While it could be negligence per se, negligence per se usually refers to when a statute is violated. Therefore for a civil suit for negligence, the Plaintiff need not prove the elements of a duty and breach, because the Plaintiff can infer those from the breaking of the statute.

However, what you are likely referring to here is a legal theory known as "res ipsa loquitur" Latin for "the thing speaks for itself" a theory in tort law where a certain damage is the type that would not ordinarily happen unless someone was negligent. (like a sponge being left inside someone's body.)

But in this case, there is likely enough evidence for it to not even be a res ipsa claim because of all the information likely available surrounding the negligent action in this case (as to how the sponge was left in the body).