Which finding might delay a cardiac catheterization procedure for a 1-year-old child?

The presence of a severe diaper rash in a 1-year-old child might delay a cardiac catheterization procedure primarily because it can raise concerns about potential infection or compromise to the skin integrity at the site where catheters may be introduced. If the diaper rash is extensive and severe, medical staff may decide to postpone the procedure to ensure that there is no complication from the existing skin condition that could lead to infection or impede recovery after the invasive procedure.

In contrast, low blood pressure and low oxygen saturation are critical parameters that could necessitate immediate medical intervention rather than a delay, as they indicate significant cardiovascular or respiratory distress that must be addressed. Allergy to food, while important, typically does not pose an immediate risk to the conduct of the cardiac catheterization itself in this context as long as there are no specific allergies to medications or materials involved in the procedure. The risk and complications associated with the existing severe diaper rash, however, can make it a more significant concern, leading to a decision to postpone the catheterization to ensure the child's safety.