbutamol to continue at home, for example 6 puffs 4 hourly for 48 hours then 4 puffs 6 hourly for 48 hours then 2-4 puffs as required.

A few other steps to consider:

Finish the course of steroids if these were started (typically 3 days total)
Provide safety-net information about when to return to hospital or seek help
Provide an individualised written asthma action plan

Question 19

Asthma

Answer 19

Asthma is a chronic inflammatory airway disease leading to variable airway obstruction. The smooth muscle in the airways is hypersensitive, and responds to stimuli by constricting and causing airflow obstruction. This bronchoconstriction is reversible with bronchodilators such as inhaled salbutamol.

Asthma is one of a number of atopic conditions, which include asthma, eczema, hay fever and food allergies. Patients with one of these conditions are more likely to have others. These conditions characteristically run in families, so always ask about family history and don’t be surprised if their brother, mother or “everyone in the family” has asthma, eczema and allergies.

Question 20

Presentation Suggesting a Diagnosis of Asthma

Answer 20

Episodic symptoms with intermittent exacerbations
Diurnal variability, typically worse at night and early morning
Dry cough with wheeze and shortness of breath
Typical triggers
A history of other atopic conditions such as eczema, hayfever and food allergies
Family history of asthma or atopy
Bilateral widespread “polyphonic” wheeze heard by a healthcare professional
Symptoms improve with bronchodilators

Question 21

Presentation Indicating a Diagnosis Other Than Asthma

Answer 21

Wheeze only related to coughs and colds, more suggestive of viral induced wheeze
Isolated or productive cough
Normal investigations
No response to treatment
Unilateral wheeze suggesting a focal lesion, inhaled foreign body or infection

Question 22

Typical triggers of asthma

Answer 22

Dust (house dust mites)
Animals
Cold air
Exercise
Smoke
Food allergens (e.g. peanuts, shellfish or eggs)

Question 23

Diagnosis of Asthma

Answer 23

There is no gold standard test or diagnostic criteria for asthma. A diagnosis is made clinically based on a typical history and examination. Children are usually not diagnosed with asthma until they are at least 2 to 3 years old. When there is a low probability of asthma and the child is symptomatic, consider referral to a specialist for diagnosis.

When there is an intermediate or high probability of asthma, a trial of treatment can be implemented and if the treatment improves symptoms a diagnosis can be made.

There are investigations that can be used where there is an intermediate probability of asthma or diagnostic doubt:

Spirometry with reversibility testing (in children aged over 5 years)
Direct bronchial challenge test with histamine or methacholine
Fractional exhaled nitric oxide (FeNO)
Peak flow variability measured by keeping a diary of peak flow measurements several times a day for 2 to 4 weeks

Question 24

Long term management of asthma

Answer 24

The treatment here is based on the 2016 BTS/SIGN guidelines. It is a summary to help your understanding and learning and it is essential that you consult guidelines and seniors before treating patients.

The principles of using the stepwise ladder are to:

Start at the most appropriate step for the severity of the symptoms
Review at regular intervals based on the severity
Step up and down the ladder based on symptoms
Aim to achieve no symptoms or exacerbations on the lowest dose and number of treatments
Always check inhaler technique and adherence at each review

Question 25

Asthma Medical Therapy in Under 5 Years

Answer 25

Start a short-acting beta-2 agonist inhaler (e.g. salbutamol) as required
Add a low dose corticosteroid inhaler or a leukotriene antagonist (i.e. oral montelukast)
Add the other option from step 2.
Refer to a specialist.

Question 26

Asthma Medical Therapy Aged 5 – 12 Years

Answer 26

Start a short-acting beta-2 agonist inhaler (e.g. salbutamol) as required
Add a regular low dose corticosteroid inhaler
Add a long-acting beta-2 agonist inhaler (e.g. salmeterol). Continue salmeterol only if the patient has a good response.
Titrate up the corticosteroid inhaler to a medium dose. Consider adding:
Oral leukotriene receptor antagonist (e.g. montelukast)
Oral theophylline
Increase the dose of the inhaled corticosteroid to a high dose.
Referral to a specialist. They may require daily oral steroids.

