Towards the Automated Analysis and Database Development of Defibrillator Data from Cardiac Arrest

Table 2

The variables describing device operation and therapy with descriptive names, variable names, coding, and explanation of each variable.

	Variable; in Access database	Possible values	Description
Shock number	shkn	≥0 and <21	Shock sequence number.
Number of shock sequences recorded	ssrecord	(>0 and <31) or 99; 99 = unknown	This describes the number of electrical shocks delivered to the patient as recorded on the AED total shocks received by the patient.
Number of shocks in sequence	shks	1–31	The number of shocks without intervening CPR. For example, 1 = no stacked shocks while > 1 = stacked shocks. After 2005 no case should have stacked shock.
Mode	mode	1 = manual; 2 = semiautomatic & advisory; 9 = unknown	This is the mode of the AED at the time of the shock
EMS CPR prior to shock?	cpr	1 = yes; 2 = no; 9 = unknown	Description of if EMS CPR was administered to patient before shock was delivered.
Impedance at 1st shock	imp	Measured in Ohms	Impedence at time of first shock sequence (50–200, 999) 999 = unknown.
Energy of 1st shock	enrgy	Measured in Joules	Energy of first shock in sequence.