Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria.
Herlev Anaesthesia Critical and Emergency Care Science Unit (ACES), Department of Anaesthesiology, Copenhagen University Hospital Herlev-Gentofte, Copenhagen, Denmark.
Cochrane Database Syst Rev. 2023 May 22;5(5):CD004128. doi: 10.1002/14651858.CD004128.pub5.
Good neurological outcome after cardiac arrest is difficult to achieve. Interventions during the resuscitation phase and treatment within the first hours after the event are critical for a favourable prognosis. Experimental evidence suggests that therapeutic hypothermia is beneficial, and several clinical studies on this topic have been published. This review was originally published in 2009; updated versions were published in 2012 and 2016.
To evaluate the benefits and harms of therapeutic hypothermia after cardiac arrest in adults compared to standard treatment.
We used standard, extensive Cochrane search methods. The latest search date was 30 September 2022.
We included randomised controlled trials (RCTs) and quasi-RCTs in adults comparing therapeutic hypothermia after cardiac arrest with standard treatment (control). We included studies with adults cooled by any method, applied within six hours of cardiac arrest, to target body temperatures of 32 °C to 34 °C. Good neurological outcome was defined as no or only minor brain damage allowing people to live an independent life.
We used standard Cochrane methods. Our primary outcome was 1. neurological recovery. Our secondary outcomes were 2. survival to hospital discharge, 3. quality of life, 4. cost-effectiveness and 5.
We used GRADE to assess certainty.
We found 12 studies with 3956 participants reporting the effects of therapeutic hypothermia on neurological outcome or survival. There were some concerns about the quality of all the studies, and two studies had high risk of bias overall. When we compared conventional cooling methods versus any type of standard treatment (including a body temperature of 36 °C), we found that participants in the therapeutic hypothermia group were more likely to reach a favourable neurological outcome (risk ratio (RR) 1.41, 95% confidence interval (CI) 1.12 to 1.76; 11 studies, 3914 participants). The certainty of the evidence was low. When we compared therapeutic hypothermia with fever prevention or no cooling, we found that participants in the therapeutic hypothermia group were more likely to reach a favourable neurological outcome (RR 1.60, 95% CI 1.15 to 2.23; 8 studies, 2870 participants). The certainty of the evidence was low. When we compared therapeutic hypothermia methods with temperature management at 36 °C, there was no evidence of a difference between groups (RR 1.78, 95% CI 0.70 to 4.53; 3 studies; 1044 participants). The certainty of the evidence was low. Across all studies, the incidence of pneumonia, hypokalaemia and severe arrhythmia was increased amongst participants receiving therapeutic hypothermia (pneumonia: RR 1.09, 95% CI 1.00 to 1.18; 4 trials, 3634 participants; hypokalaemia: RR 1.38, 95% CI 1.03 to 1.84; 2 trials, 975 participants; severe arrhythmia: RR 1.40, 95% CI 1.19 to 1.64; 3 trials, 2163 participants). The certainty of the evidence was low (pneumonia, severe arrhythmia) to very low (hypokalaemia). There were no differences in other reported adverse events between groups.
AUTHORS' CONCLUSIONS: Current evidence suggests that conventional cooling methods to induce therapeutic hypothermia may improve neurological outcomes after cardiac arrest. We obtained available evidence from studies in which the target temperature was 32 °C to 34 °C.
心脏骤停后获得良好的神经功能预后较为困难。心脏骤停复苏阶段的干预措施和事件发生后最初几小时内的治疗对预后具有重要意义。实验证据表明，低温治疗有益，并且已经发表了多项关于该主题的临床研究。本综述最初发表于 2009 年；随后在 2012 年和 2016 年进行了更新。
评估与标准治疗相比，心脏骤停后成人接受低温治疗的益处和危害。
我们使用了标准的、广泛的 Cochrane 检索方法。最新检索日期为 2022 年 9 月 30 日。
我们纳入了比较心脏骤停后成人低温治疗与标准治疗（对照组）的随机对照试验（RCT）和准随机对照试验。我们纳入了使用任何方法冷却、在心脏骤停后 6 小时内应用、目标体温为 32°C 至 34°C 的成人的研究。良好的神经功能预后定义为无或仅有轻微脑损伤，使患者能够独立生活。
我们使用了标准的 Cochrane 方法。我们的主要结局是 1. 神经恢复。我们的次要结局是 2. 存活至出院，3. 生活质量，4. 成本效益，5. 不良事件。我们使用 GRADE 评估证据确定性。
我们发现了 12 项研究，共有 3956 名参与者报告了低温治疗对神经功能预后或存活率的影响。所有研究的质量都存在一些担忧，其中两项研究的总体偏倚风险较高。当我们将常规冷却方法与任何类型的标准治疗（包括体温 36°C）进行比较时，我们发现低温治疗组患者更有可能达到良好的神经功能预后（风险比（RR）1.41，95%置信区间（CI）1.12 至 1.76；11 项研究，3914 名参与者）。证据的确定性为低。当我们将低温治疗与预防发热或不降温进行比较时，我们发现低温治疗组患者更有可能达到良好的神经功能预后（RR 1.60，95%CI 1.15 至 2.23；8 项研究，2870 名参与者）。证据的确定性为低。当我们将低温治疗方法与 36°C 的体温管理进行比较时，两组之间没有证据表明存在差异（RR 1.78，95%CI 0.70 至 4.53；3 项研究；1044 名参与者）。证据的确定性为低。在所有研究中，接受低温治疗的患者肺炎、低钾血症和严重心律失常的发生率增加（肺炎：RR 1.09，95%CI 1.00 至 1.18；4 项试验，3634 名参与者；低钾血症：RR 1.38，95%CI 1.03 至 1.84；2 项试验，975 名参与者；严重心律失常：RR 1.40，95%CI 1.19 至 1.64；3 项试验，2163 名参与者）。证据的确定性为低（肺炎、严重心律失常）至非常低（低钾血症）。两组之间在其他报告的不良事件方面没有差异。
目前的证据表明，常规冷却方法诱导低温治疗可能改善心脏骤停后的神经功能预后。我们从目标体温为 32°C 至 34°C 的研究中获得了可用的证据。
