Heliox for croup in children

  • Review
  • Intervention

Authors


Abstract

Background

Croup, a common acute clinical syndrome in children up to the age of six, is thought to be triggered by a viral infection, and is characterised by a varying degree of respiratory distress due to upper airway inflammation and oedema of the subglottic mucosa. Corticosteroids, now part of the standard treatment for croup, improve symptoms but it takes time for their full effect to be achieved. Meanwhile, the child remains at risk of deterioration and developing respiratory failure necessitating emergency intubation and ventilation. Helium-oxygen (heliox) inhalation has been successful in the treatment of upper airway obstruction. Anecdotal evidence suggests that heliox relieves respiratory distress in children, but it remains unclear whether there is robust evidence to support the implementation of heliox for croup into clinical practice.

Objectives

To examine the effect of heliox on relieving symptoms and distress, determined by a croup score (a tool for measuring the severity of croup) or clinical assessment variables, through comparisons with placebo or active treatment(s) in children with croup.

Search methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2) which contains the Acute Respiratory Infections (ARI) Group's Specialised Register; MEDLINE (1950 to June week 3 2009); EMBASE (1974 to 2009 week 25) and CINAHL (1982 to June 2009).

Selection criteria

Randomised controlled trials (RCTs) and quasi-RCTs comparing the effect of helium-oxygen mixtures with placebo or any active treatment in children with croup.

Data collection and analysis

Both authors independently identified and assessed citations for relevance. We assessed included trials for risk of bias using allocation concealment, blinding of intervention, completeness of outcome data, selective outcome reporting and other potential source of bias. We calculated mean differences for continuous data. We presented data not suitable for statistical analysis as descriptive data.

Main results

Two eligible RCTs were included (22 intervention, 22 controls). Neither trial compared heliox inhalation with placebo. One study compared heliox with 30% humidified oxygen whilst the other compared it to 100% oxygen with additional racaemic epinephrine nebulisation. There was no significant difference in change of croup score between intervention and control groups.

Authors' conclusions

At present there is a lack of evidence to establish the effect of heliox inhalation in the treatment of croup in children. A methodologically well-designed and adequately powered RCT is needed to assess whether there is a role for heliox therapy in the management of children with croup.

摘要

背景

氦氧治療用於兒童的哮吼

哮吼,一種常見於6歲以下兒童的嚴重臨床症候群,被認為是由病毒感染所引起,特徵是由上呼吸道發炎及聲門下黏膜水腫所造成不同程度的呼吸窘迫。皮質類固醇是現今標準治療哮吼用藥之一,可以改善症狀但需要時間效果才會完全出現。在這段時間內,兒童仍然身處於惡化和轉變為呼吸衰竭到需要緊急氣管插管和呼吸器協助的危險。氦氧(氦氧混合氣)吸入性治療曾經成功地治療上呼吸道阻塞。之前的證據顯示氦氧改善了兒童的呼吸衰竭,然而是否有足夠的證據支持在臨床上氦氧用於治療兒童的哮吼,則仍然不是很清楚。

目標

藉由比較積極治療時哮吼得分(一種測量哮吼嚴重度的評分工具)或與安慰劑組比較臨床評估項目的差異來探討氦氧對於改善兒童哮吼的症狀和窘迫的效果。

搜尋策略

我們檢索了Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009年,第2期),其中包含急性呼吸道感染(ARI)Group's Specialised Register; MEDLINE(1950年至2009年6月第3週),EMBASE(1974年2009年第25週)和CINAHL(1982年至2009年6月)。

選擇標準

比較氦氧混合氣與安慰劑或任何積極治療用於兒童哮吼的隨機對照試驗(RCTs)和半隨機對照試驗

資料收集與分析

兩位作者獨立地識別及評估引用文獻的相關性。對於納入的試驗,我們評估偏差的風險,項目包含分組是否隱匿、介入時是否blinding、結果資料是否完整、是否選擇性的結果報告和其他潛在偏差的來源。針對連續性數據,我們計算平均差異 (mean difference) 。不適合統計分析的資料則以描述性資料呈現。

主要結論

兩個合適的隨機對照試驗被納入(22個實驗組,22個對照組)。沒有試驗比較氦氧與安慰劑。其中一個研究與氦氧比較的是30%的濕氧,另一個研究比較的則是100%的氧氣合併快速腎上腺素霧化吸入性治療。結果顯示實驗組和對照組的哮吼評分並沒有顯著差異。

作者結論

目前缺乏證據確立吸入氦氧對於治療兒童哮吼的效果,需要一個方法設計完善而且有足夠效力的隨機對照試驗來評估氦氧治療在處理兒童哮吼的角色。

翻譯人

本摘要由衛生署臺北醫院張維修翻譯。

此翻譯計畫由臺灣國家衛生研究院 (National Health Research Institutes, Taiwan) 統籌。

總結

氦氧混合氣(氦氧)治療小兒哮吼:哮吼是一種常見於6歲以下兒童的急性疾病。它會導致上呼吸道阻塞並造成不同程度的呼吸窘迫。氦氧混合氣(氦氧),是一種密度比空氣及氧氣低的氣體,被認為可以提高氣流量,從而減少病態性狹窄的上呼吸道的流動阻力。因此被認為是可以改善臨床上的窘迫症狀。透過這次回朔性探討,我們發現了兩個評估氦氧在減輕兒童哮吼嚴重度的試驗。沒有研究發現氦氧治療可以顯著改善。但是這兩個試驗規模太小且有方法設計上的限制(共44人參加)。由於缺乏品質良好的試驗,目前並沒有證據來斷定是否氦氧能夠有效緩解小兒哮吼的症狀。尚需一個方法設計完善且有足夠數量參與者的試驗來評估氦氧治療在兒童哮吼是否具有角色。

Plain language summary

Helium-oxygen (heliox) treatment for croup in children

Croup is an acute illness commonly seen in children up to the age of six years. It causes upper airway obstruction resulting in varying degree of respiratory distress. Helium-oxygen (heliox), a gas with lower density than air or oxygen, is thought to improve gas flow and thus reduce flow resistance in the pathologically narrowed upper airway. This is believed to improve clinical symptoms of distress. By undertaking this review we found two trials assessing the effect of heliox on reducing symptom severity in children with croup. Neither study found a significant improvement with heliox treatment. However, both trials were small (total of 44 participants) and had a number of methodological limitations. Due to the lack of quality trials there is currently insufficient evidence to conclude whether heliox is effective in relieving symptoms in croup. A methodologically well-designed trial with a sufficient number of participants is needed to assess whether there is a role for heliox therapy in children with croup.

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