Intervention Review
Oxygen therapy for acute myocardial infarction
Editorial Group: Cochrane Heart Group
Published Online: 16 JUN 2010
Assessed as up-to-date: 27 FEB 2010
DOI: 10.1002/14651858.CD007160.pub2
Copyright © 2010 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
Database Title
Additional Information
How to Cite
Cabello JB, Burls A, Emparanza JI, Bayliss S, Quinn T. Oxygen therapy for acute myocardial infarction. Cochrane Database of Systematic Reviews 2010, Issue 6. Art. No.: CD007160. DOI: 10.1002/14651858.CD007160.pub2.
Publication History
- Publication Status: New
- Published Online: 16 JUN 2010
Abstract
Background
Oxygen (O
Objectives
To review the evidence from randomised controlled trials to establish whether routine use of inhaled oxygen in acute myocardial infarction (AMI) improves patient-centred outcomes, in particular pain and death.
Search methods
The following bibliographic databases were searched (to the end of February 2010): Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, MEDLINE In-Process, EMBASE, CINAHL, LILACS and PASCAL, British Library ZETOC, Web of Science ISI Proceedings. Experts were also contacted to identify any studies. No language restrictions were applied.
Selection criteria
Randomised controlled trials of people with suspected or proven AMI, less than 24 hours after onset, in which the intervention was inhaled oxygen (at normal pressure) compared to air and regardless of co-therapies provided these were the same in both arms of the trial.
Data collection and analysis
Two review authors independently reviewed the titles and abstracts of identified studies to see if they met the inclusion criteria and independently undertook the data extraction. The quality of studies and the risk of bias were assessed according to guidance in the Cochrane Handbook. The primary outcomes were death, pain and complications. The measure of effect used was the relative risk (RR).
Main results
Three trials involving 387 patients were included and 14 deaths occurred. The pooled RR of death was 2.88 (95% CI 0.88 to 9.39) in an intention-to-treat analysis and 3.03 (95% CI 0.93 to 9.83) in patients with confirmed AMI. While suggestive of harm, the small number of deaths recorded meant that this could be a chance occurrence. Pain was measured by analgesic use. The pooled RR for the use of analgesics was 0.97 (95% CI 0.78 to 1.20).
Authors' conclusions
There is no conclusive evidence from randomised controlled trials to support the routine use of inhaled oxygen in patients with acute AMI. A definitive randomised controlled trial is urgently required given the mismatch between trial evidence suggestive of possible harm from routine oxygen use and recommendations for its use in clinical practice guidelines.
Plain language summary
Routine use of oxygen in people who have had a heart attack
Most guidelines for the treatment of people who are having a heart attack recommend that the patient should be given oxygen to breathe. We looked for the evidence to support this practice by searching for randomised controlled trials that compared the outcomes in patients given oxygen to the outcomes for patients given normal air to breathe. We were primarily interested in seeing whether there was a difference in the number of people who died but we also looked at whether administering oxygen reduced pain.
We found three randomised controlled trials that compared one group given oxygen to another group given air. These trials involved a total of 387 patients of whom 14 died. Of those who died, nearly three times as many people known to have been given oxygen died compared to those known to have been given air. However, because the trials had few participants and few deaths this result does not necessarily mean that giving oxygen increases the risk of death. The difference in numbers may have occurred simply by chance. Nonetheless, since the evidence suggests that oxygen may in fact be harmful, we think it is important to evaluate this widely used treatment in a large trial, as soon as possible, to make sure that current practice is not causing harm to people who have had a heart attack.
Resumen
Antecedentes
Oxigenoterapia para el infarto agudo de miocardio
Aunque el oxígeno (O
Objetivos
Examinar las pruebas de los ensayos controlados aleatorios para establecer si el uso sistemático de oxígeno inhalado en el infarto agudo de miocardio (IAM) mejora los resultados del paciente, especialmente, el dolor y la muerte.
Estrategia de búsqueda
Se hicieron búsquedas en las siguientes bases de datos bibliográficas (hasta el final de febrero 2010): Registro Cochrane Central de Ensayos Controlados (Cochrane Central Register of Controlled Trials, CENTRAL) (The Cochrane Library), MEDLINE, MEDLINE InProcess, EMBASE, CINAHL, LILACS y PASCAL, British Library ZETOC, Web of Science ISI Proceedings. También se estableció contacto con los expertos para identificar cualquier estudio. No se aplicó ninguna restricción en cuanto al idioma.
Criterios de selección
Ensayos controlados aleatorios de pacientes con IAM presunto o comprobado, de menos de 24 horas de evolución, en que la intervención fue el oxígeno inhalado (a presión normal) comparado con el aire, y de forma independiente de otros tratamientos concomitantes, siempre que fuesen los mismos cotratamienos en ambos brazos del ensayo.
