AED
study shows that the device is easy to use.
February
2005, MERGINET—
Laypersons need only minimal training
to
adequately perform audio-prompted cardiopulmonary resuscitation
(CPR) and to
effectively use external defibrillators, according to findings
of two
recent studies.
One
study, in the February 2005 Emergency Medicine Journal , involved
24 laypersons, aged 19 to 52 years, whose only knowledge of CPR
came
from media depictions. The laypersons performed CPR on a Laerdal
Resusc®i
Anne manikin and attached Laerdal Heartstart® First Aid Automatic
External Defibrillator (AED). The 12 who performed CPR without
using audio
prompts did compressions at a rate of 52 per minute. About 15
percent of
them did correct ventilations, and less than 25 percent used correct
depth and compression position. The remaining 12 subjects did
CPR using
the audio prompts and did compressions at a rate of 87 per minute.
About
51 percent of these ventilations were correct, but less than 20
percent
performed compressions at the correct position and depth.
When
the initial no-prompt group was re-evaluated while using audio
prompts, CPR performance improved somewhat—compression rate
was 91 per
minute and 47 percent of ventilations were correct. The other
group showed
similar efficacy when they repeated their CPR evaluation without
audio
prompts. But in both groups, only about 25 percent showed correct
positioning and depth of compressions.
The
volunteers then received CPR training, according to the New Zealand
Resuscitation Council's CPR guidelines for laypeople, until they
performed compressions between 90 and 110 per minute and provided
correct
ventilations and compressions 60 percent of the time. When researchers
reassessed the group's CPR skills eight weeks later, the now-trained
volunteers performed compressions at rates between 93 and 99 per
minute, and
about 66 to 77 percent did ventilations correctly. And while 73
percent
of the volunteers stated they were more confident performing CPR
with
the audio prompts, less than 30 percent used correct compression
position and depth even after training.
The
authors suggest that significant improvements in the depth and
volume of compressions and ventilations may require future audio
prompts
that give better instruction, monitor performance, and provide
correctional feedback.
A
second study, in the February 2005 Critical Care, evaluated 236
first-year medical students—of whom about 12 percent were
EMTs, paramedics
and nurses—on their AED performance before and after receiving
15
minutes of prespecified usage instructions using the Medtronic
Physio-Control® LIFEPAK® CR-T AED trainer during a mock
cardiac arrest with the
Laerdal Resusci® Anne manikin.
The
preinstruction evaluation showed a mean 81.2 second time to shock,
correct pad placement in slightly more than 85 percent, and adequate
safety in about 94 percent. After instruction, the time to shock
decreased to 56.8 seconds, almost 93 percent correctly placed
the pads, and 97
percent displayed adequate safety.
The
authors conclude that laypersons need only minimal background
instruction to safely and quickly use an AED. They add that all
tested
volunteers in this study delivered a shock in less than one minute
after
minimal AED instruction, and advocate the use of simple instructions
for
public access defibrillation programs.