Review of Bronchiolitis on A4Medicine. Seaosonal viral illness charecterised by fever , nasal discharge and dry , wheezy cough

Occurs in children < 2 yrs and most commonly in 1st year of life Most common serious respiratory illness in infancy Peak between 3-6 months Symptoms peak between 3-5 days- then improve 90 % infnats will get better within 3 weeks Seasonal ↑↑ during winter and early spring ( N America and Europe ) Re-infection during a single season is possible

Diagnosing bronchiolitis-
Coryzal prodrome lasting 1-3 days followed by persistent cough and either tachypnoe or chest rececssion ( or both ) either wheeze or crackles on chest auscultation ( or both ) fever ( in around 30 % of cases usually < 39° ) high fever is uncommon ( ie > 39° ) poor feeding ( after 3-5 days of illness ) → rapid respiratory rate may not permit time for sucking and swallowing 

Young infants ( particularly < 6 weeks old ) may present with apnoe without other clinical signs

Signs of resp illness may include
 Tachypnoe Intercostal and/ or subcostal retractions Accessory muscle use Nasal flaring Grunting Colour change or apnoe Low O2 saturation Diagnosis is clinical
 based on hx and clinical findings

Breastfeeding reduces
 risk of RSV related admissions

 Smoking ↑ risk of admission

Examination-Oxygen saturation Hydration status ( CRT , Pulse rate, skin turgor etc ) Resp distress- RR , IC/SC recession , nasal flaring

Pathology-Viral illness ( Respiratory syncytial virus ) RSV is the pathogen in 70-80 % cases Other viruses including human metapneumovirus ( HMPV ) , influenza , rhinovirus , adenovirus and parainfluenza virus can all cause a similar clinical picture Transmission is by droplet and direct contact of respiratory secretions ( RSV ) or via enviornmental surfaces ( eg skin , clothes ) Mucous plugs obstruct bronchioles → can cause hyperinflation or collapse of the distal lung tissue Even small ↓ in diameter caused by inflammation and secretions → impairs laminar airflow leading to respiratory distress

Apnoe ( observed or reported ) Child looks seriously unwell Severe respiratory distress ( grunting , marked chest recession , RR > 70 ) Central cyanosis Sats persistently < 92 % on air- Admit emergency 999

RR > 60 /min Difficulty with breastfeeding or inadequate 
oral fluid intake (50-75 % of usual vol ) Clinical hydration- consider admission

Risk factors severe disease-Age < 12 weeks History of prematurity ( < 32 weeks ) Underlying cardiopulmonary disease Neuromuscular disorder Immunodeficiency

Suspected impending respiratory failure-Signs of exhaustion ( listlessness or ↓ resp effort ) Recurrent apnoe Failure to maintain adequate O2 saturation despite O2 supplementation

Treatment not recommended- Antibiotics Hypertonic saline Adrenaline ( nebulised ) Salbutamol Montelukast Ipratropium bromide Systemic or inhaled corticosteroids A combination of systemic and nebulised adrenaline Antivirals

Supplemental Oxygen is a mainstay of
 treatment in hospital

Prognosis- From onset most
 infants would be asymptomatic 
by 2 weeks- a small proportion will still 
have symptoms 
after 4 weeks

safety-netting –Recognise red flag symptoms

○ worsening work of breathing ( eg grunting , nasal flaring , marked chest recession )
○ fluid intake is 50-75 % of normal or no wet nappy for 12 hrs
○ apnoe or cyanosis
○ exhaustion ( for eg not responding normally to social cues , wakes only with prolonged stimulation )
 Not to smoke in child’s home ( symptoms can get ↑ severe ) How to get immediate help