Pressure modification for improving usage of continuous positive airway pressure machines in adults with obstructive sleep apnoea

 

Abstract

Background

Continuous Positive Airways Pressure (CPAP) is considered to be the cornerstone of therapy for obstructive sleep apnoea (OSA). However, compliance with this treatment is frequently poor, which may lead to ongoing symptoms of sleep disruption, daytime sleepiness and poor waking cognitive function. Mechanical interventions which involve changing the way that positive pressure is delivered, and the addition of humidification, might improve compliance.

Objectives

To determine the efficacy of pressure level modifications and additional humidification in increasing CPAP machine usage.

Search methods

We searched the Cochrane Airways Group Specialised Register (September 2008).

Selection criteria

Randomised controlled trials (RCTs) assessing interventions to improve compliance with CPAP usage. Control groups received fixed pressure CPAP.

Data collection and analysis

Two authors assessed articles for inclusion in the review and extracted data. We made attempts to obtain additional unpublished data from the trialists.

Main results

Forty-five studies met the inclusion criteria (1874 participants). Auto-CPAP (30 studies, 1136 participants): a statistically significant difference in machine usage of 0.21 hours/night (0.08 to 0.35) was observed in favour of auto-CPAP from cross-over studies. This difference is of questionable clinical significance. Pooled effect estimates from parallel group trials detected a similar sized difference for average nightly machine usage, but this was not statistically significant. Evidence from parallel group studies did not identify a statistically significant difference between pressure modes in Epworth Sleepiness Scores, but there was an overall reduction of 0.64 units with cross-over studies (-0.12 to -1.16) in favour of auto-CPAP. Parallel group studies did not identify a significant difference. More participants preferred auto-CPAP to fixed CPAP where this was measured. Bi-level PAP (six studies, 285 participants): no significant differences were observed in machine usage. One small study found no difference in preference. C-Flex (six studies, 318 participants): no significant difference was observed in machine usage. Humidification (three studies, 135 participants): there were conflicting findings between the studies. Two parallel group trials found no significant difference in machine usage, whereas a cross-over study found a significant difference.

Authors' conclusions

Improvement in average machine use of auto-CPAP was superior in studies with a cross-over design; the point estimate in parallel group trials was similar, but did not reach statistical significance. It is uncertain how use of machines in study settings relates to 'real world' use. Where preference was measured participants preferred auto-CPAP to fixed pressure CPAP. Further studies are required to assess the evidence for Bi-PAP, C-Flex^TM and humidification. The studies assembled were characterised by high machine usage in the control groups, and low withdrawal rates. Future studies need to consider the effects of treatment in participants with more mild disease, and those who struggle to accept therapy despite persistent symptoms.

 

Plain language summary

The effects of different pressure delivery interventions for improving use of continuous positive airway pressure in the treatment of obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is caused by intermittent airway closure during sleep such that airflow stops despite continued efforts to breathe. Continuous positive airways pressure (CPAP) can be an effective treatment for this condition but requires regular use, and many people cannot tolerate it, or do not use it every night. Attempts to improve compliance with treatment have included changes to the mechanical devices used to deliver airway pressure, such as auto-CPAP, bi-level PAP, expiratory pressure relief and additional humidification. We examined the evidence for these different approaches. None led to large increases in hours of use, though when asked, most participants expressed a preference for the auto-CPAP machine rather than fixed pressure. When bi-level PAP and fixed CPAP were compared, initial patient acceptance was greater for bi-level PAP in one study, but long-term usage in those accepting treatment was similar for both devices. Expiratory pressure relief (C-flex^TM) did not show improvement in hours of use and symptom scores. According to the evidence currently available, compliance with positive airway pressure therapy for OSA is similar, irrespective of the mode of delivery (e.g. fixed, auto-titrating or bi-level device).

 

摘要

背景

壓力改變以改善連續氣道正壓機器在成人阻塞性睡眠呼吸中止症的使用

連續氣道正壓(CPAP)被認為是睡眠呼吸中止症(OSA)的主要療法。然而，這種療法的遵從度不佳，因而導致不斷出現睡眠的干擾、日間嗜睡及清醒時認知功能不佳。改變正壓輸送方式的機械式介入措施以及加上濕潤處置可能會改善依從度。

目標

確認壓力水平改變及加上濕潤處置在增加CPAP機械使用的效益。

搜尋策略

我們搜尋Cochrane Airways Group Specialised Register(2008年9月)。

選擇標準

評估採用CPAP的治療措施以改善遵從度的隨機控制試驗(RCTS)。對照組使用固定壓力的CPAP。

資料收集與分析

兩名作者評估文章能否納入回顧並摘取數據。我們嘗試從研究人員處取得未被刊載的額外數據。

主要結論

有45項研究符合納入標準(1974名參與者)。AutoCPAP(30項研究，1136名參與者)：交叉研究顯示使用autoCPAP在每晚使用機器的時數在統計學上有顯著差異(0.08至0.35)。此一差異之臨床意義仍有疑問，集合平行組別試驗之結果顯示平均詢問機械使用有類似差異，但不具統計學上的意義。平行組別研究對各種壓力模式之Epworth睡眠分數並未呈現統計學上有意義的差別，但交叉研究顯示autoCPAP在整體上減少0.64單位(−0.12至−1.16)。平行組別研究並未呈顯顯著差異。較多參與者認為autoCPAP較優於固定CPAP。Bilevel PAP(6項研究，285名參與者)：機器使用未見有意義的差別。一項小規模的研究並未呈現喜好上的差異。CFlex(6項研究，318名參與者)：機器使用未見有意義的差別。濕潤處置(3項研究，135名參與者)：試驗之間呈現矛盾的結果。兩項平行組別試驗未發現機器使用有意義的差異，然而，一項交叉試驗顯示有意義的差異。

作者結論

交叉研究顯示autoCPAP較能改善平均機器使用，平行組別試驗的點估計有相似結果，但未達統計學上的意義。研究中對於機器的實際使用情況並不明確。在喜好度的測量顯示參與者認為autoCPAP優於固定壓力CPAP。有關BiPAP，CFlexTM及濕潤處置的證據仍須進一步的研究來評估。被蒐集探討的研究的共同特色是對照組有高的機器使用度及低的退出率。未來研究須考量疾病較輕的受試者的治療效果，以及縱使仍有症狀而不願接受治療的病人。

翻譯人

本摘要由中國醫藥大學附設醫院陳祖裕翻譯。

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

總結

不同壓力輸送之介入措施在改善阻塞性睡眠呼吸中止症病人對連續氣道正壓使用的效果。阻塞性睡眠呼吸中止症(OSA)是患者在睡眠時呼吸道間歇性關閉，縱使用力呼吸仍無法通氣。連續氣道正壓(CPAP)可作為此症之有效療法，但需規律使用，另有許多人無法耐受，或沒有每晚都使用。嘗試改善治療遵從度的方法包括改變輸送氣道壓力的機械式設計，如autoCPAP、bilevel PAP、呼氣壓力釋出，附加濕潤等。我們檢視這些不同處置方式的證據，並無一項可致使用時數大增，但在詢問病人時，大多數參與者表示autoCPAP機械優於固定壓力。當比較bilevel PAP及固定式CPAP時，有一項研究顯示病人在開始時的接受度以bilevel PAP較高，但經長期使用則兩項設計導致治療的接受度卻相近。呼氣壓力釋出(CFlexTM)並未呈現改善使用時數及症狀分數。根據現有的證據，無論使用何種設計(如固定式、自動式、或bilevel設計)，以正壓氣道治療阻塞性睡眠呼吸中止症之遵從度均相近。