Hyperbaric oxygen therapy for the adjunctive treatment of traumatic brain injury

 

Abstract

Background

Traumatic brain injury is a common health problem with significant effect on quality of life. Hyperbaric oxygen therapy (HBOT) has been suggested to improve oxygen supply to the injured brain and reduce the volume of brain that will ultimately perish. It is postulated that adding HBOT to the standard intensive care regimen may reduce patient death and disability.

Objectives

To assess the benefits and harms of adjunctive HBOT for traumatic brain injury.

Search methods

We searched CENTRAL, MEDLINE, EMBASE, CINAHL and DORCTHIM databases; the searches were last updated in January 2009. We searched reference lists of eligible articles, handsearched relevant journals and contacted researchers.

Selection criteria

Randomised studies comparing the effect of therapeutic regimens which included HBOT with those that did not, on patients with traumatic brain injury.

Data collection and analysis

Three authors independently evaluated trial quality and extracted data.

Main results

Five trials were included in this review (229 participants receiving HBOT and 213 in the control group). There was no significantly altered risk of unfavourable outcome with HBOT (relative risk (RR) for unfavourable outcome with HBOT 0.51, 95% CI 0.25 to 1.08, P = 0.08). Pooled data show a significant reduction in the risk of dying when HBOT was added to the treatment regimen (RR 0.69, 95% CI 0.54 to 0.88, P = 0.003) and suggests we would have to treat seven patients to avoid one extra death (number-needed-to-treat (NNT) 7, 95% CI 4 to 22). One trial suggested favourably lower intracranial pressure in patients receiving HBOT in whom myringotomies had been performed (weighted mean difference (WMD) with myringotomy -8.2 mmHg, 95% CI -14.7 mmHg to -1.7 mmHg, P = 0.01); another trial reported a significantly better GCS in patients treated with HBOT. There was a reported incidence of 13% for significant pulmonary impairment in the HBOT group versus 0% in the non-HBOT group (P = 0.007).

Authors' conclusions

In people with traumatic brain injury, while the addition of HBOT may reduce the risk of death, there is little evidence that the survivors have a good outcome. The routine application of HBOT to these patients cannot be justified from this review. Given the modest number of patients, methodological shortcomings of included trials and poor reporting, the result should be interpreted cautiously. An appropriately powered trial of high methodological rigour is required to define which patients, if any, can be expected to benefit most from HBOT.

 

Plain language summary

Does hyperbaric oxygen therapy improve the survival and quality of life in patients with traumatic brain injury?

Traumatic brain injury is a major cause of death and disability. Not all damage to the brain occurs at the moment of injury; reduction of the blood flow and oxygen supply to the brain can occur afterwards and cause further secondary brain damage, which is itself an important cause of avoidable death and disability. In the early stages after injury it is therefore important that efforts are made to minimise secondary brain damage to provide the best chances of recovery.

Hyperbaric oxygen therapy (HBOT) has been proposed as a treatment for minimising secondary brain damage by improving the oxygen supply to the brain. Patients undergoing HBOT are placed inside a specially designed chamber in which 100% oxygen is delivered at a greater than normal atmospheric pressure. It is sometimes used as a treatment to increase the supply of oxygen to the injured brain, in an attempt to reduce the area of brain that will die.

The effectiveness of HBOT on the recovery of brain-injured patients is uncertain. There is also concern regarding potential adverse effects of the therapy, including damage to the ears, sinuses and lungs from the effects of pressure, temporary worsening of short-sightedness, claustrophobia and oxygen poisoning.

In an attempt to address the uncertainty surrounding the use of HBOT, the authors of this review identified all high quality trials investigating the effectiveness of HBOT in traumatically brain-injured patients of all ages.

The authors found five eligible studies involving 442 patients. The combined results suggest that HBOT reduces the risk of death; however, there is no good evidence that these survivors have improved outcome in terms of quality of life. It is possible, therefore, that the overall effect of hyperbaric oxygen is to make it more likely that people will survive with severe disability after such injuries. The authors conclude that the routine use of HBOT in brain-injured patients cannot be justified by the findings of this review.

Due to the small number of trials with a limited number of participants, it is not possible to be confident in the findings; further large, high quality trials are required to define the true extent of benefit from HBOT.

