Final answer:
The nurse should call for help and activate the emergency response team. If the client is unresponsive and pulseless, the nurse should start performing CPR.
Step-by-step explanation:
When a client's telemetry monitor indicates ventricular fibrillation (VF), the nurse should take immediate action. The first step should be to call for help and activate the emergency response team. They should then assess the client's responsiveness and check for a pulse. If the client is unresponsive and pulseless, the nurse should start performing cardiopulmonary resuscitation (CPR) by initiating chest compressions and providing rescue breaths.
It is important to note that defibrillation is the most common treatment for ventricular fibrillation, but it usually requires a defibrillator device, which may not be readily available at the nurse's immediate disposal.