CCM：达到目标体温的时间对心脏骤停幸存者是否重要？一项系统综述与荟萃分析

Abstract

Objectives: To identify the impact of early hypothermic temperature control (HTC) initiation and achievement on neurologic outcomes after cardiac arrest. Secondary endpoints assessed: 1) overall survival, 2) body temperature at hospital admission, 3) time taken to reach targeted temperature, and 4) adverse events. Subgroup analyses assessed: 1) HTC induction method, 2) presenting rhythms (shockable vs. nonshockable), and 3) timing of HTC initiation (during cardiopulmonary resuscitation [CPR] vs. post-return of spontaneous circulation [ROSC]).

目的：明确早期低温温度控制（hypothermic temperature control, HTC）的启动与达成对心脏骤停后神经功能预后的影响。次要终点包括：1）总体生存率；2）入院时的体温；3）达到目标体温所需时间；4）不良事件。亚组分析评估：1）HTC诱导方式；2）初始心律（可电击 vs. 不可电击）；3）HTC启动时机（心肺复苏[CPR]期间 vs. 自主循环恢复[ROSC]后）。

Data sources: PubMed, Cochrane Library, U.S. National Library of Medicine, MedRxiv, BioRxiv.

数据来源：PubMed、Cochrane Library、美国国家医学图书馆、MedRxiv、BioRxiv。

Study selection: Prospective randomized controlled trials enrolling comatose adult cardiac arrest patients that assessed the efficacy of early cooling (defined by initiation of HTC within 30 min of ROSC) against late cooling.

研究筛选：纳入对昏迷成年心脏骤停患者的前瞻性随机对照试验，比较早期降温（定义为ROSC后30分钟内启动HTC）与延迟降温的疗效。

Data extraction: Two reviewers independently conducted study selection, data extraction, and assessment of evidence quality. Full texts were jointly reviewed, with discrepancies resolved by a third reviewer through discussion and consensus.

数据提取：两名评审员独立进行研究筛选、数据提取及证据质量评估。全文经共同审阅，分歧由第三位评审员通过讨论达成共识解决。

Data synthesis: Of 7269 citations, 11 met the inclusion criteria. Early cooling did not improve neurologic outcomes (risk ratio [RR], 1.01; 95% CI, 0.94-1.14) nor survival (RR, 1.01; 95% CI, 0.92-1.11). Nasal evaporative cooling initiated during resuscitation may benefit patients with shockable rhythms (RR, 1.40; 95% CI, 1.00-1.96), while administering cold fluid during CPR was associated with a higher risk of rearrest. Cooling was initiated in the prehospital phase in ten studies, nine of which failed to achieve target temperature (32-34°C) by hospital admission. The median time to reach target temperature ranged from 38 to 360 minutes.

数据合成：在7269条引文中，11项符合纳入标准。早期降温未改善神经功能预后（风险比[RR] 1.01；95%置信区间[CI] 0.94–1.14），也未提高生存率（RR 1.01；95% CI 0.92–1.11）。在复苏期间启动的鼻腔蒸发降温可能对可电击心律患者有益（RR 1.40；95% CI 1.00–1.96），而在CPR期间输注冷液体则与再骤停风险升高相关。十项研究在院前阶段启动降温，其中九项在入院时未达到目标体温（32–34°C）。达到目标体温的中位时间为38至360分钟不等。

Conclusions: Early HTC showed no neurologic nor survival benefit in cardiac arrest survivors. Nasal evaporative cooling during CPR may benefit those with shockable rhythms. Delays in reaching the target temperature may underlie the failure of HTC. Future studies should evaluate whether achieving target temperature, for example, within 30 minutes, rapidly improves outcomes.

结论：早期HTC对心脏骤停幸存者的神经功能预后和生存率均无获益。CPR期间的鼻腔蒸发降温可能对可电击心律患者有益。达到目标体温的延迟可能是HTC未能起效的原因。未来研究应评估是否在例如30分钟内快速达到目标体温可改善预后。