Question 27

Asthma Medical Therapy Aged Over 12 Years (Same as Adults)

Answer 27

Start a short-acting beta 2 agonist inhaler (e.g. salbutamol) as required
Add a regular low dose corticosteroid inhaler
Add a long-acting beta-2 agonist inhaler (e.g. salmeterol). Continue salmeterol only if the patient has a good response.
Titrate up the corticosteroid inhaler to a medium dose. Consider a trial of an oral leukotriene receptor antagonist (i.e. montelukast), oral theophylline or an inhaled LAMA (i.e. tiotropium).
Titrate the inhaled corticosteroid up to a high dose. Combine additional treatments from step 4, including the option of an oral beta 2 agonist (i.e. oral salbutamol). Refer to specialist.
Add oral steroids at the lowest dose possible to achieve good control under specialist guidance.

Question 28

Inhaled Corticosteroids in Children

Answer 28

A potential exam scenario is discussing inhaled steroids with a parent that is worried about potential side effects. A common question is whether they slow growth. There is evidence that inhaled steroids can slightly reduce growth velocity and can cause a small reduction in final adult height of up to 1cm when used long term (for more than 12 months). This effect was dose-dependent, meaning it was less of a problem with smaller doses.

It is worth putting this in context for the parent by explaining that these are effective medications that work to prevent poorly controlled asthma and asthma attacks that could lead to higher doses of oral steroids being given. Poorly controlled asthma can lead to a more significant impact on growth and development. The child will also have regular asthma reviews to ensure they are growing well and on the minimal dose required to effectively control symptoms.

Question 29

Inhaler Technique

Answer 29

Inhaler technique is a key aspect of good asthma management. The better the technique, the more medication reaches the lungs. Poor technique results in medication in the mouth or the back of the throat. This reduces the effectiveness of the medication and leads to complications such as oral thrush with steroid inhalers.

Ideally, inhalers should be used with a spacer device to maximise their effectiveness. There are multiple types of inhaler with different techniques. This focuses on the technique used for the typical salbutamol metered dosed inhaler (MDI). There are also dry powder inhalers that require the patient to inhale quickly and deeply to draw the powder into the lungs.

Question 30

MDI technique without a spacer:

Answer 30

Remove the cap
Shake the inhaler (depending on the type)
Sit or stand up straight
Lift the chin slightly
Fully exhale
Make a tight seal around the inhaler between the lips
Take a steady breath in whilst pressing the canister
Continue breathing for 3 – 4 seconds after pressing the canister
Hold the breath for 10 seconds or as long as comfortably possible
Wait 30 seconds before giving a further dose
Rinse the mouth after using a steroid inhaler

Question 31

MDI technique with a spacer:

Answer 31

Assemble the spacer
Shake the inhaler (depending on the type)
Attach the inhaler to the correct end
Sit or stand up straight
Lift the chin slightly
Make a seal around the spacer mouthpiece or place the mask over the face
Spray the dose into the spacer
Take steady breaths in and out 5 times until the mist is fully inhaled
Alternatively exhale fully before putting making a seal with the spacer, spray the dose and take one deep breath in to inhale the mist in one breath before holding for 10 seconds.

Spacers should be cleaned once a month. Avoid scrubbing the inside and allow them to air dry to avoid creating static. Static can interact with the mist and prevent the medication being inhaled.

TOM TIP: Teaching inhaler technique is a common exam task, so practice with colleagues. It is important to check inhaler technique during asthma review. If you come across a poorly controlled asthmatic who states they are taking their inhalers as prescribed, consider whether their inhaler technique is adequate, as this may be the cause of their poor asthma control.

