Controlled Delivery of High vs Low Humidity vs Mist Therapy for Croup in Emergency Departments

Division of Pediatric Emergency Medicine, The Hospital for Sick Children, and University of Toronto, Toronto, Ontario.
JAMA The Journal of the American Medical Association (Impact Factor: 30.39). 04/2006; 295(11):1274-80. DOI: 10.1001/jama.295.11.1274
Source: PubMed

ABSTRACT Children with croup are often treated with humidity even though this is not scientifically based, consumes time, and can be harmful. Although humidity using the traditional blow-by technique is similar to room air and no water droplets reach the nasopharynx, particles sized for laryngeal deposition (5-10 microm) could be beneficial.
To determine whether a significant difference in the clinical Westley croup score exists in children with moderate to severe croup who were admitted to the emergency department and who received either 100% humidity or 40% humidity via nebulizer or blow-by humidity.
A randomized, single-blind, controlled trial conducted between 2001 and 2004 in a tertiary care pediatric emergency department.
A convenience sample of 140 previously healthy children 3 months to 10 years of age with Westley croup score of more than 1 or 2 or higher (scoring system range, 0-17); 21 families refused participation.
Thirty-minute administration of humidity using traditional blow-by technique (commonly used placebo, n = 48), controlled delivery of 40% humidity (optimally delivered placebo, n = 46), or 100% humidity (n = 46) with water particles of mass median diameter 6.21 microm.
A priori defined change in the Westley croup score from baseline to 30 and 60 minutes in the 3 groups.
Groups were comparable before treatment. At 30 minutes the difference in the improvement in the croup score between the blow-by and low-humidity groups was 0.03 (95% confidence interval [CI], -0.72 to 0.66), between low- and high-humidity groups, 0.16 (95% CI, -0.86 to 0.53), and between blow-by and high-humidity groups, 0.19 (95% CI, -0.87 to 0.49). Results were similar at 60 minutes. Differences between groups in pulse and respiratory rates and oxygen saturation changes were insignificant, as were proportions of excellent responders; proportions with croup score of 0 at study conclusion; and proportions receiving dexamethasone, epinephrine, or requiring additional medical care or hospitalization.
One hundred percent humidity with particles specifically sized to deposit in the larynx failed to result in greater improvement than 40% humidity or humidity by blow-by technique. This study does not support the use of humidity for moderate croup for patients treated in the emergency department. Identifier: NCT00230841.


Available from: Derek Stephens, Apr 21, 2015
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    Evidence-Based Child Health A Cochrane Review Journal 05/2012; 7(3). DOI:10.1002/ebch.1842
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    Paediatric Respiratory Reviews 04/2013; 14(2). DOI:10.1016/j.prrv.2013.02.010 · 2.22 Impact Factor
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    ABSTRACT: Background Croup is a common childhood illness characterized by barky cough, stridor, hoarseness and respiratory distress. Children with severe croup are at risk for intubation. Nebulized epinephrine (NE) may prevent intubation.Objectives To evaluate the efficacy and safety of NE in children presenting to emergency department (ED) or admitted to hospital with croup.Search methodsWe searched CENTRAL (The Cochrane Library 2010, Issue 4), containing the Cochrane Acute Respiratory Infections Group's Specialized Register, MEDLINE (1966 to November Week 1, 2010), EMBASE (1980 to November 2010), Web of Science (1974 to November 2010), CINAHL (1982 to November 2010) and Scopus (1996 to November 2010).Selection criteriaRandomized controlled trials (RCTs) or quasi-RCTs of children with croup evaluated in an ED or admitted to hospital. Comparisons were: NE versus placebo, racemic NE versus L-epinephrine (an isomer), and NE delivered by intermittent positive pressure breathing (IPPB) versus NE without IPPB. Primary outcome was change in croup score post-treatment. Secondary outcomes were rate and duration of intubation and hospitalization, croup return visit, parental anxiety and side effects.Data collection and analysisTwo authors independently identified potentially relevant studies by title and abstract (when available) and examined relevant studies using a priori inclusion criteria, followed by methodologic quality assessment. One author extracted data while the second checked accuracy. We performed standard statistical analyses.Main resultsEight studies (225 participants) were included. NE was associated with croup score improvement 30 minutes post-treatment (three RCTs, standardized mean difference (SMD) -0.94; 95% confidence interval (CI) -1.37 to -0.51; I2 statistic = 0%). This effect was not significant two and six hours post-treatment. NE was associated with significantly shorter hospital stay than placebo (one RCT, mean difference -32.0 hours; 95% CI -59.1 to -4.9). Comparing racemic and L-epinephrine, no difference in croup score was found after 30 minutes (SMD 0.33; 95% CI -0.42 to 1.08). After two hours, L-epinephrine showed significant reduction compared with racemic epinephrine (one RCT, SMD 0.87; 95% CI 0.09 to 1.65). There was no significant difference in croup score between administration of NE via IPPB versus nebulization alone at 30 minutes (one RCT, SMD -0.14; 95% CI -1.24 to 0.95) or two hours (SMD -0.72; 95% CI -1.86 to 0.42).Authors' conclusionsNE is associated with clinically and statistically significant transient reduction of symptoms of croup 30 minutes post-treatment. Evidence does not favor racemic epinephrine or LE, or IPPB over simple nebulization.Plain Language SummaryNebulized epinephrine for croup in childrenCroup is a common childhood illness that is usually caused by a viral infection. Symptoms of croup include a hoarse voice, a 'barking' cough and noisy breathing. These symptoms are the result of swelling that occurs in the area of the windpipe (trachea) just below the voice box (larynx). Although most cases of croup are mild and resolve on their own, occasionally the swelling can be severe enough to cause difficulty in breathing. In these children, epinephrine (also called adrenaline) is a medication that is inhaled as a mist to temporarily shrink the swollen area in the trachea.This review looked at trials of inhaled epinephrine for the treatment of children with croup. Compared to no medication, inhaled epinephrine improved croup symptoms in children at 30 minutes following treatment (three studies, 94 children). This treatment effect disappeared two hours after treatment (one study, 20 children). However, children's symptoms did not become worse than prior to treatment. No study measured adverse events. This review is comprised of only eight studies and the number of included children was small (225). Few studies examined similar outcomes, therefore data could often not be pooled and conclusions are based on one or few studies.
    Evidence-Based Child Health A Cochrane Review Journal 07/2012; 7(4). DOI:10.1002/ebch.1856