A nurse working on the cardiac unit hears an alarm and finds one of the heart monitor screens at the nurse's station is displaying a straight line, indicating a client is in cardiac arrest. Which of the following actions should the nurse take first?
1) Call a code and initiate cardiopulmonary resuscitation (CPR).
2) Administer epinephrine intravenously.
3) Check the client's pulse and assess responsiveness.
4) Retrieve the defibrillator and prepare for defibrillation.