住院医师在施行CPR时高估了时间

摘要：根据研究者于本周发刊之胸腔医学期刊、以及美国胸腔医师学会第37届年会上的发表，住院医师与实习医师在施行心肺复苏术（CPR）时很可能多估了实际进行的时间。 Eisen医师表示，这对于病患预后可能有很不良的影响。CPR有严谨的步骤，且是高度时间依赖性的，要根据不同药物的作用起始时间与作用时间长度，特别是肾上腺素，以......

　　根据研究者于本周发刊之胸腔医学期刊、以及美国胸腔医师学会第37届年会上的发表，住院医师与实习医师在施行心肺复苏术（CPR）时很可能多估了实际进行的时间。
　　
　　主要研究者纽约市贝斯以色列医学中心Lewis A. Eisen医师表示，对于病患预后可能有很不良的影响。
　　
　　CPR有严谨的步骤，且是高度时间依赖性的，要根据不同药物的作用起始时间与作用时间长度，特别是肾上腺素，以及给予电击以回复可视节律最有效的时间点。Eisen医师表示，如果时间点过去了，那么CPR成功的可能性就会降低。
　　
　　在我们的医疗机构中，每月都会有一组新的专业人员负责施行急救，包括已经接受CPR模拟训练以及通过高级心脏救命术训练的住院医师与实习医师；Eisen医师与其同事在他们接受完训练后进行计时，以评估他们认为进行急救所需的时间是多少。
　　
　　Eisen医师报告，他们对于时间的认知是扭曲的，他们高估了施行的时间长度。
　　
　　每个新的团队参与施行CPR时，一位第三年的住院医师会参与急救，该场景从一位实习医师回应心跳停止的呼救开始，在事件发生后30秒钟，其他的实习医师加入，再经过30秒钟，住院医师加入，研究者中的其中一位记录流程中每个步骤所需的时间。
　　
　　在完成急救后，Eisen医师的团队要求受试者独立地写下在这次的急救过程中总共花费了多少时间。Eisen医师表示，平均下来的时间为383.6秒；平均来说，受试者认为的时间长度比实际上多了43秒，平均绝对误差为163秒，或大约是2.5分钟。
　　
　　这在认知上是很大的差异，范围从低估了286秒到高估了685秒。男性比女性容易高估时间的长度，实习医师比住院医师更容易低估了时间长度。Eisen医师表示，平均来说，我们的工作人员认为该次急救所花的时间比实际上久。
　　
　　他的评论是，文献显示，当人们在压力很大的情况之下，他们会觉得时间过得非常缓慢，或许这有部分演化上的依据，就像我们在被一只老虎攻击时，这将给我们的脑袋有时间去应付。
　　
　　纽约的研究者们指出，这种情况的缺点是，ACLS流程中许多药物的投予及技术的施行是根据时间顺序进行的。
　　
　　麦迪逊威斯康辛大学医学临床教授与肺癌中心医疗主任Steven W. Brown医师回应表示，最成功的复苏发生在当药物注射到身体之后，且必须以时间顺序先后进行。
　　
　　Brown医师表示，当我们参与急救时，我们有一个人可以负责计时，经常给我们提醒，我们正极力地同时进行许多工作，当我们专注于病患时，我们并没有注意到体内的生理时钟；他重申Eisen医师所观察到的，当我们处于负面压力的情况下，我们认为时间过得非常慢。
　　
　　我们所学到的是，我们需要码表；Brown医师表示，他并没有对Eisen医师的发现感到意外，我们无法依赖正在进行急救的人们来追踪时间，这太…当我们看到住院医师在6分钟的急救过程中错估1或2分钟，这样的差异是显著的。
　　
　　Eisen医师与Brown医师表示无相关资金上的往来。

Residents Overestimate Time When Performing CPR

By Martha Kerr
Medscape Medical News

Residents and interns are likely to overestimate how much time actually passes during cardiopulmonary resuscitation (CPR), investigators reported here this week at CHEST 2007, the American College of Chest Physicians 73rd Annual Scientific Assembly.

This could have a significant adverse effect on patient outcome, said principal investigator Lewis A. Eisen, MD, of Beth Israel Medical Center in New York City.

CPR is driven by a strict protocol that is highly time dependent and is based on the onset and duration of action of various medications, in particular epinephrine, as well as the most effective timing of the delivery of shocks to restore a viable rhythm.

If the timing is off, successful CPR is less likely to happen, Dr. Eisen said.

"At our institution, a new code team is assigned every month, consisting of residents and interns who train on manikins and who are drilled in [Advanced Cardiopulmonary Life Support; ACLS] algorithms." Dr. Eisen and colleagues timed each new group after they had finished their training to assess their concept of how much time was required to run a code.

"Their perception of time was really distorted," Dr. Eisen reported. "They overestimated how much time was involved."

Each new team participated in CPR scenarios, with a third-year resident running the code. The scenario began with 1 intern responding to a cardiac arrest. Thirty seconds after the start of the scenario, the remaining interns joined in, and 30 seconds after that, the residents entered. One of the investigators recorded the times of each step of the algorithm.

After completing the code, Dr. Eisen's team asked the subjects independently how much time they thought had elapsed during the code.

The mean scenario took 383.6 seconds. "On average, subjects felt the scenario took about 43 seconds longer than it actually had. The mean absolute error was 163 seconds, or about 2.5 minutes," Dr. Eisen said.

There was a huge variation in perception, from an underestimation of 286 seconds at one end of the range to an overestimation of 685 seconds at the other.

Men were more likely to overestimate and women were more likely to underestimate scenario time. Interns were more likely to underestimate scenario time than residents.

"On average, house staff believes that the scenario takes longer than it actually does," Dr. Eisen noted.

"The literature shows that when people are in very stressful situations, they feel like time is passing very slowly.... Maybe this has some evolutionary basis, like when we were being attacked by a tiger it gave our brains the ability to react," he commented.

This disadvantage in this situation is that the ACLS protocol requires that drugs and other maneuvers be given in a very timed-based order, the New York investigator pointed out.

"Most successful resuscitations occur when medications are given systematically and in a timely fashion," echoed Steven W. Brown, MD, medical director of the Lung Center and a clinical professor of medicine at the University of Wisconsin in Madison.

"When we run a code, we have 1 person dedicated to a time clock, giving us frequent feedback.... We're multitasking to the maximum. When we're so focused on the patient, we're not focused on internal Circadian rhythms," Dr. Brown said. He reiterated what Dr. Eisen observed, that "when we're in situations with negative stress, we think time is moving very slowly.

"The clinical lesson is that we need a time-keeper." Dr. Brown said, adding that he wasn't surprised by Dr. Eisen's findings. "We can't rely on the person running the code to keep track of the time, too.... When we're seeing residents being off by a minute or 2 in a 6-minute code, that variation is pretty significant."

Dr. Eisen and Dr. Brown have disclosed no relevant financial relationships.

CHEST 2007: American College of Chest Physicians 73rd Annual Scientific Assembly. Presented October 22, 2007.

发布日期：2008-3-26

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