Respiratory - Bronchiolitis and Viral-Induced Wheeze Flashcards
What is bronchiolitis?
Inflammation and infection in the bronchioles
What is the most common cause of bronchiolitis
Respiratory syncytial virus
(RSV)
Who is affected by bronchiolitis?
Children under 1 year
Most common in under 6 months
Rarely diagnosed in children up to 2 years, particularly ex-premature babies with chronic lung disease
Why do viruses have such a profound affect on infants?
Airways are very narrow
Inflammation and mucus therefore has a large effect on ability to circulate air to alveoli
Causes wheeze and crackles
How does bronchiolitis present?
Coryzal symptoms
Signs of respiratory distress
Dyspnoea
Tachypnoea
Poor feeding
Low-grade fever
Wheeze and crackles on auscultation
What are the signs of respiratory distress?
Tachypnoea
Accessory muscle use
Nasal flaring
Head bobbing
Tracheal tugging
Cyanosis
Intercostal and subcostal recessions
How does RSV progress?
Bronchiolitis starts as URTI with coryzal symptoms
50% get better
Chest symptoms over first 1-2 days after coryzal symptoms
Symptoms worst on day 3 or 4
Lats 7-10 days
What are children with bronchiolitis more likely to experience?
Viral induced wheeze during childhood
When are infants with bronchiolitis admitted to hospital?
Respiratory distress
Sats under 92%
RR >70
Under 3 months
Less than half of normal milk intake
Pre-existing conditions
Dehydration
Parents unable to cope
How is bronchiolitis managed?
High-flow humidified oxygen via tight nasal cannula
NG to ensure adequate intake
Avoid overfeeding as full stomach can restrict breathing
Saline drops and nasal suctioning to clear secretions
Oxygen
When is ventilatory support used?
As the child gets more tired unable to adequately ventilate
Stepped up using
High flow humidified oxygen, adds PEEP
CPAP
Intubation and ventilation
What is used to assess ventilation?
Capillary blood gas from the toe
What can be used to medically manage RSV?
Palivizumab
Targets RSV
Monthly injection
Given to high risk babies
Not a true vaccine, passive protection, circulates until encounters virus, activates immune system to fight virus
Circulating antibodies decrease over time, hence monthly injection
What causes a viral-induced wheeze?
Small airways encounter a virus
Inflammation and oedema which resitrcts airflow
Inflammation also triggers smooth muscles of the airway to constrict, further narrowing the space
What are the differences between a viral-induced wheeze and asthma?
Presenting before 3 years old
No atopic history
Only occurs during viral infections
