ZOLL E Series, Operator'S Manual, Page: 44 / 133

Advisory Defibrillation
9650-1210-01 Rev. T 4-3
.
The Shock Conversion Estimator (Optional)
The Shock Conversion Estimator is an optional
enhancement to the E Series unit’s ECG Rhythm
Analysis Function. The Shock Conversion Estimator can
assist rescuers in maximizing the effectiveness of initial
therapy for cardiac arrest victims by estimating the
probability that the current ECG rhythm will be
successfully converted by an immediate defibrillation
shock. When the probability that a shock will be
successful is low, the performance of CPR may be more
beneficial to victim resuscitation efforts than shock
delivery.
After the E Series unit has performed its analysis of a
patient’s ECG rhythm and determined that it is
shockable, the Shock Conversion Estimator (when
configured) evaluates the heart rhythm and calculates a
value called the Shock Predictive Index (SPI). The unit
then compares the patient’s SPI value to the SPI factory
default threshold. If the patient’s SPI value after the first
ECG Rhythm Analysis is less than this threshold, there is
a greater than 95% probability that the shock will
not
convert the patient’s heart rhythm to an organized
rhythm. Under this condition, the unit issues the NO
SHOCK ADVISED prompt, indicating that the preferred
method of treatment for the patient should be CPR. The
unit can, optionally, display the decision result of the SCE
system next to the shock decision, with the message
SHOCK ADVISED SCE HIGH or NO SHOCK ADV. SCE
LOW.
If the patient’s SPI value is greater than the configured
SPI threshold, the unit operates as previously described
and issues the SHOCK ADVISED prompt.
The E Series unit can be configured to use the Shock
Conversion Estimator for as many as the first four ECG
Rhythm Analyses after the unit is powered on. For more
information on configuration settings for the Shock
Conversion Estimator, refer to the
E Series Configuration
Guide .
The Shock Predictive Index
By default, the Shock Predictive Index threshold is
configured for a conversion sensitivity of greater than
95%. This value describes the likelihood that the
patient’s shockable rhythm will not be converted to an
organized rhythm by shock delivery when the SPI is
below the default threshold setting. Under these
conditions, it may be advisable to continue CPR for an
additional period before attempting defibrillation therapy.
The Medical Director can adjust the SPI threshold to
favor either shock delivery or CPR performance when
SPI values are low. For more information on adjusting
the SPI threshold, refer to the E Series Configuration
Guide.
Note: Refer to Appendix A for more information on the
background and clinical results of the Shock
Conversion Estimator system.
WARNING
Performance of the Shock Conversion Estimator has
not been demonstrated in patients under 8 years of
age or less than 55 lbs (25 kg).
Sync
On/Off
DEFIB 200J SEL.
Alar ms
ID#
Wave 2 Param
00:01
SHOCK ADVISED
ECG
DEFIB 200J SEL.
ID# Param
00:01
ECG
Alar ms
Sync
On/Off
NO SHOCK ADV. SCE LOW
Sync
On/Off
DEFIB 200J SEL.
Alar ms ID# Param
00:01
SHOCK ADVISED SCE HIGH
ECG