Bronchiolitis update

Bronchiolitis usually starts with a two to three day prodromal phase of coryzal symptoms. Other symptoms and signs include cough, rapid respiratory rate, hyperinflation and wheeze and crackles. Fever does not always occur but if present it is usually low grade (less than 39°C). Absence of fever should not preclude a diagnosis of bronchiolitis. In the first 72 hours of the illness infants may get worse before starting to improve.^2,3

Increased respiratory rate can be a marker of the severity of bronchiolitis, but apnoea may be a presenting feature, especially in very young or premature infants. Many infants will have poor feeding as result of dyspnoea and feeding problems are often a reason for hospital admission. Bronchiolitis can be assessed as mild, moderate or severe (Table 1).² Most infants with acute bronchiolitis will have mild disease and can be managed at home with support. However, it is important to provide caregivers with information on how to recognise deterioration in the infant’s condition, and what to do if this occurs.

Diagnosis is made clinically based on a typical history (e.g. wheeze with recent coryzal symptoms and/or cough) and findings on clinical examination. Wheeze is usually a prominent characteristic of bronchiolitis but can also occur in other conditions common in infants and young children, primarily, asthma, transient infant wheeze (see box below) and rarely pneumonia.

The frequency of presentation of these wheezing phenotypes is influenced by age, with RSV bronchiolitis occurring almost exclusively in the first 12 months of life and peaking at six months.

Only a minority of infants who wheeze in the first year of life will have asthma. Some of these infants will have strong risk factors, such as parental asthma or eczema. A definite response to bronchodilators and asthma can be recognised from an early age. In others, the trend towards a recurrent wheezy illness responsive to bronchodilators, is only apparent after a period of months or years. Risk factors for asthma include eczema in the infant, wheeze without a cold (interval symptoms), more than two episodes of wheezing with a cold and family history of atopy.

Fine inspiratory crackles in all lung fields are a common finding in acute bronchiolitis but are not a characteristic of asthma. Infants with no crackles and only intermittent wheezing are unlikely to have true bronchiolitis but may have viral bronchitis with wheeze, or other acute or recurrent causes of wheeze.³ Coarse crackles, which clear or change on coughing, indicate the presence of mucus in large airways which can occur in asthma.

The presence of wheeze, in addition to increased respiratory rate and indrawing, may indicate a diagnosis of bronchiolitis rather than pneumonia. However, it should be noted that wheeze may occasionally be seen in infants aged less than two months with pneumonia.²

Investigations are rarely necessary

Investigations, with the exception of oximetry, are not routinely indicated in the diagnosis or in determining the severity of bronchiolitis. If there are concerns about hypoxia, or if oxygen saturation is less than 92%, the infant should be referred.

Routine blood and urine cultures are not recommended for infants presenting with uncomplicated bronchiolitis. FBC, ESR and CRP are not reliable predictors of disease severity and are not helpful for differentiating between bacterial and viral infection. Chest X-ray is not routinely indicated and is not useful for differentiating between viral and bacterial infection.

Bronchodilators, inhaled or systemic corticosteroids or antibiotics are not recommended for the treatment of bronchiolitis in primary care.^2,3

The management of bronchiolitis in primary care is focused on providing support and information. In the first 72 hours of the illness infants may get worse before starting to improve. An infant who is seen early in the course of the illness may need to be re-assessed to check for any deterioration.² Parents/caregivers of infants who have been assessed with mild or moderate illness, where symptoms have been present for more than 72 hours, need only reassurance.²

Caregivers should be given clear information about how to recognise any worsening of the infant’s condition and asked to bring the infant back for reassessment if this occurs. It is also important to inform caregivers of the location of support services, such as after hours clinics or hospitals, in case the infant’s condition deteriorates.

When to refer

Infants with severe symptoms or who deteriorate may require referral for consideration of oxygen, nasogastric feeding and intravenous fluids.

Refer all infants with:

• Respiratory rate > 70/min
• Nasal flare and grunting
• History of apnoea
• Poor feeding - lack of interest, choking, less than 50% of usual fluid intake in the preceding 24 hours
• Lethargy
• Severe chest wall recession
• Cyanosis

The threshold for referral to hospital should be lowered in infants less than two months of age, or those born at less than 32 weeks gestation, and infants with respiratory or cardiac comorbidity (e.g. chronic lung disease, congenital heart disease).²

Social factors such as the home environment, ability of caregivers to cope and distance to a hospital may also determine the need to refer.

Re-infection is common

As re-infection is common, advice should be given on how to reduce the risk of infection, and how to prevent the spread of infection to other infants in the family/whānau.

• Take time to clearly explain bronchiolitis, what is meant by a viral infection and check the parents understanding. Provide simple written information if possible
• Ask about housing conditions and find out about services in your community that may be able to assist if needed
• Encourage parents to keep rooms, where the baby lives, at a constant comfortable temperature
• Encourage and support a smokefree environment
• Encourage parents to return or seek assistance if there are concerns about baby’s breathing, ability to feed or general wellbeing
• Bronchiolitis is easily spread, so encourage good hygiene practices such as hand washing before and after handling the baby. People who have a cold or flu-like illness should try and avoid contact with infants.

Caregiver advice for bronchiolitis

Your child has bronchiolitis. This is very common in children under one-year-old and is caused by a virus. Bronchiolitis can usually be managed safely at home

1. What to expect and how you can help your child
   
   You can expect your child to get a lot better after the first three days, although their cough may linger for several weeks.
   Medicines are not helpful for children with bronchiolitis but you can help keep your child comfortable by:
   • Offering small feeds of breast milk or infant formula regularly
   • Keeping your baby warm but not too hot
   • Giving your baby as much rest as possible
   • Don’t smoke in the house or around your baby
   • Keeping your baby’s nose clear. If it is blocked or crusty you can use saline nose drops (from a pharmacy)
   • Keeping your baby away from other children so as not to spread the disease
2. When should I seek help?
   
   You can expect your child to improve so you should get urgent advice from a doctor or nurse if they get worse. Any one of the following may be a sign of the illness getting worse:
   • Breathing fast, has noisy breathing and is having to use extra effort to breathe
   • Looking unwell and/or very pale
   • Taking less than half of their normal feeds
   • Vomiting
   • Has not wet a nappy for six hours
3. Danger signals
   
   The following are danger signs. Dial 111 or contact a doctor immediately if your child has any of the following:
   • Blue lips and tongue
   • Severe difficulty breathing
   • Is becoming less responsive
   • Is pale
   • Is floppy
   • Periods of stopping breathing