ZOLL E Series Monitor Defibrillator Rev M - Manual (Page 28)

Chapter 2 Configuration Parameters
22 9650-1201-01 Rev. M
Values are as follows:
SCE Level
This parameter allows you to set one of the following SCE Levels: HIGH, MEDIUM, or LOW.
The SCE Levels correspond to SPI thresholds in the following manner:
Table 2-1. Accuracy Table of SCE Levels and Corresponding SPI Thresholds
Note: Table 2-1 is based on data from the ZOLL Database that was constructed using 258
patient records and a total of 586 delivered shocks. Refer to the Appendix A in the
E Series Operator’s Guide for more information on the ZOLL Database.
The SCE system compares the computed SPI number to the SPI threshold. If the computed
number is less than the threshold and the algorithm is configured to alter advisory decisions, the
system will change a SHOCK ADVISED decision to NO SHOCK ADVISED for a pre-
configured number of ECG analyses after power up.
You can adjust the SCE Level to emphasize greater sensitivity or specificity. Sensitivity is
defined as the number of correctly predicted successful shocks (shocks that convert) divided by
the total number of successful shocks. Specificity is defined as the number of correctly
predicted unsuccessful shocks (shocks that did not convert) divided by the total number of
shocks that did not convert. The default setting of HIGH results in a SPI threshold of
7.4 mV-Hz, with 57% specificity and 95% sensitivity.
By setting the SCE Level to HIGH (which corresponds with a lower SPI threshold),
sensitivity will increase and specificity will decrease — this favors delivering a shock even
when conversion probability is estimated to be low. The HIGH setting favors earlier
shocks, but could deliver shocks that are ineffective and delay compressions. By setting
the SCE Level to LOW (which corresponds with a higher SPI threshold), it will result in
lower sensitivity and higher specificity — this favors the immediate resumption of CPR
over low estimated probability of successful shocks. The LOW setting favors delivering
compressions and the later delivery of shock, but it could delay a shock for a convertible
rhythm. Refer to the 2005 AHA Guidelines for CPR and ECC regarding the importance
of performing early CPR during resuscitation.
Refer to Table 2-1 for a complete listing of SCE Level settings and their corresponding SPI
thresholds, sensitivities, and specificities.
Note: If the Enable SCE parameter is set to Off, this parameter will not function.
Possible Values: Yes, No
Default: No
SCE Level SPI Threshold
(mV-Hz)
Sensitivity
%
Specificity
%
HIGH 7.4 95 57
MEDIUM 8.3 90 65
LOW 10.8 80 80