Paediatrics Flashcards
Causes of Pneumonia in a Newborn
Organisms from the mother’s genital tract, particularly group B streptococcus but also Gram-negative enterococci and bacilli
Causes of Pneumonia in Infants and young children
Respiratory viruses, particularly RSV are most common.
Bacterial infections include Streptococcus pneumoniae or H. influenzae. Bordatella pertussis and Chlamydia trachomatis can also cause pneumonia at this age. An infrequent but serious cause is Staphylococcus aureus.
Viruses are the most common cause in younger children, whereas bacterias are more common in older children.
Causes of Pneumonia in children over 5 years
Mycoplasma pneumoniae, Streptococcus pneumoniae and Chlamydia pneumoniae are the main causes.
Viruses are the most common cause in younger children, whereas bacterias are more common in older children.
Clinical features of Pneumonia
Fever, cough and rapid breathing usually preceded by a URTI.
O/E Tachypnoea Nasal flaring Chest indrawing. End inspiratory coarse crackles over affected area
Classic signs like consolidation with dullness on percussion, decreased breath sounds, bronchial breathing may be absent in children.
In contrast to asthma, the most sensitive clinical sign of pneumonia in children is increased RR
Indications for admission for suspected Pneumonia
O2 sats <92%
recurrent Apnoea
grunting and or inability to maintain adequate fluid/feed intake
Antibiotics for Pneumonia in newborns, older infants and children
newborns - broad-spectrum IV antibiotics
older infants - oral amoxicillin with broader spectrum antibiotics like co-amoxiclav reserved for complicated/unresponsive pneumonia
children - amoxicillin or oral macrolide such as erythromycin.
There is no advantage in giving IV rather than oral treatment in mild/moderate pneumonia
In pneumonia, small parapneumonic effusions occur in up to one-third of children and may resolve with appropriate antibiotics. What does a persistent fever despite 48 hrs of antibiotic suggest?
A pleural effusion requiring draining. This should be done with US guidance.
Placement of a small-bore chest drain and regular instillation of a fibrinolytic agent are usually effective. Video -assisted thoracoscopic surgery or thoracotomy and decortication is sometimes necessary in refractory cases.
There may be blunting of the costophrenic angle on the chest X-ray. Some of these effusions develop into empyema and fibrin strands may form, leading to septations - These are formed from fibrin and divide the fluid into separate pockets
What does decortication mean?
Decortication is a medical procedure involving the surgical removal of the surface layer, membrane, or fibrous cover of an organ. The procedure is usually performed when the lung is covered by a thick, inelastic pleural peel restricting lung expansion.
Which children require follow-up after having pneumonia?
Those with evidence of lobar collapse or atelectasis should have a repeat chest X-ray after 4-6 weeks to check that the lung fields look normal
Follow-up is not generally erquired for children with simple consolidation on chest X-ray.
Virtually all children make a full recovery.
Chronic lung infections cause a persistent ‘wet’ cough and require further investigation. What are some common organisms that cause persistent bacterial bronchitis?
In persistent bacterial bronchitis, there is persistent inflammation of the lower airways driven by chronic infection.
Commomn organisms are:
Haemophilus influenze
Moraxella catarrhalis
It may be a precursors to bronchiectasis if investigations and treatment are not instituted.
How are chronic lung infections investigated and treated?
Referral to a specialist in paediatric respiratory disorders
Bacterial growth from bronchial lavage/sputum
Treatment with high dose antibiotics such as co-amoxiclav
physiotherapy.
What do bronchiectasis and persistent bacterial bronchitis cause in children?
Chronic lung infections with a persistent wet sounding cough.
Cystic fibrosis
Primary ciliary dyskinesia
Immunodeficiency
Chronic aspiration
all cause what type of bronchiectasis?
Generalized bronchiectasis.
A plain X-ray may show gross bronchiectasis
Focal bronchiectasis is due to…?
previous severe pneumonia
congenital lung abnormality
obstruction by a foreign body.
