BACKGROUND:The ongoing TANGO2 (Telephone Assisted CPR. AN evaluation of efficacy amonGst cOmpression only and standard CPR) trial is designed to evaluate whether compression-only cardiopulmonary resuscitation (CPR) by trained laypersons is noninferior to standard CPR in adult out-of-hospital cardiac arrest. This pilot study assesses feasibility, safety, and intermediate clinical outcomes as part of the larger TANGO2 survival trial.METHODS:Emergency medical dispatch calls of suspected out-of-hospital cardiac arrest were screened for inclusion at 18 dispatch centers in Sweden between January 1, 2017, and March 12, 2020. Inclusion criteria were witnessed event, bystander on the scene with previous CPR training, age above 18 years of age, and no signs of trauma, pregnancy, or intoxication. Cases were randomized 1:1 at the dispatch center to either instructions to perform compression-only CPR (intervention) or instructions to perform standard CPR (control). Feasibility included evaluation of inclusion, randomization, and adherence to protocol. Safety measures were time to emergency medical service dispatch CPR instructions, and to start of CPR, intermediate clinical outcome was defined as 1-day survival.RESULTS:Of 11 838 calls of suspected out-of-hospital cardiac arrest screened for inclusion, 2168 were randomized and 1250 (57.7%) were out-of-hospital cardiac arrests treated by the emergency medical service. Of these, 640 were assigned to intervention and 610 to control. Crossover from intervention to control occurred in 16.3% and from control to intervention in 18.5%. The median time from emergency call to ambulance dispatch was 1 minute and 36 s (interquartile range, 1.1–2.2) in the intervention group and 1 minute and 30 s (interquartile range, 1.1–2.2) in the control group. Survival to 1 day was 28.6% versus 28.4% (P=0.984) for intervention and control, respectively.CONCLUSIONS:In this national randomized pilot trial, compression-only CPR versus standard CPR by trained laypersons was feasible. No differences in safety measures or short-term survival were found between the 2 strategies. Efforts to reduce crossover are important and may strengthen the ongoing main trial that will assess differences in long-term survival.REGISTRATION:URL: https://www.clinicaltrials.gov; Unique identifier: NCT02401633.

中文翻译：

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对院外心脏骤停中经过培训的外行人员进行仅按压或标准心肺复苏：瑞典的一项全国随机试验

背景：正在进行的 TANGO2（电话辅助 CPR。仅按压和标准 CPR 的疗效评估）试验旨在评估由经过培训的外行人员进行的仅按压心肺复苏 (CPR) 是否不劣于成人院外的标准 CPR心脏停搏。这项试点研究评估了可行性、安全性和中期临床结果，作为更大规模的 TANGO2 生存试验的一部分。方法：从 1 月 1 日到2017 年和 2020 年 3 月 12 日。纳入标准为目击事件、现场旁观者接受过心肺复苏培训、年龄超过 18 岁、无外伤、怀孕或中毒迹象。在调度中心，病例按照 1:1 的比例随机分配，接受仅按压心肺复苏（干预）的指示或执行标准心肺复苏（控制）的指示。可行性包括评估纳入、随机化和遵守方案。安全措施是紧急医疗服务派遣 CPR 指示的时间，以及开始 CPR 的时间，中间临床结果定义为 1 天生存率。 结果：在筛选纳入的 11 838 个疑似院外心脏骤停的呼叫中，有 2168 个被纳入随机分组，其中 1250 名（57.7%）因院外心脏骤停而接受紧急医疗服务治疗。其中，640 人被分配为干预组，610 人被分配为对照组。从干预到控制的交叉发生率为 16.3%，从控制到干预的交叉发生率为 18.5%。干预组从紧急呼叫到救护车派遣的中位时间为 1 分 36 秒（四分位距，1.1-2.2），对照组为 1 分 30 秒（四分位距，1.1-2.2）。干预组和对照组的 1 天生存率分别为 28.6% 和 28.4%（P = 0.984）。结论：在这项全国随机试点试验中，由经过培训的外行人员进行单纯按压心肺复苏与标准心肺复苏是可行的。两种策略之间没有发现安全措施或短期生存差异。减少交叉的努力很重要，并且可能会加强正在进行的主要试验，该试验将评估长期生存的差异。注册：URL：https://www.clinicaltrials.gov；唯一标识符：NCT02401633。