Question 32

Presentation of pneumonia

Answer 32

Pneumonia is simply an infection of the lung tissue. It causes inflammation of the lung tissue and sputum filling the airways and alveoli. Pneumonia can be seen as consolidation on a chest xray. It can be caused by a bacteria, virus or atypical bacteria such as mycoplasma.

Presentation

Cough (typically wet and productive)
High fever (> 38.5ºC)
Tachypnoea
Tachycardia
Increased work of breathing
Lethargy
Delirium (acute confusion associated with infection)

Question 33

Signs of pneumonia

Answer 33

There may be a derangement in basic observations. These can indicate sepsis secondary to the pneumonia:

Tachypnoea (raised respiratory rate)
Tachycardia (raised heart rate)
Hypoxia (low oxygen)
Hypotension (shock)
Fever
Confusion

There are characteristic chest signs of pneumonia:

Bronchial breath sounds. These are harsh breath sounds that are equally loud on inspiration and expiration. These are caused by consolidation of the lung tissue around the airway.
Focal coarse crackles caused by air passing through sputum similar to using a straw to blow into a drink.
Dullness to percussion due to lung tissue collapse and/or consolidation.

Question 34

Causes of pneumonia

Answer 34

Bacterial

Streptococcus pneumonia is most common
Group A strep (e.g. Streptococcus pyogenes)
Group B strep occurs in pre-vaccinated infants, often contracted during birth as it often colonises the vagina.
Staphylococcus aureus. This causes typical chest xray findings of pneumatocoeles (round air filled cavities) and consolidations in multiple lobes.
Haemophilus influenza particularly affects pre-vaccinated or unvaccinated children.
Mycoplasma pneumonia, an atypical bacteria with extra-pulmonary manifestations (e.g. erythema multiforme).

Viral

Respiratory syncytial virus (RSV) is the most common viral cause
Parainfluenza virus
Influenza virus

Question 35

Investigating pneumonia

Answer 35

A chest xray is the investigation of choice for diagnosing pneumonia. It is not routinely required, but can be useful if there is diagnostic doubt or in severe or complicated cases.

Sending sputum cultures and throat swabs for bacterial cultures and viral PCR can establish the causative organism and guide treatment. All patients with sepsis should have blood cultures. Capillary blood gas analysis can be helpful in assessing or monitoring respiratory or metabolic acidosis and the blood lactate level in unwell patients.

Question 36

Managing pneumonia

Answer 36

Pneumonia should be treated with antibiotics according to local guidelines.

Amoxicillin is often used first line. Adding a macrolide (erythromycin, clarithromycin or azithromycin) will cover atypical pneumonia. Macrolides can be used as monotherapy in patients with a penicillin allergy.

IV antibiotics can be used when there is sepsis or a problem with intestinal absorption.

Oxygen is used as required to maintain saturations above 92%.

Question 37

Recurrent Lower Respiratory Tract Infections

Answer 37

When a child is having recurrent admission requiring antibiotics for a lower respiratory tract infections it is worth considering further investigations for underlying lung or immune system pathology.

A thorough history (including family history) and examination is needed to assess for reflux, aspiration, neurological disease, heart disease, asthma, cystic fibrosis, primary ciliary dyskinesia and immune deficiency.

The following tests can be done:

Full blood count to check levels of various white blood cells.
Chest xray to screen for any structural abnormality in the chest or scarring from the infections.
Serum immunoglobulins to test for low levels of certain antibody classes indicating selective antibody deficiency.
Test immunoglobulin G to previous vaccines (i.e. pneumococcus and haemophilus). Some patients are unable to convert IgM to IgG, and therefore cannot form long term immunity to that bug. This is called an immunoglobulin class-switch recombination deficiency.
Sweat test to check for cystic fibrosis.
HIV test, especially if mum’s status is unknown or positive.