Obtención y análisis de los datos
Dos revisores examinaron de forma independiente los títulos y los resúmenes de los estudios identificados para comprobar si satisfacían los criterios de inclusión y, del mismo modo, extrajeron los datos. Se evaluó la calidad de los estudios y el riesgo de sesgo según la orientación en el Manual Cochrane. Las medidas de resultado primarias fueron muerte, dolor y complicaciones. La medida de efecto usada fue el riesgo relativo (RR).
Resultados principales
Se incluyeron tres ensayos que incluían a 387 pacientes y se produjeron 14 muertes. El RR agrupado de muerte fue de 2,88 (IC del 95%: 0,88 a 9,39) en un análisis por intención de tratar (intentiontotreat anlaysis) y 3,03 (IC del 95%: 0,93 a 9,83) en pacientes con IAM confirmado. Aunque estos datos sugieren cierto daño, el número pequeño de muertes registradas hace que pueda pensarse en un evento ocasional. El dolor se midió mediante el uso de analgésicos. El RR agrupado del uso de analgésicos fue de 0,97 (IC del 95%: 0,78 a 1,20).
Conclusiones de los autores
No existen pruebas concluyentes derivadas de los ensayos controlados aleatorios que apoyen el uso sistemático del oxígeno inhalado en pacientes con IAM. Se requiere de manera urgente un ensayo controlado aleatorio definitivo, dada la desigualdad entre las pruebas de ensayos que sugieren un posible efecto perjudicial con el uso sistemático de oxígeno y dadas las recomendaciones para su uso en la práctica clínica.
Traducción
Traducción realizada por el Centro Cochrane Iberoamericano
摘要
背景
急性心肌梗塞的氧氣治療
氧氣 (O2) 被廣泛地建議用於治療心肌梗塞，但有一篇敘述性的文獻回顧指出此舉可能是弊多於利。系統性的文獻回顧則認為，目前尚未有充分的證據可確認氧氣是否會減少、增加或根本不影響心臟缺血的情形或心肌梗塞的面積。
目標
回顧隨機對照試驗所得的證據，以確立吸入氧氣在急性心肌梗塞 (AMI) 的例行性使用是否能促進以病人為中心的相關預後，特別是在疼痛與死亡方面。
搜尋策略
至2010年2月底，搜尋了下列的書目資料庫：Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library) 、MEDLINE、MEDLINE InProcess、EMBASE、CINAHL、LILACS and PASCAL、British Library ZETOC、Web of Science ISI Proceedings，並聯繫專家以找出相關研究。文獻搜尋不受語言限制。
選擇標準
隨機對照試驗，研究對象為發病24小時內的AMI疑似或確定患者，介入措施為吸入氧氣 (常壓下) 對照於一般空氣，且不論其他合併治療為何，在試驗的兩個組別皆要相同。
資料收集與分析
兩位回顧作者獨立地檢視研究的標題與摘要是否符合篩選標準，並各自擷取資料。研究的品質和偏誤風險依照Cochrane Handbook的標準來評估。主要結果指標為死亡、疼痛和併發症，以相對危險性 (RR) 來判定影響程度。
主要結論
共選取了3個試驗，包括387位病患，有14位患者死亡。死亡的合併RR以治療意向分析法 (intentiontotreat analysis) 計算為2.88 (95% 信賴區間CI: 0.88 – 9.83) ，而在AMI確診病患間則是3.03 (95% CI: 0.93 – 9.83) ；雖然結果顯示氧氣有害，但死亡者僅為少數因此可能為巧合。疼痛是以鎮痛劑的使用來測量的，使用鎮痛劑的合併RR為0.97 (95% CI: 0.78 – 1.20) 。
作者結論
隨機對照試驗無法提供確切的證據來支持吸入性氧氣在急性AMI患者的例行性使用。目前的隨機試驗證據暗示例行性的氧氣使用有害，與臨床診療指引的建議不符，因此急需設計完善的隨機對照試驗來進一步釐清。
翻譯人
本摘要由劉家毓翻譯。
此翻譯計畫由臺灣國家衛生研究院 (National Health Research Institutes, Taiwan) 統籌。
總結
心臟病發者的例行性氧氣使用：大部分的臨床指引都建議，對於心臟病發患者應該給予純氧呼吸。我們搜尋了比較給予病患純氧和一般空氣的隨機對照試驗，以探討現有證據是否支持這樣的慣例。我們首要關注的問題是病患死亡數在兩組是否有差別，也檢視了給予純氧是否能減輕疼痛。我們一共找到3個隨機對照試驗是比較給予純氧和一般空氣，這些試驗共包括387位病患，其中有14位死亡。死亡者中，接受純氧者是接受一般空氣者的將近三倍，但因這些試驗的受試者較少、死亡者更少，所以這樣的結果並不盡然代表給予純氧會增加死亡的風險，兩組的死亡數差異可能為隨機的巧合。儘管現有證據顯示純氧可能有害，這個慣例目前仍廣泛地施行，我們認為應盡快地進行一個大型試驗來確定其是否對心臟病發患者有害。