A plain X-ray may show gross bronchiectasis.
Bronchoscopy is usually indicated to exclude a structural cause.
What is the epidemiology of Cystic fibrosis and is it autosomal dominant or recessive?
CF is the most common life-limiting autosomal recessive condition in caucasians with an incidence of 1 in 2500 live births and a carrier rate of 1 in 25. It is less common in other ethnic groups. Life expectancy has increased with a projected life expectancy for current newborns into the 40s.
A defective protein called CF transmembrane conductance regulator (CFTR), a cyclic AMP-dependent chloride channel found in the membrane of cells is the cause of what illness?
Cystic fibrosis
The gene for CFTR is located on what chromosome?
Chromosome 7. Over 900 different gene mutations have been discovered. By far the most frequent mutation (78%) is ΔF508
In cystic fibrosis, different mutation classes of the CFTR protein can cause either reduced amounts of functional CFTR or a normal amount of CFTR with reduced function. Newer therapies are targeting specific classes of mutation.
How many specific classes of mutation are there?
6
Drugs are classified as CFTR potentiators and correctors.
Potentiators e.g. Ivacaftor are helpful in class III (channel opening defect) and IV (pore abnormality)
Correctors e.g. Lumicaftor are helpful in class II (ΔF508; incorrectly folded, cannot traffic to membrane)
CF is a multisystem disorder which results from abnormal ion transport across epithelial cells. This reduces the airway surface liquid layer and impairs ciliary function leading to chronic endobronchial infection by which organisms?
initially:
Staphylococcus aureus
Haemophilus influenzae
subsequently:
Pseudomonas aeruginosa.
Burkholderia species
Defective CFTR causes deregulation of inflammation and defence against infection.
In CF, thick viscoid meconium in the intestine leads to meconium ileus in what percentage of infants?
10-20%
In CF, the pancreatic ducts become blocked by thick secretions leading to enzyme deficiencies and malabsorption.
What glands are also affected?
Abnormal function of sweat glands results in excessive concentrations of sodium and chloride in sweat.
Immunoreactive trypsinogen (IRT) is raised in newborn infants with what disease?
Cystic fibrosis. All newborn infants in the UK are screened for CF. This reduces diagnostic delay and lowers risk of presenting with faltering growth or established chronic infection.
IRT is measured in routine heel-prick bloods taken for biochemical screening.
Samples with a raised IRT are screened for common CF gene mutations and infants with two mutations have a sweat test to confirm diagnosis.
If a child with CF is not identified by screening, it may present clinically with recurrent chest infections, faltering growth or malabsorption.
Chronic infection is caused by which specific bacteria?
initially:
Staphylococcus aureus
Haemophilus influenzae
subsequently:
Pseudomonas aeruginosa.
Burkholderia species
Chronic infection leads to bronchiectasis and abscess formation.
What are the clinical features of cystic fibrosis in newborns?
Diagnosed through newborn screening
Meconium ileus
What are the clinical features of cystic fibrosis in infancy?
Prolonged neonatal jaundice (Jaundice is probably due to extrahepatic biliary obstruction from bile of increased density, with secondary intrahepatic bile stasis.)
Growth faltering
Recurrent chest infections
Malabsorption, steatorrhoea
What are the clinical features of cystic fibrosis in a young child?
Bronchiectasis
Rectal prolapse (Frequent coughing or hard-to-pass stools can occasionally cause rectal prolapse; In some cases, rectal prolapse is the first noticeable sign of cystic fibrosis. It’s not very common in children without cystic fibrosis, but it does occur.)
Nasal polyp (common in people with cystic fibrosis, affecting between 10 to 50 percent. Polyps are small, sac-like growths of inflamed nasal mucosa caused by chronic inflammation in the nasal lining.)
Sinusitis (as respiratory epithelium is affected by CF)
What are the clinical features of cystic fibrosis in an older child and adolescent?
