乌鸦传媒

For children with croup, adding cold outdoor air to mainstay treatment proved beneficial for reducing the intensity of symptoms, especially in moderate cases, a randomized controlled trial showed.

After administration of a single dose of oral dexamethasone, 49.2% of kids exposed to outdoor cold air for 30 minutes had a decrease in Westley Croup Score (WCS) by 2 or more points from baseline compared with 23.7% of those exposed to indoor ambient room air (P=0.007), reported Johan Siebert, MD, of Geneva Children's Hospital in Switzerland, and colleagues.

Among the 118 kids ages 3 months to 10 years in the study, those with moderate croup (WCS of 3 to 5) benefited the most, with 63.3% in the outdoor group experiencing a decrease in WCS by 2 or more points from baseline compared with 17.2% in the indoor group (P<0.001), they noted in .

"Arrival of children with croup in emergency departments [EDs] is frequent during the croup seasonal peaks," Siebert told 乌鸦传媒 in an email. "Croup represents the leading cause of ED visits for upper airway obstruction in pediatrics. On arrival, parents frequently report an improvement in symptoms during the journey with exposure to outdoor cold air. But there was no evidence supporting this intervention to date. Hence, our research team decided to carry out this trial."

The findings "were in line" with what parents have reported for years, he noted, "and legitimize a simple, common-sense intervention to be carried out before children arrive in EDs, perhaps limiting the influx, or to be easily implemented in EDs if conditions allow."

"There is now evidence that initial exposure to outdoor cold air plays a role in improving croup symptoms, particularly in moderate cases, as an adjunct to oral dexamethasone," Siebert added. "This intervention could be easily used by clinicians."

When patients improved, WCS at 30 minutes was most frequently reduced by 2 to 3 points. More patients showed a reduction of 2 points from their baseline WCS in the intervention group (32.2%) compared with the control group (20.3%), which was the same for a reduction of 3 points in WCS -- 13.6% in the intervention group and 3.4% in the control group.

Notably, at 60 minutes after triage, the effect of exposure to outdoor cold air no longer made a difference between the two groups.

Seven days post-triage, using follow-up interviews with parents or guardians and modified outpatient croup scores, the number of children with no persisting symptoms was slightly higher in the intervention group. Symptoms had completely resolved in 44.2% of kids in the outdoor air group versus 32.1% of kids in the indoor air group. However, total score at day 7 was not different between the two groups (P=0.28).

This open-label study included 118 kids who attended a tertiary pediatric emergency department. All participants were categorized as having mild to moderate croup with a WCS of at least 2.

The mean age of trial participants was 32 months, and 69% were boys. On average, the difference between outdoor and indoor temperatures was 20°C, and the difference for humidity was 38%.

Participants were randomized 1:1 to either a 30-minute exposure to outdoor cold air or to indoor room temperature air immediately after triage and administration of single-dose oral dexamethasone.

No adverse events related to the intervention were reported.

Limitations to the study included the difficulty in assessing the effect of possible confounding distraction in both groups, Siebert and colleagues wrote, noting that patients with croup show fewer symptoms when they are not agitated.

Additionally, due to practical reasons related to limited resources for healthcare providers at night -- when croup symptoms peak -- the allocation group could not be blinded, they added, leading to possible bias in clinical assessment by the physician in charge.

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