Overview of the shock advisory system, Appendix – Physio-Control LIFEPAK 15 User Manual

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APPENDIX

LIFEPAK 15 Monitor/Defibrillator Operating Instructions

C-1

Overview of the Shock Advisory System

The Shock Advisory System (SAS) is an ECG analysis system built into the biphasic LIFEPAK 15

monitor/defibrillator that advises the operator as to whether it detects a shockable or nonshockable

rhythm. This system makes it possible for individuals who are not trained to interpret ECG rhythms

to provide potentially lifesaving therapy to victims of ventricular fibrillation or pulseless ventricular

tachycardia.

The Shock Advisory System contains the following features:

• Electrode Contact Determination

• Automated Interpretation of the ECG

• Operator Control of Shock Therapy

• Continuous Patient Surveillance System (CPSS)

• Motion Detection

The Shock Advisory System is active when the LIFEPAK 15 monitor/defibrillator is used as an

automated external defibrillator (AED). CPSS may be activated during monitoring.

Upon the user pressing

the

(shock) button

, the LIFEPAK 15 monitor/defibrillator delivers the

shock therapy to the patient.

Electrode Contact Determination

The Shock Advisory System measures the patient's transthoracic impedance through the therapy

electrodes. If the baseline impedance is higher than a maximum limit, it determines that the

electrodes do not have sufficient contact with the patient or are not properly connected to the AED.

When this occurs, ECG analysis and shock delivery are inhibited. The AED advises the operator to

connect electrodes when there is insufficient electrode contact.

Automated Interpretation of the ECG

The Shock Advisory System recommends a shock if it detects the following:

• Ventricular fibrillation—with a peak-to-peak amplitude of at least 0.08 mV.

• Ventricular tachycardia—defined as having a heart rate of at least 120 beats per minute, QRS

width of at least 0.16 seconds, and no apparent P waves.

Pacemaker pulses may prevent advisement of an appropriate shock, regardless of the patient’s

underlying rhythm. The Shock Advisory System recommends no shock for all other ECG rhythms

including asystole, pulseless electrical activity, idioventricular rhythms, bradycardia,

supraventricular tachycardias, atrial fibrillation and flutter, heart block, premature ventricular