Download Question 1

Case 1031: 'Does this chest infection require
admission...?'
Authors and Affiliations
Katrina Dawes
BA/BEd (UNSW)
Professor Rakesh Seth
Consultant Paediatrician
Wagga Wagga
Case Overview
The case looks at some of the various causes of acute respiratory distress in the paediatric population
and the management of community aquired pneumonia.
Learning Objectives
At the end of this clinical vignette, the student should know the:
clinical
features which suggest respiratory distress in children
common
causes of wheeze in children, and how to differentiate between these causes
appropriate
common
investigations to conduct on a child presenting with wheeze
pathogens responsible for viral pneumonia
management
of viral pneumonia and criteria for discharge in those who are treated as inpatients.
Question 1 : MS
Question Information:
You are a resident working the night shift in the rural hospital emergency department when a woman
brings in her 10 month year old daughter, Eden, as she has been †œsounding funny†• when she
breathes and is breathing a bit quicker than usual. Her mother reports that Eden had a runny nose four
days ago but it has cleared up, and she had a temperature of 37.4 degrees in the nighttime, but it
settled with some paracetamol. Before taking further history you decide to examine Eden to assess the
level of severity of her respiratory distress, and determine whether she needs admission.
Question:
Which of the following symptoms and signs indicate severe respiratory distress requiring urgent
admission?
Choice 1: A productive cough Score : -1
Choice Feedback:
Incorrect, a productive cough may remain for days to weeks while an infection is resolving and in
isolation is not a cause for urgent admission.
Choice 2: O2 saturation of 96% on room air Score : -1
Choice Feedback:
Incorrect, moderate respiratory distress is suggested by O2 saturations of 90-95% on room air and
severe respiratory distress is indicated by O2 saturation <90% on room air or less than <92% on
oxygen.
Choice 3: Tachycardia (HR >180bpm) and tachypnoea (RR >70bpm) Score : 2
Choice Feedback:
Correct, these are both signs of severe respiratory distress.
Choice 4: Feeding <50% of regular amount
Score : 1
Choice Feedback:
Correct, a change in feeding pattern may be the only sign of respiratory distress in infants, who are too
exhausted by the effort involved in feeding.
Question 2 : MS
Question Information:
You find out from mum that Eden has still been eating and drinking and has had regular wet nappies
and no bowel changes. She has been alert and interactive, although was grizzly through the day and
more tired and cranky than usual. Mum reports she is also teething and mentions that it could just be
due to that. Eden has had a cold once before, but this is the first time she has had any problems with
her breathing. She has no allergies and there is no history of atopy in the family. Eden has had all the
vaccinations recommended in the current immunisation schedule. You confirm this by checking her
vaccination record, and notice that her height, weight and head circumference are also tracking along
the 50th centile.
On examination Eden has a respiratory rate of 75/min, BP of 90/60mmHg, HR of 175/min, temperature
of 38.2 degrees (axillary) and has O2 saturation of 95% on room air. She is alert but irritable and has
moist mucus membranes, good capillary refill, no peripheral or central cyanosis and no coryzal
symptoms. She has no nasal flaring, grunting or stridor but does have a tracheal tug and subcostal and
sternal recession with an occasional productive cough. On auscultation there is equal but reduced air
entry on both sides, inspiratory crackles bilaterally and an expiratory wheeze throughout the chest. On
systems review she has no inflammation or exudate on throat examination and examination of her ears
shows a pearly white tympanic membrane, with no discharge, perforation or inflammation. There are no
focal neurological signs or signs of meningism and her abdomen is soft and not tender.
Question:
Which of the following diagnoses should be considered at this stage?
Choice 1: Asthma Score : -1
Choice Feedback:
Incorrect. While a wheeze raises the possibility of a diagnosis of asthma, the fact that this is her first
episode of wheeze and that it is associated with a recent cold, makes this diagnosis less likely. The
negative history of any breathing problems in the past or any atopic conditions points to other
diagnoses being more probable. Asthma is rare in infants. In an older child, asthma would be a more
likely diagnosis if they have a history of recurrent wheeze, with diurnal variation, and triggers such as
pets, dust and exercise and a personal or family history of atopy. In this instance a trial of asthma
medications might be considered.
