Intravenous drugs given as part of advanced cardiac life support failed to improve long-term survival in the first randomized controlled trial to test outcomes of this nearly universal procedure, according to a report in the November 25 issue of JAMA.

Intravenous epinephrine, atropine, and/or amiodarone are given in almost every case of out of hospital cardiac arrest in western nations, but the use of epinephrine in this setting is based almost entirely on preclinical evidence. “Because there are no randomized controlled studies showing improved survival to hospital discharge with any drugs routinely administered during CPR, we concluded such a study was warranted,” said Dr. Theresa M. Olasveengen and her associates at Oslo University Hospital.

They assessed 851 patients who required an ambulance for out-of-hospital cardiac arrest between May 2003 and April 2008. The study subjects were randomly assigned to receive standard advanced cardiac life support, which included intravenous drug administration (418 patients), or advanced cardiac life support without any intravenous drugs (433 patients).

Initially, short-term survival was better with the IV drugs (40%) than without them (25%), and more patients in the intravenous-drug group (30%) than in the no-intravenous-drug group (20%) survived to ICU admission. However, this early benefit quickly dissipated, and survival to hospital discharge – the primary outcome measure of this trial – was not significantly different between patients who received intravenous drugs (10.5%) and those who did not (9.2%).

The rates of survival with favorable neurologic outcomes also were not significantly different at 9.8% for the intravenous drug group and 8.1% for the no-intravenous-drug group, the investigators reported (JAMA 2009;302:2222-9).

In both groups, most patients who died in hospital after initial resuscitation had severe cerebral damage. It may be that intravenous drug administration represents “unproductive resuscitation of patients whose vital organ injury makes them unlikely candidates for long-term survival.”

“If present pharmacological interventions only facilitate cardiac resuscitation in patients who will ultimately experience irreversible cerebral damage, this may cause an additional burden on already overburdened ICUs,” Dr. Olasveengen and her colleagues said.

One encouraging finding was that for the highly trained paramedics in this study, administering intravenous drugs did not interfere with delivery of CPR. Some critics of drug administration have questioned whether the time-consuming and potentially distracting actions of establishing intravenous access, prepping, and administering the drugs may detract from delivery of high-quality CPR, they said.

This study was limited in that it was a single-center trial and its results may not be applicable to other emergency medical systems that have different training, infrastructure, treatment protocols, or quality of CPR. But the findings do justify undertaking larger trials of the issue, and show that it would not be unethical to withhold intravenous drugs for such a trial, they added.

Dr. Olasveengen reported receiving speakers fees from Medtronic Inc. and research support from Laerdal Medical Corp.

Copyright (c) 2009 Elsevier Global Medical News. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

据11月25日出版的《美国医学会杂志》(JAMA)报道，首项观察静脉给药作为高级心脏生命支持一部分的转归的随机对照试验表明，这种几乎全球通用的方式并不能提高患者的长期生存率。

 

在西方国家，几乎每1例院外心跳骤停的患者都会静脉应用肾上腺素、阿托品和(或)胺碘酮，但该情况下肾上腺素的应用几乎全是基于临床前证据。奥斯陆大学医院的Theresa M. Olasveengen博士及其同事们说：“因为没有随机对照试验显示心肺复苏(CPR)中的任何常规用药能提高出院时的生存率，故我们总结认为这样的一项研究是有必要的。”

 

他们评估了2003年5月~2008年4月间851例在院外发生心跳骤停需要急救的患者。这些研究对象被随机分配接受包含静脉给药的标准高级心脏生命支持(418例，静脉用药组)或不包含静脉用药的高级心脏生命支持者(433例，非静脉用药组)。

 

起初，静脉用药组的短期生存率(40%)比非静脉用药组(25%)要高，静脉用药组存活至入住重症监护病房(ICU)的患者(30%)比非静脉用药组(20%)也要多。但这种最初的优势很快便不复存在，此项试验的主要转归评价指标——静脉用药组存活至出院的患者比例 (10.5%)与非静脉用药组(9.2%)无显著性差异。

 

此项研究者报道，对于神经系统转归良好的生存者比例，静脉用药组(9.8%)与非静脉用药组(8.1%)也无显著性差异(JAMA 2009;302:2222-9)。

 

在这两组，经初步复苏后院内死亡的患者绝大多数伴有严重的脑损伤。有可能静脉用药意味着“重要脏器损伤患者的无效复苏使其无法长期存活”。

 

Olasveengen博士及其同事说：“对于那些最终会经历不可逆性脑损害的患者，如果当前药物干预只促进心脏复苏，则此发现有可能为已经不堪重负的ICU增加额外的压力”。

 

他们说：一个令人振奋的结果是，对于此研究中训练有素的护理人员来说，静脉给药并不妨碍CPR的进行。有些药物应用的评论家曾质疑，像建立静脉通道、准备并注射药物这样费时而且有可能分散注意力的工作，有可能会影响高质量CPR的实施。

 

他们补充说，此项研究的局限性在于是单中心试验，且其结果可能并不适用于其他具有不同的培训、基础设施、治疗方案和CPR质量的紧急医疗系统。但是此结果证实了进行更大规模试验的必要性，并且提示了进行这一试验时不用静脉给药并不违反伦理。

 

Olasveengen博士报告其接收了美敦力公司(Medtronic Inc.)提供的讲课费，且其研究得到了挪度医疗公司(Laerdal Medical Corp)的经费资助。

 

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