2. Clinicians should take into account the following risk factors for more serious illness when assessing and managing infants with bronchiolitis:

• Gestational age <37 weeks;*
• Younger chronological age at presentation;*
• Prenatal and/or postnatal exposure to tobacco smoke;*
• Reduced breastfeeding exposure;*
• Faltering growth/ slow weight gain (failure to thrive);
• Comorbidities including congenital heart disease, chronic lung disease, chronic neurological condition, congenital diaphragmatic hernia, trisomy 21, and other genetic disorders;
• Being an Indigenous infant†;
• Being an economically disadvantaged infant;
• Timing and severity of illness onset at hospital presentation.

*Clinicians should judge these as risk factors on a continuous scale; with higher risk of poor outcomes associated with lower gestational age, lower chronological age, fewer days of breastfeeding exposure, and greater tobacco smoke exposure.

†Indigenous status in itself is unlikely to confer risk but there remains a correlation in Australia and Aotearoa New Zealand with ethnicity and severe bronchiolitis outcomes, independent of socioeconomic status, potentially reflecting the ongoing impacts of colonisation, remote geographical isolation, and the institutional racism in our health systems.

3.b. Consider CXR in infants with an unexpected deterioration* and/or a clinical course not consistent with bronchiolitis, including concerns regarding the presence of sepsis, pneumonic consolidation, pneumothorax, empyema, immunodeficiency, pleural effusion, or significant cardiac abnormalities.

*Unexpected deterioration refers to an unexpected requirement for an escalation of care.

7. Safe discharge from hospital (either from the ED or ward) for infants with bronchiolitis should take into account risk factors (R2), the distance of the family’s residence from the hospital and their ability to return, parental health literacy, and the timing of the hospital presentation relative to the natural history of bronchiolitis (R1). Consider patients suitable for safe discharge from hospital when the following criteria are met:

1. Infant is clinically stable (defined as with mild to moderate stable respiratory effort).

2. For an infant who has not received oxygen/respiratory support and/or with SpO2≥95%, there is no need to continue to observe for maintenance of oxygen saturations. The infant may be considered for discharge based on criteria below.

For an infant who has received oxygen/respiratory support and/or with SpO2≤94%, they should be observed for maintenance of oxygen saturations in air at the following levels for 3-4 hours, including a period of sleep:
i. for infants aged ≥6 weeks with no underlying health conditions, for maintenance of SpO2≥90%;
ii. for infants aged <6 weeks, or infants aged <12 months with an underlying health condition, for maintenance of SpO2≥92%.

3. All Infants irrespective of presentation to ED or on inpatient ward should be maintaining adequate oral intake of fluids and feeds of at least 1/2 of usual volume with adequate output (>1/2 of usual wet nappies).

4. Parents and/or caregivers should feel confident to manage the infant with bronchiolitis at home.

5. Parents and/or caregivers are educated and provided with written information on possible deterioration and when to return for healthcare review.

6. Social situation allows discharge to home. The following factors should be considered: social factors, the time of day and suitable transport availability.

7. Arrange local follow-up where appropriate.

12.a. Consider the use of supplemental oxygen in the treatment of hypoxaemic* infants with bronchiolitis.

*For definitions of hypoxaemic and target oxygen saturation levels, see R12b (‘Oxygen saturation targets’).

12.b. Consider the use of supplemental oxygen in infants with bronchiolitis if their oxygen saturation is:

• Persistently <90%, for infants aged ≥6 weeks;
• Persistently <92%, for infants aged <6 weeks, or infants aged <12 months with an underlying health condition.

iv. Consider HF therapy in infants with bronchiolitis with severe disease prior to CPAP.

* For otherwise healthy infants aged ≥6 weeks: SpO2 persistently <90%. For infants aged <6 weeks, or infants aged <12 months with an underlying health condition: SpO2 persistently <92%.