What is your first action when you find a 78-year-old female in distress and her daughter performing CPR?

When responding to a situation where an individual is in distress, and CPR is already being performed, the most effective first action is to attach the AED pads. This is vital because an Automated External Defibrillator (AED) can analyze the heart's rhythm and determine if an electric shock is necessary to restore a normal heart rhythm. Early application of the AED increases the chances of survival, especially in cases of sudden cardiac arrest.

In the context of this scenario, while starting CPR or checking for a pulse might seem intuitive, the CPR is already being performed effectively by the daughter. Therefore, the priority should shift to utilizing the available technology that could provide life-saving assistance without interrupting the ongoing CPR for too long. It is also crucial to ensure that there is a continuous assessment of the patient's condition and readiness for advanced interventions, which the AED facilitates.

Calling for additional help is essential in emergencies, but if you are the responder on the scene, it’s often more effective to leverage the tools at hand, like the AED, first. Hence, attaching the AED pads is the most appropriate immediate action in this case.