Impact of Cold Air Exposure on Croup Symptoms

Study Overview
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Brief Summary
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The goal of the present randomised controlled clinical trial is to compare the efficacy of a 30-minute exposition to cold, atmospheric, outdoor air on the severity of croup symptoms with exposition to indoor room air in children with mild to moderate croup receiving a single dose of dexamethasone during winter croup outbreaks.

Detailed Description
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Croup is a viral laryngitis that represents the most common cause of acute upper airway obstruction in children. It is therefore a frequent reason for emergency department visits. The benefit of dexamethasone on croup symptoms is well established with an onset of action of at least 30 minutes. Various non-pharmacological measures, including exposition to cold air, are also thought to be effective in reducing the severity of symptoms, although this has not been demonstrated yet in the current scientific literature. The aim of the present study is to evaluate the efficacy of exposition to cold air on the symptoms of croup in children. The investigators designed a prospective, open-label, single centre randomised controlled trial to evaluate the effect of exposition to cold air on the symptoms of croup in children. The study was performed during autumn and winter croup outbreaks when outdoor air temperature was <10°C (<50°F). Participants were infants and children aged 3 months to 10 years presenting to the pediatric emergency department of our institution. Inclusion criteria were patients presenting with mild to moderate croup symptoms with Westley croup scores > or=2 (to permit a clinically relevant reduction in the Westley croup score of at least 2 points from baseline at 30 minutes), diagnosed by a triage nurse and confirmed by a senior attending pediatric emergency physician. Exclusion criteria were history or physical examination suggesting any other diagnosis, severe croup requiring immediate nebulised epinephrine, chronic respiratory disease (except asthma), underlying airway abnormalities, immunodeficiency; and contraindication to steroids. According to the recommended standards of care, all children with croup were administered a standard 0·6 mg/kg/dose oral dexamethasone at triage. Participants were randomly allocated either to the outdoor cold air exposition group or to the indoor group allocation using a single, constant 1:1 allocation ratio. Demographic data, previous exposition to cold air before presentation at pediatric emergency department, as well as vital signs and Westley croup score on arrival, and after 30 and 60 minutes, were recorded. Parents were reached by phone 7 days after the initial visit to assess the child's clinical outcome and the final diagnosis, as well as the need for further consultation or hospitalization in the meantime.

Official Title
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Outdoor Cold Air Exposure Versus Room Temperature for Croup Symptoms in Pediatric Emergency Departments: a Randomized Controlled Trial

Conditions
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Croup

Intervention / Treatment
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* Other: Outdoor cold air exposure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - children from 3 months to 10 years with clinical signs of croup and Westley croup score > or =2 Exclusion Criteria: Need for close monitoring Need for nebulized epinephrine History or physical examination suggesting any other diagnosis Chronic respiratory disease (except asthma) Underlying airway abnormalities Immunodeficiency Contraindication to steroids

Ages Eligible for Study
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Minimum Age: 3 Months
Maximum Age: 10 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Open-label randomized controlled study
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exposition group<br>Outdoor cold air exposure (<10°C or <50°F) for 30 minutes. On completion of the intervention, participants remained under observation at indoor ambient air from 30 minutes to 60 minutes from the intervention. | Other: Outdoor cold air exposure<br>* Exposure to outdoor cold air (<10°C or <50°F, intervention group) for 30 minutes. On completion of the intervention, participants remained under observation at indoor ambient air from 30 minutes to 60 minutes from the intervention.<br>|
| No Intervention: Control group<br>Indoor ambient air exposure (24-25°C or 75-77°C). Participants remained under observation at indoor ambient until 60 minutes from triage. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Westley croup score at 30 minutes | The primary outcome is the proportion of patients showing an decrease of at least 2 points in their Westley croup score at 30 minutes from triage. The 5-item Westley croup score uses a 17 points ordinal scale to assess level of consciousness (5 points), cyanosis (5 points), stridor (2 points), air entry (2 points), and chest wall retractions (3 points). Mild croup is defined as a WCS < or = 2, moderate 3-5, severe 6-11, and impending respiratory failure or >12. | at 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Westley croup score at 60 minutes | The secondary outcome is the proportion of patients showing an decrease of at least 2 points in their Westley croup score at 60 minutes from triage. The 5-item Westley croup score uses a 17 points ordinal scale to assess level of consciousness (5 points), cyanosis (5 points), stridor (2 points), air entry (2 points), and chest wall retractions (3 points). Mild croup is defined as a WCS < or = 2, moderate 3-5, severe 6-11, and impending respiratory failure or >12. | at 60 minutes | 
| Pulse oxymetry | Pulse oxymetry in % | at 0 min, at 30 and at 60 minutes from enrolment at triage | 
| Respiratory rate | Respiratory rate in breaths/min | at 0 min, at 30 and at 60 minutes from enrolment at triage | 
| Heart rate | Heart rate in beats/min | at 0 min, at 30 and at 60 minutes from enrolment at triage | 
| Telephone Outpatient derived score | Anamnestic scoring tool to estimate croup severity, derived from the original Telephone Out Patient score | at the time of leaving home for the pediatric emergency department visit; at 0 min on pediatric emergency department arrival (i.e., at triage); at day 7 from the initial visit | 
| Hospitalisation rate | Rate of hospital admission for croup | Within 7 days from the initial visit | 
| Adverse events | Parental or patient perception of adverse events related to exposure to outdoor cold air. | at 30 minutes from enrolment at triage | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Croup, Laryngitis, Laryngotracheitis, Laryngotracheobronchitis, Pediatrics, Children, Infant, Cold air