What should follow after placing AED pads on a casualty?

After placing AED pads on a casualty, it is crucial to ensure that nobody is touching the casualty during the analysis. This step is essential because the AED analyzes the heart's rhythm to determine if a shock is necessary. If someone is in contact with the casualty, it could lead to inaccurate readings and potentially endanger that person's safety.

The AED needs to have a clear environment to effectively assess the cardiac activity, so the risk of interference is minimized. Following this guideline helps ensure an accurate assessment and increases the chances of a successful defibrillation if needed.

The other options do not align with the immediate necessary actions to take after applying the AED pads. For instance, administering CPR should only be done after the analysis and if the AED determines that a shock is not required or if it has successfully delivered a shock. Starting a second evaluation or disconnecting the AED could also lead to delays in providing critical assistance.