Choice 2: Bronchiolitis Score : 1
Choice Feedback:
The symptoms of tachypnoea, increased work of breathing, expiratory wheezing and crackles are
consistent with the diagnosis of bronchiolitis. The course of her symptoms are also typical, with upper
respiratory tract symptoms, followed by lower respiratory tract signs and symptoms on days two to
three, being common.
Choice 3: Viral pneumonia Score : 1
Choice Feedback:
This is a reasonable provisional diagnosis, given her fever, cough and tachypnoea. The gradual onset
and preceding upper airway symptoms as well as her diffuse, bilateral auscultatory wheeze point
towards a viral infection.
Choice 4: Pertussis Score : -1
Choice Feedback:
This is unlikely given her clinical history. The typical presentation of an infection withBordetella
Pertussis/whooping cough is a week of coryzal symptoms and low grade fever, followed a few weeks
later by dry paroxysmal coughing fits (like a seal), with an inspiratory whoop.
Choice 5: Bacterial pneumonia Score : 1
Choice Feedback:
This is a reasonable provisional diagnosis. It can be difficult to distinguish bacterial pneumonia from
viral respiratory infections clinically as the symptoms and signs of both conditions are nonspecific.
Those with a bacterial infection may have faster onset of symptoms or more severe symptoms (higher
temperatures, more lethargic/unwell) but clinical features cannot reliably differentiate the two.
Choice 6: Viral laryngeotracheitis Score : -1
Choice Feedback:
Viral laryngeotracheitis or croup is a viral infection of the upper airway, causing erythema and oedema
of the tracheal mucosa. It†™s clinical presentation is typically a predominant harsh barking cough and
symptoms consistent with upper airway obstruction, including inspiratory stridor and coryzal symptoms.
Question 3 : FT
Question Information:
You look with dismay at the backlog of patients in the emergency department and at that moment your
friendly on-call general practitioner walks towards you. He asks what the presentation is and whether
the child needs admission.
Question:
Report the relevant findings to the on-call general practitioner, give your provisional diagnosis and
justify whether you think inpatient or outpatient management is more appropriate for this presentation.
Choice 1: null Score : 0
Choice Feedback:
This is a 10 month old girl with a 2 day history of worsening dyspnoea and cough on the background of
coryzal symptoms which have now resolved. She has been eating less and is still passing urine. Before
this incident she has been otherwise well with no significant prenatal or birth history and is within normal
range of growth parameters for her age.
On examination she is alert but irritable and appears unwell. She is tachypnoeic with a respiratory rate
of 75, tachycardic with a HR of 175bpm, febrile with an axilliary temperature of 38.2 degrees and O2
saturation of 95% on room air. She has no peripheral or central cyanosis. She has moderately
increased work of breathing with tracheal tug and subcostal and sternal recession. There is an
occasional productive cough but no stridor or grunting. On auscultation there is equal but reduced air
entry, inspiratory crackles bilaterally and an expiratory wheeze throughout the chest. There are no other
signs of focal infection, her ears and throat are clear. There are no focal neurological signs.
My provisional diagnosis is acute bronchiolitis or community acquired pneumonia. I think she should be
admitted for management given her age, her abnormal vital signs and her respiratory distress which
has the potential to deteriorate further should she become exhausted.
Question 4 : MS
Question Information:
The practitioner agrees with your decision. You decide that before you narrow down the diagnosis
further you need to provide some supportive therapy to help Eden's respiratory distress. You realise
that a chest X-ray cannot be organised until the following morning.
Question:
Which of the following management options should now be considered?
Choice 1: Intravenous fluids Score : -1
Choice Feedback:
As oral feeds are still being tolerated, and her hydration status is good, intravenous fluids are not
required as part of immediate management. It is possible that Eden may need IV fluid replacement later
in the admission if she does not tolerate oral intake due to her high respiratory rate.
Choice 2: Broad spectrum antibiotics Score : 1
Choice Feedback:
At this stage a chest X-ray (CXR) has not been obtained. A bacterial source of infection that accounts
for her symptoms of moderate to severe respiratory distress have to be considered. Antibiotics should
be commenced to account for a presumed bacterial pneumonia and prevent any possible deterioration.
If a CXR excludes a pneumonia, the antibiotics may be ceased.
Choice 3: Oxygen given via nasal prongs at 2L/min or simple facemask at 6 - 8 litres/min Score : 1
Choice Feedback:
Oxygen should also be given to infants who show signs of hypoxia, increased work of breathing or
increasing fatigue.