Question 38

Croup

Answer 38

Croup is an acute infective respiratory disease affecting young children. It typically affects children aged 6 months to 2 years, however they can be older. It is an upper respiratory tract infection causing oedema in the larynx. The classic cause of croup that you need to spot in your exams, is parainfluenza virus. It usually improves in less than 48 hours and responds well to treatment is steroids, particularly dexamethasone.

Question 39

Causes of croup

Answer 39

The common causes for croup are:

Parainfluenza
Influenza
Adenovirus
Respiratory Syncytial Virus (RSV)
Croup used to be caused by diphtheria. Croup caused by diphtheria leads to epiglottitis and has a high mortality. Vaccination mean that this is very rare in developed countries.

Question 40

Presentation of croup

Answer 40

Increased work of breathing
“Barking” cough, occurring in clusters of coughing episodes
Hoarse voice
Stridor
Low grade fever

Question 41

Managing croup

Answer 41

Most cases can be managed at home with simple supportive treatment (fluids and rest). During attacks it can help to sit the child up and comfort them. Measures should be taken to avoid spreading infection, for example hand washing and staying off school.

Oral dexamethasone is very effective. This is usually a single dose of 150 mcg/kg, which can be repeated if required after 12 hours. Prednisolone is sometimes used as an alternative where dexamethasone in not available (e.g. by GPs).

Stepwise options in severe croup to get control of symptoms:

Oral dexamethasone
Oxygen
Nebulised budesonide
Nebulised adrenalin
Intubation and ventilation

Question 42

Epiglottitis

Answer 42

Epiglottitis is inflammation and swelling of the epiglottis caused by infection, typically with haemophilus influenza type B. The epiglottis can swell to the point of completely obstructing the airway within hours of symptoms developing. Therefore, epiglottitis is a life threatening emergency.

Epiglottitis is now rare due to the routine vaccination program, which vaccinates all children against haemophilus. You need to be extra cautious and have high suspicion in children that have not had vaccines. It can present in a similar way to croup, but with a more rapid onset. In you exams keep a lookout for an unvaccinated child presenting with a fever, sore throat, difficulty swallowing that is sitting forward and drooling and suspect epiglottitis.

Question 43

Investigating epiglottitis

Answer 43

If the patient is acutely unwell and epiglottitis is suspected then investigations should not be performed. Performing a lateral xray of the neck shows a characteristic “thumb sign” or “thumbprint sign”. This is a soft tissue shadow that looks like a thumb pressed into the trachea. This is caused by the oedematous and swollen epiglottis. Neck xrays are also useful for excluding a foreign body.

Question 44

Managing epiglottitis

Answer 44

Epiglottitis is an emergency and there is an immediate risk of the airway closing. A key point that is often talked about with epiglottitis is the importance of not distressing the patient, as this could prompt closure of the airway. If you see a child with suspected epiglottitis, leave them well alone and in their comfort zone. Don’t examine them and don’t make them upset. The most important thing is to alert the most senior paediatrician and anaesthetist available.

Management of epiglottis centres around ensuring the airway is secure. Most patients do not require intubation, however there is an ongoing risk of sudden upper airway closure, so preparations need to be made to perform intubation at any time. Intubation is often difficult and needs to be performed in a controlled environment with facilities available to do a tracheostomy (intubating through the neck) if the airway completely closes. When patients are intubated they are transferred to an intensive care unit.

Additional treatment once the airway is secure:

IV antibiotics (e.g. ceftriaxone)
Steroids (i.e. dexamethasone)

Question 45

Prognosis of epiglottitis

Answer 45

Most children recover without requiring intubation. Most patients that are intubated can be extubated after a few days and also make a full recovery. Death can occur in severe cases or if it is not diagnosed and managed in time.

A common complication to be aware of is the development of an epiglottic abscess, which is a collection of pus around the epiglottis. This also threatens the airway, making it a life threatening emergency. Treatment is similar to epiglottitis.

