Respiratory: Bronchiolitis Flashcards
What is the most common cause?
Respiratory syncytial virus 75-80% cases
Also: adenovirus, parainfluenza, mycoplasma, human metapneumovirus
What age group does it typically affect?
Infants between 3 and 6 months
Can be present in children up to 1 year
It is the most common cause of serious LRTI in those less than 1 year old. True or false?
True
What are some risk factors for severe bronchiolitis?
Chronic lung disease Congenital heart disease Age < 3 months Prematurity Neuromuscular disorder - cannot easily clear airways Immunodeficiency
What symptoms are associated?
Coryzal symptoms (congestion, sore throat..) preceding: Persistent dry cough Breathlessness Wheezing Fever
What signs are associated?
Tachypnoea Tachycardia Subcostal and intercostal recession Hyperinflation of the chest Fine end inspiratory crackles
What is often the reason for admission?
Feeding difficulties associated with increasing dyspnoea
When should child be admitted?
Apnoea
Severe respiratory distress - grunting, marked chest recession, RR over 70
Central cyanosis
Persistent O2 sats less than 92% OA
Inadequate oral intake (<50-75% usual volume)
When is the condition considered mild?
Main symptoms (coryzal prodrome, persistent cough, tachypnoea and or chest recession and wheeze/ crackle)
Feeding > 75% No risk factors O2 sats > 95% Normal RR No signs of respiratory distress
What is considered moderate disease?
Main symptoms
Reduced feeding Clinical dehydration RR > 60 Sats 92-95% OA O2 > 92 on oxygen Signs of respiratory distress
What is considered severe disease?
Main symptoms
Impending respiratory failure
Exhaustion, listless, decreased respiratory effort
Recurrent apnoea
Failure to maintain O2 despite oxygen
What investigations should be done?
Test for RSV if admitted - nasopharyngeal aspirate (if positive, patient should be isolated)
Oxygen sats
Bloods, blood culture and CXR not routinely recommended, but consider if severe case or when alternative diagnosis considered e.g pneumonia or HF
How is it managed?
Largely supportive
Humidifier oxygen via head box
High flow O2 therapy / CPAP if concerns about respiratory failure
Naso/orogastric feeding if oral intake inadequate
Fluids
Saline nasal drops
What should be performed in children presenting with apnoea?
Upper airway suctioning - if secretions seen to be causing respiratory distress or feeding difficulty
What treatment is not recommended?
Antibiotics Nebulised adrenaline Salbutamol Montelukast Ipratropium bromide Corticosteroids
How can you assess the child’s hydration status?
Measure capillary refill time
Examine skin turgor and dryness of mucous membranes
Ascertain urine output
If the child does not require hospital admission, what advice should be given?
Bronchiolitis is usually self limiting and symptoms tend to peak between days 3-5
Use paracetamol or ibuprofen if child distressed due to fever
Advise parents not to reduce fever by undressing child or use of tepid sponge
Encourage fluid intake regularly, continue breastfeeding
Child child regularly, even throughout night
Seek medical advice if child deteriorates
Is RSV highly infectious?
Yes - infection control measures particularly good hand hygiene, cohort nursing, gowns and gloves have been shown to prevent cross infection to other infants in the hospital
Most infants will recover by how many weeks?
2 weeks
In rare situations, the illness may result in permanent damage to the airways called…
Bronchiolitis obliterans
Usually following adenovirus infection
What does the RSV do to cells lining the respiratory tract?
Causes them to merge, forming a large multinucleated cell = a syncytia
How is RSV spread?
Sneezing and coughing - droplet spread
Can survive several hours on contaminated surfaces
Why do children disproportionately suffer from bronchiolitis compared to adults?
There bronchioles are already narrow
Immune cells and fluid in the walls of the airway, make the walls thicker and narrows them further
Describe the impact of mucus plug formation
In addition, dead cells and mucus gets trapped in the small airways forming mucus plugs - trapped air. Over time the air diffuses into the bloodstream and the airways collapse (atelectasis)
The mucus plugs can act like one way valves - air going in, but cannot escape = air trapping and hyperinflation
Atelectasis and airtrapping both reduce the lung’s ability to bring in O2 and get rid of CO2 - can lead to hypoxaemia
What differentials are there?
Bacterial pneumonia Viral wheeze Congenital airway abnormality Congenital cardiac abnormality Reflux