Choice 4: Corticosteroids Score : -1
Choice Feedback:
There is no indication for corticosteroids. These are useful in therapy for a confirmed asthmatic with
symptoms of respiratory distress.
Choice 5: Bronchodilator Score : 0
Choice Feedback:
This can be considered in infants aged six to twelve months. A standard stat dose of salbutamol via a
nebuliser may be trialled, and the patient assessed for a response before deciding whether to order
more. Bronchodilators may be effective in bronchiolitis but this is rare.
Question 5 : MS
Question Information:
You commence Eden on oxygen and antibiotics. Eden†™s O2 saturations improve to 97% and she
appears more comfortable and you now consider the investigations you should order realising that they
will not be back to you until the morning and that you may need to make decisions before you get them.
Question:
Which of the following are the most appropriate investigations to order?
Choice 1: Full blood count Score : 1
Choice Feedback:
This is not mandatory but may be warranted to evaluate if there is a bacterial aetiology. A neutrophilia
on FBC would suggest bacterial pneumonia and can serve as a guide to the introduction of antibiotic
therapy in children.
Choice 2: Blood cultures (before commencing antibiotics) Score : 1
Choice Feedback:
This is not necessary but can be justified if you are worried. A full blood count is already being
collected, and would be reasonable to also collect blood cultures, as the patient is <1 year old has a
fever >38 degrees and a focus of infection. This is to ensure the child is not septic.
Choice 3: Urine dipstick Score : 1
Choice Feedback:
There is a correlation between bronchiolitis and UTI's. A urine dipstick can be used as an appropriate
diagnostic investigation.
Choice 4: Lumbar puncture Score : -1
Choice Feedback:
As the patient is not toxic, and there is a focus of infection identified, this is an unnecessarily invasive
and distressing investigation to conduct at this point. If the child developed signs of toxicity a lumbar
puncture would be indicated
Choice 5: Nasopharyngeal aspirate with viral polymerase chain reaction Score : 1
Choice Feedback:
Although this is not necessary if the diagnosis is clear, it can be considered for confirmation of the
causative agent, to justify antibiotic therapy being withheld. Given the young age of the patient and the
uncertainty of the diagnosis, this investigation can be justified.
Choice 6: Chest X-ray Score : 2
Choice Feedback:
This is mandatory.
Choice 7: Spirometry Score : -1
Choice Feedback:
Spirometry cannot be effectively conducted in a 10 month old infant.
Choice 8: Serum lactate Score : 1
Choice Feedback:
The presence of lactic acidosis will support the diagnosis of sepsis.
Question 6 : FT
Question Information:
A PA chest X-ray is mandatory in this case to exclude bacterial pneumonia. It is not necessary if a
diagnosis of bronchiolitis is clear, however it has a place when there is diagnostic uncertainty or an
unusual disease course, to rule out other possible causes. According to the Paediatric Infectious
Diseases Society of America Clinical Practice Guideline on Management of Community Acquired
Pneumonia in children older than 3 months, "Chest radiographs (posteroanterior and lateral) should be
obtained in all patients hospitalized for management of community-acquired pneumonia to document
the presence, size, and character of parenchymal inﬕltrates and identify complications of pneumonia
that may lead to interventions beyond antimicrobial agents and supportive medical therapy"
An AP chest X-ray is performed the next morning. There is no one available to report on the film and
you are asked by the general practitioner on-call to assess the X-ray and report it back to him, with your
differential diagnosis.
Question:
Interpret the chest X-ray in a systematic manner and outline your provisional diagnosis based on your
findings.
Source: http://www.pemcincinnati.com/blog/wp-content/uploads/2013/02/Case-7.png
Choice 1: null Score : 0
Choice Feedback:
Sample answer: This is an AP radiograph, with adequate penetration and no rotation. The most notable
feature is bilateral diffuse peribronchial infiltrates and increased haziness in the left upper zone. The
trachea is midline. There are no fractures of the bones. The heart borders are distinct and there are no
mediastinal masses evident. The cardiothoracic ratio cannot be assessed as it is an AP film, but the
heart does not seem enlarged. The diaphragm borders are clear and the costrophrenic angles are
sharp with no evidence of effusion. The lungs are equally expanded and there are no pneumothoraxes
or masses in the lung fields. As already noted there are bilateral diffuse peribronchial infiltrates, with air
bronchograms and peribronchial cuffing evident on both sides.