Question 46

Laryngomalacia

Answer 46

Laryngomalacia is a condition affecting infants, where the part of the larynx above the vocal cords (the supraglottic larynx) is structured in a way that allows it to cause partial airway obstruction. This leads to a chronic stridor on inhalation, when the larynx flops across the airway as the infant breathes in. Stridor is a harsh whistling sound caused by air being forced through an obstruction of the upper airway.

Structural Changes

There are two aryepiglottic folds at the entrance of the larynx. They run between the epiglottis and the arytenoid cartilages. They are either side of the airway and their role is to constrict the opening of the airway to prevent food or fluids entering the larynx and trachea. In laryngomalacia the aryepiglottic folds are shortened, which pulls on the epiglottis and changes it shape to a characteristic “omega” shape.

The tissue surrounding the supraglottic larynx is softer and has less tone in laryngomalacia, meaning it can flop across the airway. This happens particularly during inspiration, as the air moving through the larynx to the lungs pulls the floppy tissue across the airway to partially occlude it. This partial obstruction of the airway generates the whistling sound.

Question 47

Presentation of laryngomalacia

Answer 47

Laryngomalacia occurs in infants, peaking at 6 months. It presents with inspiratory stridor, a harsh whistling sound when breathing in. Usually this is intermittent and become more prominent when feeding, upset, lying on their back or during upper respiratory tract infections. Infants with laryngomalacia do not usually have associated respiratory distress.

It can cause difficulties with feeding, but rarely causes complete airway obstruction or other complications.

Question 48

Disease course and management of Laryngomalacia

Answer 48

The problem resolves as the larynx matures and grows and is better able to support itself, preventing it from flopping over the airway. Usually, no interventions are required and the child is left to grow out of the condition.

Rarely tracheostomy may be necessary. This involves inserting a tube through the front of the neck into the trachea, bypassing the larynx. Surgery is also an option to alter the tissue in the larynx and improve the symptoms.

Question 49

Whooping cough

Answer 49

Whooping cough is an upper respiratory tract infection caused by Bordetella pertussis (a gram negative bacteria). It is called “whooping cough”, because the coughing fits are so severe that the child is unable to take in any air between coughs and subsequently makes a loud whooping sound as they forcefully suck in air after the coughing finishes.

Children and pregnant women are vaccinated against pertussis. The vaccine becomes less effective a few years after each dose.

Question 50

Presentation of whooping cough

Answer 50

Pertussis typically starts with mild coryzal symptoms, a low grade fever and possibly a mild dry cough.

More severe coughing fits start after a week or more. These involve sudden and recurring attacks of coughing with cough free periods in between. This is described as a paroxysmal cough. Coughing fits are severe and keep building until the patient is completely out of breath. Patient typically produces a large, loud inspiratory whoop when the coughing ends. Patients can cough so hard they faint, vomit or even develop a pneumothorax. Bear in the mind that not all patients will “whoop” and infants with pertussis may present with apnoeas rather than a cough.

Question 51

Diagnosing whooping cough

Answer 51

A nasopharyngeal or nasal swab with PCR testing or bacterial culture can confirm the diagnosis within 2 to 3 weeks of the onset of symptoms.

Where the cough has been present for more than 2 weeks patients can be tested for the anti-pertussis toxin immunoglobulin G. This is tested for in the oral fluid of children aged 5 to 16 and in the blood of those aged over 17.

Question 52

Managing whooping cough

Answer 52

Pertussis is a notifiable disease. Therefore Public Health need to be notified of each case.

Management typically involves simple supportive care. Vulnerable or acutely unwell patients, those under 6 months and patients with apnoeas, cyanosis or patients with severe coughing fits may need to be admitted. Measures to prevent spread are important, such as avoiding contact with vulnerable people, disposing of tissues and careful hand hygiene.

