Hypothermia for neuroprotection in adults after cardiopulmonary resuscitation

 

Abstract

Background

Good neurologic outcome after cardiac arrest is hard to achieve. Interventions during the resuscitation phase and treatment within the first hours after the event are critical. Experimental evidence suggests that therapeutic hypothermia is beneficial, and a number of clinical studies on this subject have been published.

Objectives

We performed a systematic review and meta-analysis to assess the effectiveness of therapeutic hypothermia in patients after cardiac arrest. Neurologic outcome, survival and adverse events were our main outcome parameters. We aimed to perform individual patient data analysis if data were available, and to from subgroups according to the cardiac arrest situation.

Search methods

We searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2007 Issue 1); MEDLINE (1971 to January 2007); EMBASE (1987 to January 2007); CINAHL (1988 to January 2007); PASCAL (2000 to January 2007); and BIOSIS (1989 to January 2007).

Selection criteria

We included all randomized controlled trials assessing the effectiveness of the therapeutic hypothermia in patients after cardiac arrest without language restrictions. Studies were restricted to adult populations cooled with any cooling method applied within six hours of cardiac arrest.

Data collection and analysis

Validity measures, the intervention, outcome parameters and additional baseline variables were entered into the database. Meta-analysis was only done for a subset of comparable studies with negligible heterogeneity. For these studies individual patient data were available.

Main results

Four trials and one abstract reporting on 481 patients were included in the systematic review. Quality of the included studies was good in three out of five included studies. For the three comparable studies on conventional cooling methods all authors provided individual patient data. With conventional cooling methods patients in the hypothermia group were more likely to reach a best cerebral performance categories score of one or two (CPC, five point scale; 1= good cerebral performance, to 5 = brain death) during hospital stay (individual patient data; RR, 1.55; 95% CI 1.22 to 1.96) and were more likely to survive to hospital discharge (individual patient data; RR, 1.35; 95% CI 1.10 to 1.65) compared to standard post-resuscitation care. Across all studies there was no significant difference in reported adverse events between hypothermia and control.

Authors' conclusions

Conventional cooling methods to induce mild therapeutic hypothermia seem to improve survival and neurologic outcome after cardiac arrest. Our review supports the current best medical practice as recommended by the International Resuscitation Guidelines.

 

Plain language summary

Cooling the body after cardiac arrest

To date about one tenth to a third of successfully resuscitated patients leave hospital to live an independent life again. Clinical studies have shown that this outcome can be improved by cooling the body to about 33°C for several hours after cardiac arrest. We found five randomized trials with data on a total of 481 cardiac arrest survivors. With conventional cooling methods patients were more likely to leave hospital without major brain damage and they were more likely to survive to hospital discharge. No cooling specific adverse events were reported. In summary there is currently evidence supporting the use of conventional cooling to induce mild hypothermia in cardiac arrest survivors within the first hours of restoration of spontaneous circulation.

 

摘要

背景

低體溫應用於成人心肺復甦後之神經保護

良好的神經心臟驟停後的結果是很難實現的，在事發後前幾小時的復甦階段之干預和治療十分重要。實驗證據顯示治療性低體溫是有幫助的，很多相關的臨床研究已經發表。

目標

我們進行了一項系統回顧和統合分析，評估低體溫於心臟驟停後之治療效果。神經學的預後，存活率和不良反應是我們主要預後參數。我們的目標是在資料可取得的情況下對個別病人的資料進行分析，再根據心跳驟停情況進行次分組。

搜尋策略

我們搜尋了下列資料庫： the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2007 Issue 1); MEDLINE (1971 to January 2007); EMBASE (1987 to January 2007); CINAHL (1988 to January 2007); PASCAL (2000 to January 2007); and BIOSIS (1989 to January 2007)

選擇標準

我們納入所有隨機對照試驗評估低體溫用於心臟驟停後病患之治療效果，試驗搜尋沒有語言的限制。研究只限於成年族群在心臟驟停6小時內應用任何降溫法。

資料收集與分析

信度測量，介入性治療，預後參數和相關的基礎變量被輸入到數據庫中。統合分析只針對一些異質性可忽略的比較研究。在這些研究中，個別病人的資料是可得的。

主要結論

四組臨床試驗和一個摘要包含 481個病人被納入在此系統性審查。五分之三的納入研究有良好的品質。在這三個比較傳統降溫方式的研究，研究作者提供了所有個別病人的資料。與標準復甦後照護相比，以傳統降溫法的低體溫組病患較有可能達到住院期間之最佳腦功能性分組指標的第一級或第二級(共5個等級，1 = 良好腦功能，以5 = 腦死；個別患者數據; RR為 1.55; 95％CI為 1.22至1.96)，且比較容易活到出院(個別病人的數據; RR為 1.35; 95％CI為 1.10至1.65)。在所有的研究中，低體溫組和控制組中被報告的不良反應並沒有顯著差異。

作者結論

以傳統的降溫法用於心臟驟停引起輕度治療性低體溫似乎能改善心臟驟停後的存活率和神經學預後。我們的回顧支持目前國際復甦指南建議的最好的醫療治療。

翻譯人

本摘要由臺灣大學附設醫院吳峻宇翻譯。

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

總結

心跳驟停後之身體冷卻：到目前為止約十分之一到三分之一的成功復甦病人可出院過獨立的生活。臨床研究顯示，預後可因在心臟停止後之幾小時內，將體溫冷卻至約 33 �C而提高。我們發現有5個隨機試驗共481位心臟驟停倖存者的資料。以傳統冷卻方法之患者較有可能在離院時沒有發生重大的腦損傷，也更有可能活著出院。沒有與降溫相關之不良反應被報告。總結來說，目前的證據支持在心臟驟停倖存者恢復自主循環時的頭幾個小時內，使用傳統降溫法促使輕度低體溫。