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Three Part Question

In [infants with bronchiolitis] does [prone positioning] reduce [oxygen requirement or respiratory distress]?

Clinical Scenario

An 11-month old boy is admitted with difficulty breathing, cough and poor feeding. On examination he has bilateral wheeze with fine inspiratory crepitations and moderate recession. His oxygen saturations are 88% on room air. Management with nasogastric feeds and supplementary oxygen is commenced in line with national guidelines. The Nurse in Charge suggests placing him in the prone position. You wonder what effect ‘proning’ may have on his clinical outcome and what the evidence for this is.

Search Strategy

Searches were performed on 10 July 2021.

A search was performed on MEDLINE via PubMed for primary and secondary sources up to July 2021 using the following MeSH terms and keyword combinations: “bronchiolitis” AND “prone position” AND “infant* OR child* OR paediatric*. After performing the search, seven results were retrieved with only one relevant article identified following review of abstracts. A medical librarian duplicated the search and attained the same results.

Search Outcome

After performing the search, seven results were retrieved with only one relevant article identified following review of abstracts. A medical librarian duplicated the search and attained the same results.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Florent Baudin et al. February 2019 France	N= 14 infants, under 6 months of age hospitalised in a critical care unit with a clinical diagnosis of acute viral bronchiolitis. Randomised to receive 7cmH2O CPAP for 1 hour in prone or supine position followed by cross over.	Randomised cross over study. Single centre. Level 2b.	Median oesophageal pressure-time product per minute. Respiratory distress (the modified Wood clinical asthma score).	Median oesophageal pressure-time product per minute was significantly lower in prone position than in supine. Respiratory distress was also significantly reduced.	Very small sample size. Primary outcome measure not patient orientated.

Comment(s)

‘Proning’ has gained a great deal of exposure and media attention during the COVID-19 pandemic. In the adult critical care setting it is has been shown to significantly reduce mortality in patients ventilated with Acute Respiratory Distress Syndrome (ARDS). This resulted in its consensus led introduction into the management of conscious patients with COVID-19 on non-invasive respiratory support. In the neonatal intensive care setting there is evidence of improvement in oxygenation for neonates undergoing mechanical ventilation.5 Outside of the critical care setting in paediatric practice this management strategy far outdates the COVID-19 pandemic in the context of seasonal viral bronchiolitis but what is the evidence base for this? Our search identified only one directly relevant study. In 2019, Baudin et al carried out a physiological randomised cross over study investigating the outcomes of 14 participants under 6 months of age admitted with an acute diagnosis of viral bronchiolitis. These infants were to receive 7cmH2O of CPAP (Continuous Positive Airway Pressure) and were randomised to determine the order of their positioning, whether they were to be placed in the supine and then prone position or the converse. Numerous outcomes were measured with the primary outcome being the mean of the oesophageal pressure time product per minute over 100 breaths during the last 5 minutes of the one hour recording. The study found that the median modified Woods Clinical Asthma Score (m-WCAS) was significantly lower in the prone position than in the supine but there was no significant difference in the comfort between both positions as well as the other clinical measures. The median oesophageal pressure time product per minute was significantly lower in the prone position than supine. Measurement of numerous mechanical, clinical and neural variables suggested that the prone position eased work of breathing compared to the supine position. The authors concluded that the prone position can decrease inspiratory effort and the metabolic cost of breathing There are however significant limitations to this study. Firstly, the outcome measure is physiological and not patient orientated. It’s also limited by its small sample size and short-term evaluation of outcomes. Furthermore, potential confounding factors such as the sleeping state of the infants was not recorded. The study also examined infants on CPAP and is therefore not directly applicable to our clinical scenario. At present further high-quality studies are required to explore the utility of prone positioning in the routine management of bronchiolitis. In view of its historical use and the wider contextual evidence regarding prone positioning it is likely to be a safe intervention but this of course needs to be verified. Caregivers should be remined of safe sleeping practices for young infants outside of the clinical environment. Following the results for physiological outcomes Baudin et al have registered the PROPOSITIS study, which will investigate the impact of prone positioning, versus the supine, for infants with moderate to severe bronchiolitis receiving High Flow Nasal Cannula support. This will have a clinical outcome measure, the use of non-invasive ventilation or invasive ventilation. We look forward to seeing the published results.

Clinical Bottom Line

There is currently insufficient evidence to support the routine use of prone positioning in the management of infants with bronchiolitis. Prioritise evidenced based and nationally supported management strategies.

References

1. Florent Baudin et al. Physiological Effect of Prone Position in Children with Severe Bronchiolitis: A Randomized Cross-Over Study (BRONCHIO-DV) The Journal of Pediatrics