Macrolide antibiotics such as azithromycin, erythromycin and clarithromycin can be beneficial in the early stages (within the first 21 days) or vulnerable patients. Co-trimoxazole is an alternative to macrolides.

Close contacts with an infected patient are given prophylactic antibiotics if they are in a vulnerable group, for example pregnant women, unvaccinated infants or healthcare workers that have contact with children or pregnant women.

The symptoms typically resolve within 8 weeks, however they can last several months. It is also known as the “100-day cough” due to the potential long duration of the cough. A key complication of whooping cough is bronchiectasis.

Question 53

Chronic lung disease of prematurity

Answer 53

Chronic lung disease of prematurity (CLDP) is also known as bronchopulmonary dysplasia. It occurs in premature babies, typically those born before 28 weeks gestation. These babies suffer with respiratory distress syndrome and require oxygen therapy or intubation and ventilation at birth. Diagnosis is made based on chest xray changes and when the infant requires oxygen therapy after they reach 36 weeks gestational age.

Question 54

Features and presentation of chronic lung disease of prematurity

Answer 54

Features

Low oxygen saturations
Increased work of breathing
Poor feeding and weight gain
Crackles and wheezes on chest auscultation
Increased susceptibility to infection

Prevention

There are several measure that can be taken to minimise the risk of CLDP. Giving corticosteroids (e.g. betamethasone) to mothers that show signs of premature labour at less than 36 weeks gestation can help speed up the development of the fetal lungs before birth and reduce the risk of CLDP.

Once the neonate is born the risk of CLDP can be reduced by:

Using CPAP rather than intubation and ventilation when possible
Using caffeine to stimulate the respiratory effort
Not over-oxygenating with supplementary oxygen

Question 55

Managing chronic lung disease of prematurity

Answer 55

A formal sleep study to assess their oxygen saturations during sleep supports the diagnosis and guides management. Babies may be discharged from the neonatal unit on a low dose of oxygen to continue at home, for example 0.01 litres per minute via nasal cannula. They are followed up to wean the oxygen level over the first year of life.

Babies with CLDP require protection against respiratory syncytial virus (RSV) to reduce the risk and severity of bronchiolitis. This involves monthly injections of a monoclonal antibody against the virus called palivizumab. This is very expensive (around £500 per injection) so is reserved for babies meeting certain criteria.

Question 56

Cystic Fibrosis

Answer 56

Cystic fibrosis (CF) is an autosomal recessive genetic condition affecting mucus glands. It is caused by a genetic mutation of the cystic fibrosis transmembrane conductance regulatory gene on chromosome 7. There are many variants of this mutation, the most common is the delta-F508 mutation. This gene codes for cellular channels, particularly a type of chloride channel. Around 1 in 25 are carriers of the mutation and 1 in 2500 children have CF.

The key consequences of the cystic fibrosis mutation are:

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
Low volume thick airway secretions that reduce airway clearance, resulting in bacterial colonisation and susceptibility to airway infections
Congenital bilateral absence of the vas deferens in males. Patients generally have healthy sperm, but the sperm have no way of getting from the testes to the ejaculate, resulting in male infertility
TOM TIP: Cystic fibrosis is a common exam topic and is a favourite of examiners for testing your knowledge of genetic inheritance. Remember that cystic fibrosis is autosomal recessive. A popular scenario is: both parents are healthy, one sibling has cystic fibrosis and a second child does not have the disease, what is the likelihood of the second child being a carrier? We know the child doesn’t have the condition, so the answer is two in three.

Question 57

Presentation of cystic fibrosis

Answer 57

Cystic fibrosis is screened for at birth with the newborn bloodspot test.

Meconium ileus is often the first sign of cystic fibrosis. The first stool that a baby passes is called meconium. This is usually black and should be passed within 24 hours of birth. In about 20% of babies with CF, the meconium is thick and sticky, causing it to get stuck and obstruct the bowel. This is called meconium ileus, and is practically pathognomonic for cystic fibrosis. This presents as not passing meconium within 24 hours, abdominal distention and vomiting.