These findings are consistent with bacterial bronchopneumonia, but should be correlated with clinical
findings.
Question 7 : MS
Question Information:
The general practitioner agrees with your assessment and decides to quiz you further on your
knowledge of this condition. He asks you the following.
Question:
What are the common pathogens responsible for pneumonia in children of this age group?
Choice 1: Parainfluenza Score : 0
Choice Feedback:
This is not the most common, although it is responsible for some cases pneumonia in children.
Choice 2: Cytomegalovirus Score : -1
Choice Feedback:
This is not correct.
Choice 3: Measles Score : -1
Choice Feedback:
This is not correct.
Choice 4: Human metapneumovirus Score : 0
Choice Feedback:
This is not correct, although this virus is associated with viral LRTI in asthmatic children.
Choice 5: Respiratory syncytial virus Score : 1
Choice Feedback:
Correct. This is the most common cause of viral pneumonia in infants <5 years.
Choice 6: Adenovirus Score : 1
Choice Feedback:
Correct. Viruses are an important cause of pneumonia in this age group and adenovirus, enterovirus,
rhinovirus, and coronavirus should all be considered - but they are less common than respiratory
syncytial virus.
Choice 7: Influenza Score : 1
Choice Feedback:
This is not the most common, although it is responsible for some cases pneumonia in children.
Choice 8: Streptococcus pneumoniae Score : 2
Choice Feedback:
The most common bacterial form of pneumonia.
Choice 9: Haemophilus influenzae Score : 2
Choice Feedback:
Correct. This is a common bacterial form of pneumonia.
Choice 10: E. coli Score : -1
Choice Feedback:
Incorrect. E. coli is not often responsible for respiratory tract infections.
Choice 11: Staph aureus Score : 0
Choice Feedback:
Can be a community-acquired pneumonia in a population colonized with MRSA.
Choice 12: Pseudomonas aeruginosa Score : -1
Choice Feedback:
Hospital-acquired pneumonia.
Choice 13: Klebsiella pneumoniae Score : -1
Choice Feedback:
Incorrect. This is only seen in neonates or immunocompromised patients.
Question 8 : MS
Question Information:
You explain the diagnosis to Eden†™s mother, who is extremely worried and has many questions.
She wants to know the potential complications of pneumonia so she can watch out for them.
Question:
Which of the following are complications of pneumonia?
Choice 1: Pleural effusion Score : 1
Choice Feedback:
This is more commonly associated with bacterial pneumonia but can also occur with adenovirus
infection.
Choice 2: Respiratory failure Score : 1
Choice Feedback:
Despite basic supportive measures, children can develop worsening hypoxaemia and hypercarbia and
require intubation and mechanical ventilation. Worsening O2 saturations despite supportive therapy are
an indicator for an arterial blood gas to determine if respiratory failure is occurring (PaCO2 >50mmHg
or PaO2 <60mmHg).
Choice 3: Apnoeas Score : 1
Choice Feedback:
This is a more common complication in infants less than 8 weeks old or those who were premature with
associated lung disease, however it can affect any child and is most common in those infected with
respiratory syncytial virus.
Choice 4: Dehydration Score : 1
Choice Feedback:
This is a common complication which can occur as a result of tachypnoea, cough and decreased
feeding.
Choice 5: Cystic fibrosis Score : -1
Choice Feedback:
This is incorrect. Cystic fibrosis is an autosomal recessive inherited disorder, which is due to a gene
mutation on the long arm of chromosome 7. There is a defect of the cystic fibrosis transmembrane
conductance regulator (CFTR) which causes a failure of opening of the chloride channel in epithelial
cells. This results in decreased excretion of chloride into the airway lumen and an increased
reabsorption of sodium into the epithelial cells. This decreased excretion of sodium means there is less
excretion
of water and increased viscosity and tenacity of airway secretions.
Having pneumonia does not cause a person to develop CF, however a common presentation of CF is
recurrent respiratory infections, due to loss of innate immunity from impaired mucus clearing. For this
reason children with repeat presentations to hospital with respiratory infections should be tested for CF.
Choice 6: Lung abscess Score : 1
Choice Feedback:
Chronic or subacute lung abscesses can follow an inadequately treated pneumonia. Abscesses also
develop during the course of specific pneumonias, particularly when the infecting agent isStaph.aureus
or Klebsiella pneumoniae.
