The answer is probably the difference between the input and the output. The irrigation would really only stay in the bladder and not be absorbed to any significant extent. Any additional volume is coming from urine produced by the patient.
There are 2 pads that are used for the <em>automated external defibrillator</em>, or AED.
The pads are placed on the <em>front of the chest</em>, and the other on the <em>back</em> of the child. You are to make sure that the wires are out of the way from the area where you administer CPR.