If cystic fibrosis is not diagnosed shortly after birth it can present later in childhood with typical signs and symptoms, recurrent lower respiratory tract infections, failure to thrive or pancreatitis.

Question 58

Symptoms and signs of cystic fibrosis

Answer 58

Symptoms

Chronic cough
Thick sputum production
Recurrent respiratory tract infections
Loose, greasy stools (steatorrhoea) due to a lack of fat digesting lipase enzymes
Abdominal pain and bloating
Parents may report the child tastes particularly salty when they kiss them, due to the concentrated salt in the sweat
Poor weight and height gain (failure to thrive)

Signs

Low weight or height on growth charts
Nasal polyps
Finger clubbing
Crackles and wheezes on auscultation
Abdominal distention

Question 59

Causes of clubbing in children

Answer 59

Hereditary clubbing
Cyanotic heart disease
Infective endocarditis
Cystic fibrosis
Tuberculosis
Inflammatory bowel disease
Liver cirrhosis

Question 60

Diagnosing cystic fibrosis

Answer 60

There are three key methods for establishing a diagnosis that you should remember for your exams:

Newborn blood spot testing is performed on all children shortly after birth and picks up most cases
The sweat test is the gold standard for diagnosis
Genetic testing for CFTR gene can be performed during pregnancy by amniocentesis or chorionic villous sampling, or as a blood test after birth

Question 61

Sweat test

Answer 61

The sweat test is the key investigation to remember for cystic fibrosis. It is the gold standard for confirming the diagnosis. A patch of skin is chosen for the test, typically on the arm or leg. Pilocarpine is applied to the skin on this patch. Electrodes are placed either side of the patch and a small current is passed between the electrodes. This causes the skin to sweat. The sweat is absorbed with lab issued gauze or filter paper and sent to the lab for testing for the chloride concentration. The diagnostic chloride concentration for cystic fibrosis is more than 60mmol/l.

Question 62

Microbial colonisers in cystic fibrosis

Answer 62

Patients with cystic fibrosis struggle to clear the secretions in their airways. This creates a perfect environment with plenty of moisture and oxygen for colonies of bacteria to live and replicate. Examples of common colonisers are:

Staphylococcus aureus
Haemophilus influenza
Klebsiella pneumoniae
Escherichia coli
Burkhodheria cepacia
Pseudomonas aeruginosa
TOM TIP: The key colonisers to remember for your exams are staph aureus and pseudomonas. Patients with cystic fibrosis take long term prophylactic flucloxacillin to prevent staph aureus infection. Pseudomonas should be remembered as a particularly troublesome coloniser that is hard to treat and worsens the prognosis of patients with cystic fibrosis.

Question 63

Pseudomonas Aeruginosa

Answer 63

Once patients become colonised with pseudomonas, it can be very difficult to get rid of. Often, these bacteria can become resistant to multiple antibiotics. Colonisation with pseudomonas leads to a significant increase in morbidity and mortality in patients with CF. In the past there were gatherings and social events organised for children with cystic fibrosis to meet up and share their experiences, however this was stopped due to the risk of spreading pseudomonas. The general advice is now to avoid contact with other children with cystic fibrosis. Cystic fibrosis clinics have separate clinic rooms for children with pseudomonas to minimise the risk of transmission.

Pseudomonas colonisation can be treated with long term nebulised antibiotics such as tobramycin. Oral ciprofloxacin is also used.

