tags:
- paeds/respiAcute Bronchiolitis
Definition
An acute inflammation of the bronchioles in children below 2 y/o. Difficulty in expiration due to airway trapping.
- common in children age 3 - 6 months old
- diagnosis is made clinically
- children who have had bronchiolitis during infant more likely to get viral-induced wheeze during childhood
LRTI (lower respiratory tract infection) begins with URTI.
URT: nasal cavity - oral cavity - pharynx
LRT: larynx - trachea - bronchi - smaller bronchi - bronchioles - alveoli
Bronchitis: inflammation of bronchus usually affected older people who smokes, not infant
*bronchiolitis is a diagnosed in children below 2 y/o while asthma is diagnosed in children above 2 y/o
Risk Factor
- <6 weeks old
- premature infant
- lower weight for gestation
- immunodeficiency
- congenital heart disease
- neurological conditions
- chronic lung disease
Pathogenesis
1. Narrowing of airways due to:
- mucus hypersecretion
- cell wall thickening
- bronchospasm
*airway of infants is already small, so the secretion of mucous will significantly affect the airway flow causing wheezing and crackles
2. Air trapping:
- oxygen can be inhaled but trapped in the alveolus
- difficulty in exhalation/expiration
Course of illness
Causes
Signs & Symptoms
Signs:
- intercostal/subcostal recession
- noisy breathing/wheeze
- mild fever <39C
- signs of respiratory distress
Symptoms:
- coryzal symptoms
- runny nose
- sneezing
- mucous in the throat
- watery eyes
- cough (persistent dry)
- rapid breathing (belly breathing)
- poor feeding
Severe:
- high or low respiratory rate
- apnoea
- grunting
- cyanosis
- pale-looking
- poor feeding
Physical Examination
- dyspnoea
- tachypnoea
- apneoa - episodes of stop breathing temporarily
- intercostal/subcostal recession
- rhonchi
- crepitation (fine end-inspiratory)
- liver displaced downwards
Differential Diagnosis
- Acute asthma
- Viral induce wheeze
- Pneumonia
- Congestive heart failure
- Pertussis
Investigation
*diagnosis is made clinically
*investigation has no role in diagnosing bronchiolitis
1. Capillary blood gases
- to monitor response towards ventilation support
- ABG for more accurate oxygen level
2. CXR
- infiltrates
- air trapping
Management
Indication of admission:
- aged under 3 months
- pre-existing conditions e.g. premature, Down's syndrome, cystic fibrosis
- reduced <50-75% from normal oral intake
- clinically dehydrated e.g. reduced urine output
- respiratory rate >70
- SpO2 <92% or hypoxic
- moderate to severe respiratory distress
- apnoea
Principle of management:
- Oxygenation - keep SpO2 >92%, nasal prong (mild & moderate), CPAP (severe)
- Hydration - oral hydration (if oral intake is good), otherwise nasogastric tube or IV fluid
- Other - 3% saline nebulisation, nasal suction, saline nasal drops
*no benefits of saline nebulization, bronchodilators or corticosteroids
Prophylaxis:
Monoclonal antibody to RSV (palivizumab) given monthly by intramuscular injection reduces the number of hospital admissions in high-risk preterm infants.
Complications
- Dehydration
- Apnoea
- Secondary bacterial infection