A comparison of biphasic manual and semi-automatic external defibrillation

Background: Biphasic manual defibrillation (MD) is advocated as the preferred
strategy for paramedics ahead of semi-automatic external defibrillation (SAED)
for out-of-hospital cardiac arrest (OHCA). Methods: A systematic review
involved searching CINAHL, MEDLINE and Embase academic databases.
Comparative studies where both strategies were tested for time to first
defibrillation (TTFD) and related Utstein-based model outcomes were examined
to discern which strategy was superior. Results: Two studies met the criteria.
One study found that in 4552 SAED episodes of defibrillation (30.8% of the
14 776 total defibrillation episodes), a decrease of >10% in mean TTFD
(P<0.001) of an intial shockable rhythm was recorded. The same study reported
an overall decrease in TTFD within 2 minutes (95% CI/P<0.001), with a 68%
improved odds of receiving a shock within two minutes. SAED was associated
with a 26% reduction in the risk-adjusted odds of survival (95% CI/ P<0.009),
attributed to cardiopulmonary resuscitation (CPR) delays. The other examined
160 defibrillations in OHCA. The MD median TTFD was 7 seconds faster (95%
CI/P<0.0001) and responsible for 20% more inappropriate shocks.
Conclusions: Modern SAED is superior in reducing TTFD and inappropriate
shocks. The modern SAED and MD strategies can be enhanced by interruptionreducing
technology. New SAED algorithms can detect shockable rhythms in
3 seconds. More randomised studies need to be conducted using up-to-date
devices. A multifaceted approach incorporating technological advancements,
ongoing research and training is necessary to ensure that the most effective
defibrillation strategy is employed.