A simple prediction rule might help EMTs make a difficult decision.
Automated external defibrillators (AEDs) have improved the chances of successful
resuscitation for out-of-hospital cardiac arrest. However, emergency
medical technicians (EMTs) face decisions about
how long to continue their efforts with AEDs, given a
patient’s likelihood of survival and the dangers and costs of
emergency transport.
In a Canadian study of 1240 patients (mean age,
69; 69% men) with out-of-hospital cardiac arrest who were treated by
EMTs with AEDs,
investigators sought to validate their previously proposed
prediction rule: Termination of resuscitation should be considered
if spontaneous circulation does not return before transport is
initiated, if no
Of the patients, 94.5% had no return of
spontaneous circulation, 70.0% received no shocks, and 90.3% had
arrests not witnessed by the EMTs. The
median emergency response time was 8.0 minutes. The prediction rule
recommended termination of resuscitation for 776 patients and
emergency transport for 464 patients; 772 of the
termination-recommended patients died (99.5% positive predictive
value), and 37 of the transport-recommended patients survived (8.0%
negative predictive value). The rule’s sensitivity was 64.4%, and
its specificity was 90.2%. Although all patients were transferred to
the hospital in this validation study, only 37.4% would have been
transported if the rule had been applied.
Comment: This study validates a simple rule for making
decisions about termination of resuscitation. However, an
editorialist notes that such a rule cannot determine, for example,
how long to continue resuscitation efforts before declaring "no
return of spontaneous circulation." Another important caveat is
that this study employed resuscitation guidelines that have been
superseded by more recent ones (Journal Watch
Cardiology Jan 26 2006). Nevertheless, the prediction rule may
be useful for supplementary guidance in the field.
— Harlan M. Krumholz,
MD, SM
Published in Journal Watch Cardiology August 30, 2006