Allergic bronchopulmonary aspergillosis
Diabetes mellitus (The thick, sticky mucus that is characteristic of the disease causes scarring of the pancreas)
Cirrhosis and portal hypertension (Poor bile flow in the liver can lead to inflammation and scarring of the liver)
Distal intestinal obstruction (meconium ileus equivalent)
Pneumothorax or recurrent haemoptysis
Sterility in males (Most men with CF (97-98 percent) are infertile because of a blockage or absence of the sperm canal, known as congenital bilateral absence of the vas deferens (CBAVD))
List some clinical features of CF
Persistent wet cough Purulent sputum Hyperinflation of chest coarse inspiratory crepitaitons Expiratory wheeze finger clubbing in established disease
95% die of respiratory failure
Over 90% of children with CF have pancreatic exocrine insufficiency (Lipase, amylase and protease)
What does this cause and how can pancreatic insufficiency be diagnosed?
Maldigestion and malabsorption leading to faltering growth with frequent large, pale and greasy stools (steatorrhoea).
Pancreatic insufficiency can be diagnosed by low faecal elastase.
10-20% of infants with CF present in the neo-natal period with meconium ileus. This causes vomiting and abdominal distension and failure to pass meconium in <24 hrs. How is the obstruction relieved?
Surgery
Gastrografin enema may relieve obstruction (A gastrografin enema is a radiological examination or the large bowel. Gastrografin is a water soluble clear fluid that shows up on x-ray pictures.)
How is CF diagnosed?
Sweat test to confirm concentration of chloride in sweat is markedly elevated (CL 60-125 mmolL in CF, 10-40 mmol/L in normal children)
Sweating is induced by pilocarpine iontophoresis. A low voltage current draws pilocarpine (cholinergic parasympathomimetic agent) into the skin where it stimulates the sweat glands. (innervated by sympathetic post ganglionic fibre)
Sweat is collected in a capillary tube or absorbed onto weighted filter paper.
Confirmation can be made by testing for gene abnormalities in the CFTR protein.
Repiratory management of CF
Regular lung function measurement by spirometry.
Airway clearance manoeuvres - chest percussion, postural drainage. deep breathing exercises. physiotherapy.
Physical activity encouraged.
Continuous prophylactic oral antibiotics (Flucloxacillin) with rescue oral antibiotics
Pseudomonas infection is associated with rapid decline in lung function. This is slowed by daily nebulized Pseudomonas antibiotics
Nebulized DNase or hypertonic saline may be helpful to decrease viscosity of sputum. (DNase acts like scissors by cutting up the long DNA strands contained in white blood cells. By cutting these strands into shorter pieces, it helps to break up the thick, sticky mucus that often leads to lung infections.)
Macrolide antibiotic Azithromycin given regularly decreases respiratory exacerbations due to an immunomodulatory effect.
What therapeutic options are available for end-stage CF lung disease?
Bilateral sequential lung transplantation.
50% survival at 10 years.
Nutritional management of CF. How is pancreatic insufficiency treated?
Oral enteric-coated pancreatic replacedment threapy taken with all meals and snacks.
High-calorie diet with 150% of normal intake recommended. Overnight feeding via gastrostomy.
Fat soluble vitamin supplements
Complications of CF in teenagers and adults
Diabetes mellitus due to decreasing pancreatic endocrine function
Liver disease with hepatomegaly on liver plapation, abnormal liver funciton on blood tests and US. Regular ursodeoxycholic acid to improve flow of bile may be benificial. Liver transplant generally very successful in CF-related liver failure.
Distal intestinal obstruction syndrome (meconium ileus equivalent) - Oral laxatives
Patients with CF to avoid socialising due to transmission of virulent strains of Pseudomonas and Burkholderia.
Males lack vas deferens and are thus infertile.- Intracytoplasmic sperm injection (ICSI)
Primary ciliary dyskinesia is a congential abnormality in the structure of function of cilia lining the respiratory tract.
