Bronchiolitis

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

The main goal of treatment is to correct abnormalities in oxygenation and hydration.[44][61][63] Therefore, treatment is primarily supportive.

The majority of infants with bronchiolitis can be managed as outpatients. Indications for hospitalisation include persistent hypoxaemia, tachypnoea so severe that it impedes oral feeding or hydration, apnoea, and clinical concern for impending respiratory failure.

Supplemental oxygen

Standard oxygen therapy, administered by nasal cannula or head box, is first line.

The American Academy of Pediatrics recommends that infants who are hypoxaemic should be given supplemental oxygen to maintain an oxyhaemoglobin saturation (saturation of peripheral oxygen, SpO₂) of at least 90%, the point at which small decreases in arterial partial pressure of oxygen (PaO₂) are associated with large changes in SpO₂.[44][61]

One randomised controlled trial reported that a target SpO₂ of 90% was as safe and effective as a target SpO₂ of 94% in infants hospitalised with viral bronchiolitis. There was no significant difference between the two groups in time to resolution of symptoms, return to adequate feeding, re-admission to hospital, or adverse events. The infants with a target SpO₂ of 90% required a shorter duration of supplemental oxygen and were fit for hospital discharge sooner.[62]

No long-term neurodevelopmental outcome studies have been conducted comparing the use of lower SpO₂ targets (>90%) with higher ones (>94%). Because fever and acidosis shift the oxyhaemoglobin desaturation curve to the right, a higher SpO₂ goal may be more appropriate for children with those conditions; for example, some guidelines recommend an SpO₂ goal >92%.[63][64]

Other signs of impaired respiratory function, such as increased work of breathing or retractions, can be used as factors in deciding on supplemental oxygen therapy.

Infants with underlying cardiac or pulmonary disease may have baseline abnormalities in oxygenation. In these patients, the threshold for using supplemental oxygen may be higher.

Non-invasive ventilation

High-flow nasal cannula therapy (HFNC) delivers a humidified, heated air and oxygen mixture at high flow through a nasal cannula.[73][74] It is a safe and well-tolerated supplementary mode of non-invasive ventilation that reduces the work of breathing. It has gained increasing popularity in the care of hospitalised infants with moderately severe or severe bronchiolitis.[75]

Meta-analysis has demonstrated that HFNC is safe as an initial therapy for infants with bronchiolitis, but is not superior to either standard oxygen therapy (SOT) or nasal continuous positive airways pressure (nCPAP) in shortening length of hospital stay, reducing duration of supplemental oxygen use, preventing transfer to the intensive care unit, or preventing intubation.[73] HFNC was superior to SOT but inferior to nCPAP in preventing treatment failure (need for escalation of care).[73] HFNC may reduce the incidence of nasal trauma and abdominal overdistension in neonates, but the evidence for treatment benefits versus other means of respiratory support is very uncertain and more studies are needed to enable the formulation of evidence‐based guidelines on the use of HFNC in this group.[76]

HFNC is used as a rescue therapy for hypoxaemic children who have not responded to SOT.[77][78] One randomised controlled trial found that 61% of children who did not respond adequately to SOT did respond to HFNC, avoiding the need for intensive care admission.[79]

HFNC should not be used in infants with normoxaemic respiratory distress, and its role in infants without hypoxaemia should be confined to randomised controlled trials.[78]

Continuous positive airways pressure (CPAP) prevents the collapse of peripheral airways during expiration, and permits deflation of over-distended lung regions. Nasal CPAP may be considered for children with severe disease, particularly those who have not responded to HFNC, or who have signs of impending respiratory failure.[63][64] Signs of impending respiratory failure include: exhaustion (listlessness or decreased respiratory effort), recurrent apnoea, and failure to maintain adequate oxygen saturation despite supplemental oxygen.[64] There is insufficient evidence to determine if CPAP decreases the need for subsequent intubation and mechanical ventilation; larger, adequately powered trials are needed.[80]

Invasive ventilation

Intubation and mechanical ventilation may be necessary for children who remain unstable despite supplemental oxygen and non-invasive ventilation support.

One systematic review involving the use of CPAP or bi-level positive airway pressure in children under 2 years of age with viral bronchiolitis identified predictors of failure of non-invasive ventilation, including persistent apnoea, persistently elevated partial pressure of carbon dioxide (pCO₂) after 2 hours of therapy, lower age and weight, and lower initial heart rate with less of a decrease in heart rate following initiation of therapy.[81]

Hydration

Infants with bronchiolitis may have difficulty feeding, due to tachypnoea and increased nasal secretions.[44] Respiratory compromise can also enhance risk of aspiration.[82] Approximately half of hospitalised infants require intravenous or nasogastric fluids.[83][84]

Both intravenous and nasogastric hydration are appropriate therapies for infants with bronchiolitis who cannot eat by mouth. One Cochrane review found no significant difference between those infants who received hydration intravenously or by nasogastric tube feedings regarding duration of hospitalisation, duration of supplemental oxygen therapy, or adverse events. Nasogastric tube insertion had a higher first attempt success rate and required fewer changes in therapy than intravenous access.[85]