 

摘要

背景

高壓氧療法用於腦外傷的輔助治療

腦外傷是一種常見且對生活品質具有重要影響的健康問題。高壓氧(Hyperbaric oxygen therapy (HBOT)被認為可以促進腦外傷者的氧氣供給，並減少腦部最終死亡的體積。據推測，標準的加護照謢方案加入高壓氧療法也許會造成病患死亡及失能人數減少而達到增加腦部保存的效果。

目標

評估輔助性的高壓氧療法對於治療腦外傷的效益與傷害。

搜尋策略

我們檢索CENTRAL，MEDLINE，EMBASE，CINAHL及DORCTHIM 電子資料庫；檢索最後一次更新是在2006年4月。我們也檢索合格文章的參考文獻，人工檢索相關的期刊並連絡該領域的研究人員。

選擇標準

比較有包含高壓氧療法與排除高壓氧療法(有或沒有假手術療法)的治療方案對於腦外傷患者的效果。

資料收集與分析

三名作者分別獨立採用具有效度的OxfordScale評估相關試驗的品質並從納入的試驗中摘錄資料。

主要結論

這篇回顧包含四篇試驗(382名病患，其中199人接受高壓氧療法，而183人為對照)。有傾向有利結果的趨勢，包括全康復，Glasgow分數為1或2，或回復日常生活的正常活動(高壓氧療法者有良好結果的relative risk [RR]為1.94，95% confidence interval [CI]為0.92至4.08，P = 0.08)，但沒有顯著增加。加總的資料來自三篇試驗，共327名病患的死亡率，顯示當高壓氧療法加入治療方案時死亡的風險有顯著減少(RR為0.69，95% CI為0.54至0.88，P = 0.003)。研究間的異質性不高(I2 = 0%)，且敏感度分析顯示退出研究者的分配並未影響結果。這篇分析認為我們必須治療七名病患以避免一人的額外死亡(需要被治療的病人數(number needed to treat)[NNT] 7，95% CI為4至22)。一篇試驗認為接受高壓氧療法有利於降低那些被施與鼓膜切開術病患的顱內壓(WMD with myringotomy為−8.2 mmHg，95% CI為−14.7 mmHg至−1.7 mmHg，P = 0.01)，而兩篇試驗指出接受高壓氧療法組有顯著的13%肺部損傷發生率，相較於無高壓氧療法組其發生率為0%(P = 0.007)。

作者結論

在腦外傷患者中，加入高壓氧療法治療可以顯著減少死亡風險，然而，僅少數的證據指出可以讓更多的存活者有良好的結果。這篇回顧發現無法合理的對這些病患常規應用高壓氧療法。有鑒於病患人數不多，方法學缺點與報告結果不佳，這項結果應謹慎解釋。需要一個方法學嚴謹之適當檢定力的試驗，以確定那些病患(如果有的話)因為高壓氧療法可以被期待獲得最有利的結果。

翻譯人

本摘要由高雄榮民總醫院金沁琳翻譯。

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

總結

高壓氧可以改善腦外傷病患的存活與生活品質?腦外傷是死亡與失能的主要原因。並非所有對於腦部的外傷都是發生在受傷的瞬間；事後會發生血流量與供應到腦部的氧氣減少且造成進一步的二次傷害，其本身就是一個重要之避免死亡與失能的原因。因此受傷後的早期治療是很重要的以減少二次腦部傷害，以提供復原的最佳機會。高壓氧被建議作為減少二次腦部傷害的治療，藉著改善腦部氧氣的供應。經歷高壓氧療法的患者被置於一個特殊設計的氣艙內，其內在大於一大氣壓下供給100%的氧氣。有時它被用來作為增加供應腦損傷氧氣的治療方式，以期減少腦部壞死的區域。高壓氧療法對於腦損傷病患復原的效果尚不確定。另外也有關於療法可能造成副作用的考量，包括因為壓力的影響所造成的耳朵，鼻竇與肺部傷害，短暫的近視惡化，幽閉恐懼症與氧氣中毒。試圖解決使用高壓氧療法的不確定性，這篇回顧的作者確定了所有高品質的試驗，其研究高壓氧療法對於所有年齡層之腦外傷病患的效果。作者發現四篇合格的研究，包含382名病患。合併的結果認為高壓氧療法可以減少死亡風險，然而沒有證據顯示這些存活者的生活品質有改善。因此，可能高壓氧的整體作用是對於在這種損傷後存活有嚴重失能的患者。依據這篇回顧的結果，作者推論腦損傷患者常規使用高壓氧療法是不合理的。由於只有有限研究對象的少量小型試驗，因此這些結果可能不可信；需要進一步大型，高品質的試驗以確定高壓氧療法其效益的真實範圍。