What are the features of this disease?
impaired mucociliary clerance; recurrent infection of the upper and lower respiratory tract bronchiectasis recurrent productive cough purulent nsal discharge chronic ear infections
50% have dextrocardia and situs inversus(kartagner syndrome)
How is primary ciliary dyskinesia diagnosed and treated?
Examination of the structure and function of the cilia of nasal epithelial cells brushed from the nose.
Daily physiotherapy to clear secretions
Proactive treatment of infections with antibiotics
appropriate ENT followup.
Immunodeficiency can cause severe, unusual or recurrent chest infections in children. This may be secondary to an illness, e.g. malignant disease or its treatment with chemotherapy.
Less commonly it is due to HIV infection or a primary immune deficiency.
What do igG deficiencies predispose to?
Infections with polysaccharide-encapsulated bacteria such as S.pneumoniae.
Immunodeficiency can cause severe, unusual or recurrent chest infections in children. This may be secondary to an illness, e.g. malignant disease or its treatment with chemotherapy.
Less commonly it is due to HIV infection or a primary immune deficiency.
What do cell mediated immunodeficiencies predispose to?
Opportunistic infections such as Pneumocystis jirovecii and fungi
Immunodeficiency can cause severe, unusual or recurrent chest infections in children. This may be secondary to an illness, e.g. malignant disease or its treatment with chemotherapy.
Less commonly it is due to HIV infection or a primary immune deficiency.
What do neutrophil-killing defects predispose to?
Staphylococcal infection
Tuberculosis diagnosis in children with a persistent productive cough
Chest x-ray
Either a tuberculin skin test or tuberculosis blood tests (IGRA, interferon-gamma release assays)
Marked hilar or paratracheal lympahdenopathy is highly suggestive of tuberculosis.
During REM sleep, control of breathing becomes unstable and there is relaxation of voluntary muscles making the upper airway more likely to collapse
Sleep disordered breathing occurs either due to airway obstruction , central hypo ventilation or a combination of these.
What are some key aspects of the history?
Loud snoring Witnessed pauses in breathing(apnoea) Restlessness Disturbed sleep Excessive daytime sleepiness or hyperactivity Learning and behaviour problems Faltering growth Pulmonary hypertension in severe cases
However symptoms alone are neither sensitive nor specific.
Up to 12% of pubertal school children snore.
True prevalence of obstructive sleep apnoea resulting in gas-exchange abnormalities is 0.7-3%
Causes of sleep disordered breathing
Upper airway obstruction secondary to adenotonsillar hypertrophy (surgical removal dramatically improves symptoms)
Neuromuscular disease (Duchenne muscular dystrophy)
Craniofacial abnormalities (Pierre Robin sequence, achondroplasia)
Dystonia of upper airway muscles (Cerebral palsy)
Severe obesity
Down syndrome particularly at risk due to anatomical upper airway restriction and hypotonia.
Assessment of sleep disordered breathing
Overnight pulse oximetry - normal oximetry does not exclude the condition but severe physical consequences are unlikely
Sleep study (polysomnography) - HR, RR Airflow, CO2, Video recording.
Congenital central hypoventilation syndrome is a rare congenital condition resulting in disordered central control of breathing as well as other autonomic dysfunction. Life threatening hypoventilation occurs during sleep which may result in death in infancy. How is this treated?
Long term ventilation, either continuous or only during sleep.
Tracheotomy is indicated in children following
Long term ventilation - muscle weakness
Wean from ventilation - prolonged ventilation
Airway protection - facilitate clearance of secretions
It is also indicated for:
Narrow upper airways
Lower airway anomalies
What are some causes of these anomalies?
Narrow upper airways
Sublottic stenosis
Lower airway anomalies
Layngeal anomalies (atresia, haemangiomas, webs),
Pierre Robin sequence (retroganthia -> glossoptosis -> cleft palate in 50%)
Craniofacial anomalies (Crouzon disease - premature fusion of certain skull bones (craniosynostosis))