Whichever method is used, hydration therapy should be administered judiciously, so as to avoid over-hydration, which can contribute to increased airway obstruction. If intravenous therapy is required, isotonic solutions should be used, as hypotonic solutions can contribute to the risk of hyponatraemia in infants with bronchiolitis.[86] There is a paucity of data upon which to base nutrient intake guidelines for sick infants with bronchiolitis, with some studies showing that infants are hypermetabolic while others show them to be hypometabolic.[86]

Ribavirin

In addition to supportive care for respiratory failure and dehydration, ribavirin can be considered for infants with certain immunodeficiencies such as haematopoietic stem cell transplant recipients or those with haematological malignancies.[87][88]

Reviews of the literature have associated ribavirin with improved survival in haematological patients with respiratory syncytial virus (RSV), but have found no significant impact of therapy on other outcomes such as rates of mechanical ventilation or progression to severe lower respiratory tract infection.[87][88]

There is a lack of evidence to support its use in otherwise healthy infants, even with severe lower respiratory tract infection. Routine use in otherwise healthy infants is not recommended.[54][89]

Treatments with limited or no evidence

Corticosteroids

Systemic and inhaled corticosteroids do not have a clinically relevant effect on hospital admissions or length of hospitalisation.[90] [ ] Guidelines advise against their routine use in children with bronchiolitis.[44][63][64]

Systemic corticosteroid therapy is, however, sometimes prescribed for children with asthma risk factors. One placebo-controlled randomised study of infants with bronchiolitis without a history of wheezing, but with other asthma risk factors (defined as eczema or a family history of asthma in a first-degree relative), documented a decreased length of hospital stay in infants treated with dexamethasone.[91] A subsequent retrospective observational study found that corticosteroids were not associated with improved outcome in patients with bronchiolitis who were later hospitalised with asthma.[92]

Bronchodilators

Bronchodilators are not effective in the treatment of bronchiolitis, and guidelines recommend against their routine use.[44][63][64][93] Meta-analysis has demonstrated no effect of bronchodilators on oxygen saturation, hospital admission rate, or duration of illness.[93]

Antibiotics

Although children frequently receive antibacterial therapy, studies report a low prevalence of concomitant bacterial infection in bronchiolitis and a lack of effect of antibacterial treatment on outcome.[94][95][96] [ ] Guidelines advise against use of antibiotics in children with bronchiolitis.[44][63][64]

Urine cultures may be obtained from children with bronchiolitis, particularly during the work-up of febrile infants, and a positive urine culture may prompt initiation of antibiotics. However, when both abnormal urinalysis and positive urine culture are used to diagnose urinary tract infection (UTI), the prevalence of UTI in febrile infants with bronchiolitis is only 0.8%.[97] Treatment for UTI should not be instigated based on a positive urine culture alone.

Antibiotic therapy may be appropriate for some children with bronchiolitis who require intubation and mechanical ventilation for respiratory failure.[44]

Hypertonic saline

Inhaled hypertonic saline is thought to improve mucociliary clearance by increasing hydration of inspissated mucus and decreasing airway wall oedema. Its use in infants with bronchiolitis, however, is controversial. One 2023 meta-analysis found a modest reduction of about 10 hours in length of hospital stay and a slight improvement in clinical severity scores for inpatients who received hypertonic saline compared with normal saline, and a 13% reduction in hospitalisation for those who received hypertonic saline as outpatients or in the accident and emergency department.[98] [ ] However, other studies have reported mixed results, and additional meta-analyses have demonstrated less of an effect.[99][100][101] As a result, some guidelines now recommend against the use of hypertonic saline for infants with bronchiolitis.[61][63][89]

Nebulised deoxyribonuclease

Limited data suggest that nebulised deoxyribonuclease does not improve clinical outcomes, and this treatment is not currently recommended for bronchiolitis.[102]

Inhaled adrenaline (epinephrine)

Inhaled adrenaline may improve short-term outcomes for outpatients with bronchiolitis such as decreasing admission rates from the accident and emergency department.[103][104][105] [ ] However, further study is needed in this area, and routine use of inhaled adrenaline is not recommended.[44][61][63] In the inpatient setting, inhaled adrenaline has no advantage over placebo.[103] [ ] [Evidence B]

Physiotherapy

Chest physiotherapy is often utilised in infants with bronchiolitis in an attempt to increase the clearance of secretions and improve breathing. However, studies of conventional techniques (vibration, percussion, and postural drainage), as well as other techniques (forced expiratory techniques and instrumentation like intrapulmonary percussive ventilation), have not supported this practice.[106][107] There is some low-certainty evidence that slow expiratory techniques can modestly improve bronchiolitis severity scores, mostly in hospitalised infants with moderate bronchiolitis, and perhaps time to recovery.[106] Heterogeneity in both the techniques of airway clearance studied and the methods used to assess their effects limits the interpretation of meta-analyses.[108] Guidelines do not recommend chest physiotherapy routinely in the management of bronchiolitis.[44][61][63][89]

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