In ICD-10-PCS, packing is defined as?

In ICD-10-PCS, packing is defined as the act of putting material on a body region for protection. This typically involves placing sterile dressings, gauze, or other material into a wound or cavity to help promote healing, protect the area from infection, and absorb any exudate. The term "packing" specifically refers to the application of these materials rather than performing surgical procedures or manipulations that involve removal or injection.

The option correctly identifies the primary function of packing, which is focused on external treatment rather than internal procedures or surgery preparation. Thus, the use of protective materials directly correlates with the definition of packing in the context of ICD-10-PCS coding.