Doctors May Be Ending CPR Efforts Too Soon, Study Says
When a hospital patient goes into cardiac arrest, one of the most difficult questions facing the medical team is how long to continue cardiopulmonary resuscitation. Now a new study involving hundreds of hospitals suggests that often doctors may be giving up too soon.
The study found that patients have a better chance of surviving in hospitals that persist with CPR for just nine minutes longer, on average, than hospitals where efforts are halted earlier.
2010年，布鲁克林的玛摩利医院(Maimonides Medical Center)医护人员正在抢救一名心跳骤停的患者。
There are no clear, evidence-based guidelines for how long to continue CPR efforts.
The findings challenge conventional medical thinking, which holds that prolonged resuscitation for hospitalized patients is usually futile and that when patients do survive, they often suffer permanent neurological damage. To the contrary, the researchers found that patients who survived prolonged CPR and left the hospital fared as well as those who were quickly resuscitated.
The study, published online Tuesday in The Lancet, is one of the largest of its kind and one of the first to link duration of CPR efforts with survival rates. It should prompt hospitals to review their practices and to consider changes if their resuscitation efforts fall short, several experts said.
Between one and five of every 1,000 hospitalized patients suffer a cardiac arrest. Generally they are older and sicker than non-hospital patients who suffer cardiac arrest, and their outcomes are generally poor, with fewer than 20 percent surviving to be discharged from the hospital.
Dr. Zachary D. Goldberger, lead author of the new study, and his colleagues gathered data from the world’s largest registry of in-hospital cardiac arrest, maintained by the American Heart Association, identifying 64,339 patients who went into cardiac arrest at 435 hospitals in the United States between 2000 and 2008.
这项新研究的首席作者是扎卡里·D·戈德伯格(Zachary D. Goldberger)医生。他和同事们从美国心脏协会(American Heart Association)保持的全球最大住院患者心脏骤停病例数据库收集数据，从中辨别出逾6.4万名在2000年到2008年期间在美国435家医院发生心脏骤停的患者。
The researchers examined adult hospital patients in regular beds or intensive care units, excluding patients in the emergency room or who suffered arrest during procedures. They calculated the median duration of resuscitation efforts for the non-survivors rather than the survivors, in order to measure a hospital’s tendency to engage in more prolonged resuscitation efforts.
One of the first surprises was the significant variation in duration of CPR among the hospitals, ranging from a median of 16 minutes in hospitals spending the least amount of time trying to revive patients to a median of 25 minutes among those spending the most — a difference of more than 50 percent.
The researchers initially thought they would find that some patients were being subjected to protracted resuscitation efforts in vain, said the senior author, Dr. Brahmajee Nallamothu, an associate professor at the University of Michigan and a cardiologist at the Ann Arbor VA Medical Center.
该研究的资深作者布拉马基·纳拉莫苏(Brahmajee Nallamothu)医生表示，研究人员最初以为，他们将发现一些患者被无意义地实施长时间的心肺复苏术。纳拉莫苏是密歇根大学(University of Michigan)副教授，弗吉尼亚安娜堡医学中心(Ann Arbor VA Medical Center)心脏病专家。
But as it turned out, those extra minutes made a positive difference. Patients in hospitals with the longest CPR efforts were 12 percent more likely to survive and go home from the hospital than those with the shortest times.
Dr. Nallamothu and his colleagues also found that “survivors at hospitals where attempts continued for longer didn’t seem to have more neurological difficulties at the time of discharge,” he said.
The patients who got the most added benefit from prolonged CPR were those whose conditions do not respond to defibrillation, or being shocked The extra time spent on prolonged CPR may give doctors time to analyze the situation and try different interventions, they said.
“You can keep circulating blood and oxygen using CPR for sometimes well over 30 minutes and still end up with patients who survive and, importantly, have good neurological survival,” said Dr. Jerry P. Nolan, a consultant in anesthesia and critical care medicine at Royal United Hospital NHS Trust in Bath, England, who wrote a commentary accompanying the article.
“有时，你可以利用远远超过30多分钟的CPR抢救，持续给患者输氧和保持血液循环，患者最终还是有可能生存，而且更重要的是，他们的神经功能完好，”位于英格兰巴斯、隶属英国国民医疗保健服务(NHS)体系的皇家联合医院(Royal United Hospital)的麻醉及危重病医学顾问医师杰里·P·诺兰(Jerry P. Nolan)医生说道，他为这篇论文写了评语。
Dr. Stephen J. Green, associate chair of cardiology at North Shore-Long Island Jewish Health System, who was not involved in the study, said hospitals might have to modify their practices in light of the new research.
北岸—长岛犹太裔卫生系统(North Shore-Long Island Jewish Health System)心脏病学副主任、未参加这项研究的斯蒂芬·J·格林(Stephen J. Green)医生表示，根据这项新研究，医院可能必须修订各自的程序。
“You don’t want to be on the low end of this curve,” Dr. Green said. “Hospitals that are outliers should reassess what they’re doing and think about extending the duration of their CPR.”
Still, he and other experts worried that the new findings could lead to protracted efforts to resuscitate patients for whom it is inappropriate because they are at the end of their lives or for other reasons.
“There isn’t going to be a magic number,” Dr. Green said. “If you’re in there 10 to 15 minutes, you need to push higher, but as you get up higher and higher, you get to the point of very little return.”
The study authors acknowledge that their research does not indicate that longer CPR is better for every patient.
“The last thing we want is for the take-home message to be that everyone should have a long resuscitation,” Dr. Goldberger said. “We’re not able to identify an optimal duration for all patients in the hospital.”