Lower Respiratory Tract Infections Flashcards
What is Bronchiolitis?
Viral infection of the medium airways in young children causing inflammation and secretion build up. Most commonly occurs during the winter in infants/toddlers < 2 years and 90% are <9months
What are risk factors for complicated bronchiolitis?
<6 months
Underlying medical conditions such as bronchopulmonary dysplasia, congenital heart disease or cystic fibrosis
What are the clinical features of bronchiolitis?
Coryzal symptoms preceding cough Fever Tachypnoea Wheeze Inspiratory crackles Apnoea Dry cough Intercostal recession sometimes with cyanosis Reduced feeding Oxygen requirement
What are the common causes of bronchiolitis?
RSV Mycoplasma Parainfluenza and influenza Adenovirus Coronavirus Metapneumovirus Can sometimes be a secondary bacterial infection in severe cases
What investigations should be done in a child suspected of having bronchiolitis?
CXR to rule out pneumonia
Blood gases
Sats
Immunofluorescence of nasopharyngeal secretions (NPA – nasopharyngeal aspirate)
When should a child with bronchiolitis be admitted and how should a child with bronchiolitis be managed?
Admit if: respiratory distress e.g. grunting, Sats<92% on air or RR >70, apnoea or central cyanosis.
Consider admitting if inadequate feeds (50-75% of normal), clinical dehydration or RR >60.
Give supportive care such as fluids and humidified oxygen +/- mechanical ventilation
Condition usually peaks at day 5-7 of infection
Nasogastric feeds if required
Suction if excessive upper airway secretions
Palivizumab – monoclonal antibody given to those at risk of RSV such as premature infants, those with lung or heart abnormalities and immunocompromised infants.
What is a viral induced wheeze?
A child too young to be diagnosed with asthma who develop a wheeze when suffering from a viral infection but has no wheeze symptoms in-between viral infections. Peak is around 2 years and resolves by 5.
What are the clinical features of a viral induced wheeze?
Coryzal prodrome Dry cough Hyperinflated Diffuse wheeze No crepitations Difficulty breathing
What casues viral induced wheeze?
Rhinovirus most common RSV Parainfluenza and influenza Adenovirus Coronavirus Metapneumovirus Passive smoking (prolongs symptoms)
How should children with viral induced wheeze be managed?
Happy wheezers – no treatment necessary
If distressed or have high work of breathing, then treatment should be trial of salbutamol via spacer inhaler
Next Montelukast or Ipratropium bromide
Nutrition and hydration if needed
What are the long term implications of viral induced wheeze?
Children eventually grow out of it but if recurrent may consider 4-8 weeks trial of inhaled steroid or montelukast
If chronic consider Cystic fibrosis, TB, foreign body or asthma
How should a mild/moderate acute wheeze in a child be managed?
Mild/moderate – sats >92%, RR <30 in over 5s and <40 under 5s, no/minimal accessor muscle use, feeding well or talking normally and wheeze only audible via stethoscope.
10 puffs of salbutamol via inhaler or nebulised salbutamol (2.5mg/5mg), reassess every 30 minutes, if not improving consider ipratropium bromide or steroids.
How should a severe acute wheeze in a child be managed?
Severe
Sats <92%, RR >30 in over 5s and >49 in under 5s, use of accessory muscles, too breathless to feed or talk and audible wheeze.
High flow oxygen, nebulised salbutamol, and ipratropium bromide
Oral steroids
Continuous reassessment over 30minutes
Consider IV salbutamol, magnesium sulphate or aminophylline
What are the clinical features of a community acquired pneumonia?
Malaise Poor feeding Respiratory distress – tachypnoea Tachypnoea and high fever Wet cough Cyanosis Intercostal recession and accessory muscle use Older children like adults – pleuritic pain, crackles +/- wheeze and bronchial breathing Crepitations Reduced air entry
How should a suspected community acquired pneumonia be investigated?
CXR
FBC
Sputum cultures
What commonly causes community acquired Pneumonia?
Viral > bacterial
New-born – GBS, gram negative enterococci and bacilli
Infants and young children – RSV most common virus and Strep Pneumoniae are most common bacterial. Also, Haemophilus influenzae, pertussis, chlamydia and staph aureus.
Children > 5yrs – strep pneumoniae, Mycoplasma pneumoniae and chlamydia pneumoniae
How can you distinguish between a viral and bacterial pneumonia?
Bacterial >2 years Mostly >38.5 degrees Onset abrupt and toxic + No prodrome No others ill in family
Features Unilateral signs Pleuritic chest Wet and productive cough No wheeze
Viral <2 years Mostly <38.5 degrees Onset gradual with coryza Yes with URTI/rash/conjunctivitis Bilateral signs
Features
Rash and myalgia
Dry cough
Wheeze
How should a child with pneumonia be managed?
Admit if O2 < 92% or in respiratory distress
Those with moderate symptoms can be sent home as usually viral and nothing we can do
If bacterial or severe: amoxicillin is 1st line otherwise co-amoxiclav (if associated with H.influenza), azithromycin or clarithromycin for 5-7 days (if mycoplasma or chlamydia).
If moderate or severe (recession and cyanosis) then IV Cefuroxime and PO erythromicin
Note children do not swallow sputum until they are 8 years old
When should you suspected TB in children?
Suspect if: Overseas contacts, odd CXR and anorexia. Diagnosis via Tuberculin test or interferon gamma blood test or 3x sputum test (Ziehl-Neelsen stain)
What is whooping cough?
LRTI caused by Bordetella pertussis (gram negative). Low mortality rate usually due to secondary pneumonia but severe in young children. Significant morbidity in infants under 2.
How is pertussis transmitted and what is the incubation period?
Transmitted by aerosol droplet with an incubation period of 3-12 days.
How long is someone with pertussis infective for?
Infectious from 6 days after exposure to 3 weeks after onset of symptoms.
How long does the pertussis vaccine last for?
Vaccine only lasts 6 years so cannot be eradicated.
Describe the 3 phases of whooping cough and its clinical features
3 Phases
Catarrhal phase – 2-3 days of coryza
Paroxysmal phase – from 10-100-day cough with apnoea, bouts of coughing ending in vomiting, cough followed by whoop (due to inspiration against closed glottis), worse at night or after feeds.
Convalescent phase – chronic cough that lasts for 4 weeks
Often coinfection with RSV
Common in infants and adultescents over 14
Absolute lymphocytosis
Incubation period is 10-14 days
What investigations should be done in suspected pertussis?
PCR via nasal swab
CXR
Diagnostic criteria
Suspected in those with a 14-day cough and one of the following: paroxysmal cough, inspiratory whoop (uncommon in young children), post-tussive vomiting and undiagnosed apnoeic attacks in young infants.
What complications can occur form pertussis?
100-day cough and pneumonia Coughing may lead to petechiae Seizures Inguinal hernias Conjunctival, retina and CNS bleeds (rare) Bronchiectasis
How is pertussis managed?
NOTIFIABLE DISEASE
Admit if < 6 months
Macrolide such as Clarithromycin and antibiotic prophylaxis for household contacts
Prevention – Vaccination but not always effective, 30% of cases come from fully vaccinated children.
Vaccinating mother during pregnancy very important - offered at 20-32 weeks
