Use of the Portable CPR Unit LIFEPAK 500 AED. This unit will do automated CPR using the electronic unit, disposable electrodes and audio instructions built into the unit. (1) Determine status of patient breathing and pulse (Use the unit only if there is lack of consciousness, breathing and pulse). Call 911. (2) Place patient on dry surface and dry off chest area. (3) Administer CPR continuously as normal avoiding touching the patient during analysis and shock phases. (4) Apply electrodes from disposable pack. Heart electrode to left side of patient below nipple. Reference electrode goes on right side of patient diagonal above right nipple. Use one set of electrodes to clean off hair if necessary. (5) Connect electrodes to the unit. (6) Follow instructions as directed by audio from unit and screen instructions.