Final answer:
The red and foul-smelling lochia on a 1 day PP patient is indicative of a potential infection, which is a deviation from the expected characteristics of normal postpartum lochia.
Step-by-step explanation:
The nurse assessing the lochia in a 1 day postpartum (PP) patient, finding it red and foul-smelling, determines that this assessment finding indicates the presence of infection. Normal lochia rubra is expected to be red in color and last for 2-3 days following birth before transitioning to a pinkish discharge known as lochia serosa. A foul smell, however, is often a sign of infection and warrants clinical attention. Commonly, changes in lochia accompanied by unpleasant odors are cause for concern as they may indicate an endometritis or retained products of conception, necessitating medical intervention.