Where should defibrillator pads be placed on a heavily pregnant patient?

For a heavily pregnant patient, the placement of defibrillator pads is crucial due to the physical changes that occur during pregnancy. The correct placement is on the mid-axillary line. This technique is recommended to minimize the risk of unintended injury to the fetus while ensuring effective defibrillation on the mother. By placing the pads in this position, the electrical current can pass through the chest and heart rather than putting pressure on the abdomen.

The other options would not provide the same level of safety or effectiveness. Placing pads only on the chest does not account for the altered anatomy and could potentially risk harm to the developing fetus. Positioning pads over the abdomen is inappropriate as it may expose the fetus to the electrical shock and is not effective for delivering the defibrillation to the mother's heart. Lastly, placing pads along the spine does not effectively allow the electrical current to reach the heart and, therefore, would not provide the necessary defibrillation needed in an emergency situation.