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Three Part Question

In children presenting at the ED with bronchiolitis [P], what is the change of developing severe disease [O] at different saturation levels measured with pulse oximetry [I]?

Clinical Scenario

A 4-month old child is presented at the emergency department with coryza,cough and wheeze. You see an alert, well hydrated wheezing infant with mild respiratory distress and oxygen-saturation 93%. You wonder wether it is safe to send this child with bronchiolitis home.

Search Strategy

Pubmed
[bronchiolitis] AND [oxygen saturation], limits: English language

Search Outcome

130 titels, of which 7 relevant articles. Five of these 7 relevant articles were based on data from a prospective cohort study. Two studies were retrospective, one retrospective cohortstudy and one retrospective case-control study. Only the 5 prospective cohort study were considered in this bestbet.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Parker 2009 Canada	312 children 2-23 months old with bronchiolitis at the emergency department	prospective cohort study	major medical intervention (oxygen for sat < 90%)	sat < 93%: RR 2,4 (95%CI 1,33-4,32), ARR 21% (95%CI 2-40%)
Mansbach 2008 USA	1456 children < 2 years with bronchiolitis at the emergency department	prospective cohortstudy	Hospitalisation	sat <94%: OR 2,28 (95%CI 1,56-3,34)
Voets 2006 Belgium	378 children aged 2 weeks- 2 years with RSV-bronchiolitis at the emergency department	prospective cohortstudy	hospitalisation	sat <95%: RR 4,7 (95%CI 3,47-6,51), ARR 55% (95%CI 45-65%)
Shaw 1991 USA	213 children, < 13 months with bronchiolitis at the emergency department	prospective cohortstudy	severe disease (mild disease is alert/active and well hydrated with oral fluids)	sat < 95%: RR 3,3 (95%CI 2,52-4,34)
Mulholland 1990 Australia	60 children < 16 months hospitalised with bronchiolitis	prospective cohort	FiO2>40%	sat <90%: RR 4,6 (95%CI 1,76-12,16), ARR 42% (95%CI 13-71%)

Comment(s)

The 5 relevant studies looked at that different clinical outcomes using varying oxygen-saturation levels. In none of the studies, the consequences of varying oxygen-saturation levels were considered within the studypopulation. Most studies considered hospitalisation as outcome measure, only 2 studies looked at actual need for hospitalisation, supported by the administration of supplemental oxygen. An important issue when considering the outcome measure "severity of disease", is what level of hypoxia is considered clinically relevant.

Clinical Bottom Line

Lower oxygen saturation is associated with more severe disease in children with bronchiolitis. A definitive safe value for oxygensaturation when considering discharge is not straigthforward. However it seems reasonable to consider an oxygen-saturation >92% safe enough for discharge when concerning severe respiratory symptoms.

References

1. Parker MJ Predictors of major intervention in infants with bronchiolitis Pediatric Pulmonology 2009;44:358-363
2. Mansbach JM Prospective multicenter studyof bronchiolitis: predicting safe discharges from the emergency department Pediatrics 2008;121:680-688
3. Voets S Clinical predictors of the severity of bronchiolitis European Journal of Emergency Medicine 2006;13:134-138
4. Shaw NS Outpatient assessment of infants with bronchiolitis Am J Dis Child 1991;145:151-155
5. Mulholland EK Clinical findings and severity of acute bronchiolitis The Lancet 1990;335:1259-61