Final answer:
The nurse should intervene if the green, white, or red lead is not placed correctly on the chest during an ECG. The brown lead does not require intervention as it is properly placed.
Step-by-step explanation:
In a 12-lead ECG, the standard placement of the leads is as follows:
- Green lead on the right upper chest
- White lead on the left upper chest
- Red lead on the left lower chest
- Brown lead on the middle of the chest
Therefore, the placement of the leads described in options 1, 2, and 3 would require intervention. The green lead should be on the right upper chest, the white lead should be on the left upper chest, and the red lead should be on the left lower chest. The brown lead, however, is properly placed on the middle of the chest, so it does not require intervention.