Choice 7: Epiglottitis Score : -1
Choice Feedback:
This is incorrect. Epiglottitis is a bacterial infection caused byHaemophilus Influenzae B.
Choice 8: Bronchiectasis Score : -1
Choice Feedback:
Incorrect. This is not a complication of pneumonia. Congenital predispositions include
bronchotracheomalacia.
Question 9 : MS
Question Information:
Once you have addressed Eden's mothers concerns, you start to organise the necessary management
for her admission. She has already been given oxygen, which is keeping her saturation level at 96%,
and she has had necessary investigations carried out.
Question:
Which of the following are also important aspects of her management, given your working diagnosis of
community-acquired bacterial pneumonia?
Choice 1: Nebulised adrenaline Score : -1
Choice Feedback:
This is not indicated. Nebulised adrenaline is effective in the treatment of bronchospasms due to
asthma and for viral croup
Choice 2: IV benzylpenicillin Score : 2
Choice Feedback:
This is correct. This is given on the premise Eden most likely has community-acquired pneumonia and
that the causative agent is susceptible to benzylpenicillin.
Choice 3: Insertion of an intravenous cannula Score : 1
Choice Feedback:
This would be appropriate management given that she is to be treated as an inpatient and may need
administration of fluids if she becomes to exhausted to feed.
Choice 4: Analgesia and antipyretics Score : 1
Choice Feedback:
These are not required but can be used to keep the child comfortable if they are distressed.
Choice 5: Steam therapy Score : -1
Choice Feedback:
There is no evidence to support the use of steam therapy in management of pneumonia.
Choice 6: Ribivarin (antiviral) Score : -1
Choice Feedback:
Incorrect, the most common cause of viral pneumonia is RSV which ribivarin has minimal/no effect
against. It also has toxic side effects.
Choice 7: IV ceftriaxone/cefotaxime Score : 1
Choice Feedback:
Partially correct. This is a second-line treatment used if the child is not responding appropriately to the
IV benzylpenicillin or if the child is very sick at presentation.
Question 10 : FT
Question Information:
Eden makes significant improvement over the next two days, while you are quietly celebrating your
success with managing her treatment effectively, her mum approaches you to find out when you think
they will be able to go home.
Question:
Outline the clinical parameters which suggest a patient is safe for discharge.
Choice 1: null Score : 0
Choice Feedback:
A patient is eligible for discharge when they have documented overall clinical improvement, including
level of activity, appetite, and decreased fever for at least 12†“ 24 hours. They must have consistent
pulse oximetry measurements >94-95% in room air for at least 12†“ 24 hours with no signs of
respiratory distress and must have stable baseline mental status. They should be able to tolerate any
anti-infective regimen required and the practitioner should be confident that the guardian can manage
careful observation at home, comply with therapy, and attend necessary follow-up appointments.
Synopsis
Eden is discharged home and makes a full recovery. A few weeks later you receive a lovely card
thanking you for your hard work in looking after her.
Lower respiratory tract infections are a leading cause of morbidity or mortality in the paediatric
population. They most often affect children less than 2 years of age. Nearly 80% of pneumonia in the
paediatric population has a viral aetiology with RSV being the most common. The pathogens
responsible for infection are dependent on the age group of the child with neonates most commonly
affected by gram positive cocci such as B Streptococcus and Staphlococcus aureus, or gram negative
enteric bacilli in neonates, and respiratory syncytial virus, Parainfluenza, Influenza and Adenovirus are
the most common cause in infants aged 1 month to 5 years. Bacterial agents in this age group include
Haemophilus influenza, Streptococcus pneumoniae and Staphylococcus aureus.
Although bacterial pneumonias are less common, they should be considered in the context of an
abnormal chest X-ray, an abnormal white cell count and the severity of the illness warrants that the
patient should be started on a regimen including IV benzylpenicillin and a second/third-generation
cephalosporin.
The clinical symptoms of pneumonia may include prodromal non-pulmonary symptoms such as fever,
headache and malaise. There may also be preceding coryzal symptoms followed by chest pain or
abdominal pain (particularly if a lower lobe is effected). Clinical signs may include productive cough,
increased respiratory effort demonstrated by one or more of the following: nasal flaring, grunting, head
bobbing, tracheal tug, intercostal and/or subcostal recession, tachypnoea and shallow breathing. On
auscultation findings can include crackles, decreased breath sounds, increased fremitus, dullness to
percussion and wheeze. There are no clinical signs to distinguish bacterial from viral pneumonia in
children, although bacterial pneumonia may have more severe symptoms of fever and distress.
