http://www.dispatch.com/health/health.php?story=dispatch/2005/11/13/20051113-A1-01.html


Humans outperform machines at CPR 
Columbus area was part of suspended 5-city trial for
lifesaving devices 
Sunday, November 13, 2005
Misti Crane 
THE COLUMBUS DISPATCH 
 

Man appears to have beaten machine. 

An automated CPR machine wasn’t faring as well as emergency
responders in saving heart-patients’ lives, so researchers
halted a study in Columbus and four other cities. 

Starting in June 2004, 16 Columbus ambulances and one each
in Worthington and Upper Arlington traveled with
battery-powered Auto-Pulse machines. The machines, approved
by the Food and Drug Administration and used regularly in
several communities, are designed to perform
cardiopulmonary resuscitation in place of a person. Many
expected them to be more effective than people. 

The study was to compare survival in 1,850 American and
Canadian patients, half of whom would receive CPR from the
machine, which straps around the patient’s chest. The other
half would be treated in the traditional fashion, with
paramedics and other emergency medical workers giving CPR. 

But after nine months of study, which included 306 patients
in the Columbus area, safety monitors alerted researchers:
Fewer machine-treated patients were leaving the hospital
alive. 

"It was just the opposite of what we would anticipate
happening," said Dr. Michael Sayre, an emergency physician
at Ohio State University Medical Center and leader of the
Columbus study. 

Sayre and his colleagues shared the results yesterday at
the American Heart Association’s annual Scientific Sessions
in Dallas. 

The study included 1,071 patients; 767 of them were
considered the "primary" group because their emergency
calls related specifically to heart problems. In that
group, 373 were treated manually and 394 with the machines.
The study included people from suburban Pittsburgh,
Seattle, Vancouver and Calgary. 

Four hours after the initial call to 911, a similar number
had survived — almost 25 percent of those who got CPR
manually and more than 26 percent of the AutoPulse group. 

The problem was how many of the 767 left the hospital
alive. About 10 percent of those initially treated manually
and less than 6 percent of those treated by machine lived
to go home. 

A spokesman for Zoll, the Massachusetts-based company that
sells AutoPulse machines, declined to comment. But a
statement issued Friday by Zoll CEO Richard A. Packer said
the trial was "disappointing because it was not completed."
Packer called the results "inconclusive." 

"We now better understand the challenges of such an effort,
and we plan further research," he said in the statement. 

Sayre said he had hoped that the consistent compressions
delivered by the machine would beat people, who are prone
to inconsistency and can tire during CPR. 

"We really wish it would work," he said, pointing out that
CPR rescues only a small percentage of heart patients. 

There’s no solid answer why the results came out as they
did, but Sayre had some theories. Training might not have
been sufficient, he said. Medics watched a video and
trained with the $14,000 machines, typically for a couple
of hours, Sayre said. The problem with that theory is that
outcomes should improve with experience, but the data show
no learning curve. 

Another possible explanation is that the time emergency
responders must spend strapping a person into the machine
and a subsequent delay in shocking them with a
defibrillator was detrimental, Sayre said. 

A more remote possibility is that the machine succeeded in
circulating more blood and oxygen but that doing so was
somehow harmful, Sayre said. 

"There could be something going on that we don’t
understand."

--- URG-L
Pour quitter URG-L, envoyez un message a la liste ([email protected]) 
avec, COMME SUJET, le mot REMOVE (rien d'autre).

Répondre à