Question 64

Managing cystic fibrosis

Answer 64

Cystic fibrosis will be managed by the specialist MDT. There are many aspects to management:

Chest physiotherapy several times a day is essential to clear mucus and reduce the risk of infection and colonisation
Exercise improves respiratory function and reserve, and helps clear sputum
High calorie diet is required for malabsorption, increased respiratory effort, coughing, infections and physiotherapy
CREON tablets to digest fats in patients with pancreatic insufficiency (these replace the missing lipase enzymes)
Prophylactic flucloxacillin tablets to reduce the risk of bacterial infections (particularly staph aureus)
Treat chest infections when they occur
Bronchodilators such as salbutamol inhalers can help treat bronchoconstriction
Nebulised DNase (dornase alfa) is an enzyme that can break down DNA material in respiratory secretions, making secretions less viscous and easier to clear
Nebulised hypertonic saline
Vaccinations including pneumococcal, influenza and varicella

Other Treatment Options

Lung transplantation is an option in end stage respiratory failure
Liver transplant in liver failure
Fertility treatment involving testicular sperm extraction for infertile males
Genetic counselling

Question 65

Monitoring cystic fibrosis

Answer 65

Patients with cystic fibrosis are managed and followed up in specialist clinics, typically every 6 months. They require regular monitoring of their sputum for colonisation of bacteria like pseudomonas. They also need monitoring and screening for diabetes, osteoporosis, vitamin D deficiency and liver failure.

Question 66

Prognosis of cystic fibrosis

Answer 66

Prognosis depends on multiple factors, including severity of symptoms, type of genetic mutation, adherence to treatment, frequency of infection and lifestyle. Life expectancy is improving and currently the cystic fibrosis trust gives a median life expectancy of 47 years.

90% of patients with CF develop pancreatic insufficiency
50% of adults with CF develop cystic fibrosis-related diabetes and require treatment with insulin
30% of adults with CF develop liver disease
Most males are infertile due to absent vas deferens

Question 67

Primary ciliary dyskinesia

Answer 67

Primary ciliary dyskinesia (PCD) is also known as Kartagner’s syndrome. It is an autosomal recessive condition affecting the cilia of various cells in the body. It is more common in populations where there is consanguinity, meaning the parents are related to each-other. Consanguinity increases the risk of a child having two copies of the same recessive genetic mutation.

PCD causes dysfunction of the motile cilia around the body, most notably in the respiratory tract. This leads to a buildup of mucus in the lungs, providing a great site for infection that is not easily cleared. This leads to a similar respiratory presentation to cystic fibrosis, with frequent and chronic chest infections, poor growth and bronchiectasis.

It also affects the cilia in the fallopian tubes of women and the tails (flagella) of the sperm in men, leading to reduced or absent fertility.

There is a strong link between primary ciliary dyskinesia and situs inversus.

Question 68

Kartagner’s Triad

Answer 68

Kartagner’s triad describes the three key features of PCD. Not all patients will have all three features. These are:

Paranasal sinusitis
Bronchiectasis
Situs Inversus

Question 69

Situs Inversus

Answer 69

Situs inversus is a condition where all the internal (visceral) organs are mirrored inside the body. Therefore the heart is on the right, the stomach is on the right and the liver is on the left. Dextrocardia is when only the heart is reversed.

25% of patients with situs inversus will have primary ciliary dyskinesia. 50% of patients with primary ciliary dyskinesia have situs inversus.

Situs inversus on its own does not cause any problems, and patients can expect to live a normal life. A small number have associated congenital heart disease, such as transposition of the great arteries.

Question 70

Diagnosing primary ciliary dyskinesia

Answer 70

Patients typically present with recurrent respiratory tract infections. Take a careful family history and a history of consanguinity in the parents. Examination and imaging (e.g. chest xray) can be used to diagnose situs inversus. Semen analysis can be used to investigate for male infertility.

The key investigation for establishing the diagnosis is to take a sample of the ciliated epithelium of the upper airway and examine the action of the cilia. A sample can be obtained through nasal brushing or bronchoscopy. Often several samples are required.

Question 71

Managing primary ciliary dyskinesia

Answer 71

Management is similar to cystic fibrosis and bronchiectasis with daily physiotherapy, a high calorie diet and antibiotics.