Inpatient treatment is indicated for children with moderate to severe disease. This is indicated by
respiratory distress (respiratory rate >70 breaths/minute for infants <12 months of age and >50 breaths
per minute for older children; subcostal and intercostal recession, tracheal tug, nasal flaring, head
bobbing, apnoea; grunting) O2 saturation <90% on room air, hypoxaemia despite optimal O2 therapy,
respiratory failure on ABGs (PaCO2 >50mmHg, or PaO2 <60mmHg), signs of toxicity (high fever,
drowsiness, lethargy, shock)
The level of investigations required depends on the certainty of the practitioners diagnosis based on
clinical history and examination findings. Bronchiolitis and viral pneumonia are both diagnosis which are
made clinically, however a nasopharyngeal aspirate with PCR can be useful to confirm the diagnosis,
and a chest X-ray and full blood count with cultures are useful to help determine if a bacterial aetiology
exists. This decision must be based on the severity of the illness and the clinical presentation. Chest Xray findings in viral pneumonia may show peribronchial infiltrates, however there may also be no X-ray
changes.
Potential complications of viral pneumonia include pleural effusion, respiratory failure, apnoea,
dehydration and secondary bacterial infection.
The principles of treatment of a viral pneumonia include:
- Relieving respiratory distress. This is done with O2 therapy via nasal prongs at 2 litres per minute or
simple facemask at 6 to 8 litres per minute. Fluids may also be given as part of supportive therapy if the
child is not feeding or is dehydrated. Analgesia and antipyretics may be required to relieve distress.
- Ensuring adequate oxygenation: supplemental oxygen usually ensures this, however intubation and
ventilation may be required in respiratory failure occurs.
- Preventing and treating complications. This involves monitoring for worsening symptoms and signs of
bacterial infection, effusions or toxicity
Discharge can be considered in a child who shows overall clinical improvement, including activity,
appetite, and decreased fever for at least 12†“ 24 hours. There must be consistent pulse oximetry
measurements >95% in room air for at least 12†“ 24 hours with no signs of respiratory distress and
stable baseline mental status. The practitioner should be confident that the guardian can manage
careful observation at home, comply with therapy, and attend necessary follow-up before discharge is
arranged
Acknowledgements:
We gratefully acknowledge Assistant Professor Brad Sobolewski for granting permission for the use of
the X-ray presented in this case
Resources:
National Asthma Council Australia. Australian Asthma Handbook, Version 1.0. National Asthma Council
Australia, Melbourne, 2014. Website. Available from: http://www.asthmahandbook.org.au
Royal Children†™s Hospital Melbourne †œPneumonia Guidelines†•,
http://www.rch.org.au/clinicalguide/guideline_index/Pneumonia_Guideline/
Bradley J, Byington C et al, The Management of Community-Acquired Pneumonia in Infants and
Children Older Than 3 Months of Age: Clinical Practice Guidelines by the Pediatric Infectious Diseases
Society and the Infectious Diseases Society of America
Barson W, †œPneumonia in children: Epidemiology, pathogenesis, and etiology†• UpToDate,
Kaplan S (Ed), UpToDate, Waltham, MA. (Accessed on November 25, 2013.)
†œInfants and Children: Acute Management of Bronchiolitis †“ Clinical Practice Guideline†•,
NSW Ministry of Health, January 2012
†œChildren and Infants with Fever - Acute Management†• NSW Ministry of Health, October 2010
Roberton D.M & South M. Practical Paediatrics, 6th Edition. Churchill Livingstone Elsevier UK. 2006
Walsh B et al, Perinatal and pediatric respiratory care 3rd Edition, Saunders Elsevier, Missouri, 2010
Starr, M, †œCommunity acquired pneumonia†• in Textbook of paediatric emergency medicine
Peter Cameron (Ed), Churchill Livingstone Elsevier, 2006
Kilham H et al, Paediatrics manual : the Children's Hospital at Westmead handbook, North Ryde :
McGraw-Hill, 2009.
Updated July 2016